Genome-wide association analysis identifies loci governing mercury accumulation in maize.

PubMed

Zhao, Zhan; Fu, Zhongjun; Lin, Yanan; Chen, Hao; Liu, Kun; Xing, Xiaolong; Liu, Zonghua; Li, Weihua; Tang, Jihua

2017-03-21

Owing to the rapid development of urbanisation and industrialisation, heavy metal pollution has become a widespread environmental problem. Maize planted on mercury (Hg)-polluted soil can absorb and accumulate Hg in its edible parts, posing a potential threat to human health. To understand the genetic mechanism of Hg accumulation in maize, we performed a genome-wide association study using a mixed linear model on an association population consisting of 230 maize inbred lines with abundant genetic variation. The order of relative Hg concentrations in different maize tissues was as follows: leaves > bracts > stems > axes > kernels. Combined two locations, a total of 37 significant single-nucleotide polymorphisms (SNPs) associated with kernels, 12 with axes, 13 with stems, 27 with bracts and 23 with leaves were detected with p < 0.0001. Each significant SNP was calculated and the SNPs significant associated with kernels, axes, stems, bracts and leaves explained 6.96%-10.56%, 7.19%-15.87%, 7.11%-10.19%, 7.16%-8.71% and 6.91%-9.17% of the phenotypic variation, respectively. Among the significant SNPs, nine co-localised with previously detected quantitative trait loci. This study will aid in the selection of Hg-accumulation inbred lines that satisfy the needs for pollution-safe cultivars and maintaining maize production.

Nutritional value and acceptability of homemade maize/sorghum-based weaning mixtures supplemented with rojo bean flour, ground sardines and peanut paste.

PubMed

Mosha, Theobald C E; Vicent, Mary M

2004-06-01

Low nutrient density in weaning foods is the major cause of under-nutrition among infants and young children in developing countries. Ten types of composite weaning diets (namely, maize-rojo beans-peanut, maize-peanut-sardines, maize-peanut-sardine-rojo beans, maize-peanut-soaked rojo beans, maize-peanut-germinated rojo beans, sorghum-rojo beans-peanut, sorghum-peanut-sardines, sorghum-peanut-sardine-rojo beans, sorghum-peanut-soaked rojo beans, and sorghum-peanut-germinated rojo beans) were formulated and assayed for proximate composition, energy, mineral density, tannin content and residual urease activity. The diets were also evaluated for storage stability under ambient conditions, sensory quality and overall acceptability. Results of the study indicated that, concentrations of protein, fat, ash, calcium, iron, zinc and copper were significantly (P<0.05) increased when plain maize and sorghum gruels were enriched with rojo beans, peanut paste and/or ground sardines. Soaking and germinating the rojo beans and dehulling the sorghum reduced the concentration of tannins in the gruels significantly (P<0.05). Residual urease activity ranged between 0.00 and 0.07 units, about 10-fold lower than the maximum level (0.8 units) allowed in weaning foods. Both maize and sorghum-based composite gruels had a short shelf-life under ambient conditions (26.4 degrees C) ranging between 4 and 6 h, with gruels containing ground sardines showing a tendency to spoil faster. All composite gruels except those containing germinated rojo beans were highly liked and accepted by consumers (P<0.05), similar to the plain maize and sorghum gruels. The maize and sorghum-based composite products therefore have a potential for use as weaning and/or supplementary foods for older infants and young children. Further investigations are suggested to extend the shelf-life of the composite products and improve the organoleptic quality of the diets containing germinated rojo beans.

Rapid and visual detection of the main chemical compositions in maize seeds based on Raman hyperspectral imaging

NASA Astrophysics Data System (ADS)

Yang, Guiyan; Wang, Qingyan; Liu, Chen; Wang, Xiaobin; Fan, Shuxiang; Huang, Wenqian

2018-07-01

Rapid and visual detection of the chemical compositions of plant seeds is important but difficult for a traditional seed quality analysis system. In this study, a custom-designed line-scan Raman hyperspectral imaging system was applied for detecting and displaying the main chemical compositions in a heterogeneous maize seed. Raman hyperspectral images collected from the endosperm and embryo of maize seed were acquired and preprocessed by Savitzky-Golay (SG) filter and adaptive iteratively reweighted Penalized Least Squares (airPLS). Three varieties of maize seeds were analyzed, and the characteristics of the spectral and spatial information were extracted from each hyperspectral image. The Raman characteristic peaks, identified at 477, 1443, 1522, 1596 and 1654 cm-1 from 380 to 1800 cm-1 Raman spectra, were related to corn starch, mixture of oil and starch, zeaxanthin, lignin and oil in maize seeds, respectively. Each single-band image corresponding to the characteristic band characterized the spatial distribution of the chemical composition in a seed successfully. The embryo was distinguished from the endosperm by band operation of the single-band images at 477, 1443, and 1596 cm-1 for each variety. Results showed that Raman hyperspectral imaging system could be used for on-line quality control of maize seeds based on the rapid and visual detection of the chemical compositions in maize seeds.

Composition and toxigenic potential of the Fusarium graminearum species complex from maize ears, stalks and stubble in Brazil

USDA-ARS?s Scientific Manuscript database

Detailed knowledge of the composition and toxigenic potential of the Fusarium graminearum species complex affecting maize crops in Brazil is lacking. A multilocus genotype approach was used to identify 539 isolates from three sub-collections: 1) maize kernels (n= 110) from five states spanning sout...

The shoot stem cell niche in angiosperms: expression patterns of WUS orthologues in rice and maize imply major modifications in the course of mono- and dicot evolution.

PubMed

Nardmann, Judith; Werr, Wolfgang

2006-12-01

In Arabidopsis, stem cell homeostasis in the shoot apical meristem (SAM) is controlled by a feedback loop between WUS and CLV functions. We have identified WUS orthologues in maize and rice by a detailed phylogenetic analysis of the WOX gene family and subsequent cloning. A single WUS orthologue is present in the rice genome (OsWUS), whereas the allotetraploid maize genome contains 2 WUS paralogues (ZmWUS1 and ZmWUS2). None of the isolated grass WUS orthologues displays an organizing center-type expression pattern in the vegetative SAM as in Arabidopsis. In contrast, the grass-specific expression patterns relate to the specification of new phytomers consistent with the transcriptional expression patterns of TD1 and FON1 (CLV1 orthologues of maize and rice, respectively). Moreover, the grass WUS and CLV1 orthologues are coexpressed in all reproductive meristems, where fasciation and supernumerary floral organs occur in td1 or fon1 loss-of-function mutants. The expression patterns of WUS orthologues in both grass species compared with those of dicots imply that major changes in WUS function, which are correlated with changes in CLV1 signaling, have occurred during angiosperm evolution and raise doubts about the uniqueness of the WUS/CLV antagonism in the maintenance of the shoot stem cell niche in grasses.

Quantitative Trait Loci for Mercury Accumulation in Maize (Zea mays L.) Identified Using a RIL Population

PubMed Central

Zhang, Qinbin; Wang, Long; Zhang, Xiaoxiang; Song, Guiliang; Fu, Zhiyuan; Ding, Dong; Liu, Zonghua; Tang, Jihua

2014-01-01

To investigate the genetic mechanism of mercury accumulation in maize (Zea mays L.), a population of 194 recombinant inbred lines derived from an elite hybrid Yuyu 22, was used to identify quantitative trait loci (QTLs) for mercury accumulation at two locations. The results showed that the average Hg concentration in the different tissues of maize followed the order: leaves > bracts > stems > axis > kernels. Twenty-three QTLs for mercury accumulation in five tissues were detected on chromosomes 1, 4, 7, 8, 9 and 10, which explained 6.44% to 26.60% of the phenotype variance. The QTLs included five QTLs for Hg concentration in kernels, three QTLs for Hg concentration in the axis, six QTLs for Hg concentration in stems, four QTLs for Hg concentration in bracts and five QTLs for Hg concentration in leaves. Interestingly, three QTLs, qKHC9a, qKHC9b, and qBHC9 were in linkage with two QTLs for drought tolerance. In addition, qLHC1 was in linkage with two QTLs for arsenic accumulation. The study demonstrated the concentration of Hg in Hg-contaminated paddy soil could be reduced, and maize production maintained simultaneously by selecting and breeding maize Hg pollution-safe cultivars (PSCs). PMID:25210737

Cytoplasmic pH dynamics in maize pulvinal cells induced by gravity vector changes

NASA Technical Reports Server (NTRS)

Johannes, E.; Collings, D. A.; Rink, J. C.; Allen, N. S.; Brown, C. S. (Principal Investigator)

2001-01-01

In maize (Zea mays) and other grasses, changes in orientation of stems are perceived by pulvinal tissue, which responds to the stimulus by differential growth resulting in upward bending of the stem. The amyloplast-containing bundle sheath cells are the sites of gravity perception, although the initial steps of gravity perception and transmission remain unclear. In columella cells of Arabidopsis roots, we previously found that cytoplasmic pH (pH(c)) is a mediator in early gravitropic signaling (A.C. Scott, N.S. Allen [1999] Plant Physiol 121: 1291-1298). The question arises whether pH(c) has a more general role in signaling gravity vector changes. Using confocal ratiometric imaging and the fluorescent pH indicator carboxy seminaphtorhodafluor acetoxymethyl ester acetate, we measured pH(c) in the cells composing the maize pulvinus. When stem slices were gravistimulated and imaged on a horizontally mounted confocal microscope, pH(c) changes were only apparent within the bundle sheath cells, and not in the parenchyma cells. After turning, cytoplasmic acidification was observed at the sides of the cells, whereas the cytoplasm at the base of the cells where plastids slowly accumulated became more basic. These changes were most apparent in cells exhibiting net amyloplast sedimentation. Parenchyma cells and isolated bundle sheath cells did not show any gravity-induced pH(c) changes although all cell types responded to external stimuli in the predicted way: Propionic acid and auxin treatments induced acidification, whereas raising the external pH caused alkalinization. The results suggest that pH(c) has an important role in the early signaling pathways of maize stem gravitropism.

Genetic, Genomic, and Breeding Approaches to Further Explore Kernel Composition Traits and Grain Yield in Maize

ERIC Educational Resources Information Center

Da Silva, Helena Sofia Pereira

2009-01-01

Maize ("Zea mays L.") is a model species well suited for the dissection of complex traits which are often of commercial value. The purpose of this research was to gain a deeper understanding of the genetic control of maize kernel composition traits starch, protein, and oil concentration, and also kernel weight and grain yield. Germplasm with…

Identification and expression profiling analysis of TCP family genes involved in growth and development in maize.

PubMed

Chai, Wenbo; Jiang, Pengfei; Huang, Guoyu; Jiang, Haiyang; Li, Xiaoyu

2017-10-01

The TCP family is a group of plant-specific transcription factors. TCP genes encode proteins harboring bHLH structure, which is implicated in DNA binding and protein-protein interactions and known as the TCP domain. TCP genes play important roles in plant development and have been evolutionarily and functionally elaborated in various plants, however, no overall phylogenetic analysis or expression profiling of TCP genes in Zea mays has been reported. In the present study, a systematic analysis of molecular evolution and functional prediction of TCP family genes in maize ( Z . mays L.) has been conducted. We performed a genome-wide survey of TCP genes in maize, revealing the gene structure, chromosomal location and phylogenetic relationship of family members. Microsynteny between grass species and tissue-specific expression profiles were also investigated. In total, 29 TCP genes were identified in the maize genome, unevenly distributed on the 10 maize chromosomes. Additionally, ZmTCP genes were categorized into nine classes based on phylogeny and purifying selection may largely be responsible for maintaining the functions of maize TCP genes. What's more, microsynteny analysis suggested that TCP genes have been conserved during evolution. Finally, expression analysis revealed that most TCP genes are expressed in the stem and ear, which suggests that ZmTCP genes influence stem and ear growth. This result is consistent with the previous finding that maize TCP genes represses the growth of axillary organs and enables the formation of female inflorescences. Altogether, this study presents a thorough overview of TCP family in maize and provides a new perspective on the evolution of this gene family. The results also indicate that TCP family genes may be involved in development stage in plant growing conditions. Additionally, our results will be useful for further functional analysis of the TCP gene family in maize.

Maize defense response against the european corn borer (Ostrinia nubilaslis): a losing battle?

USDA-ARS?s Scientific Manuscript database

The goal of this research is to understand how maize stems respond to European corn borer (ECB) damage and how these defense tactics affect the invading ECB. We measured the levels of the plant hormones, jasmonic acid (JA) and ethylene, as well as the transcript levels of their key biosynthetic en...

ramosa2 encodes a LATERAL ORGAN BOUNDARY domain protein that determines the fate of stem cells in branch meristems of maize.

PubMed

Bortiri, Esteban; Chuck, George; Vollbrecht, Erik; Rocheford, Torbert; Martienssen, Rob; Hake, Sarah

2006-03-01

Genetic control of grass inflorescence architecture is critical given that cereal seeds provide most of the world's food. Seeds are borne on axillary branches, which arise from groups of stem cells in axils of leaves and whose branching patterns dictate most of the variation in plant form. Normal maize (Zea mays) ears are unbranched, and tassels have long branches only at their base. The ramosa2 (ra2) mutant of maize has increased branching with short branches replaced by long, indeterminate ones. ra2 was cloned by chromosome walking and shown to encode a LATERAL ORGAN BOUNDARY domain transcription factor. ra2 is transiently expressed in a group of cells that predicts the position of axillary meristem formation in inflorescences. Expression in different mutant backgrounds places ra2 upstream of other genes that regulate branch formation. The early expression of ra2 suggests that it functions in the patterning of stem cells in axillary meristems. Alignment of ra2-like sequences reveals a grass-specific domain in the C terminus that is not found in Arabidopsis thaliana. The ra2-dm allele suggests this domain is required for transcriptional activation of ra1. The ra2 expression pattern is conserved in rice (Oryza sativa), barley (Hordeum vulgare), sorghum (Sorghum bicolor), and maize, suggesting that ra2 is critical for shaping the initial steps of grass inflorescence architecture.

European Corn Borer (Ostrinia nubilalis) Induced Responses Enhance Susceptibility in Maize

PubMed Central

Dafoe, Nicole J.; Thomas, James D.; Shirk, Paul D.; Legaspi, Michelle E.; Vaughan, Martha M.; Huffaker, Alisa; Teal, Peter E.; Schmelz, Eric A.

2013-01-01

Herbivore-induced plant responses have been widely described following attack on leaves; however, less attention has been paid to analogous local processes that occur in stems. Early studies of maize (Zea mays) responses to stem boring by European corn borer (ECB, Ostrinia nubilalis ) larvae revealed the presence of inducible acidic diterpenoid phytoalexins, termed kauralexins, and increases in the benzoxazinoid 2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-one-glucose (HDMBOA-Glc) after 24 h of herbivory. Despite these rapidly activated defenses, larval growth was not altered in short-term feeding assays. Unexpectedly, ECB growth significantly improved in assays using stem tissue preconditioned by 48 h of larval tunneling. Correspondingly, measures of total soluble protein increased over 2.6-fold in these challenged tissues and were accompanied by elevated levels of sucrose and free linoleic acid. While microarray analyses revealed up-regulation of over 1100 transcripts, fewer individual protein increases were demonstrable. Consistent with induced endoreduplication, both wounding and ECB stem attack resulted in similar significant expansion of the nucleus, nucleolus and levels of extractable DNA from challenged tissues. While many of these responses are triggered by wounding alone, biochemical changes further enhanced in response to ECB may be due to larval secreted effectors. Unlike other Lepidoptera examined, ECB excrete exceedingly high levels of the auxin indole-3-acetic acid (IAA) in their frass which is likely to contact and contaminate the surrounding feeding tunnel. Stem exposure to a metabolically stable auxin, such as 2,4-dichlorophenoxyacetic acid (2,4-D), promoted significant protein accumulation above wounding alone. As a future testable hypothesis, we propose that ECB-associated IAA may function as a candidate herbivore effector promoting the increased nutritional content of maize stems. PMID:24023868

Nutritive value of maize silage in relation to dairy cow performance and milk quality.

PubMed

Khan, Nazir A; Yu, Peiqiang; Ali, Mubarak; Cone, John W; Hendriks, Wouter H

2015-01-01

Maize silage has become the major forage component in the ration of dairy cows over the last few decades. This review provides information on the mean content and variability in chemical composition, fatty acid (FA) profile and ensiling quality of maize silages, and discusses the major factors which cause these variations. In addition, the effect of the broad range in chemical composition of maize silages on the total tract digestibility of dietary nutrients, milk production and milk composition of dairy cows is quantified and discussed. Finally, the optimum inclusion level of maize silage in the ration of dairy cows for milk production and composition is reviewed. The data showed that the nutritive value of maize silages is highly variable and that most of this variation is caused by large differences in maturity at harvest. Maize silages ensiled at a very early stage (dry matter (DM) < 250 g kg(-1)) were particularly low in starch content and starch/neutral detergent fibre (NDF) ratio, and resulted in a lower DM intake (DMI), milk yield and milk protein content. The DMI, milk yield and milk protein content increased with advancing maturity, reaching an optimum level for maize silages ensiled at DM contents of 300-350 g kg(-1), and then declined slightly at further maturity beyond 350 g kg(-1). The increases in milk (R(2) = 0.599) and protein (R(2) = 0.605) yields with maturity of maize silages were positively related to the increase in starch/NDF ratio of the maize silages. On average, the inclusion of maize silage in grass silage-based diets improved the forage DMI by 2 kg d(-1), milk yield by 1.9 kg d(-1) and milk protein content by 1.2 g kg(-1). Further comparisons showed that, in terms of milk and milk constituent yields, the optimum grass/maize silage ratio depends on the quality of both the grass and maize silages. Replacement of grass silage with maize silage in the ration, as well as an increasing maturity of the maize silages, altered the milk FA profile of the dairy cows, notably, the concentration of the cis-unsaturated FAs, C18:3n-3 and n-3/n-6 ratio decreased in milk fat. Despite variation in nutritive value, maize silage is rich in metabolizable energy and supports higher DMI and milk yield. Harvesting maize silages at a DM content between 300 and 350 g kg(-1) and feeding in combination with grass silage results in a higher milk yield of dairy cows. © 2014 Society of Chemical Industry.

Fusarium diseases of maize associated with mycotoxin contamination of agricultural products intended to be used for food and feed.

PubMed

Oldenburg, Elisabeth; Höppner, Frank; Ellner, Frank; Weinert, Joachim

2017-08-01

Infections of maize with phytopathogenic and toxinogenic Fusarium spp. may occur throughout the cultivation period. This can cause different types of diseases in vegetative and generative organs of the plant. Along with these infections, mycotoxins are often produced and accumulated in affected tissues, which could pose a significant risk on human and animal health when entering the food and feed chain. Most important fungal species infecting European maize belong to the Fusarium sections Discolour and Liseola, the first being more prevalent in cooler and humid climate regions than the second predominating in warmer and dryer areas. Coexistence of several Fusarium spp. pathogens in growing maize under field conditions is the usual case and may lead to multi-contamination with mycotoxins like trichothecenes, zearalenone and fumonisins. The pathways how the fungi gain access to the target organs of the plant are extensively described in relation to specific symptoms of typical rot diseases regarding ears, kernels, rudimentary ears, roots, stem, leaves, seed and seedlings. Both Gibberella and Fusarium ear rots are of major importance in affecting the toxinogenic quality of grain or ear-based products as well as forage maize used for human or animal nutrition. Although rudimentary ears may contain high amounts of Fusarium toxins, the contribution to the contamination of forage maize is minor due to their small proportion on the whole plant dry matter yield. The impact of foliar diseases on forage maize contamination is regarded to be low, as Fusarium infections are restricted to some parts on the leaf sheaths and husks. Mycotoxins produced in rotted basal part of the stem may contribute to forage maize contamination, but usually remain in the stubbles after harvest. As the probability of a more severe disease progression is increasing with a prolonged cultivation period, maize should be harvested at the appropriate maturity stage to keep Fusarium toxin contamination as low as possible. Ongoing surveillance and research is needed to recognise changes in the spectrum of dominating Fusarium pathogens involved in mycotoxin contamination of maize to ensure safety in the food and feed chain.

Maize LAZY1 mediates shoot gravitropism and inflorescence development through regulating auxin transport, auxin signaling, and light response.

PubMed

Dong, Zhaobin; Jiang, Chuan; Chen, Xiaoyang; Zhang, Tao; Ding, Lian; Song, Weibin; Luo, Hongbing; Lai, Jinsheng; Chen, Huabang; Liu, Renyi; Zhang, Xiaolan; Jin, Weiwei

2013-11-01

Auxin is a plant hormone that plays key roles in both shoot gravitropism and inflorescence development. However, these two processes appear to be parallel and to be regulated by distinct players. Here, we report that the maize (Zea mays) prostrate stem1 mutant, which is allelic to the classic mutant lazy plant1 (la1), displays prostrate growth with reduced shoot gravitropism and defective inflorescence development. Map-based cloning identified maize ZmLA1 as the functional ortholog of LAZY1 in rice (Oryza sativa) and Arabidopsis (Arabidopsis thaliana). It has a unique role in inflorescence development and displays enriched expression in reproductive organs such as tassels and ears. Transcription of ZmLA1 responds to auxin and is repressed by light. Furthermore, ZmLA1 physically interacts with a putative auxin transport regulator in the plasma membrane and a putative auxin signaling protein in the nucleus. RNA-SEQ data showed that dozens of auxin transport, auxin response, and light signaling genes were differentially expressed in la1 mutant stems. Therefore, ZmLA1 might mediate the cross talk between shoot gravitropism and inflorescence development by regulating auxin transport, auxin signaling, and probably light response in maize.

Relationship of source and sink in determining kernel composition of maize

PubMed Central

Seebauer, Juliann R.; Singletary, George W.; Krumpelman, Paulette M.; Ruffo, Matías L.; Below, Frederick E.

2010-01-01

The relative role of the maternal source and the filial sink in controlling the composition of maize (Zea mays L.) kernels is unclear and may be influenced by the genotype and the N supply. The objective of this study was to determine the influence of assimilate supply from the vegetative source and utilization of assimilates by the grain sink on the final composition of maize kernels. Intermated B73×Mo17 recombinant inbred lines (IBM RILs) which displayed contrasting concentrations of endosperm starch were grown in the field with deficient or sufficient N, and the source supply altered by ear truncation (45% reduction) at 15 d after pollination (DAP). The assimilate supply into the kernels was determined at 19 DAP using the agar trap technique, and the final kernel composition was measured. The influence of N supply and kernel ear position on final kernel composition was also determined for a commercial hybrid. Concentrations of kernel protein and starch could be altered by genotype or the N supply, but remained fairly constant along the length of the ear. Ear truncation also produced a range of variation in endosperm starch and protein concentrations. The C/N ratio of the assimilate supply at 19 DAP was directly related to the final kernel composition, with an inverse relationship between the concentrations of starch and protein in the mature endosperm. The accumulation of kernel starch and protein in maize is uniform along the ear, yet adaptable within genotypic limits, suggesting that kernel composition is source limited in maize. PMID:19917600

Impacts of Fertilization Regimes on Arbuscular Mycorrhizal Fungal (AMF) Community Composition Were Correlated with Organic Matter Composition in Maize Rhizosphere Soil

PubMed Central

Zhu, Chen; Ling, Ning; Guo, Junjie; Wang, Min; Guo, Shiwei; Shen, Qirong

2016-01-01

The understanding of the response of arbuscular mycorrhizal fungi (AMF) community composition to fertilization is of great significance in sustainable agriculture. However, how fertilization influences AMF diversity and composition is not well-established yet. A field experiment located in northeast China in typical black soil (Chernozem) was conducted and high-throughput sequencing approach was used to investigate the effects of different fertilizations on the variation of AMF community in the rhizosphere soil of maize crop. The results showed that AMF diversity in the maize rhizosphere was significantly altered by different fertilization regimes. As revealed by redundancy analysis, the application of organic manure was the most important factor impacting AMF community composition between samples with and without organic manure, followed by N fertilizer and P fertilizer inputs. Moreover, the organic matter composition in the rhizosphere, determined by GC–MS, was significantly altered by the organic manure amendment. Many of the chemical components displayed significant relationships with the AMF community composition according to the Mantel test, among those, 2-ethylnaphthalene explained the highest percentage (54.2%) of the variation. The relative contents of 2-ethylnaphthalene and 2, 6, 10-trimethyltetradecane had a negative correlation with Glomus relative abundance, while the relative content of 3-methylbiphenyl displayed a positive correlation with Rhizophagus. The co-occurrence patterns in treatments with and without organic manure amendment were analyzed, and more hubs were detected in the network of soils with organic manure amendment. Additionally, three operational taxonomic units (OTUs) belonging to Glomerales were identified as hubs in all treatments, indicating these OTUs likely occupied broad ecological niches and were always active for mediating AMF species interaction in the maize rhizosphere. Taken together, impacts of fertilization regimes on AMF community composition were correlated with organic matter composition in maize rhizosphere soil and the application of manure could activate more AMF species to interact with other species in the maize rhizosphere. This knowledge can be valuable in regulating the symbiotic system of plants and AMF, maintaining the health and high yields of crops and providing a primary basis for rational fertilization. PMID:27899920

Maize LAZY1 Mediates Shoot Gravitropism and Inflorescence Development through Regulating Auxin Transport, Auxin Signaling, and Light Response1[C][W

PubMed Central

Dong, Zhaobin; Jiang, Chuan; Chen, Xiaoyang; Zhang, Tao; Ding, Lian; Song, Weibin; Luo, Hongbing; Lai, Jinsheng; Chen, Huabang; Liu, Renyi; Zhang, Xiaolan; Jin, Weiwei

2013-01-01

Auxin is a plant hormone that plays key roles in both shoot gravitropism and inflorescence development. However, these two processes appear to be parallel and to be regulated by distinct players. Here, we report that the maize (Zea mays) prostrate stem1 mutant, which is allelic to the classic mutant lazy plant1 (la1), displays prostrate growth with reduced shoot gravitropism and defective inflorescence development. Map-based cloning identified maize ZmLA1 as the functional ortholog of LAZY1 in rice (Oryza sativa) and Arabidopsis (Arabidopsis thaliana). It has a unique role in inflorescence development and displays enriched expression in reproductive organs such as tassels and ears. Transcription of ZmLA1 responds to auxin and is repressed by light. Furthermore, ZmLA1 physically interacts with a putative auxin transport regulator in the plasma membrane and a putative auxin signaling protein in the nucleus. RNA-SEQ data showed that dozens of auxin transport, auxin response, and light signaling genes were differentially expressed in la1 mutant stems. Therefore, ZmLA1 might mediate the cross talk between shoot gravitropism and inflorescence development by regulating auxin transport, auxin signaling, and probably light response in maize. PMID:24089437

Identification of QTLs for Arsenic Accumulation in Maize (Zea mays L.) Using a RIL Population

PubMed Central

Ding, Dong; Li, Weihua; Song, Guiliang; Qi, Hongyuan; Liu, Jingbao; Tang, Jihua

2011-01-01

The Arsenic (As) concentration in different tissues of maize was analyzed using a set of RIL populations derived from an elite hybrid, Nongda108. The results showed that the trend of As concentration in the four measured tissues was leaves>stems>bracts>kernels. Eleven QTLs for As concentration were detected in the four tissues. Three QTLs for As concentration in leaves were mapped on chromosomes 1, 5, and 8, respectively. For As concentration in the bracts, two QTLs were identified, with 9.61% and 10.03% phenotypic variance. For As concentration in the stems, three QTLs were detected with 8.24%, 14.86%, and 15.23% phenotypic variance. Three QTLs were identified for kernels on chromosomes 3, 5, and 7, respectively, with 10.73%, 8.52%, and 9.10% phenotypic variance. Only one common chromosomal region between SSR marker bnlg1811 and umc1243 was detected for QTLs qLAV1 and qSAC1. The results implied that the As accumulation in different tissues in maize was controlled by different molecular mechanism. The study demonstrated that maize could be a useful plant for phytoremediation of As-contaminated paddy soil, and the QTLs will be useful for selecting inbred lines and hybrids with low As concentration in their kernels. PMID:22028786

Effect of variety and harvest date on nutritive value and ruminal degradability of ensiled maize ears.

PubMed

Terler, Georg; Gruber, Leonhard; Knaus, Wilhelm Friedrich

2017-10-01

The nutritive value of whole crop forage maize is influenced by the proportion of ears and stover in the whole crop and by the nutrient composition and digestibility characteristics of the plant parts. An experiment investigating the impact of variety, harvest date and year on the nutritive value of ensiled maize ears was carried out in three consecutive years (2007, 2008 and 2010). Nine different maize varieties were harvested at three different maturity stages (50, 55 and 60% dry matter (DM) content in the ears). After harvest, ears and stover were ensiled separately and afterwards nutrient composition and ruminal nutrient degradability (organic matter (OM), crude protein (CP) and non-fibre carbohydrates (NFC)) were analysed. Variety had a significant influence on content of CP and effective ruminal degradability (ED) of OM at low passage rates, whereas ED of CP and NFC was not affected by variety. In contrast, harvest date and year significantly influenced nutrient composition and ruminal degradability of ensiled maize ears. The content of NFC increased and the content of fibre components as well as ED of OM, CP and NFC declined with processing maturity of the maize plants. At a passage rate of 5% h -1 , ED of OM declined from 75.9% to 68.4%, ED of CP from 82.5% to 73.8% and ED of NFC from 88.0% to 82.3% between the early and late harvest date. The results of this study indicate that the nutrient composition and ruminal degradability of ensiled maize ears are affected mainly by maturity stage at harvest and by year, whereas variety has only little influence.

Lignin Down-regulation of Zea mays via dsRNAi and Klason Lignin Analysis

PubMed Central

Park, Sang-Hyuck; Ong, Rebecca Garlock; Mei, Chuansheng; Sticklen, Mariam

2014-01-01

To facilitate the use of lignocellulosic biomass as an alternative bioenergy resource, during biological conversion processes, a pretreatment step is needed to open up the structure of the plant cell wall, increasing the accessibility of the cell wall carbohydrates. Lignin, a polyphenolic material present in many cell wall types, is known to be a significant hindrance to enzyme access. Reduction in lignin content to a level that does not interfere with the structural integrity and defense system of the plant might be a valuable step to reduce the costs of bioethanol production. In this study, we have genetically down-regulated one of the lignin biosynthesis-related genes, cinnamoyl-CoA reductase (ZmCCR1) via a double stranded RNA interference technique. The ZmCCR1_RNAi construct was integrated into the maize genome using the particle bombardment method. Transgenic maize plants grew normally as compared to the wild-type control plants without interfering with biomass growth or defense mechanisms, with the exception of displaying of brown-coloration in transgenic plants leaf mid-ribs, husks, and stems. The microscopic analyses, in conjunction with the histological assay, revealed that the leaf sclerenchyma fibers were thinned but the structure and size of other major vascular system components was not altered. The lignin content in the transgenic maize was reduced by 7-8.7%, the crystalline cellulose content was increased in response to lignin reduction, and hemicelluloses remained unchanged. The analyses may indicate that carbon flow might have been shifted from lignin biosynthesis to cellulose biosynthesis. This article delineates the procedures used to down-regulate the lignin content in maize via RNAi technology, and the cell wall compositional analyses used to verify the effect of the modifications on the cell wall structure. PMID:25080235

Lignin down-regulation of Zea mays via dsRNAi and klason lignin analysis.

PubMed

Park, Sang-Hyuck; Ong, Rebecca Garlock; Mei, Chuansheng; Sticklen, Mariam

2014-07-23

To facilitate the use of lignocellulosic biomass as an alternative bioenergy resource, during biological conversion processes, a pretreatment step is needed to open up the structure of the plant cell wall, increasing the accessibility of the cell wall carbohydrates. Lignin, a polyphenolic material present in many cell wall types, is known to be a significant hindrance to enzyme access. Reduction in lignin content to a level that does not interfere with the structural integrity and defense system of the plant might be a valuable step to reduce the costs of bioethanol production. In this study, we have genetically down-regulated one of the lignin biosynthesis-related genes, cinnamoyl-CoA reductase (ZmCCR1) via a double stranded RNA interference technique. The ZmCCR1_RNAi construct was integrated into the maize genome using the particle bombardment method. Transgenic maize plants grew normally as compared to the wild-type control plants without interfering with biomass growth or defense mechanisms, with the exception of displaying of brown-coloration in transgenic plants leaf mid-ribs, husks, and stems. The microscopic analyses, in conjunction with the histological assay, revealed that the leaf sclerenchyma fibers were thinned but the structure and size of other major vascular system components was not altered. The lignin content in the transgenic maize was reduced by 7-8.7%, the crystalline cellulose content was increased in response to lignin reduction, and hemicelluloses remained unchanged. The analyses may indicate that carbon flow might have been shifted from lignin biosynthesis to cellulose biosynthesis. This article delineates the procedures used to down-regulate the lignin content in maize via RNAi technology, and the cell wall compositional analyses used to verify the effect of the modifications on the cell wall structure.

Nitrogen fertilizer rate affects root exudation, the rhizosphere microbiome and nitrogen-use-efficiency of maize

USDA-ARS?s Scientific Manuscript database

The composition and function of microbial communities present in the rhizosphere of crops has been linked to edaphic factors and root exudate composition. In this paper, we examined the effect of N fertilizer rate on maize root exudation, the associated rhizosphere community, and nitrogen-use-effici...

Genetic analysis of teosinte alleles for kernel composition traits in maize

USDA-ARS?s Scientific Manuscript database

Teosinte (Zea mays ssp. parviglumis) is the wild ancestor of modern maize (Zea mays ssp. mays). Teosinte contains greater genetic diversity compared to maize inbreds and landraces, but its use is limited by insufficient genetic resources to evaluate its value. A population of teosinte near isogenic ...

Utilizing virus-induced gene silencing for the functional characterization of maize genes during infection with the fungal pathogen Ustilago maydis.

PubMed

van der Linde, Karina; Doehlemann, Gunther

2013-01-01

While in dicotyledonous plants virus-induced gene silencing (VIGS) is well established to study plant-pathogen interaction, in monocots only few examples of efficient VIGS have been reported so far. One of the available systems is based on the brome mosaic virus (BMV) which allows gene silencing in different cereals including barley (Hordeum vulgare), wheat (Triticum aestivum), and maize (Zea mays).Infection of maize plants by the corn smut fungus Ustilago maydis leads to the formation of large tumors on stem, leaves, and inflorescences. During this biotrophic interaction, plant defense responses are actively suppressed by the pathogen, and previous transcriptome analyses of infected maize plants showed comprehensive and stage-specific changes in host gene expression during disease progression.To identify maize genes that are functionally involved in the interaction with U. maydis, we adapted a VIGS system based on the Brome mosaic virus (BMV) to maize at conditions that allow successful U. maydis infection of BMV pre-infected maize plants. This setup enables quantification of VIGS and its impact on U. maydis infection using a quantitative real-time PCR (q(RT)-PCR)-based readout.

Bt-maize (MON810) and Non-GM Soybean Meal in Diets for Atlantic Salmon (Salmo salar L.) Juveniles – Impact on Survival, Growth Performance, Development, Digestive Function, and Transcriptional Expression of Intestinal Immune and Stress Responses

PubMed Central

Gu, Jinni; Bakke, Anne Marie; Valen, Elin C.; Lein, Ingrid; Krogdahl, Åshild

2014-01-01

Responses in Atlantic salmon (Salmo salar L.) juveniles (fry) fed diets containing genetically modified maize (Bt-maize, MON810) expressing Cry1Ab protein from first-feeding were investigated during a 99-day feeding trial. Four experimental diets were made; each diet contained ∼20% maize, either Bt-maize or its near-isogenic maternal line (non-GM maize). One pair was fishmeal-based while the other pair included standard (extracted) soybean meal (SBM; 16.7% inclusion level), with the intention of investigating responses to the maize varieties in healthy fish as well as in immunologically challenged fish with SBM-induced distal intestinal inflammation, respectively. Three replicate tanks of fry (0.17±0.01 g; initial mean weight ± SEM) were fed one of the four diets and samples were taken on days 15, 36, 48 and 99. Survival, growth performance, whole body composition, digestive function, morphology of intestine, liver and skeleton, and mRNA expression of some immune and stress response parameters in the distal intestine were evaluated. After 99 days of feeding, survival was enhanced and the intended SBM-induced inflammatory response in the distal intestine of the two groups of SBM-fed fish was absent, indicating that the juvenile salmon were tolerant to SBM. Mortality, growth performance and body composition were similar in fish fed the two maize varieties. The Bt-maize fed fish, however, displayed minor but significantly decreased digestive enzyme activities of leucine aminopeptidase and maltase, as well as decreased concentration of gut bile salts, but significantly increased amylase activity at some sampling points. Histomorphological, radiographic and mRNA expression evaluations did not reveal any biologically relevant effects of Bt-maize in the gastrointestinal tract, liver or skeleton. The results suggest that the Cry1Ab protein or other compositional differences in GM Bt-maize may cause minor alterations in intestinal responses in juvenile salmon, but without affecting overall survival, growth performance, development or health. PMID:24923786

Bt-maize (MON810) and non-GM soybean meal in diets for Atlantic salmon (Salmo salar L.) juveniles--impact on survival, growth performance, development, digestive function, and transcriptional expression of intestinal immune and stress responses.

PubMed

Gu, Jinni; Bakke, Anne Marie; Valen, Elin C; Lein, Ingrid; Krogdahl, Åshild

2014-01-01

Responses in Atlantic salmon (Salmo salar L.) juveniles (fry) fed diets containing genetically modified maize (Bt-maize, MON810) expressing Cry1Ab protein from first-feeding were investigated during a 99-day feeding trial. Four experimental diets were made; each diet contained ∼20% maize, either Bt-maize or its near-isogenic maternal line (non-GM maize). One pair was fishmeal-based while the other pair included standard (extracted) soybean meal (SBM; 16.7% inclusion level), with the intention of investigating responses to the maize varieties in healthy fish as well as in immunologically challenged fish with SBM-induced distal intestinal inflammation, respectively. Three replicate tanks of fry (0.17±0.01 g; initial mean weight ± SEM) were fed one of the four diets and samples were taken on days 15, 36, 48 and 99. Survival, growth performance, whole body composition, digestive function, morphology of intestine, liver and skeleton, and mRNA expression of some immune and stress response parameters in the distal intestine were evaluated. After 99 days of feeding, survival was enhanced and the intended SBM-induced inflammatory response in the distal intestine of the two groups of SBM-fed fish was absent, indicating that the juvenile salmon were tolerant to SBM. Mortality, growth performance and body composition were similar in fish fed the two maize varieties. The Bt-maize fed fish, however, displayed minor but significantly decreased digestive enzyme activities of leucine aminopeptidase and maltase, as well as decreased concentration of gut bile salts, but significantly increased amylase activity at some sampling points. Histomorphological, radiographic and mRNA expression evaluations did not reveal any biologically relevant effects of Bt-maize in the gastrointestinal tract, liver or skeleton. The results suggest that the Cry1Ab protein or other compositional differences in GM Bt-maize may cause minor alterations in intestinal responses in juvenile salmon, but without affecting overall survival, growth performance, development or health.

Influence of genetic background on anthocyanin and copigment composition and behavior during thermoalkaline processing of maize

USDA-ARS?s Scientific Manuscript database

Visual color is a primary factor for foods purchase; identifying factors that influence in-situ color quality of pigmented maize during processing is important. We used 24 genetically distinct pigmented maize hybrids (red/blue, blue, red, and purple) to investigate the effect of pigment and copigme...

Weeds and their effect on the performance of maize and fingermillet in the mid-hills of Nepal

USDA-ARS?s Scientific Manuscript database

Relay cropping of maize with fingermillet (maize/fingermillet) is the predominant cropping system for sustaining food security in the hilly regions of Nepal. In this region weed pressure severely reduces crop yields, yet basic information on weed species composition, biomass production and their eff...

Engineering phenolics metabolism in the grasses using transcription factors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grotewold, Erich

2013-07-26

The economical competitiveness of agriculture-derived biofuels can be significantly enhanced by increasing biomass/acre yields and by furnishing the desired carbon balance for facilitating liquid fuel production (e.g., ethanol) or for high-energy solid waste availability to be used as biopower (e.g., for electricity production). Biomass production and carbon balance are tightly linked to the biosynthesis of phenolic compounds, which are found in crops and in agricultural residues either as lignins, as part of the cell wall, or as soluble phenolics which play a variety of functions in the biology of plants. The grasses, in particular maize, provide the single major sourcemore » of agricultural biomass, offering significant opportunities for increasing renewable fuel production. Our laboratory has pioneered the use of transcription factors for manipulating plant metabolic pathways, an approach that will be applied here towards altering the composition of phenolic compounds in maize. Previously, we identified a small group of ten maize R2R3-MYB transcription factors with all the characteristics of regulators of different aspects of phenolic biosynthesis. Here, we propose to investigate the participation of these R2R3-MYB factors in the regulation of soluble and insoluble maize phenolics, using a combination of over-expression and down-regulation of these transcription factors in transgenic maize cultured cells and in maize plants. Maize cells and plants altered in the activity of these regulatory proteins will be analyzed for phenolic composition by targeted metabolic profiling. Specifically, we will I) Investigate the effect of gain- and loss-of-function of a select group of R2R3-MYB transcription factors on the phenolic composition of maize plants and II) Identify the biosynthetic genes regulated by each of the selected R2R3-MYB factors. While a likely outcome of these studies are transgenic maize plants with altered phenolic composition, this research will significantly contribute to understanding how different branches of the phenolic biosynthetic grid are regulated. Given the conservation of the selected regulators in other grasses, results derived from this project are likely to provide important tools for the manipulation of phenolic compounds in other emerging biomass producers (e.g., switchgrass or miscanthus), either through conventional breeding techniques (e.g., marker-assisted breeding) or by using transgenic approaches.« less

Systemic virus-induced gene silencing allows functional characterization of maize genes during biotrophic interaction with Ustilago maydis.

PubMed

van der Linde, Karina; Kastner, Christine; Kumlehn, Jochen; Kahmann, Regine; Doehlemann, Gunther

2011-01-01

Infection of maize (Zea mays) plants with the corn smut fungus Ustilago maydis leads to the formation of large tumors on the stem, leaves and inflorescences. In this biotrophic interaction, plant defense responses are actively suppressed by the pathogen, and previous transcriptome analyses of infected maize plants showed massive and stage-specific changes in host gene expression during disease progression. To identify maize genes that are functionally involved in the interaction with U. maydis, we adapted a virus-induced gene silencing (VIGS) system based on the brome mosaic virus (BMV) for maize. Conditions were established that allowed successful U. maydis infection of BMV-preinfected maize plants. This set-up enabled quantification of VIGS and its impact on U. maydis infection using a quantitative real-time PCR (qRT-PCR)-based readout. In proof-of-principle experiments, an U. maydis-induced terpene synthase was shown to negatively regulate disease development while a protein involved in cell death inhibition was required for full virulence of U. maydis. The results suggest that this system is a versatile tool for the rapid identification of maize genes that determine compatibility with U. maydis. © (2010) Max Planck Society. Journal compilation © New Phytologist Trust (2010).

Health risk assessment and growth characteristics of wheat and maize crops irrigated with contaminated wastewater.

PubMed

Farahat, Emad A; Galal, Tarek M; Elawa, Omar E; Hassan, Loutfy M

2017-10-02

The present study evaluated the effect of untreated wastewater irrigation and its health risks in Triticum aestivum (wheat) and Zea mays (maize) cultivated at south Cairo, Egypt. Morphological measurements (stem and root lengths, number of leaves per plant, and dry weights of main organs) as well as soil, irrigation water, and plant analyses for nutrients and heavy metals were conducted in polluted and unpolluted sites. Wastewater irrigations leads to reduction in the morphological traits of the plants and reduced its vegetative biomass and yield production, with more negative impacts on maize than wheat. The concentrations of Pb, Cd, Cr, and Fe in roots and leaves of wheat were above the phytotoxic limits. Conversely, Pb, Cd, and Fe were significantly high and at phytotoxic concentrations in the leaves of maize at polluted site. The present study indicated that wheat plants tend to phytostabilize heavy metals in their roots, while maize accumulates it more in their leaves. Maize and wheat had toxic concentrations of Pb and Cd in their grains under wastewater irrigation. The health risk index showed values > 1 for Pb and Cd in polluted site for both crops, in addition to maize in unpolluted site. Consequently, this will have greatest potential to pose health risk to the consumers.

Shifts in microbial communities in soil, rhizosphere and roots of two major crop systems under elevated CO2 and O3.

PubMed

Wang, Peng; Marsh, Ellen L; Ainsworth, Elizabeth A; Leakey, Andrew D B; Sheflin, Amy M; Schachtman, Daniel P

2017-11-03

Rising atmospheric concentrations of CO 2 and O 3 are key features of global environmental change. To investigate changes in the belowground bacterial community composition in response to elevated CO 2 and O 3 (eCO 2 and eO 3 ) the endosphere, rhizosphere and soil were sampled from soybeans under eCO 2 and maize under eO 3 . The maize rhizosphere and endosphere α-diversity was higher than soybean, which may be due to a high relative abundance of Rhizobiales. Only the rhizosphere microbiome composition of the soybeans changed in response to eCO 2 , associated with an increased abundance of nitrogen fixing microbes. In maize, the microbiome composition was altered by the genotype and linked to differences in root exudate profiles. The eO 3 treatment did not change the microbial communities in the rhizosphere, but altered the soil communities where hybrid maize was grown. In contrast to previous studies that focused exclusively on the soil, this study provides new insights into the effects of plant root exudates on the composition of the belowground microbiome in response to changing atmospheric conditions. Our results demonstrate that plant species and plant genotype were key factors driving the changes in the belowground bacterial community composition in agroecosystems that experience rising levels of atmospheric CO 2 and O 3 .

Cereal grass pulvini: agronomically significant models for studying gravitropism signaling and tissue polarity.

PubMed

Clore, Amy M

2013-01-01

Cereal grass pulvini have emerged as model systems that are not only valuable for the study of gravitropism, but are also of agricultural and economic significance. The pulvini are regions of tissue that are apical to each node and collectively return a reoriented stem to a more vertical position. They have proven to be useful for the study of gravisensing and response and are also providing clues about the establishment of polarity across tissues. This review will first highlight the agronomic significance of these stem regions and their benefits for use as model systems and provide a brief historical overview. A detailed discussion of the literature focusing on cell signaling and early changes in gene expression will follow, culminating in a temporal framework outlining events in the signaling and early growth phases of gravitropism in this tissue. Changes in cell wall composition and gene expression that occur well into the growth phase will be touched upon briefly. Finally, some ongoing research involving both maize and wheat pulvini will be introduced along with prospects for future investigations.

Cell wall modifications triggered by the down-regulation of Coumarate 3-hydroxylase-1 in maize.

PubMed

Fornalé, Silvia; Rencoret, Jorge; Garcia-Calvo, Laura; Capellades, Montserrat; Encina, Antonio; Santiago, Rogelio; Rigau, Joan; Gutiérrez, Ana; Del Río, José-Carlos; Caparros-Ruiz, David

2015-07-01

Coumarate 3-hydroxylase (C3H) catalyzes a key step of the synthesis of the two main lignin subunits, guaiacyl (G) and syringyl (S) in dicotyledonous species. As no functional data are available in regards to this enzyme in monocotyledonous species, we generated C3H1 knock-down maize plants. The results obtained indicate that C3H1 participates in lignin biosynthesis as its down-regulation redirects the phenylpropanoid flux: as a result, increased amounts of p-hydroxyphenyl (H) units, lignin-associated ferulates and the flavone tricin were detected in transgenic stems cell walls. Altogether, these changes make stem cell walls more degradable in the most C3H1-repressed plants, despite their unaltered polysaccharide content. The increase in H monomers is moderate compared to C3H deficient Arabidopsis and alfalfa plants. This could be due to the existence of a second maize C3H protein (C3H2) that can compensate the reduced levels of C3H1 in these C3H1-RNAi maize plants. The reduced expression of C3H1 alters the macroscopic phenotype of the plants, whose growth is inhibited proportionally to the extent of C3H1 repression. Finally, the down-regulation of C3H1 also increases the synthesis of flavonoids, leading to the accumulation of anthocyanins in transgenic leaves. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Conservation and Diversity of Seed Associated Endophytes in Zea across Boundaries of Evolution, Ethnography and Ecology

PubMed Central

Johnston-Monje, David; Raizada, Manish N.

2011-01-01

Endophytes are non-pathogenic microbes living inside plants. We asked whether endophytic species were conserved in the agriculturally important plant genus Zea as it became domesticated from its wild ancestors (teosinte) to modern maize (corn) and moved from Mexico to Canada. Kernels from populations of four different teosintes and 10 different maize varieties were screened for endophytic bacteria by culturing, cloning and DNA fingerprinting using terminal restriction fragment length polymorphism (TRFLP) of 16S rDNA. Principle component analysis of TRFLP data showed that seed endophyte community composition varied in relation to plant host phylogeny. However, there was a core microbiota of endophytes that was conserved in Zea seeds across boundaries of evolution, ethnography and ecology. The majority of seed endophytes in the wild ancestor persist today in domesticated maize, though ancient selection against the hard fruitcase surrounding seeds may have altered the abundance of endophytes. Four TRFLP signals including two predicted to represent Clostridium and Paenibacillus species were conserved across all Zea genotypes, while culturing showed that Enterobacter, Methylobacteria, Pantoea and Pseudomonas species were widespread, with γ-proteobacteria being the prevalent class. Twenty-six different genera were cultured, and these were evaluated for their ability to stimulate plant growth, grow on nitrogen-free media, solubilize phosphate, sequester iron, secrete RNAse, antagonize pathogens, catabolize the precursor of ethylene, produce auxin and acetoin/butanediol. Of these traits, phosphate solubilization and production of acetoin/butanediol were the most commonly observed. An isolate from the giant Mexican landrace Mixteco, with 100% identity to Burkholderia phytofirmans, significantly promoted shoot potato biomass. GFP tagging and maize stem injection confirmed that several seed endophytes could spread systemically through the plant. One seed isolate, Enterobacter asburiae, was able to exit the root and colonize the rhizosphere. Conservation and diversity in Zea-microbe relationships are discussed in the context of ecology, crop domestication, selection and migration. PMID:21673982

Conservation and diversity of seed associated endophytes in Zea across boundaries of evolution, ethnography and ecology.

PubMed

Johnston-Monje, David; Raizada, Manish N

2011-01-01

Endophytes are non-pathogenic microbes living inside plants. We asked whether endophytic species were conserved in the agriculturally important plant genus Zea as it became domesticated from its wild ancestors (teosinte) to modern maize (corn) and moved from Mexico to Canada. Kernels from populations of four different teosintes and 10 different maize varieties were screened for endophytic bacteria by culturing, cloning and DNA fingerprinting using terminal restriction fragment length polymorphism (TRFLP) of 16S rDNA. Principle component analysis of TRFLP data showed that seed endophyte community composition varied in relation to plant host phylogeny. However, there was a core microbiota of endophytes that was conserved in Zea seeds across boundaries of evolution, ethnography and ecology. The majority of seed endophytes in the wild ancestor persist today in domesticated maize, though ancient selection against the hard fruitcase surrounding seeds may have altered the abundance of endophytes. Four TRFLP signals including two predicted to represent Clostridium and Paenibacillus species were conserved across all Zea genotypes, while culturing showed that Enterobacter, Methylobacteria, Pantoea and Pseudomonas species were widespread, with γ-proteobacteria being the prevalent class. Twenty-six different genera were cultured, and these were evaluated for their ability to stimulate plant growth, grow on nitrogen-free media, solubilize phosphate, sequester iron, secrete RNAse, antagonize pathogens, catabolize the precursor of ethylene, produce auxin and acetoin/butanediol. Of these traits, phosphate solubilization and production of acetoin/butanediol were the most commonly observed. An isolate from the giant Mexican landrace Mixteco, with 100% identity to Burkholderia phytofirmans, significantly promoted shoot potato biomass. GFP tagging and maize stem injection confirmed that several seed endophytes could spread systemically through the plant. One seed isolate, Enterobacter asburiae, was able to exit the root and colonize the rhizosphere. Conservation and diversity in Zea-microbe relationships are discussed in the context of ecology, crop domestication, selection and migration.

Genetic Diversity and Molecular Evolution of Chinese Waxy Maize Germplasm

PubMed Central

Zheng, Hongjian; Wang, Hui; Yang, Hua; Wu, Jinhong; Shi, Biao; Cai, Run; Xu, Yunbi; Wu, Aizhong; Luo, Lijun

2013-01-01

Waxy maize (Zea mays L. var. certaina Kulesh), with many excellent characters in terms of starch composition and economic value, has grown in China for a long history and its production has increased dramatically in recent decades. However, the evolution and origin of waxy maize still remains unclear. We studied the genetic diversity of Chinese waxy maize including typical landraces and inbred lines by SSR analysis and the results showed a wide genetic diversity in the Chinese waxy maize germplasm. We analyzed the origin and evolution of waxy maize by sequencing 108 samples, and downloading 52 sequences from GenBank for the waxy locus in a number of accessions from genus Zea. A sharp reduction of nucleotide diversity and significant neutrality tests (Tajima’s D and Fu and Li’s F*) were observed at the waxy locus in Chinese waxy maize but not in nonglutinous maize. Phylogenetic analysis indicated that Chinese waxy maize originated from the cultivated flint maize and most of the modern waxy maize inbred lines showed a distinct independent origin and evolution process compared with the germplasm from Southwest China. The results indicated that an agronomic trait can be quickly improved to meet production demand by selection. PMID:23818949

Processing maize flour and corn meal food products

PubMed Central

Gwirtz, Jeffrey A; Garcia-Casal, Maria Nieves

2014-01-01

Corn is the cereal with the highest production worldwide and is used for human consumption, livestock feed, and fuel. Various food technologies are currently used for processing industrially produced maize flours and corn meals in different parts of the world to obtain precooked refined maize flour, dehydrated nixtamalized flour, fermented maize flours, and other maize products. These products have different intrinsic vitamin and mineral contents, and their processing follows different pathways from raw grain to the consumer final product, which entail changes in nutrient composition. Dry maize mechanical processing creates whole or fractionated products, separated by anatomical features such as bran, germ, and endosperm. Wet maize processing separates by chemical compound classification such as starch and protein. Various industrial processes, including whole grain, dry milling fractionation, and nixtamalization, are described. Vitamin and mineral losses during processing are identified and the nutritional impacts outlined. Also discussed are the vitamin and mineral contents of corn. PMID:24329576

ZmNST3 and ZmNST4 are master switches for secondary wall deposition in maize (Zea mays L.).

PubMed

Xiao, Wenhan; Yang, Yue; Yu, Jingjuan

2018-01-01

Secondary walls are the most abundant biomass produced by plants, and they consist mainly of lignin, cellulose and hemicellulose. Understanding how secondary wall biosynthesis is regulated could potentially provide genetic tools for engineering biomass components, especially in maize and Sorghum bicolor. Although many works have focused on secondary wall biosynthesis in dicotyledons, little has been reported for these monocotyledons. In this study, we cloned two NAC transcriptional factor genes, ZmNST3 and ZmNST4, and analyzed their functions in maize secondary wall formation process. ZmNST3 and ZmNST4 were expressed specifically in secondary wall-forming cells, expression of ZmNST3/4 can restore the pendent phenotype of Arabidopsis nst1nst3 double mutant. ZmNST3/4-overexpressing Arabidopsis and maize displayed a thickened secondary wall in the stem, and knockdown maize showed defective secondary wall deposition. ZmNST3/4 could regulate the expression of ZmMYB109/128/149. Our results revealed that ZmNST3/4 are master switches of the maize secondary wall biosynthesis process and provides new evidence that the secondary wall regulatory pathway is conserved in different plant species. Copyright © 2017. Published by Elsevier B.V.

Rapid and accurate identification of in vivo-induced haploid seeds based on oil content in maize

PubMed Central

Melchinger, Albrecht E.; Schipprack, Wolfgang; Würschum, Tobias; Chen, Shaojiang; Technow, Frank

2013-01-01

The needs of a growing human population require rapid and efficient development of improved cultivars by plant breeders. The doubled haploid (DH) technology enables generating completely homozygous lines in a single step and, thus, is central to modern genetics and breeding approaches. Rapid and reliable identification of seeds with a haploid embryo after in vivo haploid induction is elementary in the method utilized in maize but current systems have severe shortcomings preventing their use in many germplasm types. Here, we describe an alternative method for discrimination of haploid from diploid seeds based on differences in their oil content stemming from pollination with high oil inducers. After presenting some fundamental theory, we provide a proof-of-concept with experimental results, demonstrating acceptable error rates across different germplasm. Our approach represents a breakthrough in DH technology in maize, because it is amenable to automated high-throughput screening and applicable to any maize germplasm worldwide. PMID:23820577

Randomly amplified polymorphic-DNA analysis for detecting genotoxic effects of Boron on maize (Zea mays L.).

PubMed

Sakcali, M Serdal; Kekec, Guzin; Uzonur, Irem; Alpsoy, Lokman; Tombuloglu, Huseyin

2015-08-01

This study was carried out to investigate the genotoxic effect of boron (B) on maize using randomly amplified polymorphic DNA (RAPD) method. Experimental design was conducted under 0, 5, 10, 25, 50, 100, 125, and 150 ppm B exposures, and physiological changes have revealed a sharp decrease in root growth rates from 28% to 85%, starting from 25 ppm to 150 ppm, respectively. RAPD-polymerase chain reaction (PCR) analysis shows that DNA alterations are clearly observed from beginning to 100 ppm. B-induced inhibition in root growth had a positive correlation with DNA alterations. Total soluble protein, root and stem lengths, and B content analysis in root and leaves encourage these results as a consequence. These preliminary findings reveal that B causes chromosomal aberration and genotoxic effects on maize. Meanwhile, usage of RAPD-PCR technique is a suitable biomarker to detect genotoxic effect of B on maize and other crops for the future. © The Author(s) 2013.

Holistic and component plant phenotyping using temporal image sequence.

PubMed

Das Choudhury, Sruti; Bashyam, Srinidhi; Qiu, Yumou; Samal, Ashok; Awada, Tala

2018-01-01

Image-based plant phenotyping facilitates the extraction of traits noninvasively by analyzing large number of plants in a relatively short period of time. It has the potential to compute advanced phenotypes by considering the whole plant as a single object (holistic phenotypes) or as individual components, i.e., leaves and the stem (component phenotypes), to investigate the biophysical characteristics of the plants. The emergence timing, total number of leaves present at any point of time and the growth of individual leaves during vegetative stage life cycle of the maize plants are significant phenotypic expressions that best contribute to assess the plant vigor. However, image-based automated solution to this novel problem is yet to be explored. A set of new holistic and component phenotypes are introduced in this paper. To compute the component phenotypes, it is essential to detect the individual leaves and the stem. Thus, the paper introduces a novel method to reliably detect the leaves and the stem of the maize plants by analyzing 2-dimensional visible light image sequences captured from the side using a graph based approach. The total number of leaves are counted and the length of each leaf is measured for all images in the sequence to monitor leaf growth. To evaluate the performance of the proposed algorithm, we introduce University of Nebraska-Lincoln Component Plant Phenotyping Dataset (UNL-CPPD) and provide ground truth to facilitate new algorithm development and uniform comparison. The temporal variation of the component phenotypes regulated by genotypes and environment (i.e., greenhouse) are experimentally demonstrated for the maize plants on UNL-CPPD. Statistical models are applied to analyze the greenhouse environment impact and demonstrate the genetic regulation of the temporal variation of the holistic phenotypes on the public dataset called Panicoid Phenomap-1. The central contribution of the paper is a novel computer vision based algorithm for automated detection of individual leaves and the stem to compute new component phenotypes along with a public release of a benchmark dataset, i.e., UNL-CPPD. Detailed experimental analyses are performed to demonstrate the temporal variation of the holistic and component phenotypes in maize regulated by environment and genetic variation with a discussion on their significance in the context of plant science.

Gravity-stimulated changes in auxin and invertase gene expression in maize pulvinal cells

NASA Technical Reports Server (NTRS)

Long, Joanne C.; Zhao, Wei; Rashotte, Aaron M.; Muday, Gloria K.; Huber, Steven C.; Brown, C. S. (Principal Investigator)

2002-01-01

Maize (Zea mays) stem gravitropism involves differential elongation of cells within a highly specialized region, the stem internodal pulvinus. In the present study, we investigated factors that control gravitropic responses in this system. In the graviresponding pulvinus, hexose sugars (D-Glc and D-Fru) accumulated asymmetrically across the pulvinus. This correlated well with an asymmetric increase in acid invertase activity across the pulvinus. Northern analyses revealed asymmetric induction of one maize acid invertase gene, Ivr2, consistent with transcriptional regulation by gravistimulation. Several lines of evidence indicated that auxin redistribution, as a result of polar auxin transport, is necessary for gravity-stimulated Ivr2 transcript accumulation and differential cell elongation across the maize pulvinus. First, the auxin transport inhibitor, N-1-naphthylphthalamic acid, inhibited gravistimulated curvature and Ivr2 transcript accumulation. Second, a transient gradient of free indole-3-acetic acid (IAA) across the pulvinus was apparent shortly after initiation of gravistimulation. This temporarily free IAA gradient appears to be important for differential cell elongation and Ivr2 transcript accumulation. This is based on the observation that N-1-naphthylphthalamic acid will not inhibit gravitropic responses when applied to pulvinus tissue after the free IAA gradient peak has occurred. Third, IAA alone can stimulate Ivr2 transcript accumulation in non-gravistimulated pulvini. The gravity- and IAA-stimulated increase in Ivr2 transcripts was sensitive to the protein synthesis inhibitor, cycloheximide. Based on these results, a two-phase model describing possible relationships between gravitropic curvature, IAA redistribution, and Ivr2 expression is presented.

Apoplastic infusion of sucrose into stem internodes during female flowering does not increase grain yield in maize plants grown under nitrogen-limiting conditions.

PubMed

Peng, Yunfeng; Li, Chunjian; Fritschi, Felix B

2013-08-01

Nitrogen (N) limitation reduces leaf growth and photosynthetic rates of maize (Zea mays), and constrains photosynthate translocation to developing ears. Additionally, the period from about 1 week before to 2 weeks after silking is critical for establishing the reproductive sink capacity necessary to attain maximum yield. To investigate the influence of carbohydrate availability in plants of differing N status, a greenhouse study was performed in which exogenous sucrose (Suc) was infused around the time of silking into maize stems grown under different N regimes. N deficiency significantly reduced leaf area, leaf longevity, leaf chlorophyll content and photosynthetic rate. High N-delayed leaf senescence, particularly of the six uppermost leaves, compared to the other two N treatments. While N application increased ear leaf soluble protein concentration, it did not influence glucose and suc concentrations. Interestingly, ear leaf starch concentration decreased with increasing N application. Infusion of exogenous suc tended to increase non-structural carbohydrate concentrations in the developing ears of all N treatments at silking and 6 days after silking. However, leaf photosynthetic rates were not affected by suc infusion, and suc infusion failed to increase grain yield in any N treatment. The lack of an effect of suc infusion on ear growth and the high ear leaf starch concentration of N-deficient maize, suggest that yield reduction under N deficiency may not be due to insufficient photosynthate availability to the developing ear during silking, and that yield reduction under N deficiency may be determined at an earlier growth stage. Copyright © Physiologia Plantarum 2012.

MicroRNA528 Affects Lodging Resistance of Maize by Regulating Lignin Biosynthesis under Nitrogen-Luxury Conditions.

PubMed

Sun, Qing; Liu, Xiaogang; Yang, Juan; Liu, Wenwen; Du, Qingguo; Wang, Hongqiu; Fu, Chunxiang; Li, Wen-Xue

2018-06-04

Lodging under nitrogen (N)-luxury conditions substantially reduces crop yield and seed quality. However, the molecular mechanisms of plant lodging resistance remain largely unclear, especially in maize. We report here that the expression of ZmmiR528, a monocot-specific microRNA, is induced by N luxury but reduced by N deficiency. We show by the thioacidolysis and acetyl bromide analysis that N luxury significantly reduces the generation of H, G, and S monomers of the lignin as well as its total content in maize shoots. We further demonstrate that ZmLACCASE3 (ZmLAC3) and ZmLACCASE5 (ZmLAC5), which encode the copper-containing laccases, are the targets of ZmmiR528. In situ hybridization showed that ZmmiR528 is mainly expressed in maize vascular tissues. Knockdown of ZmmiR528 or overexpression of ZmLAC3 significantly increased the lignin content and rind penetrometer resistance of maize stems. In contrast, transgenic maize plants overexpressing ZmmiR528 had reduced lignin content and rind penetrometer resistance and were prone to lodging under N-luxury conditions. RNA-sequencing analysis revealed that ZmPAL7 and ZmPAL8 are upregulated in transgenic maize lines downregulating ZmmiR528. Under N-luxury conditions, the expression levels of ZmPALs were much higher in ZmmiR528-knockdown lines than in the wild type and transgenic maize lines overexpressing ZmmiR528. Taken together, these results indicate that, by regulating the expression of ZmLAC3 and ZmLAC5, ZmmiR528 affects maize lodging resistance under N-luxury conditions. Copyright © 2018 The Author. Published by Elsevier Inc. All rights reserved.

Sequence of Changes in Maize Responding to Soil Water Deficit and Related Critical Thresholds

PubMed Central

Ma, Xueyan; He, Qijin; Zhou, Guangsheng

2018-01-01

The sequence of changes in crop responding to soil water deficit and related critical thresholds are essential for better drought damage classification and drought monitoring indicators. This study was aimed to investigate the critical thresholds of maize growth and physiological characteristics responding to changing soil water and to reveal the sequence of changes in maize responding to soil water deficit both in seedling and jointing stages based on 2-year’s maize field experiment responding to six initial soil water statuses conducted in 2013 and 2014. Normal distribution tolerance limits were newly adopted to identify critical thresholds of maize growth and physiological characteristics to a wide range of soil water status. The results showed that in both stages maize growth characteristics related to plant water status [stem moisture content (SMC) and leaf moisture content (LMC)], leaf gas exchange [net photosynthetic rate (Pn), transpiration rate (Tr), and stomatal conductance (Gs)], and leaf area were sensitive to soil water deficit, while biomass-related characteristics were less sensitive. Under the concurrent weather conditions and agronomic managements, the critical soil water thresholds in terms of relative soil moisture of 0–30 cm depth (RSM) of maize SMC, LMC, net Pn, Tr, Gs, and leaf area were 72, 65, 62, 60, 58, and 46%, respectively, in seedling stage, and 64, 64, 51, 53, 48, and 46%, respectively, in jointing stage. It indicated that there is a sequence of changes in maize responding to soil water deficit, i.e., their response sequences as soil water deficit intensified: SMC ≥ LMC > leaf gas exchange > leaf area in both stages. This sequence of changes in maize responding to soil water deficit and related critical thresholds may be better indicators of damage classification and drought monitoring. PMID:29765381

Different effects of transgenic maize and nontransgenic maize on nitrogen-transforming archaea and bacteria in tropical soils.

PubMed

Cotta, Simone Raposo; Dias, Armando Cavalcante Franco; Marriel, Ivanildo Evódio; Andreote, Fernando Dini; Seldin, Lucy; van Elsas, Jan Dirk

2014-10-01

The composition of the rhizosphere microbiome is a result of interactions between plant roots, soil, and environmental conditions. The impact of genetic variation in plant species on the composition of the root-associated microbiota remains poorly understood. This study assessed the abundances and structures of nitrogen-transforming (ammonia-oxidizing) archaea and bacteria as well as nitrogen-fixing bacteria driven by genetic modification of their maize host plants. The data show that significant changes in the abundances (revealed by quantitative PCR) of ammonia-oxidizing bacterial and archaeal communities occurred as a result of the maize host being genetically modified. In contrast, the structures of the total communities (determined by PCR-denaturing gradient gel electrophoresis) were mainly driven by factors such as soil type and season and not by plant genotype. Thus, the abundances of ammonia-oxidizing bacterial and archaeal communities but not structures of those communities were revealed to be responsive to changes in maize genotype, allowing the suggestion that community abundances should be explored as candidate bioindicators for monitoring the possible impacts of cultivation of genetically modified plants. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Functional diversification of maize RNA polymerase IV and V subtypes via alternative catalytic subunits

DOE PAGES

Haag, Jeremy R.; Brower-Toland, Brent; Krieger, Elysia K.; ...

2014-10-02

Unlike nuclear multisubunit RNA polymerases I, II, and III, whose subunit compositions are conserved throughout eukaryotes, plant RNA polymerases IV and V are nonessential, Pol II-related enzymes whose subunit compositions are still evolving. Whereas Arabidopsis Pols IV and V differ from Pol II in four or five of their 12 subunits, respectively, and differ from one another in three subunits, proteomic analyses show that maize Pols IV and V differ from Pol II in six subunits but differ from each other only in their largest subunits. Use of alternative catalytic second subunits, which are nonredundant for development and paramutation, yieldsmore » at least two sub-types of Pol IV and three subtypes of Pol V in maize. Pol IV/Pol V associations with MOP1, RMR1, AGO121, Zm_DRD1/CHR127, SHH2a, and SHH2b extend parallels between paramutation in maize and the RNA-directed DNA methylation pathway in Arabidopsis.« less

Functional diversification of maize RNA polymerase IV and V subtypes via alternative catalytic subunits

PubMed Central

Haag, Jeremy R.; Brower-Toland, Brent; Krieger, Elysia K.; Sidorenko, Lyudmila; Nicora, Carrie D.; Norbeck, Angela D.; Irsigler, Andre; LaRue, Huachun; Brzeski, Jan; McGinnis, Karen; Ivashuta, Sergey; Pasa-Tolic, Ljiljana; Chandler, Vicki L.; Pikaard, Craig S.

2014-01-01

Summary Unlike nuclear multisubunit RNA polymerases I, II and III, whose subunit compositions are conserved throughout eukaryotes, plant RNA Polymerases IV and V are non-essential, Pol II-related enzymes whose subunit compositions are still evolving. Whereas Arabidopsis Pols IV and V differ from Pol II in four or five of their twelve subunits, respectively, and differ from one another in three subunits, proteomic analyses show that maize Pols IV and V differ from Pol II in six subunits, but differ from each other only in their largest subunits. Use of alternative catalytic second-subunits, which are non-redundant for development and paramutation, yields at least two subtypes of Pol IV, and three subtypes of Pol V in maize. Pol IV/V associations with MOP1, RMR1, AGO121, Zm_DRD1/CHR127, SHH2a and SHH2b extend parallels between paramutation in maize and the RNA-directed DNA methylation pathway in Arabidopsis. PMID:25284785

Variation in cell wall composition among forage maize (Zea mays L.) inbred lines and its impact on digestibility: analysis of neutral detergent fiber composition by pyrolysis-gas chromatography-mass spectrometry.

PubMed

Fontaine, Anne-Sophie; Bout, Siobhán; Barrière, Yves; Vermerris, Wilfred

2003-12-31

Cell wall digestibility is an important determinant of forage quality, but the relationship between cell wall composition and digestibility is poorly understood. We analyzed the neutral detergent fiber (NDF) fraction of nine maize inbred lines and one brown midrib3 mutant with pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). Among 29 pyrolysis fragments that were quantified, two carbohydrate-derived and six lignin-derived fragments showed statistically significant genetic variation. The pyrolysis products 4-vinyl phenol and 2,6-dimethoxy-4-vinyl phenol were negatively correlated with digestibility, whereas furfural and 3-(4-hydroxyphenyl)-3-oxopropanal showed a positive correlation with digestibility. Linear discriminant analysis of the pyrolysis data resulted in the resolution of groups of inbred lines with different digestibility properties based on their chemical composition. These analyses reveal that digestibility is governed by complex interactions between different cell wall compounds, but that several pyrolysis fragments can be used as markers to distinguish between maize lines with different digestibility.

Quantification of phenolic acids and antioxidant potential of inbred, hybrid and composite cultivars of maize under different nitrogen regimes.

PubMed

Ganie, Arshid Hussain; Yousuf, Peerzada Yasir; Ahad, Amjid; Pandey, Renu; Ahmad, Sayeed; Aref, Ibrahim M; Noor, Jewel Jameeta; Iqbal, Muhammad

2016-11-01

Maize (Zea mays L.) is a multipurpose crop, which is immensely used worldwide for its nutritional as well as medicinal properties. This study evaluates the effect of varying concentrations of nitrogen (N) on accumulation of phenolic acids and antioxidant activity in different maize cultivars, including inbreds, hybrids and a composite, which were grown in natural light under controlled temperature (30°C/20°C D/N) and humidity (80%), with sufficient (4.5mM) and low (0.05mM) nitrogen supply. Seeds of different cultivars were powdered and extracted in a methanol:water (80:20) mixture through reflux at 60-75°C, and the extracts obtained were subjected to high performance thin layer chromatography (HPTLC), using ethyl acetate: acetic acid: formic acid: water (109:16:12:31) solvent system for the separation of phenolic acids. Antioxidant activity of the extracts was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and H2O2-scavenging activity assays. At sufficient nitrogen condition, the contents of different phenolic acids were higher in the composite cultivar (8.7 mg g-1 d.wt. in gallic acid to 39.3 mg g-1 d.wt. in cinnamic and salicylic acids) than in inbreds and hybrids. Under low nitrogen condition, the phenolic acids contents declined significantly in inbreds and hybrids, but remained almost unaffected in the composite. The antioxidant activity was also the maximum in the composite, and declined similarly as phenolic acids under low nitrogen supply, showing a significant reduction in inbreds and hybrids only. Therefore, the maize composite has a potential for being used as a nutraceutical in human-health sector.

Changes in nitrogen metabolism and antioxidant enzyme activities of maize tassel in black soils region of northeast China

PubMed Central

Xu, Hongwen; Lu, Yan; Xie, Zhiming; Song, Fengbin

2014-01-01

Two varieties of maize (Zea mays L.) grown in fields in black soils of northeast China were tested to study the dynamic changes of nitrogen metabolism and antioxidant enzyme activity in tassels of maize. Results showed that antioxidant enzyme activity in tassels of maize increased first and then decreased with the growing of maize, and reached peak value at shedding period. Pattern of proline was consistent with antioxidant enzyme activity, showing that osmotic adjustment could protect many enzymes, which are important for cell metabolism. Continuous reduction of soluble protein content along with the growing of maize was observed in the study, which indicated that quantitative material and energy were provided for pollen formation. Besides, another major cause was that a large proportion of nitrogen was used for the composition of structural protein. Nitrate nitrogen concentrations of tassels were more variable than ammonium nitrogen, which showed that nitrate nitrogen was the favored nitrogen source for maize. PMID:25324855

Maize (Zea mays L) cultivars nutrients concentration in leaves and stalks

USDA-ARS?s Scientific Manuscript database

There is pressure for crop residue removal for use as biofuel, animal feed, animal bedding and many other functions which may increase nutrient export. However, there is little information about nutritional composition of maize stover considering the wide variability of cultivars used. The aim of th...

Genome-wide association study and pathway level analysis of tocochromanol levels in maize grain

USDA-ARS?s Scientific Manuscript database

Tocopherols and tocotrienols, collectively known as tocochromanols, are the major lipid-soluble antioxidants in maize (Zea mays L.) grain. Given that individual tocochromanols differ in their degree of vitamin E activity, variation for tocochromanol composition and content in grain from among divers...

Genetic variability of the phloem sap metabolite content of maize (Zea mays L.) during the kernel-filling period.

PubMed

Yesbergenova-Cuny, Zhazira; Dinant, Sylvie; Martin-Magniette, Marie-Laure; Quilleré, Isabelle; Armengaud, Patrick; Monfalet, Priscilla; Lea, Peter J; Hirel, Bertrand

2016-11-01

Using a metabolomic approach, we have quantified the metabolite composition of the phloem sap exudate of seventeen European and American lines of maize that had been previously classified into five main groups on the basis of molecular marker polymorphisms. In addition to sucrose, glutamate and aspartate, which are abundant in the phloem sap of many plant species, large quantities of aconitate and alanine were also found in the phloem sap exudates of maize. Genetic variability of the phloem sap composition was observed in the different maize lines, although there was no obvious relationship between the phloem sap composition and the five previously classified groups. However, following hierarchical clustering analysis there was a clear relationship between two of the subclusters of lines defined on the basis of the composition of the phloem sap exudate and the earliness of silking date. A comparison between the metabolite contents of the ear leaves and the phloem sap exudates of each genotype, revealed that the relative content of most of the carbon- and nitrogen-containing metabolites was similar. Correlation studies performed between the metabolite content of the phloem sap exudates and yield-related traits also revealed that for some carbohydrates such as arabitol and sucrose there was a negative or positive correlation with kernel yield and kernel weight respectively. A posititive correlation was also found between kernel number and soluble histidine. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

CERES–Maize Model for Determining the Optimum Planting Dates of Early Maturing Maize Varieties in Northern Nigeria

PubMed Central

Adnan, Adnan A.; Jibrin, Jibrin M.; Kamara, Alpha Y.; Abdulrahman, Bassam L.; Shaibu, Abdulwahab S.; Garba, Ismail I.

2017-01-01

Field trials were carried out in the Sudan Savannah of Nigeria to assess the usefulness of CERES–maize crop model as a decision support tool for optimizing maize production through manipulation of plant dates. The calibration experiments comprised of 20 maize varieties planted during the dry and rainy seasons of 2014 and 2015 at Bayero University Kano and Audu Bako College of Agriculture Dambatta. The trials for model evaluation were conducted in 16 different farmer fields across the Sudan (Bunkure and Garun—Mallam) and Northern Guinea (Tudun-Wada and Lere) Savannas using two of the calibrated varieties under four different sowing dates. The model accurately predicted grain yield, harvest index, and biomass of both varieties with low RMSE-values (below 5% of mean), high d-index (above 0.8), and high r-square (above 0.9) for the calibration trials. The time series data (tops weight, stem and leaf dry weights) were also predicted with high accuracy (% RMSEn above 70%, d-index above 0.88). Similar results were also observed for the evaluation trials, where all variables were simulated with high accuracies. Estimation efficiencies (EF)-values above 0.8 were observed for all the evaluation parameters. Seasonal and sensitivity analyses on Typic Plinthiustalfs and Plinthic Kanhaplustults in the Sudan and Northern Guinea Savannas were conducted. Results showed that planting extra early maize varieties in late July and early maize in mid-June leads to production of highest grain yields in the Sudan Savanna. In the Northern Guinea Savanna planting extra-early maize in mid-July and early maize in late July produced the highest grain yields. Delaying planting in both Agro-ecologies until mid-August leads to lower yields. Delaying planting to mid-August led to grain yield reduction of 39.2% for extra early maize and 74.4% for early maize in the Sudan Savanna. In the Northern Guinea Savanna however, delaying planting to mid-August resulted in yield reduction of 66.9 and 94.3% for extra-early and early maize, respectively. PMID:28702039

Genetic Determinants for Enzymatic Digestion of Lignocellulosic Biomass Are Independent of Those for Lignin Abundance in a Maize Recombinant Inbred Population

DOE PAGES

Penning, Bryan W.; Sykes, Robert W.; Babcock, Nicholas C.; ...

2014-06-27

Biotechnological approaches to reduce or modify lignin in biomass crops are predicated on the assumption that it is the principal determinant of the recalcitrance of biomass to enzymatic digestion for biofuels production. We defined quantitative trait loci (QTL) in the Intermated B73 x 3 Mo17 recombinant inbred maize (Zea mays) population using pyrolysis molecular-beam mass spectrometry to establish stem lignin content and an enzymatic hydrolysis assay to measure glucose and xylose yield. Among five multiyear QTL for lignin abundance, two for 4-vinylphenol abundance, and four for glucose and/or xylose yield, not a single QTL for aromatic abundance and sugar yieldmore » was shared. A genome-wide association study for lignin abundance and sugar yield of the 282- member maize association panel provided candidate genes in the 11 QTL of the B73 and Mo17 parents but showed that many other alleles impacting these traits exist among this broader pool of maize genetic diversity. B73 and Mo17 genotypes exhibited large differences in gene expression in developing stem tissues independent of allelic variation. Combining these complementary genetic approaches provides a narrowed list of candidate genes. A cluster of SCARECROW-LIKE9 and SCARECROW-LIKE14 transcription factor genes provides exceptionally strong candidate genes emerging from the genome-wide association study. In addition to these and genes associated with cell wall metabolism, candidates include several other transcription factors associated with vascularization and fiber formation and components of cellular signaling pathways. Finally, these results provide new insights and strategies beyond the modification of lignin to enhance yields of biofuels from genetically modified biomass.« less

Genetic Determinants for Enzymatic Digestion of Lignocellulosic Biomass Are Independent of Those for Lignin Abundance in a Maize Recombinant Inbred Population1[W][OPEN

PubMed Central

Penning, Bryan W.; Sykes, Robert W.; Babcock, Nicholas C.; Dugard, Christopher K.; Held, Michael A.; Klimek, John F.; Shreve, Jacob T.; Fowler, Matthew; Ziebell, Angela; Davis, Mark F.; Decker, Stephen R.; Turner, Geoffrey B.; Mosier, Nathan S.; Springer, Nathan M.; Thimmapuram, Jyothi; Weil, Clifford F.; McCann, Maureen C.; Carpita, Nicholas C.

2014-01-01

Biotechnological approaches to reduce or modify lignin in biomass crops are predicated on the assumption that it is the principal determinant of the recalcitrance of biomass to enzymatic digestion for biofuels production. We defined quantitative trait loci (QTL) in the Intermated B73 × Mo17 recombinant inbred maize (Zea mays) population using pyrolysis molecular-beam mass spectrometry to establish stem lignin content and an enzymatic hydrolysis assay to measure glucose and xylose yield. Among five multiyear QTL for lignin abundance, two for 4-vinylphenol abundance, and four for glucose and/or xylose yield, not a single QTL for aromatic abundance and sugar yield was shared. A genome-wide association study for lignin abundance and sugar yield of the 282-member maize association panel provided candidate genes in the 11 QTL of the B73 and Mo17 parents but showed that many other alleles impacting these traits exist among this broader pool of maize genetic diversity. B73 and Mo17 genotypes exhibited large differences in gene expression in developing stem tissues independent of allelic variation. Combining these complementary genetic approaches provides a narrowed list of candidate genes. A cluster of SCARECROW-LIKE9 and SCARECROW-LIKE14 transcription factor genes provides exceptionally strong candidate genes emerging from the genome-wide association study. In addition to these and genes associated with cell wall metabolism, candidates include several other transcription factors associated with vascularization and fiber formation and components of cellular signaling pathways. These results provide new insights and strategies beyond the modification of lignin to enhance yields of biofuels from genetically modified biomass. PMID:24972714

Genetic Determinants for Enzymatic Digestion of Lignocellulosic Biomass Are Independent of Those for Lignin Abundance in a Maize Recombinant Inbred Population.

PubMed

Penning, Bryan W; Sykes, Robert W; Babcock, Nicholas C; Dugard, Christopher K; Held, Michael A; Klimek, John F; Shreve, Jacob T; Fowler, Matthew; Ziebell, Angela; Davis, Mark F; Decker, Stephen R; Turner, Geoffrey B; Mosier, Nathan S; Springer, Nathan M; Thimmapuram, Jyothi; Weil, Clifford F; McCann, Maureen C; Carpita, Nicholas C

2014-08-01

Biotechnological approaches to reduce or modify lignin in biomass crops are predicated on the assumption that it is the principal determinant of the recalcitrance of biomass to enzymatic digestion for biofuels production. We defined quantitative trait loci (QTL) in the Intermated B73 × Mo17 recombinant inbred maize (Zea mays) population using pyrolysis molecular-beam mass spectrometry to establish stem lignin content and an enzymatic hydrolysis assay to measure glucose and xylose yield. Among five multiyear QTL for lignin abundance, two for 4-vinylphenol abundance, and four for glucose and/or xylose yield, not a single QTL for aromatic abundance and sugar yield was shared. A genome-wide association study for lignin abundance and sugar yield of the 282-member maize association panel provided candidate genes in the 11 QTL of the B73 and Mo17 parents but showed that many other alleles impacting these traits exist among this broader pool of maize genetic diversity. B73 and Mo17 genotypes exhibited large differences in gene expression in developing stem tissues independent of allelic variation. Combining these complementary genetic approaches provides a narrowed list of candidate genes. A cluster of SCARECROW-LIKE9 and SCARECROW-LIKE14 transcription factor genes provides exceptionally strong candidate genes emerging from the genome-wide association study. In addition to these and genes associated with cell wall metabolism, candidates include several other transcription factors associated with vascularization and fiber formation and components of cellular signaling pathways. These results provide new insights and strategies beyond the modification of lignin to enhance yields of biofuels from genetically modified biomass. © 2014 American Society of Plant Biologists. All Rights Reserved.

Irrigation and Maize Cultivation Erode Plant Diversity Within Crops in Mediterranean Dry Cereal Agro-Ecosystems.

PubMed

Fagúndez, Jaime; Olea, Pedro P; Tejedo, Pablo; Mateo-Tomás, Patricia; Gómez, David

2016-07-01

The intensification of agriculture has increased production at the cost of environment and biodiversity worldwide. To increase crop yield in dry cereal systems, vast farmland areas of high conservation value are being converted into irrigation, especially in Mediterranean countries. We analyze the effect of irrigation-driven changes on the farm biota by comparing species diversity, community composition, and species traits of arable plants within crop fields from two contrasting farming systems (dry and irrigated) in Spain. We sampled plant species within 80 fields of dry wheat, irrigated wheat, and maize (only cultivated under irrigation). Wheat crops held higher landscape and per field species richness, and beta diversity than maize. Within the same type of crop, irrigated wheat hosted lower plant diversity than dry wheat at both field and landscape scales. Floristic composition differed between crop types, with higher frequencies of perennials, cosmopolitan, exotic, wind-pollinated and C4 species in maize. Our results suggest that irrigation projects, that transform large areas of dry cereal agro-ecosystems into irrigated crop systems dominated by maize, erode plant diversity. An adequate planning on the type and proportion of crops used in the irrigated agro-ecosystems is needed in order to balance agriculture production and biodiversity conservation.

Genetic analysis of arsenic accumulation in maize using QTL mapping

NASA Astrophysics Data System (ADS)

Fu, Zhongjun; Li, Weihua; Xing, Xiaolong; Xu, Mengmeng; Liu, Xiaoyang; Li, Haochuan; Xue, Yadong; Liu, Zonghua; Tang, Jihua

2016-02-01

Arsenic (As) is a toxic heavy metal that can accumulate in crops and poses a threat to human health. The genetic mechanism of As accumulation is unclear. Herein, we used quantitative trait locus (QTL) mapping to unravel the genetic basis of As accumulation in a maize recombinant inbred line population derived from the Chinese crossbred variety Yuyu22. The kernels had the lowest As content among the different maize tissues, followed by the axes, stems, bracts and leaves. Fourteen QTLs were identified at each location. Some of these QTLs were identified in different environments and were also detected by joint analysis. Compared with the B73 RefGen v2 reference genome, the distributions and effects of some QTLs were closely linked to those of QTLs detected in a previous study; the QTLs were likely in strong linkage disequilibrium. Our findings could be used to help maintain maize production to satisfy the demand for edible corn and to decrease the As content in As-contaminated soil through the selection and breeding of As pollution-safe cultivars.

Genetic analysis of arsenic accumulation in maize using QTL mapping.

PubMed

Fu, Zhongjun; Li, Weihua; Xing, Xiaolong; Xu, Mengmeng; Liu, Xiaoyang; Li, Haochuan; Xue, Yadong; Liu, Zonghua; Tang, Jihua

2016-02-16

Arsenic (As) is a toxic heavy metal that can accumulate in crops and poses a threat to human health. The genetic mechanism of As accumulation is unclear. Herein, we used quantitative trait locus (QTL) mapping to unravel the genetic basis of As accumulation in a maize recombinant inbred line population derived from the Chinese crossbred variety Yuyu22. The kernels had the lowest As content among the different maize tissues, followed by the axes, stems, bracts and leaves. Fourteen QTLs were identified at each location. Some of these QTLs were identified in different environments and were also detected by joint analysis. Compared with the B73 RefGen v2 reference genome, the distributions and effects of some QTLs were closely linked to those of QTLs detected in a previous study; the QTLs were likely in strong linkage disequilibrium. Our findings could be used to help maintain maize production to satisfy the demand for edible corn and to decrease the As content in As-contaminated soil through the selection and breeding of As pollution-safe cultivars.

Use of the Stable Nitrogen Isotope to Reveal the Source-Sink Regulation of Nitrogen Uptake and Remobilization during Grain Filling Phase in Maize

PubMed Central

Yang, Lan; Guo, Song; Chen, Qinwu; Chen, Fanjun; Yuan, Lixing; Mi, Guohua

2016-01-01

Although the remobilization of vegetative nitrogen (N) and post-silking N both contribute to grain N in maize (Zea mays L.), their regulation by grain sink strength is poorly understood. Here we use 15N labeling to analyze the dynamic behaviors of both pre- and post-silking N in relation to source and sink manipulation in maize plants. The results showed that the remobilization of pre-silking N started immediately after silking and the remobilized pre-silking N had a greater contribution to grain N during early grain filling, with post-silking N importance increasing during the later filling stage. The amount of post-silking N uptake was largely driven by post-silking dry matter accumulation in both grain as well as vegetative organs. Prevention of pollination during silking had less effect on post-silking N uptake, as a consequence of compensatory growth of stems, husk + cob and roots. Also, leaves continuously export N even though grain sink was removed. The remobilization efficiency of N in the leaf and stem increased with increasing grain yield (hence N requirement). It is suggested that the remobilization of N in the leaf is controlled by sink strength but not the leaf per se. Enhancing post-silking N uptake rather than N remobilization is more likely to increase grain N accumulation. PMID:27606628

Lipophilic metabolite profiling of maize and sorghum seeds and seedlings, and their pest spotted stem borer larvae: a standardized GC-MS based approach.

PubMed

Kumar, Sandeep; Dhillon, Mukesh K

2015-03-01

In order to better understand the biochemical interactions and to identify new biomarkers for plant resistance against insects, we proposed a suitable lipophilic profiling method for insects and their host plants. The critical components of GC-MS based analysis are: sample amount, extraction, derivatization, temperature gradient, run time, and identification of peaks. For lipophilic metabolite profiling of maize and sorghum, and their insect pest, spotted stem borer larvae, we recommend 100 mg sample weight for seeds and insect samples (whole insect body), and 200 mg for seedlings. Maize and sorghum seeds required less time for fat extraction in comparison to their seedlings and the pest fed on these seedlings. GC-MS was standardized for better separation and intensity of peaks using different temperature gradients in the range of 180-300 C. A total of 48 lipophilic compounds encompassing various classes based on their functional groups such as fatty acids, fatty alcohols, hydrocarbons, sterols and terpenoids, vitamin derivative, etc. were separated in the seedlings (30), seeds (14), and the pest (26) in the retention time range of 3.22 to 29.41 min. This method could be useful to study nutritional aspects of different field crops in relation to various stresses apart from the analysis of lipophilic compounds for better understanding of insect-plant interactions.

[Effect of conservation tillage on weeds in a rotation system on the Loess Plateau of eastern Gansu, Northwest China].

PubMed

Zhao, Yu-xin; Lu, Jiao-yun; Yang, Hui-min

2015-04-01

A field study was conducted to investigate the influences of no-tillage, stubble retention and crop type on weed density, species composition and community feature in a rotation system (winter wheat-common vetch-maize) established 12 years ago on the Loess Plateau of eastern Gansu. This study showed that the weed species composition, density and community feature varied with the change of crop phases. No-tillage practice increased the weed density at maize phase, while rotation with common vetch decreased the density in the no-tillage field. Stubble retention reduced the weed density under maize phase and the lowest density was observed in the no-tillage plus stubble retention field. No-tillage practice significantly increased the weed species diversity under winter wheat phase and decreased the diversity under common vetch phase. At maize phase, a greater species diversity index was observed in the no-tillage field. These results suggested that no-tillage practice and stubble retention possibly suppress specific weeds with the presence of some crops and crop rotation is a vital way to controlling weeds in a farming system.

Sheep manure vermicompost supplemented with a native diazotrophic bacteria and mycorrhizas for maize cultivation.

PubMed

Gutiérrez-Miceli, F A; Moguel-Zamudio, B; Abud-Archila, M; Gutiérrez-Oliva, V F; Dendooven, L

2008-10-01

An orthogonal experimental design L9 (3(4)) with 10 repetitions was used to investigate the effect of Glomus claroideum (0, 1 or 2g(-1) plant), G. fasciculatum (0, 1 or 2g plant(-1)), native diazotrophic bacteria (0, 10(3) and 10(5) UFC ml(-1)) and sheep manure vermicompost (0%, 5% and 10% v/v) on maize plant growth, N and P in leaves and mycorrhization percent. Vermicompost explained most of the variation found for leaf number, wet weight, stem height, and diameter. Both mycorrhizas increased the plant wet weight but G. fasciculatum the most. Mycorrhization increased the P content, but not the N content. Mycorrhizal colonization increased when diazotrophic bacteria and vermicompost were added. It was found that weight of maize plants cultivated in peat moss amended with vermicompost increased when supplemented with G. fasciculatum and diazotrophic bacteria.

No adverse effects of transgenic maize on population dynamics of endophytic Bacillus subtilis strain B916-gfp.

PubMed

Sun, Chongsi; Geng, Lili; Wang, Meiling; Shao, Gaoxiang; Liu, Yongfeng; Shu, Changlong; Zhang, Jie

2017-02-01

Endophytic bacterial communities play a key role in promoting plant growth and combating plant diseases. However, little is known about their population dynamics in plant tissues and bulk soil, especially in transgenic crops. This study investigated the colonization of transgenic maize harboring the Bacillus thuringiensis (Bt) cry1Ah gene by Bacillus subtilis strain B916-gfp present in plant tissues and soil. Bt and nontransgenic maize were inoculated with B916-gfp by seed soaking, or root irrigation under both laboratory greenhouse and field conditions. During the growing season, B916-gfp colonized transgenic as well as nontransgenic plants by both inoculation methods. No differences were observed in B916-gfp population size between transgenic and nontransgenic plants, except at one or two time points in the roots and stems that did not persist over the examination period. Furthermore, planting transgenic maize did not affect the number of B916-gfp in bulk soil in either laboratory or field trials. These results indicate that transgenic modification of maize with the cry1Ah gene has no influence on colonization by the endophytic bacteria B916-gfp present in the plant and in bulk soil. © 2016 The Authors. MicrobiologyOpenpublished by John Wiley & Sons Ltd.

Genome-wide identification, phylogeny and expression analyses of SCARECROW-LIKE(SCL) genes in millet (Setaria italica).

PubMed

Liu, Hongyun; Qin, Jiajia; Fan, Hui; Cheng, Jinjin; Li, Lin; Liu, Zheng

2017-07-01

As a member of the GRAS gene family, SCARECROW - LIKE ( SCL ) genes encode transcriptional regulators that are involved in plant information transmission and signal transduction. In this study, 44 SCL genes including two SCARECROW genes in millet were identified to be distributed on eight chromosomes, except chromosome 6. All the millet genes contain motifs 6-8, indicating that these motifs are conserved during the evolution. SCL genes of millet were divided into eight groups based on the phylogenetic relationship and classification of Arabidopsis SCL genes. Several putative millet orthologous genes in Arabidopsis , maize and rice were identified. High throughput RNA sequencing revealed that the expressions of millet SCL genes in root, stem, leaf, spica, and along leaf gradient varied greatly. Analyses combining the gene expression patterns, gene structures, motif compositions, promoter cis -elements identification, alternative splicing of transcripts and phylogenetic relationship of SCL genes indicate that the these genes may play diverse functions. Functionally characterized SCL genes in maize, rice and Arabidopsis would provide us some clues for future characterization of their homologues in millet. To the best of our knowledge, this is the first study of millet SCL genes at the genome wide level. Our work provides a useful platform for functional analysis of SCL genes in millet, a model crop for C 4 photosynthesis and bioenergy studies.

Comparison of species composition and fumonisin production in Aspergillus section Nigri populations in maize kernels from USA and Italy.

PubMed

Susca, Antonia; Moretti, Antonio; Stea, Gaetano; Villani, Alessandra; Haidukowski, Miriam; Logrieco, Antonio; Munkvold, Gary

2014-10-01

Fumonisin contamination of maize is considered a serious problem in most maize-growing regions of the world, due to the widespread occurrence of these mycotoxins and their association with toxicosis in livestock and humans. Fumonisins are produced primarily by species of Fusarium that are common in maize grain, but also by some species of Aspergillus sect. Nigri, which can also occur on maize kernels as opportunistic pathogens. Understanding the origin of fumonisin contamination in maize is a key component in developing effective management strategies. Although some fungi in Aspergillus sect. Nigri are known to produce fumonisins, little is known about the species which are common in maize and whether they make a measurable contribution to fumonisin contamination of maize grain. In this work, we evaluated populations of Aspergillus sect. Nigri isolated from maize in USA and Italy, focusing on analysis of housekeeping genes, the fum8 gene and in vitro capability of producing fumonisins. DNA sequencing was used to identify Aspergillus strains belonging to sect. Nigri, in order to compare species composition between the two populations, which might influence specific mycotoxicological risks. Combined beta-tubulin/calmodulin sequences were used to genetically characterize 300 strains (199 from Italy and 101 from USA) which grouped into 4 clades: Aspergillus welwitschiae (syn. Aspergillus awamori, 14.7%), Aspergillus tubingensis (37.0%) and Aspergillus niger group 1 (6.7%) and group 2 (41.3%). Only one strain was identified as Aspergillus carbonarius. Species composition differed between the two populations; A. niger predominated among the USA isolates (69%), but comprised a smaller percentage (38%) of Italian isolates. Conversely, A. tubingensis and A. welwitschiae occurred at higher frequencies in the Italian population (42% and 20%, respectively) than in the USA population (27% and 5%). The evaluation of FB2 production on CY20S agar revealed 118 FB2 producing and 84 non-producing strains distributed among the clades: A. welwitschiae, A. niger group 1 and A. niger group 2, confirming the potential of Aspergillus sect. Nigri species to contribute to total fumonisin contamination of maize. A higher percentage of A. niger isolates (72.0%) produced FB2 compared to A. welwitschiae (36.6%). The percentage of FB2-producing A. niger strains was similar in the USA and Italian populations; however, the predominance of A. niger in the USA population suggests a higher potential for fumonisin production. Some strains with fum8 present in the genome did not produce FB2in vitro, confirming the ineffectiveness of fum8 presence as a predictor of FB2 production. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of feeding Mediterranean buffalo sorghum silage versus maize silage on the rumen microbiota and milk fatty acid content.

PubMed

Ann Huws, Sharon; Chiariotti, Antonella; Sarubbi, Fiorella; Carfì, Francesca; Pace, Vilma

2012-01-01

Sorghum presents a sustainable feedstock for Mediterranean buffaloes due to its reduced water and nitrogen requirements compared with maize, which is currently fed primarily. We investigated the effects of feeding sorghum as opposed to maize on Mediterranean buffalo rumen microbial diversity and milk fatty acid content. Four cannulated lactating Mediterranean buffalo cows were fed a basal diet for one month before switching either to maize or sorghum-silage based diets for a 3-month period. Buffaloes were then changed over to the contrasting diet for a further one month. Rumen and milk samples were collected at the end of each month. DGGE- and T-RFLP-based dendrograms generated from rumen samples did not show an effect of diet on rumen bacterial diversity. Milk samples also did not differ in terms of their fatty acid content post sorghum feeding as compared with maize feeding. Thus, sorghum provides an environmentally beneficial alternative to maize for feeding Mediterranean buffalo with little effect on rumen microbial diversity or milk fatty acid composition compared with maize feeding.

Variation in chemical composition and physical characteristics of cereal grains from different genotypes.

PubMed

Rodehutscord, Markus; Rückert, Christine; Maurer, Hans Peter; Schenkel, Hans; Schipprack, Wolfgang; Bach Knudsen, Knud Erik; Schollenberger, Margit; Laux, Meike; Eklund, Meike; Siegert, Wolfgang; Mosenthin, Rainer

2016-01-01

Genotypes of cereal grains, including winter barley (n = 21), maize (n = 27), oats (n = 14), winter rye (n = 22), winter triticale (n = 21) and winter wheat (n = 29), were assayed for their chemical composition and physical characteristics as part of the collaborative research project referred to as GrainUp. Genotypes of one grain species were grown on the same site, except maize. In general, concentrations of proximate nutrients were not largely different from feed tables. The coefficient of variation (CV) for the ether extract concentration of maize was high because the data pool comprised speciality maize bred for its high oil content. A subset of 8 barley, 20 rye, 20 triticale and 20 wheat samples was analysed to differ significantly in several carbohydrate fractions. Gross energy concentration of cereal grains could be predicted from proximate nutrient concentration with good accuracy. The mean lysine concentration of protein was the highest in oats (4.2 g/16 g N) and the lowest in wheat (2.7 g/16 g N). Significant differences were also detected in the concentrations of macro elements as well as iron, manganese, zinc and copper. Concentrations of arsenic, cadmium and lead were below the limit of detection. The concentration of lower inositol phosphates was low, but some inositol pentaphosphates were detected in all grains. In barley, relatively high inositol tetraphosphate concentration also was found. Intrinsic phytase activity was the highest in rye, followed by triticale, wheat, barley and maize, and it was not detectable in oats. Substantial differences were seen in the thousand seed weight, test weight, falling number and extract viscoelasticity characteristics. The study is a comprehensive overview of the composition of different cereal grain genotypes when grown on the same location. The relevance of the variation in composition for digestibility in different animal species will be subject of other communications.

Nutritional Properties Assessment of Endogenous and Improved Varieties of Maize (Zea mays L.) Grown in Southern Benin.

PubMed

Josiane, Semassa Adjobignon; Bienvenu, Anihouvi Victor; Wilfried, Padonou Segla; Adolphe, Adjanohoun; Djima, Aly; Joachin, Gbenou; Lamine, Baba-Moussa

2017-01-01

A wide range of maize varieties is used in Benin but information on the nutritional characteristics of these varieties are not well known. This study aims to assess the nutritional composition of maize varieties in use in the southern region of Benin with the purpose of providing consumers accurate information for better choice. Moisture, ash, protein, fiber and fat contents were determined according to Association of Official Analytical Chemists and American Association of Cereal Chemists methods. Sugar and organic acids were assessed using High Performance Liquid Chromatography methods and amino acids profile was established according to Rosen method using glutamic acid. The maize varieties were classified into 5 clusters according to their macro nutrients composition and 4 clusters based on their sugar and organic acids contents. Varieties of group 5 were very rich in protein (14.34 g/100 g), while the highest fat content (7.22 g/100 g) was observed for group 2 varieties. The highest carbohydrate contents obtained were 80.64 g/100 g, 80.11 g/100 g and 79.15 g/100 g for groups 1, 4 and 5 varieties respectively. Moreover the dendrogram gave four homogeneous clusters according to sugars and organic acids composition. Varieties of groups 2, 3 and 4 had almost the same fructose contents ranging between 0.04 and 0.06%; varieties of group 1 contained the highest contents of raffinose, sucrose and glucose; those of group 2 were very rich in propionate and fructose. It is concluded that some of maize varieties investigated contained high level of protein. Furthermore glutamic acid was the predominant amino acid while the least amino acid was methionine. Those varieties, owing to their protein and amino acids contents could have many benefits by providing vital constituents to the body.

Soya bean meal increases litter moisture and foot pad dermatitis in maize and wheat based diets for turkeys but maize and non-soya diets lower body weight.

PubMed

Hocking, P M; Vinco, L J; Veldkamp, T

2018-04-01

1. A 2 × 2 factorial experiment was conducted to compare the effects of wheat or maize based diets differing in dietary electrolyte balance (DEB) on litter moisture and foot pad dermatitis (FPD) at 4, 8 and 12 weeks of age in heavy-medium turkeys. A second objective was to investigate the effects on foot pad dermatitis of the interaction between dietary composition and artificially increasing litter moisture by adding water to the litter. 2. High DEB diets contained soya as the main protein source whereas low DEB diets did not contain soya bean meal. Diets were formulated to be iso-caloric and iso-nitrogenous in each of 3 successive 4-week phases following recommended dietary compositions. DEB concentrations were 330, 290 and 250 mEq/kg in high DEB diets and 230, 200 and 180 mEq/kg in low DEB diets. 3. Litter moisture and mean FPD score were higher in turkeys fed on high DEB diets compared with low DEB diets whereas there was no difference between maize and wheat. 4. Food intake was similar and body weight was lower after litter moisture was artificially raised in the wet compared with the dry litter treatment and there was no interaction with dietary composition. 5. Mean body weight and feed intake were higher in turkeys fed on wheat compared with maize and in high DEB compared with low DEB diets at 12 weeks of age. 6. Lowering dietary DEB for turkeys may improve litter moisture and lower the prevalence of FPD in commercial turkey flocks.

Assessment of water sources to plant growth in rice based cropping systems by stable water isotopes

NASA Astrophysics Data System (ADS)

Mahindawansha, Amani; Kraft, Philipp; Racela, Heathcliff; Breuer, Lutz

2016-04-01

Rice is one of the most water-consuming crops in the world. Understanding water source utilization of rice will help us to improve water use efficiency (WUE) in paddy management. The objectives of our study are to evaluate the isotopic compositions of surface ponded water, soil water, irrigation water, groundwater, rain water and plant water and based on stable water isotope signatures to evaluate the contributions of various water sources to plant growth (wet rice, aerobic rice and maize) together with investigating the contribution of water from different soil horizons for plant growth in different maturity periods during wet and dry seasons. Finally we will compare the water balances and crop yields in both crops during both seasons and calculate the water use efficiencies. This will help to identify the most efficient water management systems in rice based cropping ecosystems using stable water isotopes. Soil samples are collected from 9 different depths at up to 60 cm in vegetative, reproductive and matured periods of plant growth together with stem samples. Soil and plant samples are extracted by cryogenic vacuum extraction. Root samples are collected up to 60 cm depth from 10 cm intercepts leading calculation of root length density and dry weight. Groundwater, surface water, rain water and irrigation water are sampled weekly. All water samples are analyzed for hydrogen and oxygen isotope ratios (d18O and dD) using Los Gatos Research DLT100. Rainfall records, ground water level, surface water level fluctuations and the amount of water irrigated in each field will be measured during the sampling period. The direct inference approach which is based on comparing isotopic compositions (dD and d18O) between plant stem water and soil water will be used to determine water sources taken up by plant. Multiple-source mass balance assessment can provide the estimated range of potential contributions of water from each soil depth to root water uptake of a crop. These evaluations will be used to determine the proportion of water from upper soil horizons and deep horizons for rice and maize in different maturity periods during wet and dry seasons. Finally we will estimate the influence of groundwater and surface water by irrigation water and/or by precipitation. First results of the sampling during the wet season 2015 will be presented.

Genetic resources for maize cell wall biology.

PubMed

Penning, Bryan W; Hunter, Charles T; Tayengwa, Reuben; Eveland, Andrea L; Dugard, Christopher K; Olek, Anna T; Vermerris, Wilfred; Koch, Karen E; McCarty, Donald R; Davis, Mark F; Thomas, Steven R; McCann, Maureen C; Carpita, Nicholas C

2009-12-01

Grass species represent a major source of food, feed, and fiber crops and potential feedstocks for biofuel production. Most of the biomass is contributed by cell walls that are distinct in composition from all other flowering plants. Identifying cell wall-related genes and their functions underpins a fundamental understanding of growth and development in these species. Toward this goal, we are building a knowledge base of the maize (Zea mays) genes involved in cell wall biology, their expression profiles, and the phenotypic consequences of mutation. Over 750 maize genes were annotated and assembled into gene families predicted to function in cell wall biogenesis. Comparative genomics of maize, rice (Oryza sativa), and Arabidopsis (Arabidopsis thaliana) sequences reveal differences in gene family structure between grass species and a reference eudicot species. Analysis of transcript profile data for cell wall genes in developing maize ovaries revealed that expression within families differed by up to 100-fold. When transcriptional analyses of developing ovaries before pollination from Arabidopsis, rice, and maize were contrasted, distinct sets of cell wall genes were expressed in grasses. These differences in gene family structure and expression between Arabidopsis and the grasses underscore the requirement for a grass-specific genetic model for functional analyses. A UniformMu population proved to be an important resource in both forward- and reverse-genetics approaches to identify hundreds of mutants in cell wall genes. A forward screen of field-grown lines by near-infrared spectroscopic screen of mature leaves yielded several dozen lines with heritable spectroscopic phenotypes. Pyrolysis-molecular beam mass spectrometry confirmed that several nir mutants had altered carbohydrate-lignin compositions.

Impact of different bioenergy crops on N-cycling bacterial and archaeal communities in soil.

PubMed

Mao, Yuejian; Yannarell, Anthony C; Davis, Sarah C; Mackie, Roderick I

2013-03-01

Biomass production for bioenergy may change soil microbes and influence ecosystem properties. To explore the impact of different bioenergy cropping systems on soil microorganisms, the compositions and quantities of soil microbial communities (16S rRNA gene) and N-cycling functional groups (nifH, bacterial amoA, archaeal amoA and nosZ genes) were assessed under maize, switchgrass and Miscanthus x giganteus at seven sites representing a climate gradient (precipitation and temperature) in Illinois, USA. Overall, the site-to-site variation in community composition surpassed the variation due to plant type, and microbial communities under each crop did not converge on a 'typical' species assemblage. Fewer than 5% of archaeal amoA, bacterial amoA, nifH and nosZ OTUs were significantly different among these crops, but the largest differences observed at each site were found between maize and the two perennial grasses. Quantitative PCR revealed that the abundance of the nifH gene was significantly higher in the perennial grasses than in maize, and we also found significantly higher total N in the perennial grass soils than in maize. Thus, we conclude that cultivation of these perennial grasses, instead of maize, as bioenergy feedstocks can improve soil ecosystem nitrogen sustainability by increasing the population size of N-fixing bacteria. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

Constitutive expression of fluorescent protein by Aspergillus var. niger and Aspergillus carbonarius to monitor fungal colonization in maize plants.

PubMed

Palencia, Edwin Rene; Glenn, Anthony Elbie; Hinton, Dorothy Mae; Bacon, Charles Wilson

2013-09-01

Aspergillus niger and Aspergillus carbonarius are two species in the Aspergillus section Nigri (black-spored aspergilli) frequently associated with peanut (Arachis hypogea), maize (Zea mays), and other plants as pathogens. These infections are symptomless and as such are major concerns since some black aspergilli produce important mycotoxins, ochratoxins A, and the fumonisins. To facilitate the study of the black aspergilli-maize interactions with maize during the early stages of infections, we developed a method that used the enhanced yellow fluorescent protein (eYFP) and the monomeric red fluorescent protein (mRFP1) to transform A. niger and A. carbonarius, respectively. The results were constitutive expressions of the fluorescent genes that were stable in the cytoplasms of hyphae and conidia under natural environmental conditions. The hyphal in planta distribution in 21-day-old seedlings of maize were similar wild type and transformants of A. niger and A. carbonarius. The in planta studies indicated that both wild type and transformants internally colonized leaf, stem and root tissues of maize seedlings, without any visible disease symptoms. Yellow and red fluorescent strains were capable of invading epidermal cells of maize roots intercellularly within the first 3 days after inoculation, but intracellular hyphal growth was more evident after 7 days of inoculation. We also tested the capacity of fluorescent transformants to produce ochratoxin A and the results with A. carbonarius showed that this transgenic strain produced similar concentrations of this secondary metabolite. This is the first report on the in planta expression of fluorescent proteins that should be useful to study the internal plant colonization patterns of two ochratoxigenic species in the Aspergillus section Nigri. © 2013.

Synergy between root hydrotropic response and root biomass in maize (Zea mays L.) enhances drought avoidance.

PubMed

Eapen, Delfeena; Martínez-Guadarrama, Jesús; Hernández-Bruno, Oralia; Flores, Leonardo; Nieto-Sotelo, Jorge; Cassab, Gladys I

2017-12-01

Roots of higher plants change their growth direction in response to moisture, avoiding drought and gaining maximum advantage for development. This response is termed hydrotropism. There have been few studies of root hydrotropism in grasses, particularly in maize. Our goal was to test whether an enhanced hydrotropic response of maize roots correlates with a better adaptation to drought and partial/lateral irrigation in field studies. We developed a laboratory bioassay for testing hydrotropic response in primary roots of 47 maize elite DTMA (Drought Tolerant Maize for Africa) hybrids. After phenotyping these hybrids in the laboratory, selected lines were tested in the field. Three robust and three weak hybrids were evaluated employing three irrigation procedures: normal irrigation, partial lateral irrigation and drought. Hybrids with a robust hydrotropic response showed growth and developmental patterns, under drought and partial lateral irrigation, that differed from weak hydrotropic responders. A correlation between root crown biomass and grain yield in hybrids with robust hydrotropic response was detected. Hybrids with robust hydrotropic response showed earlier female flowering whereas several root system traits, such as projected root area, median width, maximum width, skeleton width, skeleton nodes, average tip diameter, rooting depth skeleton, thinner aboveground crown roots, as well as stem diameter, were considerably higher than in weak hydrotropic responders in the three irrigation procedures utilized. These results demonstrate the benefit of intensive phenotyping of hydrotropism in primary roots since maize plants that display a robust hydrotropic response grew better under drought and partial lateral irrigation, indicating that a selection for robust hydrotropism might be a promising breeding strategy to improve drought avoidance in maize. Copyright © 2017 Elsevier B.V. All rights reserved.

Maize YABBY Genes drooping leaf1 and drooping leaf2 Regulate Plant Architecture[OPEN

PubMed Central

Briggs, Sarah; Bradbury, Peter J.

2017-01-01

Leaf architecture directly influences canopy structure, consequentially affecting yield. We discovered a maize (Zea mays) mutant with aberrant leaf architecture, which we named drooping leaf1 (drl1). Pleiotropic mutations in drl1 affect leaf length and width, leaf angle, and internode length and diameter. These phenotypes are enhanced by natural variation at the drl2 enhancer locus, including reduced expression of the drl2-Mo17 allele in the Mo17 inbred. A second drl2 allele, produced by transposon mutagenesis, interacted synergistically with drl1 mutants and reduced drl2 transcript levels. The drl genes are required for proper leaf patterning, development and cell proliferation of leaf support tissues, and for restricting auricle expansion at the midrib. The paralogous loci encode maize CRABS CLAW co-orthologs in the YABBY family of transcriptional regulators. The drl genes are coexpressed in incipient and emergent leaf primordia at the shoot apex, but not in the vegetative meristem or stem. Genome-wide association studies using maize NAM-RIL (nested association mapping-recombinant inbred line) populations indicated that the drl loci reside within quantitative trait locus regions for leaf angle, leaf width, and internode length and identified rare single nucleotide polymorphisms with large phenotypic effects for the latter two traits. This study demonstrates that drl genes control the development of key agronomic traits in maize. PMID:28698237

RNA-Seq Analysis Reveals MAPKKK Family Members Related to Drought Tolerance in Maize

PubMed Central

Ren, Wen; Yang, Fengling; He, Hang; Zhao, Jiuran

2015-01-01

The mitogen-activated protein kinase (MAPK) cascade is an evolutionarily conserved signal transduction pathway that is involved in plant development and stress responses. As the first component of this phosphorelay cascade, mitogen-activated protein kinase kinase kinases (MAPKKKs) act as adaptors linking upstream signaling steps to the core MAPK cascade to promote the appropriate cellular responses; however, the functions of MAPKKKs in maize are unclear. Here, we identified 71 MAPKKK genes, of which 14 were novel, based on a computational analysis of the maize (Zea mays L.) genome. Using an RNA-seq analysis in the leaf, stem and root of maize under well-watered and drought-stress conditions, we identified 5,866 differentially expressed genes (DEGs), including 8 MAPKKK genes responsive to drought stress. Many of the DEGs were enriched in processes such as drought stress, abiotic stimulus, oxidation-reduction, and metabolic processes. The other way round, DEGs involved in processes such as oxidation, photosynthesis, and starch, proline, ethylene, and salicylic acid metabolism were clearly co-expressed with the MAPKKK genes. Furthermore, a quantitative real-time PCR (qRT-PCR) analysis was performed to assess the relative expression levels of MAPKKKs. Correlation analysis revealed that there was a significant correlation between expression levels of two MAPKKKs and relative biomass responsive to drought in 8 inbred lines. Our results indicate that MAPKKKs may have important regulatory functions in drought tolerance in maize. PMID:26599013

Transient dissociation of polyribosomes and concurrent recruitment of calreticulin and calmodulin transcripts in gravistimulated maize pulvini

NASA Technical Reports Server (NTRS)

Heilmann, I.; Shin, J.; Huang, J.; Perera, I. Y.; Davies, E.

2001-01-01

The dynamics of polyribosome abundance were studied in gravistimulated maize (Zea mays) stem pulvini. During the initial 15 min of gravistimulation, the amount of large polyribosomes transiently decreased. The transient decrease in polyribosome levels was accompanied by a transient decrease in polyribosome-associated mRNA. After 30 min of gravistimulation, the levels of polyribosomes and the amount of polyribosome-associated mRNA gradually increased over 24 h up to 3- to 4-fold of the initial value. Within 15 min of gravistimulation, total levels of transcripts coding for calreticulin and calmodulin were elevated 5-fold in maize pulvinus total RNA. Transcripts coding for calreticulin and calmodulin were recruited into polyribosomes within 15 min of gravistimulation. Over 4 h of gravistimulation, a gradual increase in the association of calreticulin and calmodulin transcripts with polyribosomes was seen predominantly in the lower one-half of the maize pulvinus; the association of transcripts for vacuolar invertase with polyribosomes did not change over this period. Our results suggest that within 15 min of gravistimulation, the translation of the majority of transcripts associated with polyribosomes decreased, resembling a general stress response. Recruitment of calreticulin and calmodulin transcripts into polyribosomes occurred predominantly in the lower pulvinus one-half during the first 4 h when the presentation time for gravistimulation in the maize pulvinus is not yet complete.

Reduced Root Cortical Cell File Number Improves Drought Tolerance in Maize1[C][W][OPEN

PubMed Central

Chimungu, Joseph G.; Brown, Kathleen M.

2014-01-01

We tested the hypothesis that reduced root cortical cell file number (CCFN) would improve drought tolerance in maize (Zea mays) by reducing the metabolic costs of soil exploration. Maize genotypes with contrasting CCFN were grown under well-watered and water-stressed conditions in greenhouse mesocosms and in the field in the United States and Malawi. CCFN ranged from six to 19 among maize genotypes. In mesocosms, reduced CCFN was correlated with 57% reduction of root respiration per unit of root length. Under water stress in the mesocosms, genotypes with reduced CCFN had between 15% and 60% deeper rooting, 78% greater stomatal conductance, 36% greater leaf CO2 assimilation, and between 52% to 139% greater shoot biomass than genotypes with many cell files. Under water stress in the field, genotypes with reduced CCFN had between 33% and 40% deeper rooting, 28% lighter stem water oxygen isotope enrichment (δ18O) signature signifying deeper water capture, between 10% and 35% greater leaf relative water content, between 35% and 70% greater shoot biomass at flowering, and between 33% and 114% greater yield than genotypes with many cell files. These results support the hypothesis that reduced CCFN improves drought tolerance by reducing the metabolic costs of soil exploration, enabling deeper soil exploration, greater water acquisition, and improved growth and yield under water stress. The large genetic variation for CCFN in maize germplasm suggests that CCFN merits attention as a breeding target to improve the drought tolerance of maize and possibly other cereal crops. PMID:25355868

Baseline sensitivity of maize borers in India to the Bacillus thuringiensis insecticidal proteins Cry1A.105 and Cry2Ab2.

PubMed

Jalali, Sushil K; Yadavalli, Lalitha; Ojha, Rakshit; Kumar, Pradyumn; Sulaikhabeevi, Suby B; Sharma, Reema; Nair, Rupa; Kadanur, Ravi C; Kamath, Subray P; Komarlingam, Mohan S

2015-08-01

Among the major pests of maize in India are two stem borers, Chilo partellus (Swinhoe) and Sesamia inferens (Walker), and an earworm, Helicoverpa armigera (Hübner). As a pest control strategy, transgenic Bacillus thuringiensis (Bt) maize hybrids are undergoing regulatory trials in India. We have determined the sensitivity of the target lepidopterans to the insecticidal Bt proteins expressed in Bt maize, as this determines product efficacy and the resistance management strategy to be adopted. Maize hybrids with event MON89034 express two insecticidal Bt proteins, Cry1A.105 and Cry2Ab2. Sensitivity profiles of 53 populations of C. partellus, 21 populations of S. inferens and 21 populations of H. armigera, collected between 2008 and 2013 from maize-growing areas in India, to Cry1A.105 and Cry2Ab2 proteins were generated through dose-response assays. Cry1A.105 protein was the most effective to neonates of C. partellus (mean MIC90 range 0.30-1.0 µg mL(-1) ) and H. armigera (mean MIC90 range 0.71-8.22 µg mL(-1) ), whereas Cry2Ab2 (mean MIC90 range 0.65-1.70 µg mL(-1) ) was the most effective to S. inferens. Populations of C. partellus, S. inferens and H. armigera were susceptible to the Bt proteins Cry1A.105 and Cry2Ab2. The Bt sensitivity data will serve as precommercialisation benchmarks for resistance monitoring purposes. © 2014 Society of Chemical Industry.

Nutrient composition, ruminal degradability and whole tract digestibility of whole crop maize silage from nine current varieties.

PubMed

Gruber, Leonhard; Terler, Georg; Knaus, Wilhelm

2018-04-01

Since maize silage is an important forage in cattle nutrition, it is important to know its nutritive value. Much effort is put into breeding maize, and several new varieties are introduced on the market every year. This requires periodical analyses of the nutritive value of current maize varieties for the formulation of cattle rations. The aim of this study was to examine the nutritive value of whole crop maize silage (WCMS) from nine maize varieties in 3 consecutive years. For the analysis of nutrient composition and ruminal degradability of organic matter (OM), crude protein (CP), neutral detergent fibre (aNDFom) and non-fibre carbohydrates (NFC), varieties were harvested at three harvest dates (50%, 55% and 60% dry matter content in ear). Due to capacity limitations, the digestibility of WCMS was tested only for the middle harvest date. The CP and acid detergent fibre (ADFom) content was affected (p < 0.05) while aNDFom and NFC content was not influenced by variety. With advancing maturity, CP, aNDFom and ADFom content declined while NFC content increased. Variety influenced effective ruminal degradability (ED) of nutrients, except for CP. The ED of all examined nutrients decreased as maturity advanced from first to third harvest date. Digestibility of OM, ADFom and NFC was significantly and digestibility of aNDFom was tendentially (p = 0.064) influenced by variety. Additionally, an effect of year and a harvest date × year interaction was found for almost all examined parameters. In conclusion, variety, harvest date and year influence the nutritive value of WCMS. A comparison with earlier studies shows that current varieties have a higher fibre digestibility and a slower-ripening stover compared to older varieties.

Ameliorating Effects of Exogenously Applied Proline on Seed Composition, Seed Oil Quality and Oil Antioxidant Activity of Maize (Zea mays L.) under Drought Stress

PubMed Central

Ali, Qasim; Anwar, Farooq; Ashraf, Muhammad; Saari, Nazamid; Perveen, Rashida

2013-01-01

This study was carried out to appraise whether or not the exogenous application of a potential osmoprotectant, proline, could ameliorate the adverse effects of drought stress on maize seed and seed oil composition, as well as oil antioxidant activity. Water stress reduced the kernel sugar, oil, protein and moisture contents and most of the seed macro- and micro-elements analyzed in both maize cultivars but it increased the contents of seed fiber and ash. Water stress increased the oil oleic acid content with a subsequent decrease in the amount of linoleic acid, resulting in an increased oil oleic/linoleic ratio for both maize cultivars. However, no variation was observed in oil stearic and palmitic acids content due to water stress. A considerable drought induced an increase in seed oil α-, γ-, δ- and total tocopherols and flavonoids were observed in both maize cultivars. However, oil phenolic and carotenoid content as well as 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging activity decreased. Foliar-applied proline significantly increased the content of seed sugar, oil, protein, moisture, fiber and ash in both maize cultivars under well irrigated and water deficit conditions. Furthermore, exogenous application of proline increased the oil oleic and linoleic acid contents. The concentrations of antioxidant compounds namely phenolics, carotenoids, flavonoids and tocopherols estimated in the seed oil increased due to foliar-applied proline under water deficit conditions that was positively correlated with the enhanced oil DPPH free radical scavenging activity. Moreover, the increase in the contents of these antioxidant compounds and oil antioxidant activity due to the foliar application of proline was noted to be more pronounced under water deficit conditions. PMID:23344043

Genetic Resources for Maize Cell Wall Biology1[C][W][OA

PubMed Central

Penning, Bryan W.; Hunter, Charles T.; Tayengwa, Reuben; Eveland, Andrea L.; Dugard, Christopher K.; Olek, Anna T.; Vermerris, Wilfred; Koch, Karen E.; McCarty, Donald R.; Davis, Mark F.; Thomas, Steven R.; McCann, Maureen C.; Carpita, Nicholas C.

2009-01-01

Grass species represent a major source of food, feed, and fiber crops and potential feedstocks for biofuel production. Most of the biomass is contributed by cell walls that are distinct in composition from all other flowering plants. Identifying cell wall-related genes and their functions underpins a fundamental understanding of growth and development in these species. Toward this goal, we are building a knowledge base of the maize (Zea mays) genes involved in cell wall biology, their expression profiles, and the phenotypic consequences of mutation. Over 750 maize genes were annotated and assembled into gene families predicted to function in cell wall biogenesis. Comparative genomics of maize, rice (Oryza sativa), and Arabidopsis (Arabidopsis thaliana) sequences reveal differences in gene family structure between grass species and a reference eudicot species. Analysis of transcript profile data for cell wall genes in developing maize ovaries revealed that expression within families differed by up to 100-fold. When transcriptional analyses of developing ovaries before pollination from Arabidopsis, rice, and maize were contrasted, distinct sets of cell wall genes were expressed in grasses. These differences in gene family structure and expression between Arabidopsis and the grasses underscore the requirement for a grass-specific genetic model for functional analyses. A UniformMu population proved to be an important resource in both forward- and reverse-genetics approaches to identify hundreds of mutants in cell wall genes. A forward screen of field-grown lines by near-infrared spectroscopic screen of mature leaves yielded several dozen lines with heritable spectroscopic phenotypes. Pyrolysis-molecular beam mass spectrometry confirmed that several nir mutants had altered carbohydrate-lignin compositions. PMID:19926802

Nutritional composition and antinutritional properties of maize ogi cofermented with pigeon pea.

PubMed

Okafor, Uchechukwu I; Omemu, Adebunkola M; Obadina, Adewale O; Bankole, Mobolaji O; Adeyeye, Samuel A O

2018-03-01

Maize was cofermented with pigeon pea for ogi production and evaluated for nutritional (proximate composition, minerals, vitamins, and amino acid profile analyses) and antinutritional (phytate, tannin, and trypsin inhibitor activity analyses) qualities. White maize and pigeon pea were mixed at ratios of 90:10, 80:20, 70:30, 60:40, and 50:50, respectively, with 100:0 serving as the control. Mixtures were cofermented for 96 hr at 27°C ± 2°C and nutritional, mineral, and antinutritional qualities were analyzed using analysis of variance. Results of proximate analysis showed that the values were significantly difference at p  ≤   .05. Maize cofermented with pigeon pea at a ratio of 60:40 had the highest protein (22.79 mg/100 g), fat (19.27 mg/100 g), ash (2.98 mg/100 g), crude fiber (0.73 mg/100 g), and lowest moisture (1.98 mg/100 g) content, and was significantly ( p  ≤   .05) different from the other ratios. Of all the mixtures analyzed, 60:40 was significantly ( p  ≤   .05) different and had the highest Vitamin B 1 , B 2 , and B 3 contents. Amino acid profile results showed that maize cofermented with pigeon pea at a ratio of 60:40 showed the highest contents of lysine (93.95 mg/g), tryptophan (20.38 mg/g), isoleucine (54.78 mg/g), phenylalanine (86.23 mg/g), leucine (109.55 mg/g), and valine (68.29 mg/g), respectively, and was significantly ( p  ≤   .05) different from the other ratios. Results of antinutritional analysis showed low phytate, tannin, and trypsin inhibitor values in maize cofermented with pigeon pea at a ratio of 60:40 when compared with other ratios. The cofermented maize-pigeon pea product 60:40 had high amino acid profile than the others.

Comparison of fractionation methods for nitrogen and starch in maize and grass silages.

PubMed

Ali, M; de Jonge, L H; Cone, J W; van Duinkerken, G; Blok, M C; Bruinenberg, M H; Hendriks, W H

2016-06-01

In in situ nylon bag technique, many feed evaluation systems use a washing machine method (WMM) to determine the washout (W) fraction and to wash the rumen incubated nylon bags. As this method has some disadvantages, an alternate modified method (MM) was recently introduced. The aim of this study was to determine and compare the W and non-washout (D+U) fractions of nitrogen (N) and/or starch of maize and grass silages, using the WMM and the MM. Ninety-nine maize silage and 99 grass silage samples were selected with a broad range in chemical composition. The results showed a large range in the W, soluble (S) and D+U fractions of N of maize and grass silages and the W, insoluble washout (W-S) and D+U fractions of starch of maize silages, determined by both methods, due to variation in their chemical composition. The values for N fractions of maize and grass silages obtained with both methods were found different (p < 0.001). Large differences (p < 0.001) were found in the D+U fraction of starch of maize silages which might be due to different methodological approaches, such as different rinsing procedures (washing vs. shaking), duration of rinsing (40 min vs. 60 min) and different solvents (water vs. buffer solution). The large differences (p < 0.001) in the W-S and D+U fractions of starch determined with both methods can led to different predicted values for the effective rumen starch degradability. In conclusion, the MM with one recommended shaking procedure, performed under identical and controlled experimental conditions, can give more reliable results compared to the WMM, using different washing programs and procedures. Journal of Animal Physiology and Animal Nutrition © 2015 Blackwell Verlag GmbH.

Stacking transgenic event DAS-Ø15Ø7-1 alters maize composition less than traditional breeding.

PubMed

Herman, Rod A; Fast, Brandon J; Scherer, Peter N; Brune, Alyssa M; de Cerqueira, Denise T; Schafer, Barry W; Ekmay, Ricardo D; Harrigan, George G; Bradfisch, Greg A

2017-10-01

The impact of crossing ('stacking') genetically modified (GM) events on maize-grain biochemical composition was compared with the impact of generating nonGM hybrids. The compositional similarity of seven GM stacks containing event DAS-Ø15Ø7-1, and their matched nonGM near-isogenic hybrids (iso-hybrids) was compared with the compositional similarity of concurrently grown nonGM hybrids and these same iso-hybrids. Scatter plots were used to visualize comparisons among hybrids and a coefficient of identity (per cent of variation explained by line of identity) was calculated to quantify the relationships within analyte profiles. The composition of GM breeding stacks was more similar to the composition of iso-hybrids than was the composition of nonGM hybrids. NonGM breeding more strongly influenced crop composition than did transgenesis or stacking of GM events. These findings call into question the value of uniquely requiring composition studies for GM crops, especially for breeding stacks composed of GM events previously found to be compositionally normal. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Production and economic performance of F1-crossbred dairy cattle fed non-conventional protein supplements in Zimbabwe.

PubMed

Gusha, Jacob; Manyuchi, Clive Rolex; Imbayarwo-Chikosi, Venancio Edward; Hamandishe, Vimbayi Rangaridzo; Katsande, Simbarashe; Zvinorova, Plaxedis Ivy

2014-01-01

The effects of supplementing crossbred cows with non-conventional protein sources on dry matter intake, milk yield parameters and economic returns were investigated. Twenty-five lactating F1 Holstein-Mashona crossbreds averaging 115 ± 24 days in milk were used. Five treatments, total mixed ration (TMR), urea-treated maize stover, untreated maize stover, Macroptilium atropurpureum (Siratro) hay and veld hay, were randomly assigned to cows and replicated five times in a completely randomised design. Nutrient composition, intake, milk yield and economic returns were determined. M. atropurpureum hay, urea-treated maize stover and TMR had equal crude protein content. Daily dry matter intake and yield differed significantly among the treatment diets (P < 0.05). Cows on TMR, urea-treated maize stover and M. atropurpureum consumed more (P < 0.05) than cows on untreated maize stover and veld hay. Supplementing with TMR, urea-treated maize stover and M. atropurpureum hay increased (P < 0.05) milk yields. Mean daily milk yield was highest for cows supplemented with urea-treated maize stover. Percent fat, protein and total solids in milk from cows fed urea-treated stover compared favourably to that of milk for cows supplemented with TMR. Income over supplement cost was highest for cows supplemented with M. atropurpureum hay and urea-treated maize stover. Urea-treated maize stover and M. atropurpureum can therefore be used as a replacer protein supplements for dairy cattle in Zimbabwe.

Polymer composites prepared from heat-treated starch and styrene-butadiene latex

USDA-ARS?s Scientific Manuscript database

Thermoplastic starch/latex polymer composites were prepared using styrene–butadiene (SB) latex and heat-treated cornstarch. The composites were prepared in a compression mold at 130 °C, with starch content 20%. An amylose-free cornstarch, waxy maize, was used for this research and the heat treatment...

Metabolic fingerprint of Brazilian maize landraces silk (stigma/styles) using NMR spectroscopy and chemometric methods.

PubMed

Kuhnen, Shirley; Bernardi Ogliari, Juliana; Dias, Paulo Fernando; da Silva Santos, Maiara; Ferreira, Antônio Gilberto; Bonham, Connie C; Wood, Karl Vernon; Maraschin, Marcelo

2010-02-24

Aqueous extract from maize silks is used by traditional medicine for the treatment of several ailments, mainly related to the urinary system. This work focuses on the application of NMR spectroscopy and chemometric analysis for the determination of metabolic fingerprint and pattern recognition of silk extracts from seven maize landraces cultivated in southern Brazil. Principal component analysis (PCA) of the (1)H NMR data set showed clear discrimination among the maize varieties by PC1 and PC2, pointing out three distinct metabolic profiles. Target compounds analysis showed significant differences (p < 0.05) in the contents of protocatechuic acid, gallic acid, t-cinnamic acid, and anthocyanins, corroborating the discrimination of the genotypes in this study as revealed by PCA analysis. Thus the combination of (1)H NMR and PCA is a useful tool for the discrimination of maize silks in respect to their chemical composition, including rapid authentication of the raw material of current pharmacological interest.

Modeling and analysis of film composition on mechanical properties of maize starch based edible films.

PubMed

Prakash Maran, J; Sivakumar, V; Thirugnanasambandham, K; Kandasamy, S

2013-11-01

The present study investigates the influence of composition (content of maize starch (1-3 g), sorbitol (0.5-1.0 ml), agar (0.5-1.0 g) and tween-80 (0.1-0.5 ml)) on the mechanical properties (tensile strength, elongation, Young's modulus, puncture force and puncture deformation) of the maize starch based edible films using four factors with three level Box-Behnken design. The edible films were obtained by casting method. The results showed that, tween-80 increases the permeation of sorbitol in to the polymer matrix. Increasing concentration of sorbitol (hydrophilic nature and plasticizing effect of sorbitol) decreases the tensile strength, Young's modulus and puncture force of the films. The results were analyzed by Pareto analysis of variance (ANOVA) and second order polynomial models were obtained for all responses with high R(2) values (R(2)>0.95). 3D response surface plots were constructed to study the relationship between process variables and the responses. Copyright © 2013 Elsevier B.V. All rights reserved.

Effects of amaranth addition on the pro-vitamin A content, and physical and antioxidant properties of extruded pro-vitamin A-biofortified maize snacks.

PubMed

Beswa, Daniso; Dlamini, Nomusa R; Amonsou, Eric O; Siwela, Muthulisi; Derera, John

2016-01-15

Pro-vitamin A-biofortified maize snacks with added leafy vegetable may have a potential as nutritious and health-promoting products, especially in addressing vitamin A deficiency, which is prevalent in developing regions. The objective of the study was to determine the effects of adding amaranth leaf powder on the physical, antioxidant properties and pro-vitamin A content of extruded pro-vitamin A-biofortified maize snacks. Extruded snacks were processed using four pro-vitamin A-biofortified maize varieties that were composited with amaranth leaf powder at 0%, 1% and 3% (w/w) substitution levels. At higher amaranth concentration, the expansion ratio of the snacks decreased, while their hardness increased by as much as 93%. The physical quality of the snacks may therefore need improvement. As amaranth was increased, the phenolic content and antioxidant activity of the snacks increased as well as the pro-vitamin A content. Pro-vitamin A-biofortified maize with added amaranth has a potential for use in nutritious and healthy extruded snacks. There are limited studies reporting on processing pro-vitamin A maize with complementary plant foods, which is common with white maize in southern Africa; thus the current study serves as a baseline. © 2015 Society of Chemical Industry.

Embolized stems recover overnight in Zea Mays: the role of soil water, root pressure, and nighttime transpiration

USDA-ARS?s Scientific Manuscript database

It is not currently well-understood how much xylem conductance is lost in maize plants during the day, if conductance is recovered during the night, or what soil water conditions are required for recovery to take place. To answer these questions we designed a greenhouse experiment whereby two genet...

[Properties of maize stalk biochar produced under different pyrolysis temperatures and its sorption capability to naphthalene].

PubMed

Huang, Hua; Wang, Ya-Xiong; Tang, Jing-Chun; Tang, Jing-Chun; Zhu, Wen-Ying

2014-05-01

Biochar was made from maize stalk under three different temperatures of 300, 500 and 700 degreeC. The elemental composition of biochar was measured by elemental analyzer. Scanning electron microscope (SEM) was used to measure the surface morphology. Sorption of naphthalene to biochar was researched by batch sorption experiments. Results showed that, with the increase of temperature, C content increased from 66. 79% to 76. 30% , H and O contents decreased from 4.92% and 19. 25% to 3. 18% and 9.53%, respectively; H/C, O/C, (O + N)/C, aromaticity and hydrophobicity increased, and polarity decreased. SEM results showed that maize stalk biochar was platy particles, and its roughness of surface increased with increasing temperature. The sorption of naphthalene on biochar followed the Lagergren pseudo-second order dynamic sorption model. Initial sorption rate and equilibrium sorption capacity increased as preparation temperatures increased at the same initial concentration of naphthalene. The isotherm sorption behavior can be described by the Freundlich model, which indicated that, as pyrolysis temperature increased, the sorption capacity of biochar increased, and nonlinearity increased first and then decreased. Biochar derived from maize stalk had distinct features when compared with other feedstocks, and its elemental composition, surface features and sorption behaviors were significantly influenced by pyrolysis temperature.

Mapping the diversity of maize races in Mexico.

PubMed

Perales, Hugo; Golicher, Duncan

2014-01-01

Traditional landraces of maize are cultivated throughout more than one-half of Mexico's cropland. Efforts to organize in situ conservation of this important genetic resource have been limited by the lack of knowledge of regional diversity patterns. We used recent and historic collections of maize classified for race type to determine biogeographic regions and centers of landrace diversity. We also analyzed how diversity has changed over the last sixty years. Based on racial composition of maize we found that Mexico can be divided into 11 biogeographic regions. Six of these biogeographic regions are in the center and west of the country and contain more than 90% of the reported samples for 38 of the 47 races studied; these six regions are also the most diverse. We found no evidence of rapid overall decline in landrace diversity for this period. However, several races are now less frequently reported and two regions seem to support lower diversity than in previous collection periods. Our results are consistent with a previous hypothesis for diversification centers and for migration routes of original maize populations merging in western central Mexico. We provide maps of regional diversity patterns and landrace based biogeographic regions that may guide efforts to conserve maize genetic resources.

Mapping the Diversity of Maize Races in Mexico

PubMed Central

Perales, Hugo; Golicher, Duncan

2014-01-01

Traditional landraces of maize are cultivated throughout more than one-half of Mexico's cropland. Efforts to organize in situ conservation of this important genetic resource have been limited by the lack of knowledge of regional diversity patterns. We used recent and historic collections of maize classified for race type to determine biogeographic regions and centers of landrace diversity. We also analyzed how diversity has changed over the last sixty years. Based on racial composition of maize we found that Mexico can be divided into 11 biogeographic regions. Six of these biogeographic regions are in the center and west of the country and contain more than 90% of the reported samples for 38 of the 47 races studied; these six regions are also the most diverse. We found no evidence of rapid overall decline in landrace diversity for this period. However, several races are now less frequently reported and two regions seem to support lower diversity than in previous collection periods. Our results are consistent with a previous hypothesis for diversification centers and for migration routes of original maize populations merging in western central Mexico. We provide maps of regional diversity patterns and landrace based biogeographic regions that may guide efforts to conserve maize genetic resources. PMID:25486121

Accumulation of 5-hydroxynorvaline in maize (Zea mays) leaves is induced by insect feeding and abiotic stress.

PubMed

Yan, Jian; Lipka, Alexander E; Schmelz, Eric A; Buckler, Edward S; Jander, Georg

2015-02-01

Plants produce a wide variety of defensive metabolites to protect themselves against herbivores and pathogens. Non-protein amino acids, which are present in many plant species, can have a defensive function through their mis-incorporation during protein synthesis and/or inhibition of biosynthetic pathways in primary metabolism. 5-Hydroxynorvaline was identified in a targeted search for previously unknown non-protein amino acids in the leaves of maize (Zea mays) inbred line B73. Accumulation of this compound increases during herbivory by aphids (Rhopalosiphum maidis, corn leaf aphid) and caterpillars (Spodoptera exigua, beet armyworm), as well as in response to treatment with the plant signalling molecules methyl jasmonate, salicylic acid and abscisic acid. In contrast, ethylene signalling reduced 5-hydroxynorvaline abundance. Drought stress induced 5-hydroxynorvaline accumulation to a higher level than insect feeding or treatment with defence signalling molecules. In field-grown plants, the 5-hydroxynorvaline concentration was highest in above-ground vegetative tissue, but it was also detectable in roots and dry seeds. When 5-hydroxynorvaline was added to aphid artificial diet at concentrations similar to those found in maize leaves and stems, R. maidis reproduction was reduced, indicating that this maize metabolite may have a defensive function. Among 27 tested maize inbred lines there was a greater than 10-fold range in the accumulation of foliar 5-hydroxynorvaline. Genetic mapping populations derived from a subset of these inbred lines were used to map quantitative trait loci for 5-hydroxynorvaline accumulation to maize chromosomes 5 and 7. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

A Fungal Effector With Host Nuclear Localization and DNA-Binding Properties Is Required for Maize Anthracnose Development.

PubMed

Vargas, Walter A; Sanz-Martín, José M; Rech, Gabriel E; Armijos-Jaramillo, Vinicio D; Rivera, Lina P; Echeverria, María Mercedes; Díaz-Mínguez, José M; Thon, Michael R; Sukno, Serenella A

2016-02-01

Plant pathogens have the capacity to manipulate the host immune system through the secretion of effectors. We identified 27 putative effector proteins encoded in the genome of the maize anthracnose pathogen Colletotrichum graminicola that are likely to target the host's nucleus, as they simultaneously contain sequence signatures for secretion and nuclear localization. We functionally characterized one protein, identified as CgEP1. This protein is synthesized during the early stages of disease development and is necessary for anthracnose development in maize leaves, stems, and roots. Genetic, molecular, and biochemical studies confirmed that this effector targets the host's nucleus and defines a novel class of double-stranded DNA-binding protein. We show that CgEP1 arose from a gene duplication in an ancestor of a lineage of monocot-infecting Colletotrichum spp. and has undergone an intense evolution process, with evidence for episodes of positive selection. We detected CgEP1 homologs in several species of a grass-infecting lineage of Colletotrichum spp., suggesting that its function may be conserved across a large number of anthracnose pathogens. Our results demonstrate that effectors targeted to the host nucleus may be key elements for disease development and aid in the understanding of the genetic basis of anthracnose development in maize plants.

Hydraulic conductivity of soil-grown lupine and maize unbranched roots and maize root-shoot junctions.

PubMed

Meunier, Félicien; Zarebanadkouki, Mohsen; Ahmed, Mutez A; Carminati, Andrea; Couvreur, Valentin; Javaux, Mathieu

2018-01-26

Improving or maintaining crop productivity under conditions of long term change of soil water availability and atmosphere demand for water is one the big challenges of this century. It requires a deep understanding of crop water acquisition properties, i.e. root system architecture and root hydraulic properties among other characteristics of the soil-plant-atmosphere continuum. A root pressure probe technique was used to measure the root hydraulic conductances of seven-week old maize and lupine plants grown in sandy soil. Unbranched root segments were excised in lateral, seminal, crown and brace roots of maize, and in lateral roots of lupine. Their total hydraulic conductance was quantified under steady-state hydrostatic gradient for progressively shorter segments. Furthermore, the axial conductance of proximal root regions removed at each step of root shortening was measured as well. Analytical solutions of the water flow equations in unbranched roots developed recently and relating root total conductance profiles to axial and radial conductivities were used to retrieve the root radial hydraulic conductivity profile along each root type, and quantify its uncertainty. Interestingly, the optimized root radial conductivities and measured axial conductances displayed significant differences across root types and species. However, the measured root total conductances did not differ significantly. As compared to measurements reported in the literature, our axial and radial conductivities concentrate in the lower range of herbaceous species hydraulic properties. In a final experiment, the hydraulic conductances of root junctions to maize stem were observed to highly depend on root type. Surprisingly maize brace root junctions were an order of magnitude more conductive than the other crown and seminal roots, suggesting potential regulation mechanism for root water uptake location and a potential role of the maize brace roots for water uptake more important than reported in the literature. Copyright © 2018 Elsevier GmbH. All rights reserved.

Tissue-specific patterns of lignification are disturbed in the brown midrib2 mutant of maize (Zea mays L.).

PubMed

Vermerris, W; Boon, J J

2001-02-01

Despite recent progress, several aspects of lignin biosynthesis, including variation in lignin composition between species and between tissues within a given species, are still poorly understood. The analysis of mutants affected in cell wall biosynthesis may help increase the understanding of these processes. We have analyzed the maize brown midrib2 (bm2) mutant, one of the four bm mutants of maize, using pyrolysis-mass spectrometry (Py-MS) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). Vascular tissues from the leaf blade and leaf sheath from different parts of the plant were investigated and compared to the corresponding samples from a wild-type plant of the same genetic background (inbred line A619). Multivariate analysis revealed that the bm2 mutant had reduced amounts of di- and trimeric lignin derivatives, notably species with m/z 272 and m/z 330, and that the ratio of guaiacyl residues to polysaccharides was reduced in the bm2 mutant. In addition, differences in cell wall composition between different parts of the plant (blade versus sheath, young versus old tissue) were much less pronounced in the bm2 mutant. These changes suggest that the functional Bm2 gene is important for the establishment of tissue-specific cell wall composition.

Contributions of wheat and maize residues to soil organic carbon under long-term rotation in north China.

PubMed

Wang, Jinzhou; Wang, Xiujun; Xu, Minggang; Feng, Gu; Zhang, Wenju; Yang, Xueyun; Huang, Shaomin

2015-06-23

Soil organic carbon (SOC) dynamics in agro-ecosystem is largely influenced by cropping. However, quantifying the contributions of various crops has been lacking. Here we employed a stable isotopic approach to evaluate the contributions of wheat and maize residues to SOC at three long-term experimental sites in north China. Soil samples were collected from 0-20, 20-40, 40-60, 60-80 and 80-100 cm after 13 and 20 years of wheat-maize rotation, and SOC and its stable (13)C composition were determined. Our data showed that the δ(13)C value of SOC varied, on average, from -22.1‰ in the 0-20 cm to -21.5‰ in the 80-100 cm. Carbon input through maize residues ranged from 35% to 68% whereas the contribution of maize residues to SOC (0-40 cm) ranged from 28% to 40%. Our analyses suggested that the retention coefficient was in the range of 8.0-13.6% for maize residues and 16.5-28.5% for wheat residues. The two-fold higher retention coefficient of wheat versus maize residues was due to the differences in the quality of residues and probably also in the temperature during the growing season. Our study highlighted the importance of crop management on carbon sequestration in agricultural lands.

Potential of Using Maize Cobs in Pig Diets — A Review

PubMed Central

Kanengoni, A. T.; Chimonyo, M.; Ndimba, B. K.; Dzama, K.

2015-01-01

The quest to broaden the narrow range of feed ingredients available to pig producers has prompted research on the use of low cost, unconventional feedstuffs, which are typically fibrous and abundant. Maize cobs, a by-product of a major cereal grown worldwide, have potential to be used as a pig feed ingredient. Presently, maize cobs are either dumped or burnt for fuel. The major challenge in using maize cobs in pig diets is their lignocellulosic nature (45% to 55% cellulose, 25% to 35% hemicellulose, and 20% to 30% lignin) which is resistant to pigs’ digestive enzymes. The high fiber in maize cobs (930 g neutral detergent fiber/kg dry matter [DM]; 573 g acid detergent fiber/kg DM) increases rate of passage and sequestration of nutrients in the fiber reducing their digestion. However, grinding, heating and fermentation can modify the structure of the fibrous components in the maize cobs and improve their utilization. Pigs can also extract up to 25% of energy maintenance requirements from fermentation products. In addition, dietary fiber improves pig intestinal health by promoting the growth of lactic acid bacteria, which suppress proliferation of pathogenic bacteria in the intestines. This paper reviews maize cob composition and the effect on digestibility of nutrients, intestinal microflora and growth performance and proposes the use of ensiling using exogenous enzymes to enhance utilization in diets of pigs. PMID:26580433

A high-throughput core sampling device for the evaluation of maize stalk composition

PubMed Central

2012-01-01

Background A major challenge in the identification and development of superior feedstocks for the production of second generation biofuels is the rapid assessment of biomass composition in a large number of samples. Currently, highly accurate and precise robotic analysis systems are available for the evaluation of biomass composition, on a large number of samples, with a variety of pretreatments. However, the lack of an inexpensive and high-throughput process for large scale sampling of biomass resources is still an important limiting factor. Our goal was to develop a simple mechanical maize stalk core sampling device that can be utilized to collect uniform samples of a dimension compatible with robotic processing and analysis, while allowing the collection of hundreds to thousands of samples per day. Results We have developed a core sampling device (CSD) to collect maize stalk samples compatible with robotic processing and analysis. The CSD facilitates the collection of thousands of uniform tissue cores consistent with high-throughput analysis required for breeding, genetics, and production studies. With a single CSD operated by one person with minimal training, more than 1,000 biomass samples were obtained in an eight-hour period. One of the main advantages of using cores is the high level of homogeneity of the samples obtained and the minimal opportunity for sample contamination. In addition, the samples obtained with the CSD can be placed directly into a bath of ice, dry ice, or liquid nitrogen maintaining the composition of the biomass sample for relatively long periods of time. Conclusions The CSD has been demonstrated to successfully produce homogeneous stalk core samples in a repeatable manner with a throughput substantially superior to the currently available sampling methods. Given the variety of maize developmental stages and the diversity of stalk diameter evaluated, it is expected that the CSD will have utility for other bioenergy crops as well. PMID:22548834

Aberrant splicing in maize rough endosperm3 reveals a conserved role for U12 splicing in eukaryotic multicellular development

PubMed Central

Barbazuk, W. Brad

2017-01-01

RNA splicing of U12-type introns functions in human cell differentiation, but it is not known whether this class of introns has a similar role in plants. The maize ROUGH ENDOSPERM3 (RGH3) protein is orthologous to the human splicing factor, ZRSR2. ZRSR2 mutations are associated with myelodysplastic syndrome (MDS) and cause U12 splicing defects. Maize rgh3 mutants have aberrant endosperm cell differentiation and proliferation. We found that most U12-type introns are retained or misspliced in rgh3. Genes affected in rgh3 and ZRSR2 mutants identify cell cycle and protein glycosylation as common pathways disrupted. Transcripts with retained U12-type introns can be found in polysomes, suggesting that splicing efficiency can alter protein isoforms. The rgh3 mutant protein disrupts colocalization with a known ZRSR2-interacting protein, U2AF2. These results indicate conserved function for RGH3/ZRSR2 in U12 splicing and a deeply conserved role for the minor spliceosome to promote cell differentiation from stem cells to terminal fates. PMID:28242684

The CLAVATA receptor FASCIATED EAR2 responds to distinct CLE peptides by signaling through two downstream effectors.

PubMed

Je, Byoung Il; Xu, Fang; Wu, Qingyu; Liu, Lei; Meeley, Robert; Gallagher, Joseph P; Corcilius, Leo; Payne, Richard J; Bartlett, Madelaine E; Jackson, David

2018-03-15

Meristems contain groups of indeterminate stem cells, which are maintained by a feedback loop between CLAVATA ( CLV ) and WUSCHEL ( WUS ) signaling. CLV signaling involves the secretion of the CLV3 peptide and its perception by a number of Leucine-Rich-Repeat (LRR) receptors, including the receptor-like kinase CLV1 and the receptor-like protein CLV2 coupled with the CORYNE (CRN) pseudokinase. CLV2, and its maize ortholog FASCIATED EAR2 (FEA2) appear to function in signaling by CLV3 and several related CLV3/EMBRYO-SURROUNDING REGION (CLE) peptide ligands. Nevertheless, how signaling specificity is achieved remains unknown. Here we show that FEA2 transmits signaling from two distinct CLE peptides, the maize CLV3 ortholog ZmCLE7 and ZmFON2-LIKE CLE PROTEIN1 (ZmFCP1) through two different candidate downstream effectors, the alpha subunit of the maize heterotrimeric G protein COMPACT PLANT2 (CT2), and ZmCRN. Our data provide a novel framework to understand how diverse signaling peptides can activate different downstream pathways through common receptor proteins. © 2018, Je et al.

The ubiquitous presence of exopolygalacturonase in maize suggests a fundamental cellular function for this enzyme.

PubMed

Dubald, M; Barakate, A; Mandaron, P; Mache, R

1993-11-01

Exopolygalacturonase (exoPG) is a pectin-degrading enzyme abundant in maize pollen. Using immunochemistry and in situ hybridization it is shown that in addition to its presence in pollen, exoPG is also present in sporophytic tissues, such as the tapetum and mesophyll cells. The enzyme is located in the cytoplasm of pollen and of some mesophyll cells. In other mesophyll cells, the tapetum and the pollen tube, exoPG is located in the cell wall. The measurement of enzyme activity shows that exoPG is ubiquitous in the vegetative organs. These results suggest a general function for exoPG in cell wall edification or degradation. ExoPG is encoded by a closely related multigene family. The regulation of the expression of one of the exoPG genes was analyzed in transgenic tobacco. Reporter GUS activity was detected in anthers, seeds and stems but not in leaves or roots of transgenic plants. This strongly suggests that the ubiquitous presence of exoPG in maize is the result of the expression of different exoPG genes.

[Genetic improvement of breeding materials in tropical and sub- tropical maize].

PubMed

Sansern, Jampatong; Chaba, Jampatong

2011-12-01

In the present study, 122 maize local cultivars and adapted exotic germplasm from Thailand were used to develop open pollinate varieties (OPVs) using modified ear-to-row scheme, top-cross or test-cross programmes. Ten new maize OPVs with distinct characters were created based on the precise breeding objectives and directional design. The selection of breeding materials was based upon three factors: elite performance, broad adaptability, and genetic diversity. The synthesizing system provided four features: genetic mixing and recombination, equal comparable genetic contribution, mild selection pressure, and maximum intermating for genetic equilibrium (i.e., the female traits were close for the genetic com-positions). Subsequently, Suwan 1 composite and its deritives (Suwan 2, Suwan 3 composite, Suwan 5 and KS24 synthetics), KS6 and KS28 synthetics with the dent type of different origins, and Caripeno DMR composite, KS23, and KS27 synthetics with the dent type of Non-Suwan 1 origin were developed. These OPVs had been improved for 2~13 cycles using S1 recurrent selection method. About 50 inbred lines were developed from these OPVs, and 16 elite single (three-way) crosses were combined and released from these inbred lines. At present, at least one parental inbred line of all the tropical hybrids was derived from Suwan (KS) germplasm in Thailand. Based on the theory of the synthesizing OPVs and developing inbred lines, this paper discussed the genetic moderate diversity, relationship, heterotic group, and patterns for synthesizing OPVs, and inspiration for composed OPVs to heterosis breeding.

Effect of rising atmospheric carbon dioxide concentration on the protein composition of cereal grain.

PubMed

Wroblewitz, Stefanie; Hüther, Liane; Manderscheid, Remy; Weigel, Hans-Joachim; Wätzig, Hermann; Dänicke, Sven

2014-07-16

The present study investigates effects of rising atmospheric CO2 concentration on protein composition of maize, wheat, and barley grain, especially on the fractions prolamins and glutelins. Cereals were grown at different atmospheric CO2 concentrations to simulate future climate conditions. Influences of two nitrogen fertilization levels were studied for wheat and barley. Enriched CO2 caused an increase of globulin and B-hordein of barley. In maize, the content of globulin, α-zein, and LMW polymers decreased, whereas total glutelin, zein, δ-zein, and HMW polymers rose. Different N supplies resulted in variations of barley subfractions and wheat globulin. Other environmental influences showed effects on the content of nearly all fractions and subfractions. Variations in starch-protein bodies caused by different CO2 treatments could be visualized by scanning electron microscopy. In conclusion, climate change would have impacts on structural composition of proteins and, consequently, on the nutritional value of cereals.

Potential Accumulative Effect of the Herbicide Glyphosate on Glyphosate-Tolerant Maize Rhizobacterial Communities over a Three-Year Cultivation Period

PubMed Central

Barriuso, Jorge; Marín, Silvia; Mellado, Rafael P.

2011-01-01

Background Glyphosate is a herbicide that is liable to be used in the extensive cultivation of glyphosate-tolerant cultivars. The potential accumulation of the relative effect of glyphosate on the rhizobacterial communities of glyphosate-tolerant maize has been monitored over a period of three years. Methodology/Principal Findings The composition of rhizobacterial communities is known to vary with soil texture, hence, the analyses have been performed in two agricultural fields with a different soil texture. The accumulative effects of glyphosate have been monitored by means of high throughput DNA pyrosequencing of the bacterial DNA coding for the 16S rRNA hypervariable V6 region from rhizobacterial communities. The relative composition of the rhizobacterial communities does vary in each field over the three-year period. The overall distribution of the bacterial phyla seems to change from one year to the next similarly in the untreated and glyphosate-treated soils in both fields. The two methods used to estimate bacterial diversity offered consistent results and are equally suitable for diversity assessment. Conclusions/Significance The glyphosate treatment during the three-year period of seasonal cultivation in two different fields did not seem to significantly change the maize rhizobacterial communities when compared to those of the untreated soil. This may be particularly relevant with respect to a potential authorisation to cultivate glyphosate-tolerant maize in the European Union. PMID:22096595

Chemical composition, starch digestibility and antioxidant capacity of tortilla made with a blend of quality protein maize and black bean.

PubMed

Grajales-García, Eva M; Osorio-Díaz, Perla; Goñi, Isabel; Hervert-Hernández, Deisy; Guzmán-Maldonado, Salvador H; Bello-Pérez, Luis A

2012-01-01

Tortilla and beans are the basic components in the diet of people in the urban and rural areas of Mexico. Quality protein maize is suggested for tortilla preparation because it presents an increase in lysine and tryptophan levels. Beans contain important amounts of dietary fiber. The objective of this study was to prepare tortilla with bean and assesses the chemical composition, starch digestibility and antioxidant capacity using a quality protein maize variety. Tortilla with bean had higher protein, ash, dietary fiber and resistant starch content, and lower digestible starch than control tortilla. The hydrolysis rate (60 to 50%) and the predicted glycemic index (88 to 80) of tortilla decreased with the addition of bean in the blend. Extractable polyphenols and proanthocyanidins were higher in the tortilla with bean than control tortilla. This pattern produced higher antioxidant capacity of tortilla with bean (17.6 μmol Trolox eq/g) than control tortilla (7.8 μmol Trolox eq/g). The addition of bean to tortilla modified the starch digestibility and antioxidant characteristics of tortilla, obtaining a product with nutraceutical characteristics.

The mechanisms of low nitrogen induced weakened photosynthesis in summer maize (Zea mays L.) under field conditions.

PubMed

Wei, Shanshan; Wang, Xiangyu; Shi, Deyang; Li, Yanhong; Zhang, Jiwang; Liu, Peng; Zhao, Bin; Dong, Shuting

2016-08-01

Soil nitrogen (N) shortage is a problem which affects many developing nations. Crops grown with low soil N levels show a marked decrease in the rate of photosynthesis and this deficiency reduces crop yield significantly. Therefore, developing a better understanding of the mechanisms by which low N levels cause decreased photosynthesis is crucial for maize agriculture. To better understand this process, we assessed the responses of photosynthesis traits and enzymatic activities in the summer maize cultivar Denghai 618 under field conditions with and without the use of N fertilisers. We measured photosynthesis parameters, and compared proteome compositions to identify the mechanisms of physiological and biochemical adaptations to N deficiency in maize. We observed that parameters that indicated the rate of photosynthesis decreased significantly under N deficiency, and this response was associated with leaf senescence. Moreover, we identified 37 proteins involved in leaf photosynthesis, and found that N deficiency significantly affected light-dependent and light-independent reactions in maize leaf photosynthesis. Although further analysis is required to fully elucidate the roles of these proteins in the response to N deficiency, our study identified candidate proteins which may be involved in the regulatory mechanisms involved in reduced photosynthesis under low N conditions in maize. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Influence of gamma-irradiation and maize lipids on the production of aflatoxin B1 by Aspergillus flavus.

PubMed

Aziz, Nagy H; el-Zeany, Samia A; Moussa, Lotfy A A

2002-10-01

The effect of gamma-irradiation and maize lipids on aflatoxin B1 production by Aspergillus flavus artificially inoculated into sterilized maize at reduced water activity (aw 0.84) was investigated. By increasing the irradiation doses the total viable population of A. flavus decreased and the fungus was completely inhibited at 3.0 kGy. The amounts of aflatoxin B1 were enhanced at irradiation dose levels 1.0 and 1.5 kGy in both full-fat maize (FM) and defatted maize (DM) media and no aflatoxin B1 production at 3.0 kGy gamma-irradiation over 45 days of storage was observed. The level in free lipids of FM decreased gradually, whereas free fatty acid values and fungal lipase activity increased markedly by increasing the storage periods. The free fatty acid values decreased by increasing the irradiation dose levels and there was a significant enhancement of fungal lipase activity at doses of 1.0 and 1.50 kGy. The ability of A. flavus to grow at aw 0.84 and produce aflatoxin B1 is related to the lipid composition of maize. The enhancement of aflatoxin B1 at low doses was correlated to the enhancement of fungal lipase activity.

Pollen-mediated gene flow and seed exchange in small-scale Zambian maize farming, implications for biosafety assessment

NASA Astrophysics Data System (ADS)

Bøhn, Thomas; Aheto, Denis W.; Mwangala, Felix S.; Fischer, Klara; Bones, Inger Louise; Simoloka, Christopher; Mbeule, Ireen; Schmidt, Gunther; Breckling, Broder

2016-10-01

Gene flow in agricultural crops is important for risk assessment of genetically modified (GM) crops, particularly in countries with a large informal agricultural sector of subsistence cultivation. We present a pollen flow model for maize (Zea mays), a major staple crop in Africa. We use spatial properties of fields (size, position) in three small-scale maize farming communities in Zambia and estimate rates of cross-fertilisation between fields sown with different maize varieties (e.g. conventional and transgene). As an additional factor contributing to gene flow, we present data on seed saving and sharing among farmers that live in the same communities. Our results show that: i) maize fields were small and located in immediate vicinity of neighboring fields; ii) a majority of farmers saved and shared seed; iii) modeled rates of pollen-mediated gene flow showed extensive mixing of germplasm between fields and farms and iv) as a result, segregation of GM and non-GM varieties is not likely to be an option in these systems. We conclude that the overall genetic composition of maize, in this and similar agricultural contexts, will be strongly influenced both by self-organised ecological factors (pollen flow), and by socially mediated intervention (seed recycling and sharing).

Pollen-mediated gene flow and seed exchange in small-scale Zambian maize farming, implications for biosafety assessment

PubMed Central

Bøhn, Thomas; Aheto, Denis W.; Mwangala, Felix S.; Fischer, Klara; Bones, Inger Louise; Simoloka, Christopher; Mbeule, Ireen; Schmidt, Gunther; Breckling, Broder

2016-01-01

Gene flow in agricultural crops is important for risk assessment of genetically modified (GM) crops, particularly in countries with a large informal agricultural sector of subsistence cultivation. We present a pollen flow model for maize (Zea mays), a major staple crop in Africa. We use spatial properties of fields (size, position) in three small-scale maize farming communities in Zambia and estimate rates of cross-fertilisation between fields sown with different maize varieties (e.g. conventional and transgene). As an additional factor contributing to gene flow, we present data on seed saving and sharing among farmers that live in the same communities. Our results show that: i) maize fields were small and located in immediate vicinity of neighboring fields; ii) a majority of farmers saved and shared seed; iii) modeled rates of pollen-mediated gene flow showed extensive mixing of germplasm between fields and farms and iv) as a result, segregation of GM and non-GM varieties is not likely to be an option in these systems. We conclude that the overall genetic composition of maize, in this and similar agricultural contexts, will be strongly influenced both by self-organised ecological factors (pollen flow), and by socially mediated intervention (seed recycling and sharing). PMID:27694819

Pollen-mediated gene flow and seed exchange in small-scale Zambian maize farming, implications for biosafety assessment.

PubMed

Bøhn, Thomas; Aheto, Denis W; Mwangala, Felix S; Fischer, Klara; Bones, Inger Louise; Simoloka, Christopher; Mbeule, Ireen; Schmidt, Gunther; Breckling, Broder

2016-10-03

Gene flow in agricultural crops is important for risk assessment of genetically modified (GM) crops, particularly in countries with a large informal agricultural sector of subsistence cultivation. We present a pollen flow model for maize (Zea mays), a major staple crop in Africa. We use spatial properties of fields (size, position) in three small-scale maize farming communities in Zambia and estimate rates of cross-fertilisation between fields sown with different maize varieties (e.g. conventional and transgene). As an additional factor contributing to gene flow, we present data on seed saving and sharing among farmers that live in the same communities. Our results show that: i) maize fields were small and located in immediate vicinity of neighboring fields; ii) a majority of farmers saved and shared seed; iii) modeled rates of pollen-mediated gene flow showed extensive mixing of germplasm between fields and farms and iv) as a result, segregation of GM and non-GM varieties is not likely to be an option in these systems. We conclude that the overall genetic composition of maize, in this and similar agricultural contexts, will be strongly influenced both by self-organised ecological factors (pollen flow), and by socially mediated intervention (seed recycling and sharing).

Complex structure of knob DNA on maize chromosome 9. Retrotransposon invasion into heterochromatin.

PubMed Central

Ananiev, E V; Phillips, R L; Rines, H W

1998-01-01

The recovery of maize (Zea mays L.) chromosome addition lines of oat (Avena sativa L.) from oat x maize crosses enables us to analyze the structure and composition of specific regions, such as knobs, of individual maize chromosomes. A DNA hybridization blot panel of eight individual maize chromosome addition lines revealed that 180-bp repeats found in knobs are present in each of these maize chromosomes, but the copy number varies from approximately 100 to 25, 000. Cosmid clones with knob DNA segments were isolated from a genomic library of an oat-maize chromosome 9 addition line with the help of the 180-bp knob-associated repeated DNA sequence used as a probe. Cloned knob DNA segments revealed a complex organization in which blocks of tandemly arranged 180-bp repeating units are interrupted by insertions of other repeated DNA sequences, mostly represented by individual full size copies of retrotransposable elements. There is an obvious preference for the integration of retrotransposable elements into certain sites (hot spots) of the 180-bp repeat. Sequence microheterogeneity including point mutations and duplications was found in copies of 180-bp repeats. The 180-bp repeats within an array all had the same polarity. Restriction maps constructed for 23 cloned knob DNA fragments revealed the positions of polymorphic sites and sites of integration of insertion elements. Discovery of the interspersion of retrotransposable elements among blocks of tandem repeats in maize and some other organisms suggests that this pattern may be basic to heterochromatin organization for eukaryotes. PMID:9691055

Multi-Photon Micro-Spectroscopy of Biological Specimens

DTIC Science & Technology

2000-07-01

Micro-spectroscopy, multi-photon fluorescence spectroscopy, second harmonic generation, plant tissues, stem, chloroplast, protoplast, maize, Arabidopsis...harmonic generation (SHG) in the plant cell 5wall. In this case, micro-spectroscopy provides a means of verification that, indeed, SHG occurs in plant ...fluorescence microscopy -the response of plant cells to high intensity illumination," Micron (in press) 2000. 3. H.-C. Huang and C. -C Chen, "Genome

Optimizing bio-physical conditions and pre-treatment options for breaking lignin barrier of maize stover feed using white rot fungi.

PubMed

Atuhaire, Andrew M; Kabi, Fred; Okello, Samuel; Mugerwa, Swidiq; Ebong, Cyprian

2016-12-01

The greatest limitation to utilization of maize stover by ruminants as a feed is the high concentration of lignin, which limits fibre digestibility. However, ruminants can effectively utilize maize stover if its nutritive value is improved using white rot fungal species. This study was designed to determine optimal bio-physical conditions for mycelial growth and select the most ideal fungal species and pre-treatment options for improving nutritive value of maize stover. Four popular edible Pleurotus fungal species (viz. Pleurotus florida, Pleurotus ostreatus, Pleurotus sajor caju and Pleurotus pulmonarius ) were subjected to varying temperatures, pH levels, hydrogen peroxide (H 2 O 2 ) concentration and illumination to establish the extent of mycelial growth rate. Inclusion of H 2 O 2 was used to determine optimal levels for preservation and prevention of contamination from other indigenous microbiota. Effects of pre-treatment options on chemical composition and nutritive value of maize stover were also examined. Mycelial growth rate of Pleurotus species on potato dextrose agar (PDA) varied ( P  < 0.05) with temperature, pH level and H 2 O 2 concentration following a quadratic trend. Optimal temperature, pH and H 2 O 2 concentration for mycelial growth on PDA were 25 °C, 5 and 0.01 mL/L, respectively. Under the different bio-physical conditions, P. sajor caju had the highest mycelia density and growth rate. Chemical composition of solid-state fermented maize stover differed ( P  < 0.05) among the Pleurotus species. Maize stover fermented with P. sajor caju had the highest crude protein (CP) of 86.6 g/kg DM, in-vitro dry matter digestibility (IVDMD) of 731 g/kg DM, in-vitro organic matter digestibility (IVOMD) of 670.4 g/kg DM and metabolizable energy (ME) of 10.0 MJ/kg DM but with the lowest lignin (sa) of 50 g/kg DM. At 25 °C, P. sajor caju had the highest mycelial growth rate on PDA and highest lignin (sa) breakdown in the maize stover substrate. It was, therefore, selected as the most ideal fungal species for improving nutritive value of maize stover. Pre-treatment of maize stover with Lactobacillus plantarum and molasses under anaerobic condition for 7 days before inoculation with P. sajor caju resulted into a substrate with the highest ( P  < 0.05) CP (96.6 g/kg DM), IVDMD (752.3 g/kg DM), IVOMD (687.2 g/kg DM) and ME (10.2 MJ/kg DM). However, neutral detergent fiber exclusive of residual ash (NDFom) and lignin (sa) fractions decreased ( P  < 0.05) as a result of subjecting maize stover to pre-treatment with L. plantarum and molasses prior to fermentation with P. sajor caju. Therefore, pre-treatment of maize stover with L. plantarum and molasses for 7 days prior to fermentation with P. sajor caju for 14 days in darkness at 25 °C offered the greatest potential for breaking the lignin barrier.

Reduced Lateral Root Branching Density Improves Drought Tolerance in Maize1[OPEN

PubMed Central

Zhan, Ai; Schneider, Hannah

2015-01-01

An emerging paradigm is that root traits that reduce the metabolic costs of soil exploration improve the acquisition of limiting soil resources. Here, we test the hypothesis that reduced lateral root branching density will improve drought tolerance in maize (Zea mays) by reducing the metabolic costs of soil exploration, permitting greater axial root elongation, greater rooting depth, and thereby greater water acquisition from drying soil. Maize recombinant inbred lines with contrasting lateral root number and length (few but long [FL] and many but short [MS]) were grown under water stress in greenhouse mesocosms, in field rainout shelters, and in a second field environment with natural drought. Under water stress in mesocosms, lines with the FL phenotype had substantially less lateral root respiration per unit of axial root length, deeper rooting, greater leaf relative water content, greater stomatal conductance, and 50% greater shoot biomass than lines with the MS phenotype. Under water stress in the two field sites, lines with the FL phenotype had deeper rooting, much lighter stem water isotopic signature, signifying deeper water capture, 51% to 67% greater shoot biomass at flowering, and 144% greater yield than lines with the MS phenotype. These results entirely support the hypothesis that reduced lateral root branching density improves drought tolerance. The FL lateral root phenotype merits consideration as a selection target to improve the drought tolerance of maize and possibly other cereal crops. PMID:26077764

Contributions of wheat and maize residues to soil organic carbon under long-term rotation in north China

PubMed Central

Wang, Jinzhou; Wang, Xiujun; Xu, Minggang; Feng, Gu; Zhang, Wenju; Yang, Xueyun; Huang, Shaomin

2015-01-01

Soil organic carbon (SOC) dynamics in agro-ecosystem is largely influenced by cropping. However, quantifying the contributions of various crops has been lacking. Here we employed a stable isotopic approach to evaluate the contributions of wheat and maize residues to SOC at three long-term experimental sites in north China. Soil samples were collected from 0–20, 20–40, 40–60, 60–80 and 80–100 cm after 13 and 20 years of wheat-maize rotation, and SOC and its stable 13C composition were determined. Our data showed that the δ13C value of SOC varied, on average, from −22.1‰ in the 0–20 cm to −21.5‰ in the 80–100 cm. Carbon input through maize residues ranged from 35% to 68% whereas the contribution of maize residues to SOC (0–40 cm) ranged from 28% to 40%. Our analyses suggested that the retention coefficient was in the range of 8.0–13.6% for maize residues and 16.5–28.5% for wheat residues. The two-fold higher retention coefficient of wheat versus maize residues was due to the differences in the quality of residues and probably also in the temperature during the growing season. Our study highlighted the importance of crop management on carbon sequestration in agricultural lands. PMID:26100739

Metabolic changes in transgenic maize mature seeds over-expressing the Aspergillus niger phyA2.

PubMed

Rao, Jun; Yang, Litao; Guo, Jinchao; Quan, Sheng; Chen, Guihua; Zhao, Xiangxiang; Zhang, Dabing; Shi, Jianxin

2016-02-01

Non-targeted metabolomics analysis revealed only intended metabolic changes in transgenic maize over-expressing the Aspergillus niger phyA2. Genetically modified (GM) crops account for a large proportion of modern agriculture worldwide, raising increasingly the public concerns of safety. Generally, according to substantial equivalence principle, if a GM crop is demonstrated to be equivalently safe to its conventional species, it is supposed to be safe. In this study, taking the advantage of an established non-target metabolomic profiling platform based on the combination of UPLC-MS/MS with GC-MS, we compared the mature seed metabolic changes in transgenic maize over-expressing the Aspergillus niger phyA2 with its non-transgenic counterpart and other 14 conventional maize lines. In total, levels of nine out of identified 210 metabolites were significantly changed in transgenic maize as compared with its non-transgenic counterpart, and the number of significantly altered metabolites was reduced to only four when the natural variations were taken into consideration. Notably, those four metabolites were all associated with targeted engineering pathway. Our results indicated that although both intended and non-intended metabolic changes occurred in the mature seeds of this GM maize event, only intended metabolic pathway was found to be out of the range of the natural metabolic variation in the metabolome of the transgenic maize. Therefore, only when natural metabolic variation was taken into account, could non-targeted metabolomics provide reliable objective compositional substantial equivalence analysis on GM crops.

Host location and host discrimination behavior of Telenomus isis, an egg parasitoid of the African cereal stem borer Sesamia calamistis.

PubMed

Chabi-Olaye, A; Schulthess, F; Poehling, H M; Borgemeister, C

2001-04-01

In the Republic of Benin, the scelionid egg parasitoid Telenomus isis (Polaszek) is one of the most important control factors of the noctuid maize stem borer Sesamia calamistis. In the present study, the role of various sources of contact kairomones (male or virgin or mated female moths) and of the moth's oviposition substrate (leaf sheath versus filter paper: host plant species) in host location and oviposition behavior of T. isis was investigated in Munger cells, open arenas, and/or Petri dish assays. Furthermore, its ability to distinguish between unparasitized eggs and eggs parasitized by a conspecific female or by the trichogrammatid Lathromeris ovicida was studied. In the Munger cell experiment, T. isis spent more time in moths' odor fields than in the control. There was no difference between virgin and mated females. In the open arena assay, traces left by both the male and female moths acted as contact cues, which elicited an arrestment response in the parasitoid. The residence and patch retention time in the arena with virgin or mated females of S. calamistis was about 4.8 times as long as that with males. The presence of maize leaf sheaths stimulated the oviposition behavior of T. isis when compared to eggs offered on filter paper. During the first 6 hr, more eggs were parasitized on maize leaves, although there was no difference in the final number of offspring between the two substrates. In addition, if eggs of S. calamistis were offered together with different host plant species or alone, maize and sorghum were both more attractive than millet or the egg alone and equally attractive between themselves, indicating that the plant tissue influences host finding of T. isis. Both T. isis and L. ovicida recognized markings of conspecific females, and intraspecific superparasitism was therefore low. Interspecific superparasitism was more than three times higher for L. ovicida than for T. isis, indicating that only T. isis was able to recognize the marking of the other species and tried to avoid superparasitism. Emergence of parasitoids from multiparasitized eggs generally was in favor of L. ovicida regardless of species order.

Asymmetric leaves1 mediates leaf patterning and stem cell function in Arabidopsis.

PubMed

Byrne, M E; Barley, R; Curtis, M; Arroyo, J M; Dunham, M; Hudson, A; Martienssen, R A

Meristem function in plants requires both the maintenance of stem cells and the specification of founder cells from which lateral organs arise. Lateral organs are patterned along proximodistal, dorsoventral and mediolateral axes. Here we show that the Arabidopsis mutant asymmetric leaves1 (as1) disrupts this process. AS1 encodes a myb domain protein, closely related to PHANTASTICA in Antirrhinum and ROUGH SHEATH2 in maize, both of which negatively regulate knotted-class homeobox genes. AS1 negatively regulates the homeobox genes KNAT1 and KNAT2 and is, in turn, negatively regulated by the meristematic homeobox gene SHOOT MERISTEMLESS. This genetic pathway defines a mechanism for differentiating between stem cells and organ founder cells within the shoot apical meristem and demonstrates that genes expressed in organ primordia interact with meristematic genes to regulate shoot morphogenesis.

Maize Brittle stalk2 encodes a COBRA-like protein expressed in early organ development but required for tissue flexibility at maturity.

PubMed

Sindhu, Anoop; Langewisch, Tiffany; Olek, Anna; Multani, Dilbag S; McCann, Maureen C; Vermerris, Wilfred; Carpita, Nicholas C; Johal, Gurmukh

2007-12-01

The maize (Zea mays) brittle stalk2 (bk2) is a recessive mutant, the aerial parts of which are easily broken. The bk2 phenotype is developmentally regulated and appears 4 weeks after planting, at about the fifth-leaf stage. Before this time, mutants are indistinguishable from wild-type siblings. Afterward, all organs of the bk2 mutants turn brittle, even the preexisting ones, and they remain brittle throughout the life of the plant. Leaf tension assays and bend tests of the internodes show that the brittle phenotype does not result from loss of tensile strength but from loss in flexibility that causes the tissues to snap instead of bend. The Bk2 gene was cloned by a combination of transposon tagging and a candidate gene approach and found to encode a COBRA-like protein similar to rice (Oryza sativa) BC1 and Arabidopsis (Arabidopsis thaliana) COBRA-LIKE4. The outer periphery of the stalk has fewer vascular bundles, and the sclerids underlying the epidermis possess thinner secondary walls. Relative cellulose content is not strictly correlated with the brittle phenotype. Cellulose content in mature zones of bk2 mature stems is lowered by 40% but is about the same as wild type in developing stems. Although relative cellulose content is lowered in leaves after the onset of the brittle phenotype, total wall mass as a proportion of dry mass is either unchanged or slightly increased, indicating a compensatory increase in noncellulosic carbohydrate mass. Fourier transform infrared spectra indicated an increase in phenolic ester content in the walls of bk2 leaves and stems. Total content of lignin is unaffected in bk2 juvenile leaves before or after appearance of the brittle phenotype, but bk2 mature and developing stems are markedly enriched in lignin compared to wild-type stems. Despite increased lignin in bk2 stems, loss of staining with phloroglucinol and ultraviolet autofluorescence is observed in vascular bundles and sclerid layers. Consistent with the infrared analyses, levels of saponifiable hydroxycinnamates are elevated in bk2 leaves and stems. As Bk2 is highly expressed during early development, well before the onset of the brittle phenotype, we propose that Bk2 functions in a patterning of lignin-cellulosic interactions that maintain organ flexibility rather than having a direct role in cellulose biosynthesis.

[Effects of different multiple cropping systems on paddy field weed community under long term paddy-upland rotation].

PubMed

Yang, Bin-Juan; Huang, Guo-Qin; Xu, Ning; Wang, Shu-Bin

2013-09-01

Based on a long term field experiment, this paper studied the effects of different multiple cropping systems on the weed community composition and species diversity under paddy-upland rotation. The multiple cropping rotation systems could significantly decrease weed density and inhibited weed growth. Among the rotation systems, the milk vetch-early rice-late maize --> milk vetchearly maize intercropped with early soybean-late rice (CCSR) had the lowest weed species dominance, which inhibited the dominant weeds and decreased their damage. Under different multiple cropping systems, the main weed community was all composed of Monochoia vaginalis, Echinochloa crusgalli, and Sagittaria pygmae, and the similarity of weed community was higher, with the highest similarity appeared in milk vetch-early rice-late maize intercropped with late soybean --> milk vetch-early maize-late rice (CSCR) and in CCSR. In sum, the multiple cropping rotations in paddy field could inhibit weeds to a certain extent, but attentions should be paid to the damage of some less important weeds.

Structural Characterization of Lignin from Maize ( Zea mays L.) Fibers: Evidence for Diferuloylputrescine Incorporated into the Lignin Polymer in Maize Kernels.

PubMed

Del Río, José C; Rencoret, Jorge; Gutiérrez, Ana; Kim, Hoon; Ralph, John

2018-05-02

The structure of the phenolic polymer in maize grain fibers, with 5.5% Klason lignin content, has been studied. For this, the milled wood lignin (MWL) and dioxane lignin (DL) preparations were isolated and analyzed. The data indicated that the lignin in maize fibers was syringyl rich, mostly involved in β-aryl ether, resinol, and phenylcoumaran substructures. 2D NMR and derivatization followed by reductive cleavage (DFRC) also revealed the occurrence of associated ferulates together with trace amounts of p-coumarates acylating the γ-OH of lignin side chains, predominantly on S-lignin units. More interesting was the occurrence of diferuloylputrescine, a ferulic acid amide, which was identified by 2D NMR and comparison with a synthesized standard, that was apparently incorporated into this lignin. A phenylcoumaran structure involving a diferuloylputrescine coupled through 8-5' linkages to another diferuloylputrescine (or to a ferulate or a guaiacyl lignin unit) was found, providing compelling evidence for its participation in radical coupling reactions. The occurrence of diferuloylputrescine in cell walls of maize kernels and other cereal grains appears to have been missed in previous works, perhaps due to the alkaline hydrolysis commonly used for composition studies.

Effects of arbuscular mycorrhizal inoculation and biochar amendment on maize growth, cadmium uptake and soil cadmium speciation in Cd-contaminated soil.

PubMed

Liu, Ling; Li, Jiwei; Yue, Feixue; Yan, Xinwei; Wang, Fayuan; Bloszies, Sean; Wang, Yanfang

2018-03-01

Experiments conducted to understand how arbuscular mycorrhizal (AM) inoculation or biochar application affect plant growth and heavy metal uptake have thus far looked at single applications of either soil amendment. There is little evidence of their synergistic effects, in particular for plants grown in cadmium (Cd) contaminated soil. We conducted a mesocosm experiment to investigate the effect of AM inoculation (Glomus intraradices BEG 141) and/or wheat-straw biochar amendment on maize (Zea mays L. cv. Hongdan No. 897) growth, antioxidant enzymatic activities, and Cd uptake, as well as soil Cd speciation under applications of 0, 3, 6 mg Cd per kg soil. Applying either AM inoculant or biochar alone significantly increased maize growth and reduced Cd uptake. Furthermore, solo AM inoculation alleviating Cd stress more fully than biochar, in turn facilitating maize growth and decreasing soil Cd translocation into plant tissue. Still, solo biochar amendment was more effective at inducing soil alkalinization and contributing to Cd immobilization. Adding biochar together with AM inoculant significantly promoted fungal populations compared to a control. Amending soil with AM inoculant and biochar together produced the largest increase in maize growth and decrease in tissue Cd concentrations. This effect was additive, with 79.1% greater biomass, 51.42%, 82.91%, 43.96% higher activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and 50.06%, 67.19%, 58.04% and 76.19% lower Cd concentrations in roots, stems, leaves, and ears, respectively, at a 6 mg kg -1 Cd contamination rate. The combined treatment also had a synergistic effect on inducing soil alkalinization and causing Cd immobilization, and decreasing Cd phytoavailability and post-harvest transfer risks. These results suggest that AM inoculation in combination with biochar application may be applicable not only for maize production but also for phytostabilization of Cd-contaminated soil. Copyright © 2017 Elsevier Ltd. All rights reserved.

Forages and Pastures Symposium: development of and field experience with drought-tolerant maize.

PubMed

Soderlund, S; Owens, F N; Fagan, C

2014-07-01

Drought-tolerant maize hybrids currently are being marketed by several seed suppliers. Such hybrids were developed by phenotypic and marker-assisted selection or through genetic modification and tested by exposing these hybrids to various degrees of water restriction. As drought intensifies, crop yields and survival progressively decline. Water need differs among plants due to differences in root structure, evaporative loss, capacity to store water or enter temporary dormancy, and plant genetics. Availability of water differs widely not only with rainfall and irrigation but also with numerous soil and agronomic factors (e.g., soil type, slope, seeding rates, tillage practices). Reduced weed competition, enhanced pollen shed and silk production, and deep, robust root growth help to reduce the negative impacts of drought. Selected drought-tolerant maize hybrids have consistently yielded more grain even when drought conditions are not apparent either due to reduced use of soil water reserves before water restriction or due to greater tolerance of intermittent water shortages. In DuPont Pioneer trials, whole plant NDF digestibility of maize increased with water restriction, perhaps due to an increased leaf to stem ratio. Efficiency of water use, measured as dry matter or potential milk yield from silage per unit of available water, responded quadratically to water restriction, first increasing slightly but then decreasing as water restriction increased. For grain production, water restriction has its greatest negative impact during or after silking through reducing the number of kernels and reducing kernel filling. For silage production, water restriction during the vegetative growth stage negatively impacts plant height and biomass yield. Earlier planting and shorter season maize hybrids help to avoid midsummer heat stress during pollination and can reduce the number of irrigation events needed. Although drought tolerance of maize hybrids has been improved due to genetic selection or biotech approaches, selecting locally adapted hybrids or crops, adjusting seeding rates, and modifying tillage and irrigation practices are important factors that can improve efficiency of use of available water by grain and forage crops.

Modeling climate change impacts on maize growth with the focus on plant internal water transport

NASA Astrophysics Data System (ADS)

Heinlein, Florian; Biernath, Christian; Klein, Christian; Thieme, Christoph; Priesack, Eckart

2015-04-01

Based on climate change experiments in chambers and on field measurements, the scientific community expects regional and global changes of crop biomass production and yields. In central Europe one major aspect of climate change is the shift of precipitation towards winter months and the increase of extreme events, e.g. heat stress and heavy precipitation, during the main growing season in summer. To understand water uptake, water use, and transpiration rates by plants numerous crop models were developed. We tested the ability of two existing canopy models (CERES-Maize and SPASS) embedded in the model environment Expert-N5.0 to simulate the water balance, water use efficiency and crop growth. Additionally, sap flow was measured using heat-ratio measurement devices at the stem base of individual plants. The models were tested against data on soil water contents, as well as on evaporation and transpiration rates of Maize plants, which were grown on lysimeters at Helmholtz Zentrum München and in the field at the research station Scheyern, Germany, in summer 2013 and 2014. We present the simulation results and discuss observed shortcomings of the models. CERES-Maize and SPASS could simulate the measured dynamics of xylem sap flow. However, these models oversimplify plant water transport, and thus, cannot explain the underlying mechanisms. Therefore, to overcome these shortcomings, we additionally propose a new model, which is based on two coupled 1-D Richards equations, describing explicitly the plant and soil water transport. This model, which has previously successfully been applied to simulate water flux of 94 individual beech trees of an old-grown forest, will lead to a more mechanistic representation of the soil-plant-water-flow-continuum. This xylem water flux model was now implemented into the crop model SPASS and adjusted to simulate water flux of single maize plants. The modified version is presented and explained. Basic model input requirements are the plant above- and below-ground architectures. Shoot architectures were derived from terrestrial laser scanning. Root architectures of Maize plants were generated using a simple L-system. Preliminary results will be presented together with simulation results by CERES-Maize and SPASS.

Are cytological parameters of maize landraces (Zea mays ssp. mays) adapted along an altitudinal cline?

PubMed

Fourastié, María Florencia; Gottlieb, Alexandra Marina; Poggio, Lidia; González, Graciela Esther

2018-03-01

The Northwestern Argentina (NWA) highland region is one of the southernmost areas of native maize cultivation. We studied variations of different cytological parameters, such as DNA contents, presence/absence of B chromosomes (Bs), and number and sequence composition of heterochromatic knobs in ten accessions of four maize landraces growing along a broad altitudinal cline in NWA. The aim of this work was to assess variations in cytological parameters and their relationship with the crop altitude of cultivation, in an adaptive context. The A-DNA content of the A chromosome complements showed 40% of difference between the lowest (4.5 pg) and the highest (6.3 pg) 2C value. This variation could be attributed to differences in number and size of heterochromatic knobs. Fluorescent in situ hybridization studies revealed the sequence composition of each knob, with a higher proportion of knobs composed of 180-bp repeats rather than TR-1 repeats, in all accessions. We also found numerical polymorphisms and the highest frequency of Bs reported in maize to this date. These results lead us to propose that the frequencies and doses of Bs are influenced by the landrace genotypical make-up. The Bs might be maintained in higher frequencies in those accessions having lower heterochromatin content, so as to preserve an optimal nucleotype. Furthermore, selective forces acting along the altitudinal gradient might be modulating the cytological parameters studied, as suggested by the significant correlations found among them.

Comparative Proteomic Analyses Provide New Insights into Low Phosphorus Stress Responses in Maize Leaves

PubMed Central

Zhang, Kewei; Liu, Hanhan; Tao, Peilin; Chen, Huan

2014-01-01

Phosphorus deficiency limits plant growth and development. To better understand the mechanisms behind how maize responds to phosphate stress, we compared the proteome analysis results of two groups of maize leaves that were treated separately with 1,000 µM (control, +P) and 5 µM of KH2PO4 (intervention group, −P) for 25 days. In total, 1,342 protein spots were detected on 2-DE maps and 15.43% had changed (P<0.05; ≥1.5-fold) significantly in quantity between the +P and −P groups. These proteins are involved in several major metabolic pathways, including photosynthesis, carbohydrate metabolism, energy metabolism, secondary metabolism, signal transduction, protein synthesis, cell rescue and cell defense and virulence. The results showed that the reduction in photosynthesis under low phosphorus treatment was due to the down-regulation of the proteins involved in CO2 enrichment, the Calvin cycle and the electron transport system. Electron transport and photosynthesis restrictions resulted in a large accumulation of peroxides. Maize has developed many different reactive oxygen species (ROS) scavenging mechanisms to cope with low phosphorus stress, including up-regulating its antioxidant content and antioxidase activity. After being subjected to phosphorus stress over a long period, maize may increase its internal phosphorus utilization efficiency by altering photorespiration, starch synthesis and lipid composition. These results provide important information about how maize responds to low phosphorus stress. PMID:24858307

Temporal Shift of Circadian-Mediated Gene Expression and Carbon Fixation Contributes to Biomass Heterosis in Maize Hybrids.

PubMed

Ko, Dae Kwan; Rohozinski, Dominica; Song, Qingxin; Taylor, Samuel H; Juenger, Thomas E; Harmon, Frank G; Chen, Z Jeffrey

2016-07-01

Heterosis has been widely used in agriculture, but the molecular mechanism for this remains largely elusive. In Arabidopsis hybrids and allopolyploids, increased photosynthetic and metabolic activities are linked to altered expression of circadian clock regulators, including CIRCADIAN CLOCK ASSOCIATED1 (CCA1). It is unknown whether a similar mechanism mediates heterosis in maize hybrids. Here we report that higher levels of carbon fixation and starch accumulation in the maize hybrids are associated with altered temporal gene expression. Two maize CCA1 homologs, ZmCCA1a and ZmCCA1b, are diurnally up-regulated in the hybrids. Expressing ZmCCA1 complements the cca1 mutant phenotype in Arabidopsis, and overexpressing ZmCCA1b disrupts circadian rhythms and biomass heterosis. Furthermore, overexpressing ZmCCA1b in maize reduced chlorophyll content and plant height. Reduced height stems from reduced node elongation but not total node number in both greenhouse and field conditions. Phenotypes are less severe in the field than in the greenhouse, suggesting that enhanced light and/or metabolic activities in the field can compensate for altered circadian regulation in growth vigor. Chromatin immunoprecipitation-sequencing (ChIP-seq) analysis reveals a temporal shift of ZmCCA1-binding targets to the early morning in the hybrids, suggesting that activation of morning-phased genes in the hybrids promotes photosynthesis and growth vigor. This temporal shift of ZmCCA1-binding targets correlated with nonadditive and additive gene expression in early and late stages of seedling development. These results could guide breeding better hybrid crops to meet the growing demand in food and bioenergy.

Growth and development in higher plants under simulated microgravity conditions on a 3-dimensional clinostat.

PubMed

Shimazu, T; Yuda, T; Miyamoto, K; Yamashita, M; Ueda, J

2001-01-01

Growth and development of etiolated pea (Pisum sativum L. cv. Alaska) and maize (Zea mays L. cv. Golden Cross Bantam) seedlings grown under simulated microgravity conditions were intensively studied using a 3-dimensional clinostat as a simulator of weightlessness. Epicotyls of etiolated pea seedlings grown on the clinostat were the most oriented toward the direction far from cotyledons. Mesocotyls of etiolated maize seedlings grew at random and coleoptiles curved slightly during clinostat rotation. Clinostat rotation promoted the emergence of the 3rd internodes in etiolated pea seedlings, while it significantly inhibited the growth of the 1st internodes. In maize seedlings, the growth of coleoptiles was little affected by clinostat rotation, but that of mesocotyls was suppressed, and therefore, the emergence of the leaf out of coleoptile was promoted. Clinostat rotation reduced the osmotic concentration in the 1st internodes of pea seedlings, although it has little effect on the 2nd and the 3rd internodes. Clinostat rotation also reduced the osmotic concentrations in both coleoptiles and mesocotyls of maize seedlings. Cell-wall extensibilities of the 1st and the 3rd internodes of pea seedlings grown on the clinostat were significantly lower and higher as compared with those on 1 g conditions, respectively. Cell-wall extensibility of mesocotyls in seedlings grown on the clinostat also decreased. Changes in cell wall properties seem to be well correlated to the growth of each organ in pea and maize seedlings. These results suggest that the growth and development of plants is controlled under gravity on earth, and that the growth responses of higher plants to microgravity conditions are regulated by both cell-wall mechanical properties and osmotic properties of stem cells. c 2001 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

The ZmCLA4 gene in the qLA4-1 QTL controls leaf angle in maize (Zea mays L.).

PubMed

Zhang, J; Ku, L X; Han, Z P; Guo, S L; Liu, H J; Zhang, Z Z; Cao, L R; Cui, X J; Chen, Y H

2014-09-01

Maize architecture is a major contributing factor to their high level of productivity. Maize varieties with an erect-leaf-angle (LA) phenotype, which increases light harvesting for photosynthesis and grain-filling, have elevated grain yields. Although a large body of information is available on the map positions of quantitative trait loci (QTL) for LA, little is known about the molecular mechanism of these QTL. In this study, the ZmCLA4 gene, which is responsible for the qLA4-1 QTL associated with LA, was identified and isolated by fine mapping and positional cloning. The ZmCLA4 gene is an orthologue of LAZY1 in rice and Arabidopsis. Sequence analysis revealed two SNPs and two indel sites in ZmCLA4 between the D132 and D132-NIL inbred maize lines. Association analysis showed that C/T/mutation667 and CA/indel965 were strongly associated with LA. Subcellular localization verified the functions of a predicted transmembrane domain and a nuclear localization signal in ZmCLA4. Transgenic maize plants with a down-regulated ZmCLA4 RNAi construct and transgenic rice plants over-expressing ZmCLA4 confirmed that the ZmCLA4 gene located in the qLA4 QTL regulated LA. The allelic variants of ZmCLA4 in the D132 and D132-NIL lines exhibited significant differences in leaf angle. ZmCLA4 transcript accumulation was higher in D132-NIL than in D132 during all the developmental stages and was negatively correlated with LA. The gravitropic response was increased and cell shape and number at the leaf and stem junctions were altered in D132-NIL relative to D132. These findings suggest that ZmCLA4 plays a negative role in the control of maize LA through the alteration of mRNA accumulation, leading to altered shoot gravitropism and cell development. The cloning of the gene responsible for the qLA4-1 QTL provides information on the molecular mechanisms of LA in maize and an opportunity for the improvement of plant architecture with regard to LA through maize breeding. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Impact of cadmium stress on two maize hybrids.

PubMed

Vatehová, Zuzana; Malovíková, Anna; Kollárová, Karin; Kučerová, Danica; Lišková, Desana

2016-11-01

Some physiological parameters and composition of the root cell walls of two maize hybrids (monocots), the sensitive Novania and the tolerant Almansa were studied after treatment with cadmium cations. After 10 days of Cd 2+ treatment (1 × 10 -5  M and 5 × 10 -5  M), plant growth inhibition, in the sensitive hybrid in particular, as well as a certain alteration in root structure and pigment content were observed. The Cd 2+ accumulation was ten times higher in the roots than in the shoots. Chemical analyses and atomic absorption spectroscopy proved that Cd 2+ modified the composition of the root cell walls by a significant increase in the content of alkali-soluble polysaccharide fractions, particularly in the tolerant hybrid. An increase in the content of phenolic compounds, mainly in the tolerant hybrid, and a decrease in protein content were observed in the presence of Cd 2+ in the alkali fractions. The results indicate that the changes in the cell wall polysaccharide fractions and their proportion to lignin and cellulose are obviously involved in the tolerance and/or defence against Cd 2+ of the maize hybrids studied. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Chemical Composition, Starch Digestibility and Antioxidant Capacity of Tortilla Made with a Blend of Quality Protein Maize and Black Bean

PubMed Central

Grajales-García, Eva M.; Osorio-Díaz, Perla; Goñi, Isabel; Hervert-Hernández, Deisy; Guzmán-Maldonado, Salvador H.; Bello-Pérez, Luis A.

2012-01-01

Tortilla and beans are the basic components in the diet of people in the urban and rural areas of Mexico. Quality protein maize is suggested for tortilla preparation because it presents an increase in lysine and tryptophan levels. Beans contain important amounts of dietary fiber. The objective of this study was to prepare tortilla with bean and assesses the chemical composition, starch digestibility and antioxidant capacity using a quality protein maize variety. Tortilla with bean had higher protein, ash, dietary fiber and resistant starch content, and lower digestible starch than control tortilla. The hydrolysis rate (60 to 50%) and the predicted glycemic index (88 to 80) of tortilla decreased with the addition of bean in the blend. Extractable polyphenols and proanthocyanidins were higher in the tortilla with bean than control tortilla. This pattern produced higher antioxidant capacity of tortilla with bean (17.6 μmol Trolox eq/g) than control tortilla (7.8 μmol Trolox eq/g). The addition of bean to tortilla modified the starch digestibility and antioxidant characteristics of tortilla, obtaining a product with nutraceutical characteristics. PMID:22312252

Genome Regions Associated with Functional Performance of Soybean Stem Fibers in Polypropylene Thermoplastic Composites

PubMed Central

Reinprecht, Yarmilla; Arif, Muhammad; Simon, Leonardo C.; Pauls, K. Peter

2015-01-01

Plant fibers can be used to produce composite materials for automobile parts, thus reducing plastic used in their manufacture, overall vehicle weight and fuel consumption when they replace mineral fillers and glass fibers. Soybean stem residues are, potentially, significant sources of inexpensive, renewable and biodegradable natural fibers, but are not curretly used for biocomposite production due to the functional properties of their fibers in composites being unknown. The current study was initiated to investigate the effects of plant genotype on the performance characteristics of soybean stem fibers when incorporated into a polypropylene (PP) matrix using a selective phenotyping approach. Fibers from 50 lines of a recombinant inbred line population (169 RILs) grown in different environments were incorporated into PP at 20% (wt/wt) by extrusion. Test samples were injection molded and characterized for their mechanical properties. The performance of stem fibers in the composites was significantly affected by genotype and environment. Fibers from different genotypes had significantly different chemical compositions, thus composites prepared with these fibers displayed different physical properties. This study demonstrates that thermoplastic composites with soybean stem-derived fibers have mechanical properties that are equivalent or better than wheat straw fiber composites currently being used for manufacturing interior automotive parts. The addition of soybean stem residues improved flexural, tensile and impact properties of the composites. Furthermore, by linkage and in silico mapping we identified genomic regions to which quantitative trait loci (QTL) for compositional and functional properties of soybean stem fibers in thermoplastic composites, as well as genes for cell wall synthesis, were co-localized. These results may lead to the development of high value uses for soybean stem residue. PMID:26167917

Genomic Dissection of Leaf Angle in Maize (Zea mays L.) Using a Four-Way Cross Mapping Population.

PubMed

Ding, Junqiang; Zhang, Luyan; Chen, Jiafa; Li, Xiantang; Li, Yongming; Cheng, Hongliang; Huang, Rongrong; Zhou, Bo; Li, Zhimin; Wang, Jiankang; Wu, Jianyu

2015-01-01

Increasing grain yield by the selection for optimal plant architecture has been the key focus in modern maize breeding. As a result, leaf angle, an important determinant of plant architecture, has been significantly improved to adapt to the ever-increasing plant density in maize production over the past several decades. To extend our understanding on the genetic mechanisms of leaf angle in maize, we developed the first four-way cross mapping population, consisting of 277 lines derived from four maize inbred lines with varied leaf angles. The four-way cross mapping population together with the four parental lines were evaluated for leaf angle in two environments. In this study, we reported linkage maps built in the population and quantitative trait loci (QTL) on leaf angle detected by inclusive composite interval mapping (ICIM). ICIM applies a two-step strategy to effectively separate the cofactor selection from the interval mapping, which controls the background additive and dominant effects at the same time. A total of 14 leaf angle QTL were identified, four of which were further validated in near-isogenic lines (NILs). Seven of the 14 leaf angle QTL were found to overlap with the published leaf angle QTL or genes, and the remaining QTL were unique to the four-way population. This study represents the first example of QTL mapping using a four-way cross population in maize, and demonstrates that the use of specially designed four-way cross is effective in uncovering the basis of complex and polygenetic trait like leaf angle in maize.

Genomic Dissection of Leaf Angle in Maize (Zea mays L.) Using a Four-Way Cross Mapping Population

PubMed Central

Li, Xiantang; Li, Yongming; Cheng, Hongliang; Huang, Rongrong; Zhou, Bo; Li, Zhimin; Wang, Jiankang; Wu, Jianyu

2015-01-01

Increasing grain yield by the selection for optimal plant architecture has been the key focus in modern maize breeding. As a result, leaf angle, an important determinant of plant architecture, has been significantly improved to adapt to the ever-increasing plant density in maize production over the past several decades. To extend our understanding on the genetic mechanisms of leaf angle in maize, we developed the first four-way cross mapping population, consisting of 277 lines derived from four maize inbred lines with varied leaf angles. The four-way cross mapping population together with the four parental lines were evaluated for leaf angle in two environments. In this study, we reported linkage maps built in the population and quantitative trait loci (QTL) on leaf angle detected by inclusive composite interval mapping (ICIM). ICIM applies a two-step strategy to effectively separate the cofactor selection from the interval mapping, which controls the background additive and dominant effects at the same time. A total of 14 leaf angle QTL were identified, four of which were further validated in near-isogenic lines (NILs). Seven of the 14 leaf angle QTL were found to overlap with the published leaf angle QTL or genes, and the remaining QTL were unique to the four-way population. This study represents the first example of QTL mapping using a four-way cross population in maize, and demonstrates that the use of specially designed four-way cross is effective in uncovering the basis of complex and polygenetic trait like leaf angle in maize. PMID:26509792

The influence of grass silage-to-maize silage ratio and concentrate composition on methane emissions, performance and milk composition of dairy cows.

PubMed

Hart, K J; Huntington, J A; Wilkinson, R G; Bartram, C G; Sinclair, L A

2015-06-01

It is well-established that altering the proportion of starch and fibre in ruminant diets can alter ruminal and post-ruminal digestion, although quantitative evidence that this reduces enteric methane (CH4) production in dairy cattle is lacking. The objective of this study was to examine the effect of varying grass-to-maize silage ratio (70 : 30 and 30 : 70 DM basis), offered ad libitum, with either a concentrate that was high in starch or fibre, on CH4 production, intake, performance and milk composition of dairy cows. A total of 20 cows were allocated to one of the four experimental diets in a two-by-two factorial design run as a Latin square with each period lasting 28 days. Measurements were conducted during the final 7 days of each period. Cows offered the high maize silage ration had a higher dry matter intake (DMI), milk yield, milk energy output and lower CH4 emissions when expressed per kg DMI and per unit of ingested gross energy, but there was no difference in total CH4 production. Several of the milk long-chain fatty acids (FA) were affected by forage treatment with the most notable being an increase in 18:0, 18:1 c9, 18:2 c9 c12 and total mono unsaturated FA, observed in cows offered the higher inclusion of maize silage, and an increase in 18:3 c9 c12 c15 when offered the higher grass silage ration. Varying the composition of the concentrate had no effect on DMI or milk production; however, when the high-starch concentrate was fed, milk protein concentration and milk FAs, 10:0, 14:1, 15:0, 16:1, increased and 18:0 decreased. Interactions were observed for milk fat concentration, being lower in cows offered high-grass silage and high-fibre concentrates compared with the high-starch concentrate, and FA 17:0, which was the highest in milk from cows fed the high-grass silage diet supplemented with the high-starch concentrate. In conclusion, increasing the proportion of maize silage in the diets of dairy cows increased intake and performance, and reduced CH4 production, but only when expressed on a DM or energy intake basis, whereas starch-to-fibre ratio in the concentrate had little effect on performance or CH4 production.

Assessing spatiotemporal variation of drought and its impact on maize yield in Northeast China

NASA Astrophysics Data System (ADS)

Guo, Enliang; Liu, Xingpeng; Zhang, Jiquan; Wang, Yongfang; Wang, Cailin; Wang, Rui; Li, Danjun

2017-10-01

In the context of global climate change, drought has become an important factor that affects the maize yield in China. To analyse the impact of drought on maize yield loss in Northeast China in current and future climate scenarios, the Composite Meteorological Drought Index (CI) is introduced to reconstruct the following drought indicators: drought accumulative days (DAD), drought accumulative intensity (DAI), and consecutive drought days (CDD). These three drought indicators are used to describe the three-dimensional characteristics of drought in this study. Sen's slope method and three-dimensional copula functions are adopted to analyse the variety of drought features, and Ensemble Empirical Mode Decomposition (EEMD) is used to analyse the variations in maize yield. A temporal assessment of the standardized yield residuals series (SYRS) of maize from 1961 to 2014 is conducted. A panel regression model is applied to demonstrate the drought impact on maize yield at various growth stages under the RCP4.5 scenario. The results show that the drought risk level for midwest Jilin Province, western Liaoning, and eastern Heilongjiang increase with global warming in the current scenario. The shorter three-dimensional joint return periods, 44-80 yr, were mainly located in western Jilin Province, Liaodong Peninsula, and northwestern Liaoning. Eastern Heilongjiang has a slightly longer joint return period of 80-100 yr. The SYRS shows a strong statistical correlation with drought indicator variations; drought-prone regions exhibit strong positive correlations. In comparison, excess precipitation regions show strong negative correlations with drought indicators in most growth stages. Drought indicators have a relatively strong association with SYRS at the milky-mature maize growth stage, and the occurrence of drought during this period primarily determines the maize yield changes in the future. Maize yield changes are -2.04%, -2.65% and -1.57% for Liaoning, Jilin, and Heilongjiang Province under the RCP4.5 scenario. These results can be used as a tool for early warning of drought risk to maize, and will accelerate the progress of drought disaster risk management.

Trichothecene Genotype Composition of Fusarium graminearum Not Differentiated Among Isolates from Maize Stubble, Maize Ears, Wheat Spikes, and the Atmosphere in New York.

PubMed

Kuhnem, Paulo R; Spolti, Pierri; Del Ponte, Emerson M; Cummings, Jaime A; Bergstrom, Gary C

2015-05-01

In order to test the hypothesis that the trichothecene genotype composition of local populations of Fusarium graminearum is structured by specific habitats, a collection of 1,407 isolates was obtained from overwintered maize stubble, mature maize ears and wheat spikes, and the atmosphere 1.5 m aboveground during the flowering stage of these crops. These isolates were sampled at three diverse agricultural locations in New York State: namely, Aurora (sampled in 2012 and 2013) in central New York, Belmont (sampled in 2013) in southwestern New York, and Willsboro (sampled in 2013) in northeastern New York. Approximately 100 isolates of F. graminearum from each habitat were collected within a 10-mile2 area in each location. Polymerase chain reaction assays were used to identify three main B-trichothecene genotypes--3-acetyldeoxynivalenol (3-ADON), 15-ADON, or nivalenol (NIV)--based on amplification of portions of Tri3 and Tri12 genes. All but the NIV genotype were detected. The 15-ADON genotype predominated in most locations; frequencies were 92% (652/709) at Aurora, 78% (332/379) at Belmont, and 53% (167/319) at Willsboro. Frequencies of any genotype did not differ in general among the four habits in each location. An exception was in Aurora 2012, where only 5 in 24 3-ADON isolates were found in samplings from the air and grains of both crops. As viewed by the composition of trichothecene genotypes, local populations of F. graminearum appear not to be structured by these four habitats inclusive of pathogenic and saprophytic phases of the fungus life cycle. The similar frequency of 3-ADON and 15-ADON in eastern New York (Willsboro), which is less than 400 km away from the Aurora sampling location in the central area of the state, suggests that regional populations may be differentiated based on selection associated with climatic or landscape features not currently identified.

Environmental materials for remediation of soils contaminated with lead and cadmium using maize (Zea mays L.) growth as a bioindicator.

PubMed

Shi, Yu; Huang, Zhanbin; Liu, Xiujie; Imran, Suheryani; Peng, Licheng; Dai, Rongji; Deng, Yulin

2016-04-01

Heavy metal pollution is a severe environmental problem. Remediation of contaminated soils can be accomplished using environmental materials that are low cost and environmentally friendly. We evaluated the individual and combination effects of humic acid (HA), super absorbent polymer (SAP), zeolite (ZE), and fly ash composites (FC) on immobilization of lead (Pb) and cadmium (Cd) in contaminated soils. We also investigated long-term practical approaches for remediation of heavy metal pollution in soil. The biochemical and morphological properties of maize (Zea mays L.) were selected as biomarkers to assess the effects of environmental materials on heavy metal immobilization. The results showed that addition of test materials to soil effectively reduced heavy metal accumulation in maize foliage, improving chlorophyll levels, plant growth, and antioxidant enzyme activity. The test materials reduced heavy metal injury to maize throughout the growth period. A synergistic effect from combinations of different materials on immobilization of Pb and Cd was determined based on the reduction of morphological and biochemical injuries to maize. The combination of zeolite and humic acid was especially effective. Treatment with a combination of HA + SAP + ZE + FC was superior for remediation of soils contaminated with high levels of Pb and Cd.

Capacity of milk composition to identify the feeding system used to feed dairy cows.

PubMed

Vicente, Fernando; Santiago, Carme; Jiménez-Calderón, José D; Martínez-Fernández, Adela

2017-08-01

This Research Paper addresses the hypothesis that is possible to identify the type of feed used for dairy cows by means of the analysis of milk composition and the fatty acid profile of milk fat. Sixteen dairy farms were monitored during 1 year with quarterly visits between summer 2014 and spring 2015. Rations varied throughout the year due to annual dynamic change of forage production, forage rotation, variation of nutrient requirements according to physiological state of the animal, etc. The ingredients of the rations were analysed by cluster identifying five feeding systems based on the main ingredient of the diet: grazing, maize silage, grass silage, dry forage and concentrate. Milk composition could explain up to 91·3% of the total variability among feeding systems, while fatty acid profile could explain only up to 61·2% of total variability. However, when the sum of types of fatty acids and their ratios are taken, up to 93·5% of total variability could be explained. The maize silage system had the greatest milk yield, protein, solid non-fat and urea proportions, as well as the highest proportion of saturated fatty acid and lowest concentration of trans11 18 : 1, cis9 18 : 1 and 18 : 3 n3. Principal component analysis distinguishes the maize silage system from other feeding systems, both from milk composition and milk fatty acid profile. Concentrate system overlapped partially with the grazing, grass silage and dry forage systems. The latter systems had the highest concentrations of cis9 18 : 1, trans11 18 : 1 and 18 : 3, but there was no clear differentiation among them.

Performance and fat quality of heavy pigs fed maize differing in linoleic acid content.

PubMed

Della Casa, G; Bochicchio, D; Faeti, V; Marchetto, G; Poletti, E; Rossi, A; Panciroli, A; Mordenti, A L; Brogna, N

2010-01-01

Maize shows wide differences in linoleic acid due both to total lipid content and to fatty acid profile. Therefore, diets containing the same high maize percentage (up to 55%) can differ in linoleic acid content and lead to subcutaneous fats of differing suitability for raw ham curing. Two trials were performed on heavy pigs; in the first, 60 pigs (body weight 48.7+/-5.1 kg) were fed three diets made using three maize batches differing in linoleic acid due to different total lipid content, in the second trial, 40 pigs (live weight 70.4+/-3.4 kg) were fed two diets made using two maize batches differing in linoleic acid due to their fatty acid profile. Pigs were slaughtered at 170 kg of live weight. In both trials, the growth and slaughtering performance did not differ. In the first trial the three diets lead to a different content of linoleic acid both in subcutaneous (low linoleic vs medium linoleic vs high linoleic P0.01) and intramuscular fat (low linoleic vs high linoleic P0.05). In the second trial different linoleic acid content was observed for subcutaneous fat (P0.01) but not for intramuscular fat. To formulate diets for heavy pigs, it is crucial to know the linoleic acid content of the maize used, because differences of only 0.3% can lead to significant differences in fatty acids composition of depot fats.

Using 13C in cattle hair to trace back the maize level in the feeding regime-A field test.

PubMed

Hammes, Verena; Nüsse, Olaf; Isselstein, Johannes; Kayser, Manfred

2017-01-01

Sections from cattle hair serve as an isotopic archive-they contain information on the cattle diet from different time periods. We tested the reliability of 13C signatures (δ13C) in cattle tail switch hair to retrospectively trace back the annual dietary proportion of maize of different production systems without having to sample and analyze the feed. Furthermore, we investigated if differences in dietary proportion of maize during summer and winter feeding can be detected in a single tail switch hair by sampling hair only once a year. We sampled hair and obtained information on management and annual composition of diets on 23 cattle farms in northern Germany. Farms differed in dietary proportions of maize, grass and concentrates as well as in grazing regime (year-round grazing, summer grazing, no grazing). We found that the annual mean δ13C values (δ13CY) of two hair sections that contain the isotopic information of summer and winter feeding is a robust indicator for the annual proportion of maize in cattle diet on a farm. The grazing regimes could clearly be distinguished by analyzing seasonal mean δ13C values (δ13CS). We could also demonstrate short term changes in the diet changes by means of δ13CS. We conclude that the method can be used in different cattle production systems to check on dietary proportions of maize for a period of one year before sampling of hair.

Influence of Kernel Age on Fumonisin B1 Production in Maize by Fusarium moniliforme

PubMed Central

Warfield, Colleen Y.; Gilchrist, David G.

1999-01-01

Production of fumonisins by Fusarium moniliforme on naturally infected maize ears is an important food safety concern due to the toxic nature of this class of mycotoxins. Assessing the potential risk of fumonisin production in developing maize ears prior to harvest requires an understanding of the regulation of toxin biosynthesis during kernel maturation. We investigated the developmental-stage-dependent relationship between maize kernels and fumonisin B1 production by using kernels collected at the blister (R2), milk (R3), dough (R4), and dent (R5) stages following inoculation in culture at their respective field moisture contents with F. moniliforme. Highly significant differences (P ≤ 0.001) in fumonisin B1 production were found among kernels at the different developmental stages. The highest levels of fumonisin B1 were produced on the dent stage kernels, and the lowest levels were produced on the blister stage kernels. The differences in fumonisin B1 production among kernels at the different developmental stages remained significant (P ≤ 0.001) when the moisture contents of the kernels were adjusted to the same level prior to inoculation. We concluded that toxin production is affected by substrate composition as well as by moisture content. Our study also demonstrated that fumonisin B1 biosynthesis on maize kernels is influenced by factors which vary with the developmental age of the tissue. The risk of fumonisin contamination may begin early in maize ear development and increases as the kernels reach physiological maturity. PMID:10388675

ZmXTH1, a new xyloglucan endotransglucosylase/hydrolase in maize, affects cell wall structure and composition in Arabidopsis thaliana.

PubMed

Genovesi, Valeria; Fornalé, Silvia; Fry, Stephen C; Ruel, Katia; Ferrer, Pau; Encina, Antonio; Sonbol, Fathi-Mohamed; Bosch, Josep; Puigdomènech, Pere; Rigau, Joan; Caparrós-Ruiz, David

2008-01-01

Xyloglucan endotransglucosylase/hydrolases (XTHs; EC 2.4.1.207 and/or EC 3.2.1.151) are enzymes involved in the modification of cell wall structure by cleaving and, often, also re-joining xyloglucan molecules in primary plant cell walls. Using a pool of antibodies raised against an enriched cell wall protein fraction, a new XTH cDNA in maize, ZmXTH1, has been isolated from a cDNA expression library obtained from the elongation zone of the maize root. The predicted protein has a putative N-terminal signal peptide and possesses the typical domains of this enzyme family, such as a catalytic domain that is homologous to that of Bacillus macerans beta-glucanase, a putative N-glycosylation motif, and four cysteine residues in the central and C terminal regions of the ZmXTH1 protein. Phylogenetic analysis of ZmXTH1 reveals that it belongs to subgroup 4, so far only reported from Poaceae monocot species. ZmXTH1 has been expressed in Pichia pastoris (a methylotrophic yeast) and the recombinant enzyme showed xyloglucan endotransglucosylase but not xyloglucan endohydrolase activity, representing the first enzyme belonging to subgroup 4 characterized in maize so far. Expression data indicate that ZmXTH1 is expressed in elongating tissues, modulated by culture conditions, and induced by gibberellins. Transient expression assays in onion cells reveal that ZmXTH1 is directed to the cell wall, although weakly bound. Finally, Arabidopsis thaliana plants expressing ZmXTH1 show slightly increased xyloglucan endohydrolase activity and alterations in the cell wall structure and composition.

Water-Soluble Lignins from Different Bioenergy Crops Stimulate the Early Development of Maize (Zea mays, L.).

PubMed

Savy, Davide; Cozzolino, Vincenza; Vinci, Giovanni; Nebbioso, Antonio; Piccolo, Alessandro

2015-11-05

The molecular composition of water-soluble lignins isolated from four non-food bioenergy crops (cardoon CAR, eucalyptus EUC, and two black poplars RIP and LIM) was characterized in detail, and their potential bioactivity towards maize germination and early growth evaluated. Lignins were found to not affect seed germination rates, but stimulated the maize seedling development, though to a different extent. RIP promoted root elongation, while CAR only stimulated the length of lateral seminal roots and coleoptile, and LIM improved only the coleoptile development. The most significant bioactivity of CAR was related to its large content of aliphatic OH groups, C-O carbons and lowest hydrophobicity, as assessed by (31)P-NMR and (13)C-CPMAS-NMR spectroscopies. Less bioactive RIP and LIM lignins were similar in composition, but their stimulation of maize seedling was different. This was accounted to their diverse content of aliphatic OH groups and S- and G-type molecules. The poorest bioactivity of the EUC lignin was attributed to its smallest content of aliphatic OH groups and largest hydrophobicity. Both these features may be conducive of a EUC conformational structure tight enough to prevent its alteration by organic acids exuded from vegetal tissues. Conversely the more labile conformational arrangements of the other more hydrophilic lignin extracts promoted their bioactivity by releasing biologically active molecules upon the action of exuded organic acids. Our findings indicate that water-soluble lignins from non-food crops may be effectively used as plant biostimulants, thus contributing to increase the economic and ecological liability of bio-based industries.

Gene Expression Biomarkers Provide Sensitive Indicators of in Planta Nitrogen Status in Maize[W][OA

PubMed Central

Yang, Xiaofeng S.; Wu, Jingrui; Ziegler, Todd E.; Yang, Xiao; Zayed, Adel; Rajani, M.S.; Zhou, Dafeng; Basra, Amarjit S.; Schachtman, Daniel P.; Peng, Mingsheng; Armstrong, Charles L.; Caldo, Rico A.; Morrell, James A.; Lacy, Michelle; Staub, Jeffrey M.

2011-01-01

Over the last several decades, increased agricultural production has been driven by improved agronomic practices and a dramatic increase in the use of nitrogen-containing fertilizers to maximize the yield potential of crops. To reduce input costs and to minimize the potential environmental impacts of nitrogen fertilizer that has been used to optimize yield, an increased understanding of the molecular responses to nitrogen under field conditions is critical for our ability to further improve agricultural sustainability. Using maize (Zea mays) as a model, we have characterized the transcriptional response of plants grown under limiting and sufficient nitrogen conditions and during the recovery of nitrogen-starved plants. We show that a large percentage (approximately 7%) of the maize transcriptome is nitrogen responsive, similar to previous observations in other plant species. Furthermore, we have used statistical approaches to identify a small set of genes whose expression profiles can quantitatively assess the response of plants to varying nitrogen conditions. Using a composite gene expression scoring system, this single set of biomarker genes can accurately assess nitrogen responses independently of genotype, developmental stage, tissue type, or environment, including in plants grown under controlled environments or in the field. Importantly, the biomarker composite expression response is much more rapid and quantitative than phenotypic observations. Consequently, we have successfully used these biomarkers to monitor nitrogen status in real-time assays of field-grown maize plants under typical production conditions. Our results suggest that biomarkers have the potential to be used as agronomic tools to monitor and optimize nitrogen fertilizer usage to help achieve maximal crop yields. PMID:21980173

Gene expression biomarkers provide sensitive indicators of in planta nitrogen status in maize.

PubMed

Yang, Xiaofeng S; Wu, Jingrui; Ziegler, Todd E; Yang, Xiao; Zayed, Adel; Rajani, M S; Zhou, Dafeng; Basra, Amarjit S; Schachtman, Daniel P; Peng, Mingsheng; Armstrong, Charles L; Caldo, Rico A; Morrell, James A; Lacy, Michelle; Staub, Jeffrey M

2011-12-01

Over the last several decades, increased agricultural production has been driven by improved agronomic practices and a dramatic increase in the use of nitrogen-containing fertilizers to maximize the yield potential of crops. To reduce input costs and to minimize the potential environmental impacts of nitrogen fertilizer that has been used to optimize yield, an increased understanding of the molecular responses to nitrogen under field conditions is critical for our ability to further improve agricultural sustainability. Using maize (Zea mays) as a model, we have characterized the transcriptional response of plants grown under limiting and sufficient nitrogen conditions and during the recovery of nitrogen-starved plants. We show that a large percentage (approximately 7%) of the maize transcriptome is nitrogen responsive, similar to previous observations in other plant species. Furthermore, we have used statistical approaches to identify a small set of genes whose expression profiles can quantitatively assess the response of plants to varying nitrogen conditions. Using a composite gene expression scoring system, this single set of biomarker genes can accurately assess nitrogen responses independently of genotype, developmental stage, tissue type, or environment, including in plants grown under controlled environments or in the field. Importantly, the biomarker composite expression response is much more rapid and quantitative than phenotypic observations. Consequently, we have successfully used these biomarkers to monitor nitrogen status in real-time assays of field-grown maize plants under typical production conditions. Our results suggest that biomarkers have the potential to be used as agronomic tools to monitor and optimize nitrogen fertilizer usage to help achieve maximal crop yields.

Proliferation of the biocontrol agent Fusarium oxysporum f. sp. strigae and its impact on indigenous rhizosphere fungal communities in maize under different agro-ecologies.

PubMed

Zimmermann, Judith; Musyoki, Mary K; Cadisch, Georg; Rasche, Frank

2016-06-01

Our objectives were to (1) monitor the proliferation of the biocontrol agent (BCA) Fusarium oxysporum f. sp. strigae strain "Foxy-2", an effective soil-borne BCA against the parasitic weed Striga hermonthica , in the rhizosphere of maize under different agro-ecologies, and (2) investigate its impact on indigenous rhizosphere fungal community abundance and composition. Field experiments were conducted in Busia and Homa Bay districts in western Kenya during two cropping seasons to account for effects of soil type, climate, growth stage and seasonality. Maize seeds were coated with or without "Foxy-2" and soils were artificially infested with S. hermonthica seeds. One treatment with nitrogen rich organic residues ( Tithonia diversifolia ) was established to compensate hypothesized resource competition between "Foxy-2" and the indigenous fungal community. Rhizosphere soil samples collected at three growth stages (i.e., EC30, EC60, EC90) of maize were subjected to abundance measurement of "Foxy-2" and total indigenous fungi using quantitative polymerase chain reaction (qPCR) analysis. Terminal restriction fragment length polymorphism (TRFLP) analysis was used to assess potential alterations in the fungal community composition in response to "Foxy-2" presence. "Foxy-2" proliferated stronger in the soils with a sandy clay texture (Busia) than in those with a loamy sand texture (Homa Bay) and revealed slightly higher abundance in the second season. "Foxy-2" had, however, only a transient suppressive effect on total indigenous fungal abundance which ceased in the second season and was further markedly compensated after addition of T. diversifolia residues. Likewise, community structure of the indigenous fungal community was mainly altered by maize growth stages, but not by "Foxy-2". In conclusion, no adverse effects of "Foxy-2" inoculation on indigenous fungal rhizosphere communities were observed corroborating the safety of this BCA under the given agro-ecologies.

Out of sight - Profiling soil characteristics, nutrients and microbial communities affected by organic amendments down to one meter in a long-term maize cultivation experiment

NASA Astrophysics Data System (ADS)

Lehtinen, Taru; Mikkonen, Anu; Zavattaro, Laura; Grignani, Carlo; Baumgarten, Andreas; Spiegel, Heide

2016-04-01

Soil characteristics, nutrients and microbial activity in the deeper soil layers are topics not of-ten covered in agricultural studies since the main interest lies within the most active topsoils and deep soils are more time-consuming to sample. Studies have shown that deep soil does matter, although biogeochemical cycles are not fully understood yet. The main aim of this study is to investigate the soil organic matter dynamics, nutrients and microbial community composition in the first meter of the soil profiles in the long-term maize cropping system ex-periment Tetto Frati, in the vicinity of the Po River in Northern Italy. The trial site lies on a deep, calcareous, free-draining soil with a loamy texture. The following treatments have been applied since 1992: 1) maize for silage with 250 kg mineral N ha-1 (crop residue removal, CRR), 2) maize for grain with 250 kg mineral N ha-1 (crop residue incorporation, CRI), 3) maize for silage with 250 kg bovine slurry N ha-1 (SLU), 4) maize for silage with 250 kg farm yard manure N ha-1 (FYM). Soil characteristics (pH, carbonate content, soil organic carbon (SOC), aggregate stability (WSA)), and nutrients (total nitrogen (Nt), CAL-extractable phos-phorous (P) and potassium (K), potential N mineralisation) were investigated. Bacteri-al community composition was investigated with Ion PGM high-throughput sequencing at the depth of 8000 sequences per sample. Soil pH was moderately alkaline in all soil samples, in-creasing with increasing soil depth, as the carbonate content increased. SOC was significantly higher in the treatments with organic amendments (CRI, SLU and FYM) compared to CRR in 0-25 cm (11.1, 11.6, 14.7 vs. 9.8 g kg-1, respectively), but not in the deeper soil. At 50-75 cm soil depth FYM treatment revealed higher WSA compared to CRR, as well as higher CAL-extractable K (25 and 15 mg kg-1, respectively) and potential N mineralisation (11.30 and 8.78 mg N kg-1 7d-1, respectively). At 75-100 cm soil depth, SLU and FYM had the highest poten-tial N mineralisation. Microbial biomass and bacterial diversity decreased downwards the soil profile. Incorporation of crop residues alone showed no positive impacts on either biomass or diversity, whereas fertilization by FYM instead of mineral fertilizer did. Microbial community composition showed depth-related shifts: Proteobacteria and Actinobacteria dominated the upper layer, whereas Gemmatimonadetes showed the highest relative abundance in the mid-layers and Chloroflexi deeper in the soil profile. The main factor determining soil bacterial community composition in the entire dataset was not the treatments but the layers. Interesting-ly, the surface layers that we expected to be most impacted by the treatments were much more similar to each other, regardless of treatment or block, than samples from the deeper layers were to each other. This means that agricultural practices strongly influence the soil bacterial composition and reduce its wide natural heterogeneity. This calls for continuous efforts to study the deeper soil layers in the numerous long-term field experiments, where mostly the topsoils are currently studied in detail.

Maize Brittle stalk2 Encodes a COBRA-Like Protein Expressed in Early Organ Development But Required for Tissue Flexibility at Maturity1[C][OA

PubMed Central

Sindhu, Anoop; Langewisch, Tiffany; Olek, Anna; Multani, Dilbag S.; McCann, Maureen C.; Vermerris, Wilfred; Carpita, Nicholas C.; Johal, Gurmukh

2007-01-01

The maize (Zea mays) brittle stalk2 (bk2) is a recessive mutant, the aerial parts of which are easily broken. The bk2 phenotype is developmentally regulated and appears 4 weeks after planting, at about the fifth-leaf stage. Before this time, mutants are indistinguishable from wild-type siblings. Afterward, all organs of the bk2 mutants turn brittle, even the preexisting ones, and they remain brittle throughout the life of the plant. Leaf tension assays and bend tests of the internodes show that the brittle phenotype does not result from loss of tensile strength but from loss in flexibility that causes the tissues to snap instead of bend. The Bk2 gene was cloned by a combination of transposon tagging and a candidate gene approach and found to encode a COBRA-like protein similar to rice (Oryza sativa) BC1 and Arabidopsis (Arabidopsis thaliana) COBRA-LIKE4. The outer periphery of the stalk has fewer vascular bundles, and the sclerids underlying the epidermis possess thinner secondary walls. Relative cellulose content is not strictly correlated with the brittle phenotype. Cellulose content in mature zones of bk2 mature stems is lowered by 40% but is about the same as wild type in developing stems. Although relative cellulose content is lowered in leaves after the onset of the brittle phenotype, total wall mass as a proportion of dry mass is either unchanged or slightly increased, indicating a compensatory increase in noncellulosic carbohydrate mass. Fourier transform infrared spectra indicated an increase in phenolic ester content in the walls of bk2 leaves and stems. Total content of lignin is unaffected in bk2 juvenile leaves before or after appearance of the brittle phenotype, but bk2 mature and developing stems are markedly enriched in lignin compared to wild-type stems. Despite increased lignin in bk2 stems, loss of staining with phloroglucinol and ultraviolet autofluorescence is observed in vascular bundles and sclerid layers. Consistent with the infrared analyses, levels of saponifiable hydroxycinnamates are elevated in bk2 leaves and stems. As Bk2 is highly expressed during early development, well before the onset of the brittle phenotype, we propose that Bk2 functions in a patterning of lignin-cellulosic interactions that maintain organ flexibility rather than having a direct role in cellulose biosynthesis. PMID:17932309

Product diversification of banana cv. Mas Kirana off grade by using a double rotating screw extruder

NASA Astrophysics Data System (ADS)

Setyadjit, S.; Sukasih, E.; Risfaheri, R.

2018-01-01

Extrusion technology is today’s favorite technology since it has a varied, practical and consistent product form. The purpose of this research was to get precise composite flour composition so that the quality of the resulted product has optimum quality for breakfast meals. The experimental design used was Design Expert vs. 7 with response surface box-behnken. The flour composition and level to be inputted to the program were banana flour (10-50g), mung beans (10-30g), egg flour (10-20g). Formula made was based on 200 g with addition of maize flour if the amount is less than 200 g. The extrusion tool used is a Thermo Scientific double rotating screw; with Haake Reomax OS. The best results in terms of carbohydrate content is the Formula 8 with a composition of 60 g of banana flour, 20 g eggs, 20 g of green beans and 100 g maize flour. The proximate chemical content of this formula is carbohydrate 84.04%, protein 8.55%, fat 5.49%, ash content 1.24%. K-calories per 100 g is 419.5 which is higher than the standard of breakfast meals calories.

Starch and the Control of Kernel Number in Maize at Low Water Potentials1

PubMed Central

Zinselmeier, Christopher; Jeong, Byeong-Ryong; Boyer, John S.

1999-01-01

After reproduction is initiated in plants, subsequent reproductive development is sometimes interrupted, which decreases the final number of seeds and fruits. We subjected maize (Zea mays L.) to low water potentials (ψw) that frequently cause this kind of failure. We observed metabolite pools and enzyme activities in the developing ovaries while we manipulated the sugar stream by feeding sucrose (Suc) to the stems. Low ψw imposed for 5 d around pollination allowed embryos to form, but abortion occurred and kernel number decreased markedly. The ovary contained starch that nearly disappeared during this abortion. Analyses showed that all of the intermediates in starch synthesis were depleted. However, when labeled Suc was fed to the stems, label arrived at the ovaries. Solute accumulated and caused osmotic adjustment. Suc accumulated, but other intermediates did not, showing that a partial block in starch synthesis occurred at the first step in Suc utilization. This step was mediated by invertase, which had low activity. Because of the block, Suc feeding only partially prevented starch disappearance and abortion. These results indicate that young embryos abort when the sugar stream is interrupted sufficiently to deplete starch during early ovary development, and this abortion results in a loss of mature seeds and fruits. At low ψw, maintaining the sugar stream partially prevented the abortion, but invertase regulated the synthesis of ovary starch and partially prevented full recovery. PMID:10482657

Silicon Promotes Exodermal Casparian Band Formation in Si-Accumulating and Si-Excluding Species by Forming Phenol Complexes

PubMed Central

Hinrichs, Martin; Specht, André; Waßmann, Friedrich; Schreiber, Lukas; Schenk, Manfred K.

2015-01-01

We studied the effect of Silicon (Si) on Casparian band (CB) development, chemical composition of the exodermal CB and Si deposition across the root in the Si accumulators rice and maize and the Si non-accumulator onion. Plants were cultivated in nutrient solution with and without Si supply. The CB development was determined in stained root cross-sections. The outer part of the roots containing the exodermis was isolated after enzymatic treatment. The exodermal suberin was transesterified with MeOH/BF3 and the chemical composition was measured using gas chromatography-mass spectroscopy (GC-MS) and flame ionization detector (GC-FID). Laser ablation-inductively coupled plasma-mass spectroscopy (LA-ICP-MS) was used to determine the Si deposition across root cross sections. Si promoted CB formation in the roots of Si-accumulator and Si non-accumulator species. The exodermal suberin was decreased in rice and maize due to decreased amounts of aromatic suberin fractions. Si did not affect the concentration of lignin and lignin-like polymers in the outer part of rice, maize and onion roots. The highest Si depositions were found in the tissues containing CB. These data along with literature were used to suggest a mechanism how Si promotes the CB development by forming complexes with phenols. PMID:26383862

Planting increases the abundance and structure complexity of soil core functional genes relevant to carbon and nitrogen cycling

PubMed Central

Wang, Feng; Liang, Yuting; Jiang, Yuji; Yang, Yunfeng; Xue, Kai; Xiong, Jinbo; Zhou, Jizhong; Sun, Bo

2015-01-01

Plants have an important impact on soil microbial communities and their functions. However, how plants determine the microbial composition and network interactions is still poorly understood. During a four-year field experiment, we investigated the functional gene composition of three types of soils (Phaeozem, Cambisols and Acrisol) under maize planting and bare fallow regimes located in cold temperate, warm temperate and subtropical regions, respectively. The core genes were identified using high-throughput functional gene microarray (GeoChip 3.0), and functional molecular ecological networks (fMENs) were subsequently developed with the random matrix theory (RMT)-based conceptual framework. Our results demonstrated that planting significantly (P < 0.05) increased the gene alpha-diversity in terms of richness and Shannon – Simpson’s indexes for all three types of soils and 83.5% of microbial alpha-diversity can be explained by the plant factor. Moreover, planting had significant impacts on the microbial community structure and the network interactions of the microbial communities. The calculated network complexity was higher under maize planting than under bare fallow regimes. The increase of the functional genes led to an increase in both soil respiration and nitrification potential with maize planting, indicating that changes in the soil microbial communities and network interactions influenced ecological functioning. PMID:26396042

Automated Leaf Tracking using Multi-view Image Sequences of Maize Plants for Leaf-growth Monitoring

NASA Astrophysics Data System (ADS)

Das Choudhury, S.; Awada, T.; Samal, A.; Stoerger, V.; Bashyam, S.

2017-12-01

Extraction of phenotypes with botanical importance by analyzing plant image sequences has the desirable advantages of non-destructive temporal phenotypic measurements of a large number of plants with little or no manual intervention in a relatively short period of time. The health of a plant is best interpreted by the emergence timing and temporal growth of individual leaves. For automated leaf growth monitoring, it is essential to track each leaf throughout the life cycle of the plant. Plants are constantly changing organisms with increasing complexity in architecture due to variations in self-occlusions and phyllotaxy, i.e., arrangements of leaves around the stem. The leaf cross-overs pose challenges to accurately track each leaf using single view image sequence. Thus, we introduce a novel automated leaf tracking algorithm using a graph theoretic approach by multi-view image sequence analysis based on the determination of leaf-tips and leaf-junctions in the 3D space. The basis of the leaf tracking algorithm is: the leaves emerge using bottom-up approach in the case of a maize plant, and the direction of leaf emergence strictly alternates in terms of direction. The algorithm involves labeling of the individual parts of a plant, i.e., leaves and stem, following graphical representation of the plant skeleton, i.e., one-pixel wide connected line obtained from the binary image. The length of the leaf is measured by the number of pixels in the leaf skeleton. To evaluate the performance of the algorithm, a benchmark dataset is indispensable. Thus, we publicly release University of Nebraska-Lincoln Component Plant Phenotyping dataset-2 (UNL-CPPD-2) consisting of images of the 20 maize plants captured by visible light camera of the Lemnatec Scanalyzer 3D high throughout plant phenotyping facility once daily for 60 days from 10 different views. The dataset is aimed to facilitate the development and evaluation of leaf tracking algorithms and their uniform comparisons.

Lipid partitioning in maize (Zea mays L.) endosperm highlights relationships among starch lipids, amylose, and vitreousness.

PubMed

Gayral, Mathieu; Bakan, Bénédicte; Dalgalarrondo, Michele; Elmorjani, Khalil; Delluc, Caroline; Brunet, Sylvie; Linossier, Laurent; Morel, Marie-Hélène; Marion, Didier

2015-04-08

Content and composition of maize endosperm lipids and their partition in the floury and vitreous regions were determined for a set of inbred lines. Neutral lipids, i.e., triglycerides and free fatty acids, accounted for more than 80% of endosperm lipids and are almost 2 times higher in the floury than in the vitreous regions. The composition of endosperm lipids, including their fatty acid unsaturation levels, as well as their distribution may be related to metabolic specificities of the floury and vitreous regions in carbon and nitrogen storage and to the management of stress responses during endosperm cell development. Remarkably, the highest contents of starch lipids were observed systematically within the vitreous endosperm. These high amounts of starch lipids were mainly due to lysophosphatidylcholine and were tightly linked to the highest amylose content. Consequently, the formation of amylose-lysophosphatidylcholine complexes has to be considered as an outstanding mechanism affecting endosperm vitreousness.

Genetic and Quantitative Trait Locus Analysis for Bio-Oil Compounds after Fast Pyrolysis in Maize Cobs.

PubMed

Jeffrey, Brandon; Kuzhiyil, Najeeb; de Leon, Natalia; Lübberstedt, Thomas

2016-01-01

Fast pyrolysis has been identified as one of the biorenewable conversion platforms that could be a part of an alternative energy future, but it has not yet received the same attention as cellulosic ethanol in the analysis of genetic inheritance within potential feedstocks such as maize. Ten bio-oil compounds were measured via pyrolysis/gas chromatography-mass spectrometry (Py/GC-MS) in maize cobs. 184 recombinant inbred lines (RILs) of the intermated B73 x Mo17 (IBM) Syn4 population were analyzed in two environments, using 1339 markers, for quantitative trait locus (QTL) mapping. QTL mapping was performed using composite interval mapping with significance thresholds established by 1000 permutations at α = 0.05. 50 QTL were found in total across those ten traits with R2 values ranging from 1.7 to 5.8%, indicating a complex quantitative inheritance of these traits.

The B73 maize genome: complexity, diversity, and dynamics.

PubMed

Schnable, Patrick S; Ware, Doreen; Fulton, Robert S; Stein, Joshua C; Wei, Fusheng; Pasternak, Shiran; Liang, Chengzhi; Zhang, Jianwei; Fulton, Lucinda; Graves, Tina A; Minx, Patrick; Reily, Amy Denise; Courtney, Laura; Kruchowski, Scott S; Tomlinson, Chad; Strong, Cindy; Delehaunty, Kim; Fronick, Catrina; Courtney, Bill; Rock, Susan M; Belter, Eddie; Du, Feiyu; Kim, Kyung; Abbott, Rachel M; Cotton, Marc; Levy, Andy; Marchetto, Pamela; Ochoa, Kerri; Jackson, Stephanie M; Gillam, Barbara; Chen, Weizu; Yan, Le; Higginbotham, Jamey; Cardenas, Marco; Waligorski, Jason; Applebaum, Elizabeth; Phelps, Lindsey; Falcone, Jason; Kanchi, Krishna; Thane, Thynn; Scimone, Adam; Thane, Nay; Henke, Jessica; Wang, Tom; Ruppert, Jessica; Shah, Neha; Rotter, Kelsi; Hodges, Jennifer; Ingenthron, Elizabeth; Cordes, Matt; Kohlberg, Sara; Sgro, Jennifer; Delgado, Brandon; Mead, Kelly; Chinwalla, Asif; Leonard, Shawn; Crouse, Kevin; Collura, Kristi; Kudrna, Dave; Currie, Jennifer; He, Ruifeng; Angelova, Angelina; Rajasekar, Shanmugam; Mueller, Teri; Lomeli, Rene; Scara, Gabriel; Ko, Ara; Delaney, Krista; Wissotski, Marina; Lopez, Georgina; Campos, David; Braidotti, Michele; Ashley, Elizabeth; Golser, Wolfgang; Kim, HyeRan; Lee, Seunghee; Lin, Jinke; Dujmic, Zeljko; Kim, Woojin; Talag, Jayson; Zuccolo, Andrea; Fan, Chuanzhu; Sebastian, Aswathy; Kramer, Melissa; Spiegel, Lori; Nascimento, Lidia; Zutavern, Theresa; Miller, Beth; Ambroise, Claude; Muller, Stephanie; Spooner, Will; Narechania, Apurva; Ren, Liya; Wei, Sharon; Kumari, Sunita; Faga, Ben; Levy, Michael J; McMahan, Linda; Van Buren, Peter; Vaughn, Matthew W; Ying, Kai; Yeh, Cheng-Ting; Emrich, Scott J; Jia, Yi; Kalyanaraman, Ananth; Hsia, An-Ping; Barbazuk, W Brad; Baucom, Regina S; Brutnell, Thomas P; Carpita, Nicholas C; Chaparro, Cristian; Chia, Jer-Ming; Deragon, Jean-Marc; Estill, James C; Fu, Yan; Jeddeloh, Jeffrey A; Han, Yujun; Lee, Hyeran; Li, Pinghua; Lisch, Damon R; Liu, Sanzhen; Liu, Zhijie; Nagel, Dawn Holligan; McCann, Maureen C; SanMiguel, Phillip; Myers, Alan M; Nettleton, Dan; Nguyen, John; Penning, Bryan W; Ponnala, Lalit; Schneider, Kevin L; Schwartz, David C; Sharma, Anupma; Soderlund, Carol; Springer, Nathan M; Sun, Qi; Wang, Hao; Waterman, Michael; Westerman, Richard; Wolfgruber, Thomas K; Yang, Lixing; Yu, Yeisoo; Zhang, Lifang; Zhou, Shiguo; Zhu, Qihui; Bennetzen, Jeffrey L; Dawe, R Kelly; Jiang, Jiming; Jiang, Ning; Presting, Gernot G; Wessler, Susan R; Aluru, Srinivas; Martienssen, Robert A; Clifton, Sandra W; McCombie, W Richard; Wing, Rod A; Wilson, Richard K

2009-11-20

We report an improved draft nucleotide sequence of the 2.3-gigabase genome of maize, an important crop plant and model for biological research. Over 32,000 genes were predicted, of which 99.8% were placed on reference chromosomes. Nearly 85% of the genome is composed of hundreds of families of transposable elements, dispersed nonuniformly across the genome. These were responsible for the capture and amplification of numerous gene fragments and affect the composition, sizes, and positions of centromeres. We also report on the correlation of methylation-poor regions with Mu transposon insertions and recombination, and copy number variants with insertions and/or deletions, as well as how uneven gene losses between duplicated regions were involved in returning an ancient allotetraploid to a genetically diploid state. These analyses inform and set the stage for further investigations to improve our understanding of the domestication and agricultural improvements of maize.

Setting Up Decision-Making Tools toward a Quality-Oriented Participatory Maize Breeding Program

PubMed Central

Alves, Mara L.; Brites, Cláudia; Paulo, Manuel; Carbas, Bruna; Belo, Maria; Mendes-Moreira, Pedro M. R.; Brites, Carla; Bronze, Maria do Rosário; Gunjača, Jerko; Šatović, Zlatko; Vaz Patto, Maria C.

2017-01-01

Previous studies have reported promising differences in the quality of kernels from farmers' maize populations collected in a Portuguese region known to produce maize-based bread. However, several limitations have been identified in the previous characterizations of those populations, such as a limited set of quality traits accessed and a missing accurate agronomic performance evaluation. The objectives of this study were to perform a more detailed quality characterization of Portuguese farmers' maize populations; to estimate their agronomic performance in a broader range of environments; and to integrate quality, agronomic, and molecular data in the setting up of decision-making tools for the establishment of a quality-oriented participatory maize breeding program. Sixteen farmers' maize populations, together with 10 other maize populations chosen for comparison purposes, were multiplied in a common-garden experiment for quality evaluation. Flour obtained from each population was used to study kernel composition (protein, fat, fiber), flour's pasting behavior, and bioactive compound levels (carotenoids, tocopherols, phenolic compounds). These maize populations were evaluated for grain yield and ear weight in nine locations across Portugal; the populations' adaptability and stability were evaluated using additive main effects and multiplication interaction (AMMI) model analysis. The phenotypic characterization of each population was complemented with a molecular characterization, in which 30 individuals per population were genotyped with 20 microsatellites. Almost all farmers' populations were clustered into the same quality-group characterized by high levels of protein and fiber, low levels of carotenoids, volatile aldehydes, α- and δ-tocopherols, and breakdown viscosity. Within this quality-group, variability on particular quality traits (color and some bioactive compounds) could still be found. Regarding the agronomic performance, farmers' maize populations had low, but considerably stable, grain yields across the tested environments. As for their genetic diversity, each farmers' population was genetically heterogeneous; nonetheless, all farmers' populations were distinct from each other's. In conclusion, and taking into consideration different quality improvement objectives, the integration of the data generated within this study allowed the outline and exploration of alternative directions for future breeding activities. As a consequence, more informed choices will optimize the use of the resources available and improve the efficiency of participatory breeding activities. PMID:29312428

LANDSCAPE CHANGES IN A LOWLAND IN BENIN: ECOLOGICAL IMPACT ON PESTS AND NATURAL ENEMIES.

PubMed

Boucher, A; Silvie, P; Menozzi, P; Adda, C; Auzoux, S; Jean, J; Huat, J

2015-01-01

Habitat management involving conservative biological control could be a good crop pest management option in poor African countries. A survey was conducted from August 2013 to July 2014 in a rainfed lowland region near Pélébina, northern Benin, in order to characterize spatiotemporal landscape changes and investigate their influence on the main crop pests and their associated natural enemies. The area was mapped mainly regarding crop fields and fallows. Visual observations were recorded and a database was compiled. Major landscape composition changes were noted between rainy and dry seasons, which affected the presence of both pests and natural enemies. Cereals (rice, maize and sorghum) and cotton were grown in the humid season, and then okra (Abelmoschus esculentus) was the dominant vegetable crop in dry season. These modifications impacted fallow abundance throughout the lowland. Different cotton (e.g. Helicoverpa armigera, Dysdercus sp., Zonocerus variegatus) or rice (e.g. Diopsis longicornis, D. apicalis) pests were observed during dry season in okra crops. Dry season surveys of Poaceae in two types of fallows ('humid', 'dry') revealed the presence of very few stem borers: only 0.04% of stems sampled were infested by stem borers, with a mean of 1.13 larvae per stem. Known cereal stem borer species such as Busseola fusco, Coniesta ignefusalis, Sesamia calamistis were not clearly identified among these larvae because of their diapausing stage and white color. Unexpected pollinators (Hymenoptera Apidae, genus Braunsapis, Ceratina and Xylocopa) and predators (Crabronidae, genus Dasyproctus) were found in the stems. Sweep-net collection of insects in humid fallows allowed us to describe for the first time in Benin seven Diopsidae species (23% of adults bearing Laboulbeniomycetes ectoparasitic fungi). Some of these species were captured in rice fields during rainy season. Parasitoids (adult Chalcidoidae and Ichneumonoidae) were observed during both seasons but their impact on stem borers was hard to determine, even during the rainy season, due to their low abundance and the difficulty of identification. Predators (Reduviidae, Odonata) were found mainly in humid fallows and rice fields. Regarding our observations, we suggest the presence of alternate host crops such as okra during the dry season for rainy season crop pests. Moreover, fallows also had a real ecological role as a habitat resource for many guilds of insects (pollinators, pests, predators). The management of these landscape components should be the focus of a long-term study with the aim of enhancing pest management of rainy season crop pests.

Cry1Ab toxin production of MON 810 transgenic maize.

PubMed

Székács, András; Lauber, Eva; Juracsek, Judit; Darvas, Béla

2010-01-01

Levels of Cry1Ab toxin were detected in genetically modified maize of genetic event MON 810 against near isogenic maize as negative control by two commercial immunoassays. The immunoassays were characterized for their cross-reactivity (CR) between Cry1Ab protoxin and activated toxin, and were compared with each other for toxin detection in a reference plant sample. Cry1Ab toxin levels, corrected for active toxin content using the CR values obtained, were monitored in maize DK-440 BTY through the entire vegetation period. The toxin concentration was found to show a rapid rise in the leaves to 17.15 +/- 1.66 microg/g by the end of the fifth week of cultivation, followed by a gradual decline to 9.61 +/- 2.07 microg/g by the 16th week and a slight increase again to 13.51 +/- 1.96 microg/g during the last 2 weeks due to partial desiccation. Similar but lesser fluctuation of toxin levels was seen in the roots between 5.32 +/- 0.49 microg/g at the less differentiated V1 stage and 2.25 +/- 0.30 microg/g during plant development. In contrast, Cry1Ab toxin levels appeared to be stably 1.36 +/- 0.45, 4.98 +/- 0.31, 0.47 +/- 0.03, and 0.83 +/- 0.15 microg/g in the stem, anther wall, pollen, and grain, respectively. Toxin concentrations produced at the VT-R4 phenological stages under actual cultivation conditions were compared with each other in three different years within an 8-year period.

No tillage combined with crop rotation improves soil microbial community composition and metabolic activity.

PubMed

Sun, Bingjie; Jia, Shuxia; Zhang, Shixiu; McLaughlin, Neil B; Liang, Aizhen; Chen, Xuewen; Liu, Siyi; Zhang, Xiaoping

2016-04-01

Soil microbial community can vary with different agricultural managements, which in turn can affect soil quality. The objective of this work was to evaluate the effects of long-term tillage practice (no tillage (NT) and conventional tillage (CT)) and crop rotation (maize-soybean (MS) rotation and monoculture maize (MM)) on soil microbial community composition and metabolic capacity in different soil layers. Long-term NT increased the soil organic carbon (SOC) and total nitrogen (TN) mainly at the 0-5 cm depth which was accompanied with a greater microbial abundance. The greater fungi-to-bacteria (F/B) ratio was found in NTMS at the 0-5 cm depth. Both tillage and crop rotation had a significant effect on the metabolic activity, with the greatest average well color development (AWCD) value in NTMS soil at all three soil depths. Redundancy analysis (RDA) showed that the shift in microbial community composition was accompanied with the changes in capacity of utilizing different carbon substrates. Therefore, no tillage combined with crop rotation could improve soil biological quality and make agricultural systems more sustainable.

Opportunistic Market-Driven Regional Shifts of Cropping Practices Reduce Food Production Capacity of China

NASA Astrophysics Data System (ADS)

Yuan, Wenping; Liu, Shuguang; Liu, Wei; Zhao, Shuqing; Dong, Wenjie; Tao, Fulu; Chen, Min; Lin, Hui

2018-04-01

China is facing the challenge of feeding a growing population with the declining cropland and increasing shortage of water resources under the changing climate. This study identified that the opportunistic profit-driven shifts of planting areas and crop species composition have strongly reduced the food production capacity of China. First, the regional cultivation patterns of major crops in China have substantially shifted during the past five decades. Southeast and South China, the regions with abundant water resources and fewer natural disasters, have lost large planting areas of cropland in order to pursue industry and commerce. Meanwhile, Northeast and Northwest China, the regions with low water resources and frequent natural disasters, have witnessed increases in planting areas. These macroshifts have reduced the national food production by 1.02% per year. The lost grain production would have been enough to feed 13 million people. Second, the spatial shifts have been accompanied by major changes in crop species composition, with substantial increases in planting area and production of maize, due to its low water consumption and high economic returns. Consequently, the stockpile of maize in China has accounted for more than half of global stockpile, and the stock to use ratio of maize in China has exceeded the reliable level. Market-driven regional shifts of cropping practices have resulted in larger irrigation requirements and aggravated environmental stresses. Our results highlighted the need for Chinese food policies to consider the spatial shifts in cultivation, and the planting crop compositions limited by regional water resources and climate change.

Insight into the effects of different cropping systems on soil bacterial community and tobacco bacterial wilt rate.

PubMed

Niu, Jiaojiao; Chao, Jin; Xiao, Yunhua; Chen, Wu; Zhang, Chao; Liu, Xueduan; Rang, Zhongwen; Yin, Huaqun; Dai, Linjian

2017-01-01

Rotation is an effective strategy to control crop disease and improve plant health. However, the effects of crop rotation on soil bacterial community composition and structure, and crop health remain unclear. In this study, using 16S rRNA gene sequencing, we explored the soil bacterial communities under four different cropping systems, continuous tobacco cropping (control group), tobacco-maize rotation, tobacco-lily rotation, and tobacco-turnip rotation. Results of detrended correspondence analysis and dissimilarity tests showed that soil bacterial community composition and structure changed significantly among the four groups, such that Acidobacteria and Actinobacteria were more abundant in the maize rotation group (16.6 and 11.5%, respectively) than in the control (8.5 and 7.1%, respectively). Compared with the control group (57.78%), maize and lily were effective rotation crops in controlling tobacco bacterial wilt (about 23.54 and 48.67%). On the other hand, tobacco bacterial wilt rate was increased in the turnip rotation (59.62%) relative to the control. Further study revealed that the abundances of several bacterial populations were directly correlated with tobacco bacterial wilt. For example, Acidobacteria and Actinobacteria were significantly negatively correlated to the tobacco bacterial wilt rate, so they may be probiotic bacteria. Canonical correspondence analysis showed that soil pH and calcium content were key factors in determining soil bacterial communities. In conclusion, our study revealed the composition and structure of bacterial communities under four different cropping systems and may unveil molecular mechanisms for the interactions between soil microorganisms and crop health. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Arbuscular mycorrhizal fungal diversity, root colonization, and soil alkaline phosphatase activity in response to maize-wheat rotation and no-tillage in North China.

PubMed

Hu, Junli; Yang, Anna; Zhu, Anning; Wang, Junhua; Dai, Jue; Wong, Ming Hung; Lin, Xiangui

2015-07-01

Monitoring the effects of no-tillage (NT) in comparison with conventional tillage (CT) on soil microbes could improve our understanding of soil biochemical processes and thus help us to develop sound management strategies. The objective of this study was to compare the species composition and ecological function of soil arbuscular mycorrhizal (AM) fungi during the growth and rotation of crops under NT and CT. From late June 2009 to early June 2010, 32 topsoil (0-15 cm) samples from four individual plots per treatment (CT and NT) were collected at both the jointing and maturation stages of maize (Zea mays L.) and wheat (Triticum aestivum L.) from a long-term experimental field that was established in an Aquic Inceptisol in North China in June 2006. The AM fungal spores were isolated and identified and then used to calculate species diversity indices, including the Shannon- Wiener index (H'), Evenness (E), and Simpson's index (D). The root mycorrhizal colonization and soil alkaline phosphatase activity were also determined. A total of 34 species of AM fungi within nine genera were recorded. Compared with NT, CT negatively affected the soil AM fungal community at the maize sowing stage, leading to decreases in the average diversity indices (from 2.12, 0.79, and 0.82 to 1.79, 0.72, and 0.74 for H', E, and D, respectively), root mycorrhizal colonization (from 28% to 20%), soil alkaline phosphatase activity (from 0.24 to 0.19 mg/g/24 h) and available phosphorus concentration (from 17.4 to 10.5 mg/kg) at the maize jointing stage. However, reductions in diversity indices of H', E, and D were restored to 2.20, 0.81, and 0.84, respectively, at the maize maturation stage. CT should affect the community again at the wheat sowing stage; however, a similar restoration in the species diversity of AM fungi was completed before the wheat jointing stage, and the highest Jaccard index (0.800) for similarity in the species composition of soil AM fungi between CT and NT was recorded at the wheat maturation stage. Our results also demonstrated that NT resulted in the positive protection of the community structure of AM fungi and played an important role in maintaining their functionality especially for maize seedlings.

Dynamics of shearing force and its correlations with chemical compositions and in vitro dry matter digestibility of stylo (Stylosanthes guianensis) stem.

PubMed

Zi, Xuejuan; Li, Mao; Zhou, Hanlin; Tang, Jun; Cai, Yimin

2017-12-01

The study explored the dynamics of shearing force and its correlation with chemical compositions and in vitro dry matter digestibility (IVDMD) of stylo. The shearing force, diameter, linear density, chemical composition, and IVDMD of different height stylo stem were investigated. Linear regression analysis was done to determine the relationships between the shearing force and cut height, diameter, chemical composition, or IVDMD. The results showed that shearing force of stylo stem increased with plant height increasing and the crude protein (CP) content and IVDMD decreased but fiber content increased over time, resulting in decreased forage value. In addition, tall stem had greater shearing force than short stem. Moreover, shearing force is positively correlated with stem diameter, linear density and fiber fraction, but negatively correlated with CP content and IVDMD. Overall, shearing force is an indicator more direct, easier and faster to measure than chemical composition and digestibility for evaluation of forage nutritive value related to animal performance. Therefore, it can be used to evaluate the nutritive value of stylo.

Effect of lime and wood ash on the nixtamalization of maize and tortilla chemical and nutritional characteristics.

PubMed

Pappa, María Renée; de Palomo, Patricia Palacios; Bressani, Ricardo

2010-06-01

The objective of the study was to obtain information on the chemical composition, functional properties, sensory quality and protein value of tortillas made from the nixtamalization of maize using either lime or wood ashes. The Ca, K, Mg, Fe, and Zn content of lime and wood ashes showed lime to be high in Ca content while wood ash contained more K and about 71% of the Ca content of lime. Both contained relatively high levels of Mg, Fe and Zn, but more so in the wood ashes. The level of reagent for nixtamalization was set at 0.8% of the maize weight. All other processing conditions were kept constant. The pH of the cooking solution was 12.0 for lime and 10.9 for wood ash. The moisture content of maize at 60 min of cooking was 45.8% for both treatments, however after 12 h of soaking, moisture level was 51.0% for the lime treatment and only 46.8% for the ash treatment. Solids (2.4%) in the lime cooking liquor were higher than in the wood ash liquor (1.0%). Chemical composition changes were similar between treatments in masa and tortilla; however, both masa and tortillas absorbed relatively high levels of all minerals including Fe and Zn from the wood ash treatment. The different treatment influenced functional properties particularly hardness and color. Tortilla characteristics were also similar. Protein quality of both alkali cooked products was lower than that of raw corn, more so the product from the wood ash treatment. Although some differences were observed in the sensory studies, human subjects did not dislike the wood ash made tortillas.

Dietary polyunsaturated fatty acids and adaptation to chronic hypoxia alter acyl composition of serum and heart lipids.

PubMed

Balková, Patricie; Jezková, Jana; Hlavácková, Markéta; Neckár, Jan; Stanková, Barbora; Kolár, Frantisek; Novák, Frantisek; Nováková, Olga

2009-11-01

The effects of dietary supplementation with fat of different fatty acid profile and chronic intermittent hypoxia (CIH) on the fatty acid composition of serum and heart lipids were analysed. Adult male Wistar rats were fed a standard non-fat diet enriched with 10 % of lard, fish oil (n-3 PUFA) or maize oil (n-6 PUFA) for 10 weeks. After 4 weeks on the diets, each group was divided in two subgroups, either exposed to CIH in a barochamber (7000 m, twenty-five exposures) or kept at normoxia. In normoxic rats, the fish oil diet increased the level of conjugated dienes. The n-6:n-3 PUFA ratio in serum TAG, phospholipids (PL), cholesteryl esters (CE) and heart TAG, PL and diacylglycerols (DAG) followed the ratio in the fed diet (in the sequence maize oil>lard>fish oil). In heart TAG, PL and DAG, 20 : 4n-6 and 18 : 2n-6 were replaced by 22 : 6n-3 in the fish oil group. The main fatty acid in CE was 20 : 4n-6 in the lard and maize oil groups whereas in the fish oil group, half of 20 : 4n-6 was replaced by 20 : 5n-3. CIH further increased 20 : 5n-3 in CE in the fish oil group. CIH decreased the n-6:n-3 PUFA ratio in serum CE, heart TAG, PL and DAG in all dietary groups and stimulated the activity of catalase in the maize and fish oil groups. In conclusion, PUFA diets and CIH, both interventions considered to be cardioprotective, distinctly modified the fatty acid profile in serum and heart lipids with specific effects on conjugated diene production and catalase activity.

Isolation and characterization of N2 -fixing bacteria from giant reed and switchgrass for plant growth promotion and nutrient uptake.

PubMed

Xu, Jia; Kloepper, Joseph W; Huang, Ping; McInroy, John A; Hu, Chia H

2018-05-01

The aims of this study were to isolate and characterize N 2 -fixing bacteria from giant reed and switchgrass and evaluate their plant growth promotion and nutrient uptake potential for use as biofertilizers. A total of 190 bacteria were obtained from rhizosphere soil and inside stems and roots of giant reed and switchgrass. All the isolates were confirmed to have nitrogenase activity, 96.9% produced auxin, and 85% produced siderophores. Then the top six strains, including Sphingomonas trueperi NNA-14, Sphingomonas trueperi NNA-19, Sphingomonas trueperi NNA-17, Sphingomonas trueperi NNA-20, Psychrobacillus psychrodurans NP-3, and Enterobacter oryzae NXU-38, based on nitrogenase activity, were inoculated on maize and wheat seeds in greenhouse tests to assess their potential benefits to plants. All the selected strains promoted plant growth by increasing at least one plant growth parameter or increasing the nutrient concentration of maize or wheat plants. NNA-14 outperformed others in promoting early growth and nutrient uptake by maize. Specifically, NNA-14 significantly increased root length, surface area, and fine roots of maize by 14%, 12%, and 17%, respectively, and enhanced N, Ca, S, B, Cu, and Zn in maize. NNA-19 and NXU-38 outperformed others in promoting both early growth and nutrient uptake by wheat. Specifically, NNA-19 significantly increased root dry weight and number of root tips of wheat by 25% and 96%, respectively, and enhanced Ca in wheat. NXU-38 significantly increased root length, surface area, and fine roots of wheat by 21%, 13%, and 26%, respectively, and enhanced levels of Ca and Mg in wheat. It is concluded that switchgrass and giant reed are colonized by N 2 -fixing bacteria that have the potential to contribute to plant growth and nutrient uptake by agricultural crops. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Partitioning evapotranspiration via continuous sampling of water vapor isotopes over common row crops and candidate biofuel crops.

NASA Astrophysics Data System (ADS)

Miller, J. N.; Black, C. K.; Bernacchi, C.

2014-12-01

Global demand for renewable energy is accelerating land conversion from common row crops such as maize and soybean to cellulosic biofuel crops such as miscanthus and switchgrass. This land conversion is expected to alter ecohydrology via changes in evapotranspiration (ET). However, the direction in which evapotranspiration will shift, either partitioning more moisture through soil evaporation (E) or through plant transpiration (T) is uncertain. To investigate how land conversion from maize to miscanthus affects ET partitioning we measured the isotopic composition of water vapor via continuous air sampling. We obtained continuous diurnal measurements of δ2H and δ18O for miscanthus and maize on multiple days over the course of the growing season. Water vapor isotopes drawn from two heights were measured at 2 Hz using a cavity ringdown spectrometer and partitioned into components of E and T using a simple mixing equation. A second approach to partitioning was accomplished by subtracting transpiration measurements, obtained through sap flow sensors, from total ET, measured via eddy covariance. Preliminary results reveal that both methods compare favorably and that transpiration dominates variations in ET in miscanthus fields more so than in fields of maize.

Different substrates and starter inocula govern microbial community structures in biogas reactors.

PubMed

Satpathy, Preseela; Steinigeweg, Sven; Cypionka, Heribert; Engelen, Bert

2016-01-01

The influence of different starter inocula on the microbial communities in biogas batch reactors fed with fresh maize and maize silage as substrates was investigated. Molecular biological analysis by Denaturing Gradient Gel Electrophoresis (DGGE) of 16S rRNA gene fragments showed that each inoculum bore specific microbial communities with varying predominant phylotypes. Both, bacterial and archaeal DGGE profiles displayed three distinct communities that developed depending on the type of inoculum. Although maize and silage are similar substrates, different communities dominated the lactate-rich silage compared to lactate-free fresh maize. Cluster analysis of DGGE gels showed the communities of the same substrates to be stable with their respective inoculum. Bacteria-specific DGGE analysis revealed a rich diversity with Firmicutes being predominant. The other abundant phylotypes were Bacteroidetes and Synergistetes. Archaea-specific DGGE analysis displayed less diverse community structures, identifying members of the Methanosarcinales as the dominant methanogens present in all the three biogas digesters. In general, the source of inoculum played a significant role in shaping microbial communities. Adaptability of the inoculum to the substrates fed also influenced community compositions which further impacted the rates of biogas production.

Effect of electric arc furnace slag on growth and physiology of maize (Zea mays L.).

PubMed

Radić, Sandra; Crnojević, Helena; Sandev, Dubravka; Jelić, Sonja; Sedlar, Zorana; Glavaš, Katarina; Pevalek-Kozlina, Branka

2013-12-01

Basic slag, used in this study as a potential source of certain nutrients, is a byproduct of the production of steel in electric arc furnace (EAF). A pot experiment with two nutrient-poor substrates was conducted to investigate to compare the effect of EAF steel slag and fertilizers NPK + F e on growth and availability of specific nutrients to maize. Mineral content of both substrate and plant leaves, growth, chlorophyll fluorescence and photosynthetic pigments were measured following six weeks of cultivation. As steel slag also contains trace amounts of heavy metals, certain oxidative parameters (antioxidative enzyme activities and lipid peroxidation) were evaluated as well. The steel slag improved soil mineral composition, increased above ground maize biomass by providing Fe, Mn, Mg, K and partly P and improved photosynthetic parameters. The potential phytotoxicity of EAF slag containing substrates was not determined as evaluated by MDA (malondialdehyde), GR (glutathione reductase) and APX (ascorbate peroxidase) levels. The obtained results show that EAF steel slag is comparable to NPK + F e in supplying nutrients for maize growth, indicating the potential of EAF steel slag as an inexpensive and non-phytotoxic nutrient supplier especially in poor soils.

Metabolic engineering of astaxanthin biosynthesis in maize endosperm and characterization of a prototype high oil hybrid.

PubMed

Farré, Gemma; Perez-Fons, Laura; Decourcelle, Mathilde; Breitenbach, Jürgen; Hem, Sonia; Zhu, Changfu; Capell, Teresa; Christou, Paul; Fraser, Paul D; Sandmann, Gerhard

2016-08-01

Maize was genetically engineered for the biosynthesis of the high value carotenoid astaxanthin in the kernel endosperm. Introduction of a β-carotene hydroxylase and a β-carotene ketolase into a white maize genetic background extended the carotenoid pathway to astaxanthin. Simultaneously, phytoene synthase, the controlling enzyme of carotenogenesis, was over-expressed for enhanced carotenoid production and lycopene ε-cyclase was knocked-down to direct more precursors into the β-branch of the extended ketocarotenoid pathway which ends with astaxanthin. This astaxanthin-accumulating transgenic line was crossed into a high oil- maize genotype in order to increase the storage capacity for lipophilic astaxanthin. The high oil astaxanthin hybrid was compared to its astaxanthin producing parent. We report an in depth metabolomic and proteomic analysis which revealed major up- or down- regulation of genes involved in primary metabolism. Specifically, amino acid biosynthesis and the citric acid cycle which compete with the synthesis or utilization of pyruvate and glyceraldehyde 3-phosphate, the precursors for carotenogenesis, were down-regulated. Nevertheless, principal component analysis demonstrated that this compositional change is within the range of the two wild type parents used to generate the high oil producing astaxanthin hybrid.

Mesenchymal Stem Cell Therapy for Nerve Regeneration and Immunomodulation after Composite Tissue Allotransplantation

DTIC Science & Technology

2012-02-01

10-1-0927 TITLE: Mesenchymal Stem Cell Therapy for Nerve Regeneration and Immunomodulation after Composite Tissue Allotransplantation...immunosuppression. Bone Marrow Derived Mesenchymal stem cells (BM-MSCs) are pluripotent cells, capable of differentiation along multiple mesenchymal lineages into...As part of implemented transition from University of Pittsburgh to Johns Hopkins University, we optimized our mesenchymal stem cell (MSC) isolation

Physiological responses of spring rapeseed (Brassica napus) to red/far-red ratios and irradiance during pre- and post-flowering stages.

PubMed

Rondanini, Deborah P; del Pilar Vilariño, Maria; Roberts, Marcos E; Polosa, Marina A; Botto, Javier F

2014-12-01

Early shade signals promote the shade avoidance syndrome (SAS) which causes, among others, petiole and shoot elongation and upward leaf position. In spite of its relevance, these photomorphogenic responses have not been deeply studied in rapeseed (Brassica napus). In contrast to other crops like maize and wheat, rapeseed has a complex developmental phenotypic pattern as it evolves from an initial rosette to the main stem elongation and an indeterminate growth of floral raceme. In this work, we analyzed (1) morphological and physiological responses at individual level due to low red/far-red (R/FR) ratio during plant development, and (2) changes in biomass allocation, grain yield and composition at crop level in response to high R/FR ratio and low irradiance in two modern spring rapeseed genotypes. We carried out pot and field experiments modifying R/FR ratios and irradiance at vegetative or reproductive stages. In pot experiments, low R/FR ratio increased the petiole and lamina length, upward leaf position and also accelerated leaf senescence. Furthermore, low R/FR ratio reduced main floral raceme and increased floral branching with higher remobilization of soluble carbohydrates from the stems. In field experiments, low irradiance during post-flowering reduced grain yield, harvest index and grain oil content, and high R/FR ratio reaching the crop partially alleviated such effects. We conclude that photomorphogenic signals are integrated early during the vegetative growth, and irradiance has stronger effects than R/FR signals at rapeseed crop level. © 2014 Scandinavian Plant Physiology Society.

A robust and efficient method for the extraction of plant extracellular surface lipids as applied to the analysis of silks and seedling leaves of maize

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loneman, Derek M.; Peddicord, Layton; Al-Rashid, Amani

Aerial plant organs possess a diverse array of extracellular surface lipids, including both non-polar and amphipathic constituents that collectively provide a primary line of defense against environmental stressors. Extracellular surface lipids on the stigmatic silks of maize are composed primarily of saturated and unsaturated linear hydrocarbons, as well as fatty acids, and aldehydes. To efficiently extract lipids of differing polarities from maize silks, five solvent systems (hexanes; hexanes:diethyl ether (95:5); hexanes:diethyl ether (90:10); chloroform:hexanes (1:1) and chloroform) were tested by immersing fresh silks in solvent for different extraction times. Surface lipid recovery and the relative composition of individual constituents weremore » impacted to varying degrees depending on solvent choice and duration of extraction. Analyses were performed using both silks and leaves to demonstrate the utility of the solvent- and time-optimized protocol in comparison to extraction with the commonly used chloroform solvent. Overall, the preferred solvent system was identified as hexanes:diethyl ether (90:10), based on its effectiveness in extracting surface hydrocarbons and fatty acids as well as its reduced propensity to extract presumed internal fatty acids. Metabolite profiling of wildtype and glossy1 seedlings, which are impaired in surface lipid biosynthesis, demonstrated the ability of the preferred solvent to extract extracellular surface lipids rich in amphipathic compounds (aldehydes and alcohols). In addition to the expected deficiencies in dotriacontanal and dotriacontan-1-ol for gl1 seedlings, an unexpected increase in fatty acid recovery was observed in gl1 seedlings extracted in chloroform, suggesting that chloro-form extracts lipids from internal tissues of gl1 seedlings. This highlights the importance of extraction method when evaluating mutants that have altered cuticular lipid compositions. Lastly, metabolite profiling of silks from maize inbreds B73 and Mo17, exposed to different environments and harvested at different ages, revealed differences in hydrocarbon and fatty acid composition, demonstrating the dynamic nature of surface lipid accumulation on silks.« less

A robust and efficient method for the extraction of plant extracellular surface lipids as applied to the analysis of silks and seedling leaves of maize

DOE PAGES

Loneman, Derek M.; Peddicord, Layton; Al-Rashid, Amani; ...

2017-07-11

Aerial plant organs possess a diverse array of extracellular surface lipids, including both non-polar and amphipathic constituents that collectively provide a primary line of defense against environmental stressors. Extracellular surface lipids on the stigmatic silks of maize are composed primarily of saturated and unsaturated linear hydrocarbons, as well as fatty acids, and aldehydes. To efficiently extract lipids of differing polarities from maize silks, five solvent systems (hexanes; hexanes:diethyl ether (95:5); hexanes:diethyl ether (90:10); chloroform:hexanes (1:1) and chloroform) were tested by immersing fresh silks in solvent for different extraction times. Surface lipid recovery and the relative composition of individual constituents weremore » impacted to varying degrees depending on solvent choice and duration of extraction. Analyses were performed using both silks and leaves to demonstrate the utility of the solvent- and time-optimized protocol in comparison to extraction with the commonly used chloroform solvent. Overall, the preferred solvent system was identified as hexanes:diethyl ether (90:10), based on its effectiveness in extracting surface hydrocarbons and fatty acids as well as its reduced propensity to extract presumed internal fatty acids. Metabolite profiling of wildtype and glossy1 seedlings, which are impaired in surface lipid biosynthesis, demonstrated the ability of the preferred solvent to extract extracellular surface lipids rich in amphipathic compounds (aldehydes and alcohols). In addition to the expected deficiencies in dotriacontanal and dotriacontan-1-ol for gl1 seedlings, an unexpected increase in fatty acid recovery was observed in gl1 seedlings extracted in chloroform, suggesting that chloro-form extracts lipids from internal tissues of gl1 seedlings. This highlights the importance of extraction method when evaluating mutants that have altered cuticular lipid compositions. Lastly, metabolite profiling of silks from maize inbreds B73 and Mo17, exposed to different environments and harvested at different ages, revealed differences in hydrocarbon and fatty acid composition, demonstrating the dynamic nature of surface lipid accumulation on silks.« less

Stand dynamics following gap-scale exogenous disturbance in a single cohort mixed species stand in Morgan County, Tennessee

Treesearch

Brian S. Hughett; Wayne K. Clatterbuck

2014-01-01

Differences in composition, structure, and growth under canopy gaps created by the mortality of a single stem were analyzed using analysis of variance under two scenarios, with stem removed or with stem left as a standing snag. There were no significant differences in composition and structure of large diameter residual stems within upper canopy strata. Some...

Composition, Protein Profile and Rheological Properties of Pseudocereal-Based Protein-Rich Ingredients.

PubMed

Alonso-Miravalles, Loreto; O'Mahony, James A

2018-05-07

The objectives of this study were to investigate the nutrient composition, protein profile, morphology, and pasting properties of protein-rich pseudocereal ingredients (quinoa, amaranth, and buckwheat) and compare them to the more common rice and maize flours. Literature concerning protein-rich pseudocereal ingredients is very limited, mainly to protein profiling. The concentrations of macronutrients (i.e., ash, fat, and protein, as well as soluble, insoluble and total dietary fibre) were significantly higher for the protein-rich variants of pseudocereal-based flours than their regular protein content variants and the rice and maize flours. On profiling the protein component using sodium dodecyl sulfate⁻polyacrylamide gel electrophoresis (SDS-PAGE), all samples showed common bands at ~50 kDa and low molecular weight bands corresponding to the globulin fraction (~50 kDa) and albumin fraction (~10 kDa), respectively; except rice, in which the main protein was glutelin. The morphology of the starch granules was studied using scanning electron microscopy with quinoa and amaranth showing the smallest sized granules, while buckwheat, rice, and maize had the largest starch granules. The pasting properties of the ingredients were generally similar, except for buckwheat and amaranth, which showed the highest and lowest final viscosity, respectively. The results obtained in this study can be used to better understand the functionality and food applications of protein-rich pseudocereal ingredients.

Soil organic carbon dynamics in wheat-maize cropping systems of north China: application of isotope approach to long-term experiments

NASA Astrophysics Data System (ADS)

Wang, J.; Wang, X.; Xu, M.; Zhang, W.

2013-12-01

Soil organic carbon (SOC) in agro-ecosystem is largely influencedby agricultural practices such as croppingand fertilization. However, quantifying the contributions of various crops has been lacking. Here, we applied isotopic approachto study SOC dynamics under wheat-maize rotation with variousfertilization treatments atthree long-term experiment sites innorth China. Three treatments were chosen: no fertilizer (control), chemical nitrogen-phosphorus-potassium (NPK) and NPK plus straw (NPKS).Soil samples were collected from0-20, 20-40, 40-60, 60-80 and 80-100cm after 13 and 20 years of treatment, and SOC and its stable 13C compositions were determined. Generally, SOC content significantly decreased with depths, from 8.2 ×1.4 g kg-1 (in 0-20 cm) to 3.3×1.0 g kg-1 (in 80-100 cm) across all treatments and sites. Soil δ13C values at all depths, treatments and sites ranged from -24.2‰ to -21.6‰, averaged -22.8‰, indicating that ~70% of SOC was derived from wheat and previous C3 plant, and ~30% from maize and previous C4 plant.Both SOC and soil δ13C were significantly affected by fertilization managements, especiallyin 0-40 cm where linear relationship occurred between SOC and estimated C input. Overall, the slop of the linear equation, i.e., conversion efficiency, was four times greater for wheat-derived C relative to that for maize residue C. Our study indicated that maize-derived C contributed less to C sequestration in wheat-maize rotation system of north China. Figure 1. Relationships between SOC stock (0-40 cm) and accumulated C input for wheat (C3), maize (C4) and total. Significance is marked with one (P < 0.05), two (P < 0.01) and three (P < 0.001) asterisks.

Leaves from banana (Musa nana) and maize (Zea mays) have no phyto-prophylactic effects on the susceptibility of grass carp (Ctenopharyngodon idella) to Aeromonas hydrophila infection.

PubMed

Mayrhofer, Richard; Menanteau-Ledouble, Simon; Pucher, Johannes; Focken, Ulfert; El-Matbouli, Mansour

2017-11-10

The ubiquitous and opportunistic bacterial pathogen Aeromonas hydrophila has been associated with ulcerative dermatitis in fish, especially under stressful conditions. It can cause severe losses in fresh water aquaculture and is particularly prevalent in tropical and subtropical regions. Fresh leaves from maize and bananas have been used as feed supplement by fish farmers in Vietnam and it has been reported that they may have phyto-prophylactic benefits. In the present study, a feeding trial was conducted to investigate the benefits of providing maize and banana leaves as feed supplement: to determine if they were taken up and digested by grass carp (Ctenopharyngodon idella), if this uptake resulted in improved growth performance, and if leaf supplementation protected fish when challenged with A. hydrophila by intramuscular injection. All fish were fed an identical ratio of commercial pelleted feed relative to biomass. However, in 12/18 tanks, this diet was supplemented with either fresh banana leaves or fresh maize leaves; offered ad libitum. Addition of leaves increased the overall feed conversion ratio (FCR) significantly. However, if only the pellet were taken into account, then no difference was found between treatments. Changes to the isotopic composition of the fish showed leaf nutrient uptake occurred. No prophylactic effects of feeding banana or maize leaves were detected against infection with A. hydrophila, and the diet did not induce changes in the fish haematocrit. However, addition of the maize leaves was associated with significantly reduced severity of the skin lesions, which could improve the market value of the fish. Addition of the leaf supplement did not result in significantly improved growth performance. Similarly, the effect of the supplement on the fish survival to infection was not significant.

Analysis of water and nitrogen use efficiency for maize (Zea mays L.) grown on soft rock and sand compound soil.

PubMed

Wang, Huanyuan; Han, Jichang; Tong, Wei; Cheng, Jie; Zhang, Haiou

2017-06-01

Maize was grown on compound soils constituted from mixtures of soft rock and sand at different ratios, and water use efficiency (WUE), nitrogen use efficiency (NUE) and fertilizer nitrogen use efficiency (FNUE) were quantified. The data were used to assist in designing strategies for optimizing water and nitrogen management practices for maize on the substrates used. Maize was sown in composite soil prepared at three ratios of soft rock and sand (1:1, 1:2 and 1:5 v/v) in Mu Us Sandy Land, Yuyang district, Yulin city, China. Yields, amount of drainage, nitrogen (N) leaching, WUE and NUE were calculated. Then a water and nitrogen management model (WNMM) was calibrated and validated. No significant difference in evapotranspiration of maize was found among compound soils with soft rock/sand ratios of 1:1, 1:2 and 1:5, while water drainage increased significantly with increasing soft rock/sand ratio. WUE increased to 1.30 kg m -3 in compound soil with 1:2 soft rock/sand ratio. Nitrogen leaching and ammonia volatilization were the main reason for nitrogen loss, and N reduction mainly relied on crop uptake. NUE and FNUE could reach 33.1 and 24.9 kg kg -1 N respectively. Water drainage and nitrogen leaching occurred mostly during heavy rainfall or irrigation. Through a scenario analysis of different rainfall types, water and fertilizer management systems were formulated each year. This study shows that soft rock plays a key role in improving the WUE, NUE and FNUE of maize. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Replacement of grass and maize silages with lucerne silage: effects on performance, milk fatty acid profile and digestibility in Holstein-Friesian dairy cows.

PubMed

Sinclair, L A; Edwards, R; Errington, K A; Holdcroft, A M; Wright, M

2015-12-01

In total, 20 multiparous Holstein-Friesian dairy cows received one of four diets in each of four periods of 28-day duration in a Latin square design to test the hypothesis that the inclusion of lucerne in the ration of high-yielding dairy cows would improve animal performance and milk fatty acid (FA) composition. All dietary treatments contained 0.55 : 0.45 forage to concentrates (dry matter (DM) basis), and within the forage component the proportion of lucerne (Medicago sativa), grass (Lolium perenne) and maize silage (Zea mays) was varied (DM basis): control (C)=0.4 : 0.6 grass : maize silage; L20=0.2 : 0.2 : 0.6 lucerne : grass : maize silage; L40=0.4 : 0.6 lucerne : maize silage; and L60=0.6 : 0.4 lucerne : maize silage. Diets were formulated to contain a similar CP and metabolisable protein content, with the reduction of soya bean meal and feed grade urea with increasing content of lucerne. Intake averaged 24.3 kg DM/day and was lowest in cows when fed L60 (P0.05) by dietary treatment. Digestibility of DM, organic matter, CP and fibre decreased (P<0.01) with increasing content of lucerne in the diet, although fibre digestibility was similar in L40 and L60. It is concluded that first cut grass silage can be replaced with first cut lucerne silage without any detrimental effect on performance and an improvement in the milk FA profile, although intake and digestibility was lowest and plasma urea concentrations highest in cows when fed the highest level of inclusion of lucerne.

Large Root Cortical Cell Size Improves Drought Tolerance in Maize1[C][W][OPEN

PubMed Central

Chimungu, Joseph G.; Brown, Kathleen M.

2014-01-01

The objective of this study was to test the hypothesis that large cortical cell size (CCS) would improve drought tolerance by reducing root metabolic costs. Maize (Zea mays) lines contrasting in root CCS measured as cross-sectional area were grown under well-watered and water-stressed conditions in greenhouse mesocosms and in the field in the United States and Malawi. CCS varied among genotypes, ranging from 101 to 533 µm2. In mesocosms, large CCS reduced respiration per unit of root length by 59%. Under water stress in mesocosms, lines with large CCS had between 21% and 27% deeper rooting (depth above which 95% of total root length is located in the soil profile), 50% greater stomatal conductance, 59% greater leaf CO2 assimilation, and between 34% and 44% greater shoot biomass than lines with small CCS. Under water stress in the field, lines with large CCS had between 32% and 41% deeper rooting (depth above which 95% of total root length is located in the soil profile), 32% lighter stem water isotopic ratio of 18O to 16O signature, signifying deeper water capture, between 22% and 30% greater leaf relative water content, between 51% and 100% greater shoot biomass at flowering, and between 99% and 145% greater yield than lines with small cells. Our results are consistent with the hypothesis that large CCS improves drought tolerance by reducing the metabolic cost of soil exploration, enabling deeper soil exploration, greater water acquisition, and improved growth and yield under water stress. These results, coupled with the substantial genetic variation for CCS in diverse maize germplasm, suggest that CCS merits attention as a potential breeding target to improve the drought tolerance of maize and possibly other cereal crops. PMID:25293960

Cadmium toxicity in Maize (Zea mays L.): consequences on antioxidative systems, reactive oxygen species and cadmium accumulation.

PubMed

Anjum, Shakeel Ahmad; Tanveer, Mohsin; Hussain, Saddam; Bao, Mingchen; Wang, Longchang; Khan, Imran; Ullah, Ehsan; Tung, Shahbaz Atta; Samad, Rana Abdul; Shahzad, Babar

2015-11-01

Increased cadmium (Cd) accumulation in soils has led to tremendous environmental problems, with pronounced effects on agricultural productivity. Present study investigated the effects of Cd stress imposed at various concentrations (0, 75, 150, 225, 300, 375 μM) on antioxidant activities, reactive oxygen species (ROS), Cd accumulation, and productivity of two maize (Zea mays L.) cultivars viz., Run Nong 35 and Wan Dan 13. Considerable variations in Cd accumulation and in behavior of antioxidants and ROS were observed under Cd stress in both maize cultivars, and such variations governed by Cd were concentration dependent. Exposure of plant to Cd stress considerably increased Cd concentration in all plant parts particularly in roots. Wan Dan 13 accumulated relatively higher Cd in root, stem, and leaves than Run Nong 35; however, in seeds, Run Nong 35 recorded higher Cd accumulation. All the Cd toxicity levels starting from 75 μM enhanced H2O2 and MDA concentrations and triggered electrolyte leakage in leaves of both cultivars, and such an increment was more in Run Nong 35. The ROS were scavenged by the enhanced activities of superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, and glutathione peroxidase in response to Cd stress, and these antioxidant activities were higher in Wan Dan 13 compared with Run Nong 35 at all Cd toxicity levels. The grain yield of maize was considerably reduced particularly for Run Nong 35 under different Cd toxicity levels as compared with control. The Wan Dan 13 was better able to alleviate Cd-induced oxidative damage which was attributed to more Cd accumulation in roots and higher antioxidant activities in this cultivar, suggesting that manipulation of these antioxidants and enhancing Cd accumulation in roots may lead to improvement in Cd stress tolerance.

Bioaccessibility of selenium after human ingestion in relation to its chemical species and compartmentalization in maize.

PubMed

Mombo, Stéphane; Schreck, Eva; Dumat, Camille; Laplanche, Christophe; Pierart, Antoine; Longchamp, Mélanie; Besson, Philippe; Castrec-Rouelle, Maryse

2016-06-01

Selenium is a micronutrient needed by all living organisms including humans, but often present in low concentration in food with possible deficiency. From another side, at higher concentrations in soils as observed in seleniferous regions of the world, and in function of its chemical species, Se can also induce (eco)toxicity. Root Se uptake was therefore studied in function of its initial form for maize (Zea mays L.), a plant widely cultivated for human and animal food over the world. Se phytotoxicity and compartmentalization were studied in different aerial plant tissues. For the first time, Se oral human bioaccessibility after ingestion was assessed for the main Se species (Se(IV) and Se(VI)) with the BARGE ex vivo test in maize seeds (consumed by humans), and in stems and leaves consumed by animals. Corn seedlings were cultivated in hydroponic conditions supplemented with 1 mg L(-1) of selenium (Se(IV), Se(VI), Control) for 4 months. Biomass, Se concentration, and bioaccessibility were measured on harvested plants. A reduction in plant biomass was observed under Se treatments compared to control, suggesting its phytotoxicity. This plant biomass reduction was higher for selenite species than selenate, and seed was the main affected compartment compared to control. Selenium compartmentalization study showed that for selenate species, a preferential accumulation was observed in leaves, whereas selenite translocation was very limited toward maize aerial parts, except in the seeds where selenite concentrations are generally high. Selenium oral bioaccessibility after ingestion fluctuated from 49 to 89 % according to the considered plant tissue and Se species. Whatever the tissue, selenate appeared as the most human bioaccessible form. A potential Se toxicity was highlighted for people living in seleniferous regions, this risk being enhanced by the high Se bioaccessibility.

Assessing the regional impacts of increased energy maize cultivation on farmland birds.

PubMed

Brandt, Karoline; Glemnitz, Michael

2014-02-01

The increasing cultivation of energy crops in Germany substantially affects the habitat function of agricultural landscapes. Precise ex ante evaluations regarding the impacts of this cultivation on farmland bird populations are rare. The objective of this paper was to implement a methodology to assess the regional impacts of increasing energy maize cultivation on the habitat quality of agricultural lands for farmland birds. We selected five farmland bird indicator species with varying habitat demands. Using a crop suitability modelling approach, we analysed the availability of potential habitat areas according to different land use scenarios for a real landscape in Northeast Germany. The model was based on crop architecture, cultivation period, and landscape preconditions. Our results showed that the habitat suitability of different crops varied between bird species, and scenario calculations revealed an increase and a decrease in the size of the potential breeding and feeding habitats, respectively. The effects observed in scenario 1 (increased energy maize by 15%) were not reproduced in all cases in scenario 2 (increased energy maize by 30%). Spatial aggregation of energy maize resulted in a negative effect for some species. Changes in the composition of the farmland bird communities, the negative effects on farmland bird species limited in distribution and spread and the relevance of the type of agricultural land use being replaced by energy crops are also discussed. In conclusion, we suggest a trade-off between biodiversity and energy targets by identifying biodiversity-friendly energy cropping systems.

Fungal Genetics and Functional Diversity of Microbial Communities in the Soil under Long-Term Monoculture of Maize Using Different Cultivation Techniques

PubMed Central

Gałązka, Anna; Grządziel, Jarosław

2018-01-01

Fungal diversity in the soil may be limited under natural conditions by inappropriate environmental factors such as: nutrient resources, biotic and abiotic factors, tillage system and microbial interactions that prevent the occurrence or survival of the species in the environment. The aim of this paper was to determine fungal genetic diversity and community level physiological profiling of microbial communities in the soil under long-term maize monoculture. The experimental scheme involved four cultivation techniques: direct sowing (DS), reduced tillage (RT), full tillage (FT), and crop rotation (CR). Soil samples were taken in two stages: before sowing of maize (DSBS-direct sowing, RTBS-reduced tillage, FTBS-full tillage, CRBS-crop rotation) and the flowering stage of maize growth (DSF-direct sowing, RTF-reduced tillage, FTF-full tillage, CRF-crop rotation). The following plants were used in the crop rotation: spring barley, winter wheat and maize. The study included fungal genetic diversity assessment by ITS-1 next generation sequencing (NGS) analyses as well as the characterization of the catabolic potential of microbial communities (Biolog EcoPlates) in the soil under long-term monoculture of maize using different cultivation techniques. The results obtained from the ITS-1 NGS technique enabled to classify and correlate the fungi species or genus to the soil metabolome. The research methods used in this paper have contributed to a better understanding of genetic diversity and composition of the population of fungi in the soil under the influence of the changes that have occurred in the soil under long-term maize cultivation. In all cultivation techniques, the season had a great influence on the fungal genetic structure in the soil. Significant differences were found on the family level (P = 0.032, F = 3.895), genus level (P = 0.026, F = 3.313) and on the species level (P = 0.033, F = 2.718). This study has shown that: (1) fungal diversity was changed under the influence different cultivation techniques; (2) techniques of maize cultivation and season were an important factors that can influence the biochemical activity of soil. Maize cultivated in direct sowing did not cause negative changes in the fungal structure, even making it more stable during seasonal changes; (3) full tillage and crop rotation may change fungal community and soil function. PMID:29441054

Nanometer-scale structure of alkali-soluble bio-macromolecules of maize plant residues explains their recalcitrance in soil.

PubMed

Adani, Fabrizio; Salati, Silvia; Spagnol, Manuela; Tambone, Fulvia; Genevini, Pierluigi; Pilu, Roberto; Nierop, Klaas G J

2009-07-01

The quantity and quality of plant litter in the soil play an important role in the soil organic matter balance. Besides other pedo-climatic aspects, the content of recalcitrant molecules of plant residues and their chemical composition play a major role in the preservation of plant residues. In this study, we report that intrinsically resistant alkali-soluble bio-macromolecules extracted from maize plant (plant-humic acid) (plant-HA) contribute directly to the soil organic matter (OM) by its addition and conservation in the soil. Furthermore, we also observed that a high syringyl/guaiacyl (S/G) ratio in the lignin residues comprising the plant tissue, which modifies the microscopic structure of the alkali-soluble plant biopolymers, enhances their recalcitrance because of lower accessibility of molecules to degrading enzymes. These results are in agreement with a recent study, which showed that the humic substance of soil consists of a mixture of identifiable biopolymers obtained directly from plant tissues that are added annually by maize plant residues.

Morphological, Physiological and Biochemical Impact of Ink Industry Effluent on Germination of Maize (Zea mays), Barley (Hordeum vulgare) and Sorghum (Sorghum bicolor).

PubMed

Zayneb, Chaâbene; Lamia, Khanous; Olfa, Ellouze; Naïma, Jebahi; Grubb, C Douglas; Bassem, Khemakhem; Hafedh, Mejdoub; Amine, Elleuch

2015-11-01

The present study focuses on effects of untreated and treated ink industry wastewater on germination of maize, barley and sorghum. Wastewater had a high chemical oxygen demand (COD) and metal content compared to treated effluent. Germination decreased with increasing COD concentration. Speed of germination also followed the same trend, except for maize seeds exposed to untreated effluent (E), which germinated slightly faster than controls. These alterations of seedling development were mirrored by changes in soluble protein content. E exerted a positive effect on soluble protein content and maximum levels occurred after 10 days with treated effluent using coagulation/flocculation (TEc/f) process and treated effluent using combined process (coagulation/flocculation/biosorption) (TEc/f/b). Likewise, activity of α-amylase was influenced by effluent composition. Its expression depended on the species, exposure time and applied treatment. Nevertheless, current results indicated TEc/f/b had no observable toxic effects on germination and could be a beneficial alternative resource to irrigation water.

Changes in iron, zinc and chelating agents during traditional African processing of maize: Effect of iron contamination on bioaccessibility.

PubMed

Greffeuille, Valérie; Polycarpe Kayodé, A P; Icard-Vernière, Christèle; Gnimadi, Muriel; Rochette, Isabelle; Mouquet-Rivier, Claire

2011-06-15

The effect of the different unit operations of processing traditionally used to produce four maize foods commonly consumed in Africa on the nutritional composition of the products was investigated, using Benin as a study context. The impact of the processes on lipid, fibre, phytate, iron and zinc contents varied with the process. The lowest IP6/Fe and IP6/Zn molar ratios, the indices used to assess Fe and Zn bioavailability were obtained in mawè, a fermented dough. Analysis of maize products highlighted a significant increase in iron content after milling, as a result of contamination by the equipment used. Evaluation of iron bioaccessibility by in vitro enzymatic digestion followed by dialysis revealed that the iron contamination, followed by lactic acid fermentation, led to a considerable increase in bioaccessible iron content. Extrinsic iron supplied to food products by the milling equipment could play a role in iron intake in developing countries. Copyright © 2010 Elsevier Ltd. All rights reserved.

Effect of high pressure on rheological and thermal properties of quinoa and maize starches.

PubMed

Li, Guantian; Zhu, Fan

2018-02-15

Quinoa starch has small granules with relatively low gelatinization temperatures and amylose content. High hydrostatic pressure (HHP) is a non-thermal technique for food processing. In this study, effects of HHP up to 600MPa on physical properties of quinoa starch were studied and compared with those of a normal maize starch. Both starches gelatinized at 500 and 600MPa. The pressure of 600MPa completely gelatinized quinoa starch as revealed by thermal analysis. Dynamic rheological analysis showed that HHP improved the gel stability of both starches during cooling. HHP had little effects on amylopectin recrystallization and gel textural properties of starch. Overall, quinoa starch was more susceptible to HHP than maize starch. The effects of HHP on some rheological properties such as frequency dependence were different between these two types of starches. The differences could be attributed to the different composition, granular and chemical structures of starch, and the presence of granule remnants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Morphological, Thermal, and Rheological Properties of Starches from Maize Mutants Deficient in Starch Synthase III.

PubMed

Zhu, Fan; Bertoft, Eric; Li, Guantian

2016-08-31

Morphological, thermal, and rheological properties of starches from maize mutants deficient in starch synthase III (SSIII) with a common genetic background (W64A) were studied and compared with the wild type. SSIII deficiency reduced granule size of the starches from 16.7 to ∼11 μm (volume-weighted mean). Thermal analysis showed that SSIII deficiency decreased the enthalpy change of starch during gelatinization. Steady shear analysis showed that SSIII deficiency decreased the consistency coefficient and yield stress during steady shearing, whereas additional deficiency in granule-bound starch synthase (GBSS) increased these values. Dynamic oscillatory analysis showed that SSIII deficiency decreased G' at 90 °C during heating and increased it when the paste was cooled to 25 °C at 40 Hz during a frequency sweep. Additional GBSS deficiency further decreased the G'. Structural and compositional bases responsible for these changes in physical properties of the starches are discussed. This study highlighted the relationship between SSIII and some physicochemical properties of maize starch.

Ontogeny of the sheathing leaf base in maize (Zea mays).

PubMed

Johnston, Robyn; Leiboff, Samuel; Scanlon, Michael J

2015-01-01

Leaves develop from the shoot apical meristem (SAM) via recruitment of leaf founder cells. Unlike eudicots, most monocot leaves display parallel venation and sheathing bases wherein the margins overlap the stem. Here we utilized computed tomography (CT) imaging, localization of PIN-FORMED1 (PIN1) auxin transport proteins, and in situ hybridization of leaf developmental transcripts to analyze the ontogeny of monocot leaf morphology in maize (Zea mays). CT imaging of whole-mounted shoot apices illustrates the plastochron-specific stages during initiation of the basal sheath margins from the tubular disc of insertion (DOI). PIN1 localizations identify basipetal auxin transport in the SAM L1 layer at the site of leaf initiation, a process that continues reiteratively during later recruitment of lateral leaf domains. Refinement of these auxin transport domains results in multiple, parallel provascular strands within the initiating primordium. By contrast, auxin is transported from the L2 toward the L1 at the developing margins of the leaf sheath. Transcripts involved in organ boundary formation and dorsiventral patterning accumulate within the DOI, preceding the outgrowth of the overlapping margins of the sheathing leaf base. We suggest a model wherein sheathing bases and parallel veins are both patterned via the extended recruitment of lateral maize leaf domains from the SAM. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

Suppression of CINNAMOYL-CoA REDUCTASE increases the level of monolignol ferulates incorporated into maize lignins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Rebecca A.; Cass, Cynthia L.; Mazaheri, Mona

Background.The cell wall polymer lignin provides structural support and rigidity to plant cell walls, and therefore to the plant body. However, the recalcitrance associated with lignin impedes the extraction of polysaccharides from the cell wall to make plant-based biofuels and biomaterials. The cell wall digestibility can be improved by introducing labile ester bonds into the lignin backbone that can be easily broken under mild base treatment at room temperature. The FERULOYL-CoA MONOLIGNOL TRANSFERASE (FMT) enzyme, which may be naturally found in many plants, uses feruloyl-CoA and monolignols to synthesize the ester-linked monolignol ferulate conjugates. A mutation in the first lignin-specificmore » biosynthetic enzyme, CINNAMOYL-CoA REDUCTASE (CCR), results in an increase in the intracellular pool of feruloyl-CoA. Results. Maize (Zea mays) has a native putative FMT enzyme, and its ccr mutants produce an increased pool of feruloyl-CoA that can be used for conversion to monolignol ferulate conjugates. The decreased lignin content and monomers did not, however, impact the plant growth or biomass. The increase in monolignol conjugates correlated with an improvement in the digestibility of maize stem rind tissue. Conclusions. Together, increased monolignol ferulates and improved digestibility in ccr1 mutant plants suggests that they may be superior biofuel crops.« less

Suppression of CINNAMOYL-CoA REDUCTASE increases the level of monolignol ferulates incorporated into maize lignins

DOE PAGES

Smith, Rebecca A.; Cass, Cynthia L.; Mazaheri, Mona; ...

2017-05-02

Background.The cell wall polymer lignin provides structural support and rigidity to plant cell walls, and therefore to the plant body. However, the recalcitrance associated with lignin impedes the extraction of polysaccharides from the cell wall to make plant-based biofuels and biomaterials. The cell wall digestibility can be improved by introducing labile ester bonds into the lignin backbone that can be easily broken under mild base treatment at room temperature. The FERULOYL-CoA MONOLIGNOL TRANSFERASE (FMT) enzyme, which may be naturally found in many plants, uses feruloyl-CoA and monolignols to synthesize the ester-linked monolignol ferulate conjugates. A mutation in the first lignin-specificmore » biosynthetic enzyme, CINNAMOYL-CoA REDUCTASE (CCR), results in an increase in the intracellular pool of feruloyl-CoA. Results. Maize (Zea mays) has a native putative FMT enzyme, and its ccr mutants produce an increased pool of feruloyl-CoA that can be used for conversion to monolignol ferulate conjugates. The decreased lignin content and monomers did not, however, impact the plant growth or biomass. The increase in monolignol conjugates correlated with an improvement in the digestibility of maize stem rind tissue. Conclusions. Together, increased monolignol ferulates and improved digestibility in ccr1 mutant plants suggests that they may be superior biofuel crops.« less

Magnesium Fertilizer-Induced Increase of Symbiotic Microorganisms Improves Forage Growth and Quality.

PubMed

Chen, Jihui; Li, Yanpeng; Wen, Shilin; Rosanoff, Andrea; Yang, Gaowen; Sun, Xiao

2017-04-26

Magnesium (Mg) plays important roles in photosynthesis and protein synthesis; however, latent Mg deficiencies are common phenomena that can influence food quality. Nevertheless, the effects of Mg fertilizer additions on plant carbon (C):nitrogen (N):phosphorus (P) stoichiometry, an important index of food quality, are unclear and the underlying mechanisms unexplored. We conducted a greenhouse experiment using low-Mg in situ soil without and with a gradient of Mg additions to investigate the effect of Mg fertilizer on growth and stoichiometry of maize and soybean and also measure these plants' main symbiotic microorganisms: arbuscular mycorrhizal fungi (AMF) and rhizobium, respectively. Our results showed that Mg addition significantly improved both plant species' growth and also increased N and P concentrations in soybean and maize, respectively, resulting in low C:N ratio and high N:P ratio in soybean and low C:P and N:P ratios in maize. These results presumably stemmed from the increase of nutrients supplied by activation-enhanced plant symbiotic microorganisms, an explanation supported by statistically significant positive correlations between plant stoichiometry and plants' symbiotic microorganisms' increased growth with Mg addition. We conclude that Mg supply can improve plant growth and alter plant stoichiometry via enhanced activity of plant symbiotic microorganisms. Possible mechanisms underlying this positive plant-soil feedback include an enhanced photosynthetic product flow to roots caused by adequate Mg supply.

Effect of ripe fruit pulp on the sensory and nutritive quality of ready-to-eat breakfast cereal produced from maize and soybean flours and cassava starch blends.

PubMed

Enwere, N J; Ntuen, I G

2005-02-01

The effects of various concentrations of different ripe fruit pulps on the sensory and nutritive quality of breakfast cereal were studied. The breakfast cereal was formulated using 1 kg composite flour (composed of 600 g maize flour and 400 g soy flour) in addition to 100 g cassava starch, 225 g sugar and 12 g salt. Pineapple, pawpaw and banana ripe fruit pulps were added separately to the breakfast formulation at concentrations of 0, 100, 200, 300 and 400 g/kg composite flour. Using sensory evaluation, the data obtained showed that samples containing 100 g pineapple, 100 g banana pulp and 100 g pawpaw fruit pulp per kilogram of composite flour (equivalent to 7% of the total weight of the breakfast cereal formulation) were the most acceptable of all concentrations. These samples were comparable in sensory evaluation scores with the commercial breakfast cereal sample Golden morn. Chemical analysis also showed that there was increase in ss-carotene (vitamin A precursor) and vitamin C and a slight increase in the mineral content of the breakfast cereal as a result of the addition of fruit pulp.

Structure and chemistry of the sorghum grain

USDA-ARS?s Scientific Manuscript database

Sorghum is grown around the world and often under harsh and variable environmental conditions. Combined with the high degree of genetic diversity present in sorghum, this can result in substantial variability in grain composition and grain quality. While similar to other cereal grains such as maize ...

Chemical composition and functional characteristics of dietary fiber-rich powder obtained from core of maize straw.

PubMed

Lv, Jin-Shun; Liu, Xiao-Yan; Zhang, Xiao-Pan; Wang, Lin-Shuang

2017-07-15

A novel dietary fiber (MsCDF) based core of maize straw (Core) was prepared by using high boiling solvent of sodium peroxide by high pressure pretreatment (HBSHP). The composition of MsCDF, and several physicochemical properties for MsCDF related to its nutritional quality were investigated. The results revealed that the MsCDF contains high contents total dietary fiber (TDF), soluble dietary fiber (SDF), insoluble dietary fiber (IDF) and two main monosaccharaides, xylose and glucose. Meanwhile, the studies of physicochemical properties of MsCDF indicated that MsCDF performed well water-holding capacity (WHC), oil-holding capacity (OHC), Swelling, solubility (SOL), Glucose dialysis retardation index (GDRI) and adsorption capacity on cholesterol. The results of this study serve as evidence that MsCDF can be used as a functional food additive, Core can be used as a crude material to produce MsCDF and the technology of HBSHP can be used to modify the physico-chemical properties of Core. Copyright © 2017 Elsevier Ltd. All rights reserved.

Identification of nodes and internodes of chopped biomass stems by Image analysis using profile curvature and slope

USDA-ARS?s Scientific Manuscript database

Morphological components of biomass stems vary in their chemical composition and they can be better utilized when processed after segregation. Within the stem, nodes and internodes have significantly different compositions. The internodes have low ash content and are a better feedstock for bioenergy...

Exploiting the Genetic Diversity of Maize Using a Combined Metabolomic, Enzyme Activity Profiling, and Metabolic Modeling Approach to Link Leaf Physiology to Kernel Yield

PubMed Central

Yesbergenova-Cuny, Zhazira; Simons, Margaret; Chardon, Fabien; Armengaud, Patrick; Quilleré, Isabelle; Cukier, Caroline; Gibon, Yves; Limami, Anis M.; Nicolas, Stéphane; Brulé, Lenaïg; Lea, Peter J.; Maranas, Costas D.; Hirel, Bertrand

2017-01-01

A combined metabolomic, biochemical, fluxomic, and metabolic modeling approach was developed using 19 genetically distant maize (Zea mays) lines from Europe and America. Considerable differences were detected between the lines when leaf metabolic profiles and activities of the main enzymes involved in primary metabolism were compared. During grain filling, the leaf metabolic composition appeared to be a reliable marker, allowing a classification matching the genetic diversity of the lines. During the same period, there was a significant correlation between the genetic distance of the lines and the activities of enzymes involved in carbon metabolism, notably glycolysis. Although large differences were observed in terms of leaf metabolic fluxes, these variations were not tightly linked to the genome structure of the lines. Both correlation studies and metabolic network analyses allowed the description of a maize ideotype with a high grain yield potential. Such an ideotype is characterized by low accumulation of soluble amino acids and carbohydrates in the leaves and high activity of enzymes involved in the C4 photosynthetic pathway and in the biosynthesis of amino acids derived from glutamate. Chlorogenates appear to be important markers that can be used to select for maize lines that produce larger kernels. PMID:28396554

Composition of Mineral Produced by Dental Mesenchymal Stem Cells

PubMed Central

Volponi, A.A.; Gentleman, E.; Fatscher, R.; Pang, Y.W.Y.; Gentleman, M.M.; Sharpe, P.T.

2015-01-01

Mesenchymal stem cells isolated from different dental tissues have been described to have osteogenic/odontogenic-like differentiation capacity, but little attention has been paid to the biochemical composition of the material that each produces. Here, we used Raman spectroscopy to analyze the mineralized materials produced in vitro by different dental cell populations, and we compared them with the biochemical composition of native dental tissues. We show that different dental stem cell populations produce materials that differ in their mineral and matrix composition and that these differ from those of native dental tissues. In vitro, BCMP (bone chip mass population), SCAP (stem cells from apical papilla), and SHED (stem cells from human-exfoliated deciduous teeth) cells produce a more highly mineralized matrix when compared with that produced by PDL (periodontal ligament), DPA (dental pulp adult), and GF (gingival fibroblast) cells. Principal component analyses of Raman spectra further demonstrated that the crystallinity and carbonate substitution environments in the material produced by each cell type varied, with DPA cells, for example, producing a more carbonate-substituted mineral and with SCAP, SHED, and GF cells creating a less crystalline material when compared with other dental stem cells and native tissues. These variations in mineral composition reveal intrinsic differences in the various cell populations, which may in turn affect their specific clinical applications. PMID:26253190

Overexpression of GA20-OXIDASE1 impacts plant height, biomass allocation and saccharification efficiency in maize.

PubMed

Voorend, Wannes; Nelissen, Hilde; Vanholme, Ruben; De Vliegher, Alex; Van Breusegem, Frank; Boerjan, Wout; Roldán-Ruiz, Isabel; Muylle, Hilde; Inzé, Dirk

2016-03-01

Increased biomass yield and quality are of great importance for the improvement of feedstock for the biorefinery. For the production of bioethanol, both stem biomass yield and the conversion efficiency of the polysaccharides in the cell wall to fermentable sugars are of relevance. Increasing the endogenous levels of gibberellic acid (GA) by ectopic expression of GA20-OXIDASE1 (GA20-OX1), the rate-limiting step in GA biosynthesis, is known to affect cell division and cell expansion, resulting in larger plants and organs in several plant species. In this study, we examined biomass yield and quality traits of maize plants overexpressing GA20-OX1 (GA20-OX1). GA20-OX1 plants accumulated more vegetative biomass than control plants in greenhouse experiments, but not consistently over two years of field trials. The stems of these plants were longer but also more slender. Investigation of GA20-OX1 biomass quality using biochemical analyses showed the presence of more cellulose, lignin and cell wall residue. Cell wall analysis as well as expression analysis of lignin biosynthetic genes in developing stems revealed that cellulose and lignin were deposited earlier in development. Pretreatment of GA20-OX1 biomass with NaOH resulted in a higher saccharification efficiency per unit of dry weight, in agreement with the higher cellulose content. On the other hand, the cellulose-to-glucose conversion was slower upon HCl or hot-water pretreatment, presumably due to the higher lignin content. This study showed that biomass yield and quality traits can be interconnected, which is important for the development of future breeding strategies to improve lignocellulosic feedstock for bioethanol production. © 2015 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Maize proximate composition and physical properties correlations to dry-grind ethanol concentrations

USDA-ARS?s Scientific Manuscript database

Dry grind ethanol plants incur economic losses due to seasonal variations in ethanol yields. One possible cause associated with ethanol yield variability is incoming grain quality. There is little published information on factors causing variation in dry grind ethanol concentrations. The objective o...

Chemical functionalization of graphene to augment stem cell osteogenesis and inhibit biofilm formation on polymer composites for orthopedic applications.

PubMed

Kumar, Sachin; Raj, Shammy; Kolanthai, Elayaraja; Sood, A K; Sampath, S; Chatterjee, Kaushik

2015-02-11

Toward designing the next generation of resorbable biomaterials for orthopedic applications, we studied poly(ε-caprolactone) (PCL) composites containing graphene. The role, if any, of the functionalization of graphene on mechanical properties, stem cell response, and biofilm formation was systematically evaluated. PCL composites of graphene oxide (GO), reduced GO (RGO), and amine-functionalized GO (AGO) were prepared at different filler contents (1%, 3%, and 5%). Although the addition of the nanoparticles to PCL markedly increased the storage modulus, this increase was largest for GO followed by AGO and RGO. In vitro cell studies revealed that the AGO and GO particles significantly increased human mesenchymal stem cell proliferation. AGO was most effective in augmenting stem cell osteogenesis leading to mineralization. Bacterial studies revealed that interaction with functionalized GO induced bacterial cell death because of membrane damage, which was further accentuated by amine groups in AGO. As a result, AGO composites were best at inhibiting biofilm formation. The synergistic effect of oxygen containing functional groups and amine groups on AGO imparts the optimal combination of improved modulus, favorable stem cell response, and biofilm inhibition in AGO-reinforced composites desired for orthopedic applications. This work elucidates the importance of chemical functionalization of graphene in polymer composites for biomedical applications.

Resistant starch alters gut microbiome and metabolomics profiles concurrent with amelioration of chronic kidney disease in rats

USDA-ARS?s Scientific Manuscript database

Patients and animals with chronic kidney disease (CKD) exhibit profound alterations in the gut environment including shifts in microbial composition, increased fecal pH, and increased blood levels of gut microbe-derived metabolites (xeno-metabolites). The fermentable dietary fiber—high amylose maize...

Dryland Soil Hydrological Processes and Their Impacts on the Nitrogen Balance in a Soil-Maize System of a Freeze-Thawing Agricultural Area

PubMed Central

Ouyang, Wei; Chen, Siyang; Cai, Guanqing; Hao, Fanghua

2014-01-01

Understanding the fates of soil hydrological processes and nitrogen (N) is essential for optimizing the water and N in a dryland crop system with the goal of obtaining a maximum yield. Few investigations have addressed the dynamics of dryland N and its association with the soil hydrological process in a freeze-thawing agricultural area. With the daily monitoring of soil water content and acquisition rates at 15, 30, 60 and 90 cm depths, the soil hydrological process with the influence of rainfall was identified. The temporal-vertical soil water storage analysis indicated the local albic soil texture provided a stable soil water condition for maize growth with the rainfall as the only water source. Soil storage water averages at 0–20, 20–40 and 40–60 cm were observed to be 490.2, 593.8, and 358 m3 ha−1, respectively, during the growing season. The evapo-transpiration (ET), rainfall, and water loss analysis demonstrated that these factors increased in same temporal pattern and provided necessary water conditions for maize growth in a short period. The dry weight and N concentration of maize organs (root, leaf, stem, tassel, and grain) demonstrated the N accumulation increased to a peak in the maturity period and that grain had the most N. The maximum N accumulative rate reached about 500 mg m−2d−1 in leaves and grain. Over the entire growing season, the soil nitrate N decreased by amounts ranging from 48.9 kg N ha−1 to 65.3 kg N ha−1 over the 90 cm profile and the loss of ammonia-N ranged from 9.79 to 12.69 kg N ha−1. With soil water loss and N balance calculation, the N usage efficiency (NUE) over the 0–90 cm soil profile was 43%. The soil hydrological process due to special soil texture and the temporal features of rainfall determined the maize growth in the freeze-thawing agricultural area. PMID:25000400

Dryland soil hydrological processes and their impacts on the nitrogen balance in a soil-maize system of a freeze-thawing agricultural area.

PubMed

Ouyang, Wei; Chen, Siyang; Cai, Guanqing; Hao, Fanghua

2014-01-01

Understanding the fates of soil hydrological processes and nitrogen (N) is essential for optimizing the water and N in a dryland crop system with the goal of obtaining a maximum yield. Few investigations have addressed the dynamics of dryland N and its association with the soil hydrological process in a freeze-thawing agricultural area. With the daily monitoring of soil water content and acquisition rates at 15, 30, 60 and 90 cm depths, the soil hydrological process with the influence of rainfall was identified. The temporal-vertical soil water storage analysis indicated the local albic soil texture provided a stable soil water condition for maize growth with the rainfall as the only water source. Soil storage water averages at 0-20, 20-40 and 40-60 cm were observed to be 490.2, 593.8, and 358 m3 ha-1, respectively, during the growing season. The evapo-transpiration (ET), rainfall, and water loss analysis demonstrated that these factors increased in same temporal pattern and provided necessary water conditions for maize growth in a short period. The dry weight and N concentration of maize organs (root, leaf, stem, tassel, and grain) demonstrated the N accumulation increased to a peak in the maturity period and that grain had the most N. The maximum N accumulative rate reached about 500 mg m-2d-1 in leaves and grain. Over the entire growing season, the soil nitrate N decreased by amounts ranging from 48.9 kg N ha-1 to 65.3 kg N ha-1 over the 90 cm profile and the loss of ammonia-N ranged from 9.79 to 12.69 kg N ha-1. With soil water loss and N balance calculation, the N usage efficiency (NUE) over the 0-90 cm soil profile was 43%. The soil hydrological process due to special soil texture and the temporal features of rainfall determined the maize growth in the freeze-thawing agricultural area.

Comparison of stem damage and carbohydrate composition in the stem juice between sugarcane and sweet sorghum harvested before and after late fall frost

USDA-ARS?s Scientific Manuscript database

A late fall frost may significantly affect sugar crops’ stem sugar composition, yield and juice quality for biofuel and bioproduct manufacture. Research on the effects of late fall frost in sugarcane is well documented, but information is lacking for sweet sorghum. Three and six commercial cultivars...

Long-term performance of thermoplastic composite material with cotton burr and stem (CBS) as a partial filler

USDA-ARS?s Scientific Manuscript database

Rationale: Cotton burr and stem (CBS) fraction of cotton gin byproducts has shown promise as a fiber filler in thermoplastic composites, with physical and mechanical properties comparable to that made with wood fiber fillers. However, the long-term performance of this composite material is not known...

Composition of Mineral Produced by Dental Mesenchymal Stem Cells.

PubMed

Volponi, A A; Gentleman, E; Fatscher, R; Pang, Y W Y; Gentleman, M M; Sharpe, P T

2015-11-01

Mesenchymal stem cells isolated from different dental tissues have been described to have osteogenic/odontogenic-like differentiation capacity, but little attention has been paid to the biochemical composition of the material that each produces. Here, we used Raman spectroscopy to analyze the mineralized materials produced in vitro by different dental cell populations, and we compared them with the biochemical composition of native dental tissues. We show that different dental stem cell populations produce materials that differ in their mineral and matrix composition and that these differ from those of native dental tissues. In vitro, BCMP (bone chip mass population), SCAP (stem cells from apical papilla), and SHED (stem cells from human-exfoliated deciduous teeth) cells produce a more highly mineralized matrix when compared with that produced by PDL (periodontal ligament), DPA (dental pulp adult), and GF (gingival fibroblast) cells. Principal component analyses of Raman spectra further demonstrated that the crystallinity and carbonate substitution environments in the material produced by each cell type varied, with DPA cells, for example, producing a more carbonate-substituted mineral and with SCAP, SHED, and GF cells creating a less crystalline material when compared with other dental stem cells and native tissues. These variations in mineral composition reveal intrinsic differences in the various cell populations, which may in turn affect their specific clinical applications. © International & American Associations for Dental Research 2015.

Ruminal phytate degradation of maize grain and rapeseed meal in vitro and as affected by phytate content in donor animal diets and inorganic phosphorus in the buffer.

PubMed

Haese, E; Lengowski, M; Gräter, E; Föll, A; Möhring, J; Steingass, H; Schollenberger, M; Rodehutscord, M

2017-10-01

The ruminal disappearance of phytate phosphorus (InsP 6 -P) from maize grain and rapeseed meal (RSM) was determined in two in vitro studies. In experiment 1, two diets differing in phosphorus (P) and InsP 6 -P concentration were fed to the donor animals of rumen fluid (diet HP: 0.49% P in dry matter, diet LP: 0.29% P). Maize grain and RSM were incubated in a rumen fluid/saliva mixture for 3, 6, 12 and 24 h. In experiment 2, a diet similar to diet HP was fed, and the rumen fluid was mixed with artificial saliva containing 120 mg inorganic P/l (Pi) or no inorganic P (P0). Maize grain and RSM were incubated with either buffer for 3, 6, 12 and 24 h. Total P (tP) and InsP 6 concentration were analysed in the fermenter fluids and feed residues. The disappearance of InsP 6 -P from maize was completed after 12 h of incubation in both experiments. From RSM, 93% (diet LP) and 99% (diet HP) of the InsP 6 -P in experiment 1 and 80% (Pi) and 89% (P0) in experiment 2 had disappeared after 24 h of incubation. InsP 6 -P disappearance was higher when diet HP was fed (maize: 3 and 6 h; RSM: 6 and 24 h of incubation) and when rumen fluid was mixed with buffer P0 (maize: 6 h; RSM: 12 and 24 h of incubation). InsP 6 -P concentration in the fermenter fluids was higher for maize, but no accumulation of InsP 6 -P occurred, indicating a prompt degradation of soluble InsP 6 . These results confirmed the capability of rumen micro-organisms to efficiently degrade InsP 6 . However, differences between the feedstuffs and diet composition as well as the presence of inorganic P in the in vitro system influenced the degradation process. Further studies are required to understand how these factors affect InsP 6 degradation and their respective relevance in vivo. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

Influence of salicylic acid pretreatment on seeds germination and some defence mechanisms of Zea mays plants under copper stress.

PubMed

Moravcová, Šárka; Tůma, Jiří; Dučaiová, Zuzana Kovalíková; Waligórski, Piotr; Kula, Monika; Saja, Diana; Słomka, Aneta; Bąba, Wojciech; Libik-Konieczny, Marta

2018-01-01

The study was focused on the influence of salicylic acid (SA) on maize seeds germination and on some physiological and biochemical processes in maize plants growing in the hydroponic culture under copper (Cu) stress. A significant influence of SA pretreatment on the advanced induction of the maize seeds metabolic activity and the level of the endogenous SA in germinated seeds and developing roots have been stated. Although, the ability of maize seeds to uptake SA and accumulate it in the germinated roots was confirmed, the growth inhibition of Cu-stressed maize seedlings was not ameliorated by SA seeds pretreatment. Cu-stressed plants exhibited a decrease in the photosynthetic pigment concentration and the increase in non-photochemical quenching (NPQ) - an indicator of an excess energy in PSII antenna assemblies lost as a heat. The amelioration effect of SA application was found only for carotenoids content which increased in stressed plants. It was also shown that maize roots growing in stress conditions significantly differed in the chemical composition in comparison to the roots of control plants, but the SA pretreatment did not affect these differences. On the other hand, it was found that SA seed pretreatment significantly influenced the ability of stressed plants to accumulate copper in the roots. It was stated that a higher level of exogenous SA application led to a lower accumulation of Cu ions in maize roots. Cu-stressed plants exhibited higher oxidative stress in roots than in leaves which was manifested as an increase in the concentration of hydrogen peroxide due to stress factor application. We observed an increase in catalase (CAT) activity in leaves of Cu-stressed plants which corresponded with a lower H 2 O 2 content when compared with roots where the hydrogen peroxide level was higher, and the inhibition of the CAT activity was found. Furthermore, we found that the SA seed pretreatment led to a decrease in the H 2 O 2 content in the roots of the Cu-stressed plants, but it did not influence the H 2 O 2 level in leaves. The increase in hydrogen peroxide content in the roots of Cu-stressed plants correlated with a higher activity of the MnSODI and MnSODII isoforms. It was found that SA pretreatment caused a decrease in MnSODII activity accompanied by the decrease in H 2 O 2 concentration. Achieved results indicated also that the changes in the chemical composition of the root tissue under copper stress constituted protection mechanisms of blocking copper flow into other plant organs. However, it might be assumed that the root tissue remodelling under Cu stress did not only prevent against the Cu ions uptake but also limited the absorption of minerals required for the normal growth leading to the inhibition of the plant development. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Are BVOC exchanges in agricultural ecosystems overestimated? Insights from fluxes measured in a maize field over a whole growing season

NASA Astrophysics Data System (ADS)

Bachy, Aurélie; Aubinet, Marc; Schoon, Niels; Amelynck, Crist; Bodson, Bernard; Moureaux, Christine; Heinesch, Bernard

2016-04-01

Maize is the most important C4 crop worldwide. It is also the second most important crop worldwide (C3 and C4 mixed), and is a dominant crop in some world regions. Therefore, it can potentially influence local climate and air quality through its exchanges of gases with the atmosphere. Among others, biogenic volatile organic compounds (BVOC) are known to influence the atmospheric composition and thereby modify greenhouse gases lifetime and pollutant formation in the atmosphere. However, so far, only two studies have dealt with BVOC exchanges from maize. Moreover, these studies were conducted on a limited range of meteorological and phenological conditions, so that the knowledge of BVOC exchanges by this crop remains poor. Here, we present the first BVOC measurement campaign performed at ecosystem-scale on a maize field during a whole growing season. It was carried out in the Lonzée Terrestrial Observatory (LTO), an ICOS site. BVOC fluxes were measured by the disjunct by mass-scanning eddy covariance technique with a proton transfer reaction mass spectrometer for BVOC mixing ratios measurements. Outstanding results are (i) BVOC exchanges from soil were as important as BVOC exchanges from maize itself; (ii) BVOC exchanges observed on our site were much lower than exchanges observed by other maize studies, even under normalized temperature and light conditions, (iii) they were also lower than those observed on other crops grown in Europe. Lastly (iv), BVOC exchanges observed on our site under standard environmental conditions, i.e., standard emission factors SEF, were much lower than those currently considered by BVOC exchange up-scaling models. From those observations, we deduced that (i) soil BVOC exchanges should be better understood and should be incorporated in terrestrial BVOC exchanges models, and that (ii) SEF for the C4 crop plant functional type cannot be evaluated at global scale but should be determined for each important agronomic and pedo-climatic region. Moreover, as in our region (i.e., temperate climate, silty-loam soils), SEF observed on maize were much lower than SEF currently considered by models, our results tend to lower the impact of agricultural ecosystems on BVOC exchanges.

Combined role of heat and water stresses on wheat, maize and rice inter-annual variability and trend from 1980 to 2010.

NASA Astrophysics Data System (ADS)

Zampieri, M.; Ceglar, A., , Dr; Dentener, F., , Dr; van den Berg, M., , Dr; Toreti, A., , Dr

2017-12-01

Heat waves and drought are often considered the most damaging climatic stressors for wheat and maize. In this study, based on data derived from observations, we characterize and attribute the effects of these climate extremes on wheat and maize yield anomalies (at global and national scales) with respect to the mean trend from 1980 to 2010. Using a combination of up-to-date heat wave and drought indexes (i.e. the Heat Magnitude Day, HMD, and the Standardized Precipitation Evapotranspiration Index, SPEI), we have developed a composite indicator (i.e. the Combined Stress Index, CSI) that is able to capture the spatio-temporal characteristics of the underlying physical processes in the different agro-climatic regions of the world. At the global level, our diagnostic explains the 42% and the 50% of the inter-annual wheat and maize production variabilities, respectively. The relative importance of heat stress and drought in determining the yield anomalies depends on the region. Compared to maize, and in contrast to common perception, water excess affects wheat production more than drought in several countries. The index definition can be modified in order to quantify the role of combined heat and water stress events occurrence in determining the recorded yield trends as well. Climate change is increasingly limiting maize yields in several countries, especially in Europe and China. A comparable opposite signal, albeit less statistically significant, is found for the USA, which is the main world producer. As for rice, we provide a statistical evidence pointing out to the importance of considering the interactions with the horizontal surface waters fluxes carried out by the rivers. In fact, compared to wheat and maize, the CSI statistical skills in explaining rice production variability are quite reduced. This issue is particularly relevant in paddy fields and flooded lowlands where rice is mainly grown. Therefore, we have modified the procedure including a proxy for the surface freshwater availability i.e. the Standardized River Discharge Index (SRDI), defined in this study. The modified CSI explains the 35% of the global rice production inter-annual anomalies.

Hydroxycinnamate Synthesis and Association with Mediterranean Corn Borer Resistance.

PubMed

Santiago, Rogelio; Malvar, Rosa Ana; Barros-Rios, Jaime; Samayoa, Luis Fernando; Butrón, Ana

2016-01-27

Previous results suggest a relationship between maize hydroxycinnamate concentration in the pith tissues and resistance to stem tunneling by Mediterranean corn borer (MCB, Sesamia nonagrioides Lef.) larvae. This study performs a more precise experiment, mapping an F2 derived from the cross between two inbreds with contrasting levels for hydroxycinnamates EP125 × PB130. We aimed to co-localize genomic regions involved in hydroxycinnamate synthesis and resistance to MCB and to highlight the particular route for each hydroxycinnamate component in relation to the better known phenylpropanoid pathway. Seven quantitative trait loci (QTLs) for p-coumarate, two QTLs for ferulate, and seven QTLs for total diferulates explained 81.7, 26.9, and 57.8% of the genotypic variance, respectively. In relation to borer resistance, alleles for increased hydroxycinnamate content (affecting one or more hydroxycinnamate compounds) could be associated with favorable effects on stem resistance to MCB, particularly the putative role of p-coumarate in borer resistance.

Transgenic elite indica rice plants expressing CryIAc delta-endotoxin of Bacillus thuringiensis are resistant against yellow stem borer (Scirpophaga incertulas).

PubMed

Nayak, P; Basu, D; Das, S; Basu, A; Ghosh, D; Ramakrishnan, N A; Ghosh, M; Sen, S K

1997-03-18

Generation of insect-resistant, transgenic crop plants by expression of the insecticidal crystal protein (ICP) gene of Bacillus thuringiensis (Bt) is a standard crop improvement approach. In such cases, adequate expression of the most appropriate ICP against the target insect pest of the crop species is desirable. It is also considered advantageous to generate Bt-transgenics with multiple toxin systems to control rapid development of pest resistance to the ICP. Larvae of yellow stem borer (YSB), Scirpophaga incertulas, a major lepidopteran insect pest of rice, cause massive losses of rice yield. Studies on insect feeding and on the binding properties of ICP to brush border membrane receptors in the midgut of YSB larvae revealed that cryIAb and cryIAc are two individually suitable candidate genes for developing YSB-resistant rice. Programs were undertaken to develop Bt-transgenic rice with these ICP genes independently in a single cultivar. A cryIAc gene was reconstructed and placed under control of the maize ubiquitin 1 promoter, along with the first intron of the maize ubiquitin 1 gene, and the nos terminator. The gene construct was delivered to embryogenic calli of IR64, an elite indica rice cultivar, using the particle bombardment method. Six highly expressive independent transgenic ICP lines were identified. Molecular analyses and insect-feeding assays of two such lines revealed that the transferred synthetic cryIAc gene was expressed stably in the T2 generation of these lines and that the transgenic rice plants were highly toxic to YSB larvae and lessened the damage caused by their feeding.

Preliminary Studies to Characterize the Temporal Variation of Micronutrient Composition of the Above Ground Organs of Maize and Correlated Uptake Rates

PubMed Central

Martins, Karla Vilaça; Dourado-Neto, Durval; Reichardt, Klaus; de Jong van Lier, Quirijn; Favarin, José Laércio; Sartori, Felipe Fadel; Felisberto, Guilherme; Mello, Simone da Costa

2017-01-01

The improvement of agronomic practices and the use of high technology in field crops contributes for significant increases in maize productivity, and may have altered the dynamics of nutrient uptake and partition by the plant. Official recommendations for fertilizer applications to the maize crop in Brazil and in many countries are based on critical soil nutrient contents and are relatively outdated. Since the factors that interact in an agricultural production system are dynamic, mathematical modeling of the growth process turns out to be an appropriate tool for these studies. Agricultural modeling can expand our knowledge about the interactions prevailing in the soil-plant-atmosphere system. The objective of this study is to propose a methodology for characterizing the micronutrient composition of different organs and their extraction, and export during maize crop development, based on modeling nutrient uptake, crop potential evapotranspiration and micronutrient partitioning in the plant, considering the production environment. This preliminary characterization study (experimental growth analysis) considers the temporal variation of the micronutrient uptake rate in the aboveground organs, which defines crop needs and the critical nutrient content of the soil solution. The methodology allowed verifying that, initially, the highest fraction of dry matter, among aboveground organs, was assigned to the leaves. After the R1 growth stage, the largest part of dry matter was partitioned to the stalk, which in this growth stage is the main storage organ of the maize plant. During the reproductive phase, the highest fraction of dry matter was conferred to the reproductive organs, due to the high demand for carbohydrates for grain filling. The micronutrient (B, Cu, Fe, Mn, and Zn) content follows a power model, with higher values for the initial growth stages of development and leveling off to minimum values at the R6 growth stage. The proposed model allows to verify that fertilizer recommendations should be related to the temporal variability of micronutrient absorption rates, in contrast to the classic recommendation based on the critical soil micronutrient content. The maximum micronutrient absorption rates occur between the reproductive R4 and R5 growth stages. These evaluations allowed to predict the maximum micronutrient requirements, considered equal to respective stalk sap concentrations. PMID:28919900

Agrobacterium-transformed rice plants expressing synthetic cryIA(b) and cryIA(c) genes are highly toxic to striped stem borer and yellow stem borer.

PubMed

Cheng, X; Sardana, R; Kaplan, H; Altosaar, I

1998-03-17

Over 2,600 transgenic rice plants in nine strains were regenerated from >500 independently selected hygromycin-resistant calli after Agrobacterium-mediated transformation. The plants were transformed with fully modified (plant codon optimized) versions of two synthetic cryIA(b) and cryIA(c) coding sequences from Bacillus thuringiensis as well as the hph and gus genes, coding for hygromycin phosphotransferase and beta-glucuronidase, respectively. These sequences were placed under control of the maize ubiquitin promoter, the CaMV35S promoter, and the Brassica Bp10 gene promoter to achieve high and tissue-specific expression of the lepidopteran-specific delta-endotoxins. The integration, expression, and inheritance of these genes were demonstrated in R0 and R1 generations by Southern, Northern, and Western analyses and by other techniques. Accumulation of high levels (up to 3% of soluble proteins) of CryIA(b) and CryIA(c) proteins was detected in R0 plants. Bioassays with R1 transgenic plants indicated that the transgenic plants were highly toxic to two major rice insect pests, striped stem borer (Chilo suppressalis) and yellow stem borer (Scirpophaga incertulas), with mortalities of 97-100% within 5 days after infestation, thus offering a potential for effective insect resistance in transgenic rice plants.

In vivo protein quality of selected cereal-based staple foods enriched with soybean proteins.

PubMed

Acevedo-Pacheco, Laura; Serna-Saldívar, Sergio O

2016-01-01

One way to diminish protein malnutrition in children is by enriching cereal-based flours for the manufacturing of maize tortillas, wheat flour tortillas, and yeast-leavened breads, which are widely consumed among low socio-economic groups. The aim was to determine and compare the essential amino acid (EAA) scores, protein digestibility corrected amino acid scores (PDCAAS), and in vivo protein quality (protein digestibility, protein efficiency ratio (PER), biological values (BV), and net protein utilization (NPU) values) of regular versus soybean-fortified maize tortillas, yeast-leavened bread, and wheat flour tortillas. To comparatively assess differences in protein quality among maize tortillas, wheat flour tortillas, and yeast-leavened breads, EAA compositions and in vivo studies with weanling rats were performed. The experimental diets based on regular or soybean-fortified food products were compared with a casein-based diet. Food intake, weight gains, PER, dry matter and protein digestibility, BV, NPU, and PDCAAS were assessed. The soybean-fortified tortillas contained 6% of defatted soybean flour, whereas the yeast-leavened bread flour contained 4.5% of soybean concentrate. The soybean-fortified tortillas and bread contained higher amounts of lysine and tryptophan, which improved their EAA scores and PDCAAS. Rats fed diets based on soybean-fortified maize or wheat tortillas gained considerably more weight and had better BV and NPU values compared with counterparts fed with respective regular products. As a result, fortified maize tortillas and wheat flour tortillas improved PER from 0.73 to 1.64 and 0.69 to 1.77, respectively. The PER improvement was not as evident in rats fed the enriched yeast-leavened bread because the formulation contained sugar that decreased lysine availability possibly to Maillard reactions. The proposed enrichment of cereal-based foods with soybean proteins greatly improved PDCAAS, animal growth, nitrogen retention, and PER primarily in both maize and wheat flour tortillas. Therefore, these foods can help to diminish protein malnutrition among children who greatly depend on cereals as the main protein dietary source.

Overestimation of Crop Root Biomass in Field Experiments Due to Extraneous Organic Matter.

PubMed

Hirte, Juliane; Leifeld, Jens; Abiven, Samuel; Oberholzer, Hans-Rudolf; Hammelehle, Andreas; Mayer, Jochen

2017-01-01

Root biomass is one of the most relevant root parameters for studies of plant response to environmental change, soil carbon modeling or estimations of soil carbon sequestration. A major source of error in root biomass quantification of agricultural crops in the field is the presence of extraneous organic matter in soil: dead roots from previous crops, weed roots, incorporated above ground plant residues and organic soil amendments, or remnants of soil fauna. Using the isotopic difference between recent maize root biomass and predominantly C3-derived extraneous organic matter, we determined the proportions of maize root biomass carbon of total carbon in root samples from the Swiss long-term field trial "DOK." We additionally evaluated the effects of agricultural management (bio-organic and conventional), sampling depth (0-0.25, 0.25-0.5, 0.5-0.75 m) and position (within and between maize rows), and root size class (coarse and fine roots) as defined by sieve mesh size (2 and 0.5 mm) on those proportions, and quantified the success rate of manual exclusion of extraneous organic matter from root samples. Only 60% of the root mass that we retrieved from field soil cores was actual maize root biomass from the current season. While the proportions of maize root biomass carbon were not affected by agricultural management, they increased consistently with soil depth, were higher within than between maize rows, and were higher in coarse (>2 mm) than in fine (≤2 and >0.5) root samples. The success rate of manual exclusion of extraneous organic matter from root samples was related to agricultural management and, at best, about 60%. We assume that the composition of extraneous organic matter is strongly influenced by agricultural management and soil depth and governs the effect size of the investigated factors. Extraneous organic matter may result in severe overestimation of recovered root biomass and has, therefore, large implications for soil carbon modeling and estimations of the climate change mitigation potential of soils.

Automated DNA extraction from genetically modified maize using aminosilane-modified bacterial magnetic particles.

PubMed

Ota, Hiroyuki; Lim, Tae-Kyu; Tanaka, Tsuyoshi; Yoshino, Tomoko; Harada, Manabu; Matsunaga, Tadashi

2006-09-18

A novel, automated system, PNE-1080, equipped with eight automated pestle units and a spectrophotometer was developed for genomic DNA extraction from maize using aminosilane-modified bacterial magnetic particles (BMPs). The use of aminosilane-modified BMPs allowed highly accurate DNA recovery. The (A(260)-A(320)):(A(280)-A(320)) ratio of the extracted DNA was 1.9+/-0.1. The DNA quality was sufficiently pure for PCR analysis. The PNE-1080 offered rapid assay completion (30 min) with high accuracy. Furthermore, the results of real-time PCR confirmed that our proposed method permitted the accurate determination of genetically modified DNA composition and correlated well with results obtained by conventional cetyltrimethylammonium bromide (CTAB)-based methods.

Backscatter Analysis Using Multi-Temporal SENTINEL-1 SAR Data for Crop Growth of Maize in Konya Basin, Turkey

NASA Astrophysics Data System (ADS)

Abdikan, S.; Sekertekin, A.; Ustunern, M.; Balik Sanli, F.; Nasirzadehdizaji, R.

2018-04-01

Temporal monitoring of crop types is essential for the sustainable management of agricultural activities on both national and global levels. As a practical and efficient tool, remote sensing is widely used in such applications. In this study, Sentinel-1 Synthetic Aperture Radar (SAR) imagery was utilized to investigate the performance of the sensor backscatter image on crop monitoring. Multi-temporal C-band VV and VH polarized SAR images were acquired simultaneously by in-situ measurements which was conducted at Konya basin, central Anatolia Turkey. During the measurements, plant height of maize plant was collected and relationship between backscatter values and plant height was analysed. The maize growth development was described under Biologische Bundesanstalt, bundessortenamt und CHemische industrie (BBCH). Under BBCH stages, the test site was classified as leaf development, stem elongation, heading and flowering in general. The correlation coefficient values indicated high correlation for both polarimetry during the early stages of the plant, while late stages indicated lower values in both polarimetry. As a last step, multi-temporal coverage of crop fields was analysed to map seasonal land use. To this aim, object based image classification was applied following image segmentation. About 80 % accuracies of land use maps were created in this experiment. As preliminary results, it is concluded that Sentinel-1 data provides beneficial information about plant growth. Dual-polarized Sentinel-1 data has high potential for multi-temporal analyses for agriculture monitoring and reliable mapping.

Bioaccumulation and distribution of heavy metals in Maize, Oat and Sorghum Plants, grown in industrially polluted region

NASA Astrophysics Data System (ADS)

Angelova, Violina; Ivanova, Radka; Ivanov, Krasimir

2010-05-01

The uptake of heavy metals (Cd, Pb and Zn) by maize, oat and sorghum plants cultivated, under field conditions, in industrially polluted soils was studied. The experimental plots were situated at different distances (0.1, 2.0 and 15.0 km) from the source of pollution - the Non-Ferrous Metal Works near Plovdiv, Bulgaria. On reaching commercial ripeness the crops were gathered and the contents of heavy metals in their different parts - roots, stems, leaves and grains, were determined after dry ashing. The quantitative measurements were carried out with ICP. A clearly distinguished species peculiarity existed in the accumulation of heavy metals in the vegetative and reproductive organs of the studied crops. Sorghum plants accumulated larger heavy metal quantities compared to maize and oat plants, as the major part of heavy metals was retained by roots and a very small part was translocated to epigeous parts. The studied crops may be considered as metal-tolerant crops and may be cultivated on soils which are low, medium or highly contaminated with lead, zinc and cadmium, as they do not show a tendency of accumulating these elements in epigeous parts and grains above the maximum permissible concentrations. The possible use of aboveground mass and grains for animal food guarantees the economic expedience upon the selection of these crops. Acknowledgment: This work is supported by the Bulgarian Ministry of Education, Project DO-02-87/08.

Development by extrusion of soyabari snack sticks: a nutritionally improved soya-maize product based on the Nigerian snack (kokoro).

PubMed

Omueti, O; Morton, I D

1996-01-01

A nutritionally improved local snack compared to existing kokoro has been developed by extrusion cooking of different formulations of maize, soybean and condiments such as pepper, onion, salt, palm oil, plantain and banana. The improved snack was named as the 'soyabari snack stick'. The chemical composition of representative extruded products indicates a high level of crude protein, fat, energy, available lysine and improved in vitro digestibility compared to the usual maize-based products. The level of stachyose and raffinose were greatly reduced in the extruded products compared to raw soya. Formulations using various additives yielded products suitable for different consumers' preferences such as hot, sweet, bland, gritty or crispy and acceptable to taste assessors. Soyabari snack sticks were equally acceptable as Bombay mix, a product on the market in London. Sensory analysis showed no significant differences in the two products but the crude fibre content of Bombay mix was higher while the protein was slightly lower than for soyabari sticks. Local ingredients can produce acceptable extrudates.

The effect of triazole induced photosynthetic pigments and biochemical constituents of Zea mays L. (Maize) under drought stress

NASA Astrophysics Data System (ADS)

Rajasekar, Mahalingam; Rabert, Gabriel Amalan; Manivannan, Paramasivam

2016-06-01

In this investigation, pot culture experiment was carried out to estimate the ameliorating effect of triazole compounds, namely Triadimefon (TDM), Tebuconazole (TBZ), and Propiconazole (PCZ) on drought stress, photosynthetic pigments, and biochemical constituents of Zea mays L. (Maize). From 30 days after sowing (DAS), the plants were subjected to 4 days interval drought (DID) stress and drought with TDM at 15 mg l-1, TBZ at 10 mg l-1, and PCZ at 15 mg l-1. Irrigation at 1-day interval was kept as control. Irrigation performed on alternative day. The plant samples were collected on 40, 50, and 60 DAS and separated into root, stem, and leaf for estimating the photosynthetic pigments and biochemical constituents. Drought and drought with triazole compounds treatment increased the biochemical glycine betaine content, whereas the protein and the pigments contents chlorophyll-a, chlorophyll-b, total chlorophyll, carotenoid, and anthocyanin decreased when compared to control. The triazole treatment mitigated the adverse effects of drought stress by increasing the biochemical potentials and paved the way to overcome drought stress in corn plant.

Over-expression of a zeatin O-glucosylation gene in maize leads to growth retardation and tasselseed formation

PubMed Central

Rodo, Albert Pineda; Brugière, Norbert; Vankova, Radomira; Malbeck, Jiri; Olson, Jaleh M.; Haines, Sara C.; Martin, Ruth C.; Habben, Jeffrey E.; Mok, David W. S.; Mok, Machteld C.

2008-01-01

To study the effects of cytokinin O-glucosylation in monocots, maize (Zea mays L.) transformants harbouring the ZOG1 gene (encoding a zeatin O-glucosyltransferase from Phaseolus lunatus L.) under the control of the constitutive ubiquitin (Ubi) promoter were generated. The roots and leaves of the transformants had greatly increased levels of zeatin-O-glucoside. The vegetative characteristics of hemizygous and homozygous Ubi:ZOG1 plants resembled those of cytokinin-deficient plants, including shorter stature, thinner stems, narrower leaves, smaller meristems, and increased root mass and branching. Transformant leaves had a higher chlorophyll content and increased levels of active cytokinins compared with those of non-transformed sibs. The Ubi:ZOG1 plants exhibited delayed senescence when grown in the spring/summer. While hemizygous transformants had reduced tassels with fewer spikelets and normal viable pollen, homozygotes had very small tassels and feminized tassel florets, resembling tasselseed phenotypes. Such modifications of the reproductive phase were unexpected and demonstrate a link between cytokinins and sex-specific floral development in monocots. PMID:18515825

Linking Plant Nutritional Status to Plant-Microbe Interactions

PubMed Central

Carvalhais, Lilia C.; Dennis, Paul G.; Fan, Ben; Fedoseyenko, Dmitri; Kierul, Kinga; Becker, Anke; von Wiren, Nicolaus; Borriss, Rainer

2013-01-01

Plants have developed a wide-range of adaptations to overcome nutrient limitation, including changes to the quantity and composition of carbon-containing compounds released by roots. Root-associated bacteria are largely influenced by these compounds which can be perceived as signals or substrates. Here, we evaluate the effect of root exudates collected from maize plants grown under nitrogen (N), phosphate (P), iron (Fe) and potassium (K) deficiencies on the transcriptome of the plant growth promoting rhizobacterium (PGPR) Bacillus amyloliquefaciens FZB42. The largest shifts in gene expression patterns were observed in cells exposed to exudates from N-, followed by P-deficient plants. Exudates from N-deprived maize triggered a general stress response in FZB42 in the exponential growth phase, which was evidenced by the suppression of numerous genes involved in protein synthesis. Exudates from P-deficient plants induced bacterial genes involved in chemotaxis and motility whilst exudates released by Fe and K deficient plants did not cause dramatic changes in the bacterial transcriptome during exponential growth phase. Global transcriptional changes in bacteria elicited by nutrient deficient maize exudates were significantly correlated with concentrations of the amino acids aspartate, valine and glutamate in root exudates suggesting that transcriptional profiling of FZB42 associated with metabolomics of N, P, Fe and K-deficient maize root exudates is a powerful approach to better understand plant-microbe interactions under conditions of nutritional stress. PMID:23874669

Identification of lactic acid bacteria in the feces of dairy cows fed whole crop maize silage to assess the survival of silage bacteria in the gut.

PubMed

Han, Hongyan; Wang, Chao; Li, Yanbing; Yu, Zhu; Xu, Qingfang; Li, Guangpeng; Minh, Tang Thuy; Nishino, Naoki

2018-01-01

In order to assess the survival of lactic acid bacteria (LAB) in whole crop maize silage in the gut of dairy cows, one representative silage sample and three different feces samples were collected from dairy cows on three dairy farms in Hua Bei, China and three dairy farms in Kyushu, Japan. The composition of the bacterial community was examined by denaturing gradient gel electrophoresis and quantitative polymerase chain reaction. Lactobacillus acetotolerans was detected in all bunker-made maize silage samples, regardless of the dairy farm or sampling region from which they were sourced. A total of eight LAB species were detected in the maize silage samples, of which three (L. acetotolerans, L. pontis and L. casei) appeared to survive digestion. The populations of L. acetotolerans in silage and feces were 10 6-7 and 10 3-4 copies/g, respectively, indicating that, even for the LAB species showing potential survival in the gut, competition in this niche may be harsh and the population may substantially decrease during the digestion process. It may be difficult for silage LAB to survive in the gut of silage-fed dairy cows, because marked decrease in population can take place during the digestion process, even for surviving species. © 2017 Japanese Society of Animal Science.

Preliminary investigation of mineral content of pollen collected from different Serbian maize hybrids - is there any potential nutritional value?

PubMed

Kostić, Aleksandar Ž; Kaluđerović, Lazar M; Dojčinović, Biljana P; Barać, Miroljub B; Babić, Vojka B; Mačukanović-Jocić, Marina P

2017-07-01

Bee pollen has already proved to be a good supplement rich in iron and zinc. Studies on the application of flower pollen in the food industry and medicine have begun. Bearing in mind the prevalence of maize as a crop culture, its pollen will be easily available. The mineral composition of pollen of seven Serbian maize hybrids was analyzed in order to establish its nutritional value and the benefits of its implementation in the human diet using the inductively coupled plasma method. The presence of twenty four different macro- (nine) and micronutrients (fifteen) was detected. The most common minerals were phosphorus and potassium, while arsenic, cobalt, lead, nickel and molybdenum were found in some samples. Comparing the results obtained with recommended or tolerable dietary intake references for adults, it was found that maize pollen can be used as a very good source of zinc, iron, chromium and manganese for humans. With regard to selenium content, pollen samples proved to be moderately good source of this important micronutrient. Contents of some elements (Fe, Zn, Mn, Cr, Se, Al and V) showed significant differences depending on hybrid type. In some samples increased concentrations of aluminum and vanadium were recorded, which may pose a potential problem due to their toxicity. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Assessing the Metabolic Impact of Nitrogen Availability Using a Compartmentalized Maize Leaf Genome-Scale Model1[C][W][OPEN

PubMed Central

Simons, Margaret; Saha, Rajib; Amiour, Nardjis; Kumar, Akhil; Guillard, Lenaïg; Clément, Gilles; Miquel, Martine; Li, Zhenni; Mouille, Gregory; Lea, Peter J.; Hirel, Bertrand; Maranas, Costas D.

2014-01-01

Maize (Zea mays) is an important C4 plant due to its widespread use as a cereal and energy crop. A second-generation genome-scale metabolic model for the maize leaf was created to capture C4 carbon fixation and investigate nitrogen (N) assimilation by modeling the interactions between the bundle sheath and mesophyll cells. The model contains gene-protein-reaction relationships, elemental and charge-balanced reactions, and incorporates experimental evidence pertaining to the biomass composition, compartmentalization, and flux constraints. Condition-specific biomass descriptions were introduced that account for amino acids, fatty acids, soluble sugars, proteins, chlorophyll, lignocellulose, and nucleic acids as experimentally measured biomass constituents. Compartmentalization of the model is based on proteomic/transcriptomic data and literature evidence. With the incorporation of information from the MetaCrop and MaizeCyc databases, this updated model spans 5,824 genes, 8,525 reactions, and 9,153 metabolites, an increase of approximately 4 times the size of the earlier iRS1563 model. Transcriptomic and proteomic data have also been used to introduce regulatory constraints in the model to simulate an N-limited condition and mutants deficient in glutamine synthetase, gln1-3 and gln1-4. Model-predicted results achieved 90% accuracy when comparing the wild type grown under an N-complete condition with the wild type grown under an N-deficient condition. PMID:25248718

Impacts of kafirin allelic diversity, starch content, and protein digestibility on ethanol conversion efficiency in grain sorghum

USDA-ARS?s Scientific Manuscript database

Seed protein and starch composition determines the efficiency of ethanol conversion in the production of grain-based biofuels. Sorghum, highly water- and nutrient-efficient, has the potential to replace fuel crops with greater irrigation and fertiliser requirements, such as maize. However, sorghum g...

Biomass production and composition of temperate and tropical maize in central Iowa

USDA-ARS?s Scientific Manuscript database

Bioethanol production in the Midwestern U.S. has largely focused on corn (Zea mays L.) grain for starch-based ethanol production. There has been growing interest in lignocellulosic biomass as a feedstock for biofuels. Because corn adapted to the tropics does not initiate senescence as early as ada...

Composition of clusters and building blocks in amylopectins from maize mutants deficient in starch synthase III.

PubMed

Zhu, Fan; Bertoft, Eric; Seetharaman, Koushik

2013-12-18

Branches in amylopectin are distributed along the backbone. Units of the branches are building blocks (smaller) and clusters (larger) based on the distance between branches. In this study, composition of clusters and building blocks of amylopectins from dull1 maize mutants deficient in starch synthase III (SSIII) with a common genetic background (W64A) were characterized and compared with the wild type. Clusters were produced from amylopectins by partial hydrolysis using α-amylase of Bacillus amyloliquefaciens and were subsequently treated with phosphorylase a and β-amylase to produce φ,β-limit dextrins. Clusters were further extensively hydrolyzed with the α-amylase to produce building blocks. Structures of clusters and building blocks were analyzed by diverse chromatographic techniques. The results showed that the dull1 mutation resulted in larger clusters with more singly branched building blocks. The average cluster contained ~5.4 blocks in dull1 mutants and ~4.2 blocks in the wild type. The results are compared with previous results from SSIII-deficient amo1 barley and suggest fundamental differences in the cluster structures.

Scanning transmission electron microscopy methods for the analysis of nanoparticles.

PubMed

Ponce, Arturo; Mejía-Rosales, Sergio; José-Yacamán, Miguel

2012-01-01

Here we review the scanning transmission electron microscopy (STEM) characterization technique and STEM imaging methods. We describe applications of STEM for studying inorganic nanoparticles, and other uses of STEM in biological and health sciences and discuss how to interpret STEM results. The STEM imaging mode has certain benefits compared with the broad-beam illumination mode; the main advantage is the collection of the information about the specimen using a high angular annular dark field (HAADF) detector, in which the images registered have different levels of contrast related to the chemical composition of the sample. Another advantage of its use in the analysis of biological samples is its contrast for thick stained sections, since HAADF images of samples with thickness of 100-120 nm have notoriously better contrast than those obtained by other techniques. Combining the HAADF-STEM imaging with the new aberration correction era, the STEM technique reaches a direct way to imaging the atomistic structure and composition of nanostructures at a sub-angstrom resolution. Thus, alloying in metallic nanoparticles is directly resolved at atomic scale by the HAADF-STEM imaging, and the comparison of the STEM images with results from simulations gives a very powerful way of analysis of structure and composition. The use of X-ray energy dispersive spectroscopy attached to the electron microscope for STEM mode is also described. In issues where characterization at the atomic scale of the interaction between metallic nanoparticles and biological systems is needed, all the associated techniques to STEM become powerful tools for the best understanding on how to use these particles in biomedical applications.

Variation in energy sorghum hybrid TX08001 biomass composition and lignin chemistry during development under irrigated and non-irrigated field conditions

PubMed Central

Olson, Sara N.; Ritter, Kimberley B.; Herb, Dustin W.; Karlen, Steven D.; Lu, Fachuang; Ralph, John; Rooney, William L.; Mullet, John E.

2018-01-01

This study was conducted to document the extent and basis of compositional variation of shoot biomass of the energy Sorghum bicolor hybrid TX08001 during development under field conditions. TX08001 is capable of accumulating ~40 Mg/ha of dry biomass under good growing conditions and this genotype allocates ~80% of its shoot biomass to stems. After 150 days of growth TX08001 stems had a fresh/dry weight ratio of ~3:1 and soluble biomass accounted for ~30% of stem biomass. A panel of diverse energy sorghum genotypes varied ~6-fold in the ratio of stem structural to soluble biomass after 150 days of growth. Near-infrared spectroscopic analysis (NIRS) showed that TX08001 leaves accumulated higher levels of protein, water extractives and ash compared to stems, which have higher sugar, cellulose, and lignin contents. TX08001 stem sucrose content varied during development, whereas the composition of TX08001 stem cell walls, which consisted of ~45–49% cellulose, ~27–30% xylan, and ~15–18% lignin, remained constant after 90 days post emergence until the end of the growing season (180 days). TX08001 and Della stem syringyl (S)/guaiacyl (G) (0.53–0.58) and ferulic acid (FA)/para-coumaric acid (pCA) ratios were similar whereas ratios of pCA/(S+G) differed between these genotypes. Additionally, an analysis of irrigated versus non-irrigated TX08001 revealed that non-irrigated hybrids exhibited a 50% reduction in total cell wall biomass, an ~2-fold increase in stem sugars, and an ~25% increase in water extractives relative to irrigated hybrids. This study provides a baseline of information to help guide further optimization of energy sorghum composition for various end-uses. PMID:29684037

Effect of cotton bollworm (Helicoverpa armigera Hübner) caused injury on maize grain content, especially regarding to the protein alteration.

PubMed

Keszthelyi, S; Pál-Fám, F; Kerepesi, I

2011-03-01

The cotton bollworm (Helicoverpa armigera Hübner), which migrated in the Carpathian-basin from Mediterraneum in the last decades, is becoming an increasingly serious problem for maize producers in Hungary. In several regions the damage it causes has reached the threshold of economic loss, especially in the case of the sweet maize cultivation. The aim of the research was to determine the changing of ears weights and in-kernel accumulation and alteration in grain as a function of cotton bollworm mastication.Our investigation confirmed that there is an in-kernel and protein pattern change of maize grain by cotton bollworm. Our results proved the significant damaging of each part of ears by cotton bollworm masticating (the average weight loss of ears: 13.99%; the average weight loss of grains: 14.03%; the average weight loss of cobs: 13.74%), with the exception of the increasing of the grain-cob ratio. Our examinations did not prove the water loss - that is the "forced maturing" - caused by the damage. Decreasing of raw fat (control: 2.8%; part-damaged: 2.6%; damaged: 2.4%) and starch content (control: 53.1%; part-damaged: 46.6%; damaged: 44.7%) were registered as a function of injury. In contrast, the raw protein content was increased (control: 4.7%; part-damaged: 5.3%; damaged: 7.4%) by maize ear masticating. The most conspicuous effect on protein composition changing was proved by comparison of damaged grain samples by SDS PAGE. Increased amounts of 114, 50, 46 and 35 kDa molecular mass proteins were detected which explained the more than 50% elevation of raw protein content. The statistical analysis of molecular weights proved the protein realignment as a function of the pest injuries, too.

Testing Potential Effects of Maize Expressing the Bacillus thuringiensis Cry1Ab Endotoxin (Bt Maize) on Mycorrhizal Fungal Communities via DNA- and RNA-Based Pyrosequencing and Molecular Fingerprinting

PubMed Central

Kuramae, Eiko E.; Hillekens, Remy; de Hollander, Mattias; Kiers, E. Toby; Röling, Wilfred F. M.; Kowalchuk, George A.; van der Heijden, Marcel G. A.

2012-01-01

The cultivation of genetically modified (GM) crops has increased significantly over the last decades. However, concerns have been raised that some GM traits may negatively affect beneficial soil biota, such as arbuscular mycorrhizal fungi (AMF), potentially leading to alterations in soil functioning. Here, we test two maize varieties expressing the Bacillus thuringiensis Cry1Ab endotoxin (Bt maize) for their effects on soil AM fungal communities. We target both fungal DNA and RNA, which is new for AM fungi, and we use two strategies as an inclusive and robust way of detecting community differences: (i) 454 pyrosequencing using general fungal rRNA gene-directed primers and (ii) terminal restriction fragment length polymorphism (T-RFLP) profiling using AM fungus-specific markers. Potential GM-induced effects were compared to the normal natural variation of AM fungal communities across 15 different agricultural fields. AM fungi were found to be abundant in the experiment, accounting for 8% and 21% of total recovered DNA- and RNA-derived fungal sequences, respectively, after 104 days of plant growth. RNA- and DNA-based sequence analyses yielded most of the same AM fungal lineages. Our research yielded three major conclusions. First, no consistent differences were detected between AM fungal communities associated with GM plants and non-GM plants. Second, temporal variation in AMF community composition (between two measured time points) was bigger than GM trait-induced variation. Third, natural variation of AMF communities across 15 agricultural fields in The Netherlands, as well as within-field temporal variation, was much higher than GM-induced variation. In conclusion, we found no indication that Bt maize cultivation poses a risk for AMF. PMID:22885748

Effect of Genetics, Environment, and Phenotype on the Metabolome of Maize Hybrids Using GC/MS and LC/MS.

PubMed

Tang, Weijuan; Hazebroek, Jan; Zhong, Cathy; Harp, Teresa; Vlahakis, Chris; Baumhover, Brian; Asiago, Vincent

2017-06-28

We evaluated the variability of metabolites in various maize hybrids due to the effect of environment, genotype, phenotype as well as the interaction of the first two factors. We analyzed 480 forage and the same number of grain samples from 21 genetically diverse non-GM Pioneer brand maize hybrids, including some with drought tolerance and viral resistance phenotypes, grown at eight North American locations. As complementary platforms, both GC/MS and LC/MS were utilized to detect a wide diversity of metabolites. GC/MS revealed 166 and 137 metabolites in forage and grain samples, respectively, while LC/MS captured 1341 and 635 metabolites in forage and grain samples, respectively. Univariate and multivariate analyses were utilized to investigate the response of the maize metabolome to the environment, genotype, phenotype, and their interaction. Based on combined percentages from GC/MS and LC/MS datasets, the environment affected 36% to 84% of forage metabolites, while less than 7% were affected by genotype. The environment affected 12% to 90% of grain metabolites, whereas less than 27% were affected by genotype. Less than 10% and 11% of the metabolites were affected by phenotype in forage and grain, respectively. Unsupervised PCA and HCA analyses revealed similar trends, i.e., environmental effect was much stronger than genotype or phenotype effects. On the basis of comparisons of disease tolerant and disease susceptible hybrids, neither forage nor grain samples originating from different locations showed obvious phenotype effects. Our findings demonstrate that the combination of GC/MS and LC/MS based metabolite profiling followed by broad statistical analysis is an effective approach to identify the relative impact of environmental, genetic and phenotypic effects on the forage and grain composition of maize hybrids.

Performance and meat quality characteristics of broilers fed fermented mixture of grated cassava roots and palm kernel cake as replacement for maize.

PubMed

Chukwukaelo, A K; Aladi, N O; Okeudo, N J; Obikaonu, H O; Ogbuewu, I P; Okoli, I C

2018-03-01

Performance and meat quality characteristics of broilers fed fermented mixture of grated cassava roots and palm kernel cake (FCP-mix) as a replacement for maize were studied. One hundred and eighty (180), 7-day-old broiler chickens were divided into six groups of 30 birds, and each group replicated thrice. Six experimental diets were formulated for both starter and finisher stages with diets 1 and 6 as controls. Diet 1 contained maize whereas diet 6 contained a 1:1 mixture of cassava root meal (CRM) and palm kernel cake (PKC). In diets 2, 3, 4, and 5, the FCP-mix replaced maize at the rate of 25, 50, 75, and 100%, respectively. Each group was assigned to one experimental diet in a completely randomized design. The proximate compositions of the diets were evaluated. Live weight, feed intake, feed conversion ratio (FCR), carcass weight, and sensory attributes of the meats were obtained from each replicate and data obtained was analyzed statistically. The results showed that live weight, average daily weight gain (ADWG), average daily feed intake (ADFI), and FCR of birds on treatment diets were better than those on the control diets (Diets 1 and 6). The feed cost per kilogram weight gained decreased with inclusion levels of FCP-mix. Birds on diet 1 recorded significantly (p < 0.05) higher dressing percentage than those on the other five treatments. The sensory attributes of the chicken meats were not significantly (p > 0.05) affected by the inclusion of FCP-mix in the diets. FCP-mix is a suitable substitute for maize in broiler diet at a replacement level of up to 100% for best live weight, carcass weight yield, and meat quality.

Genetic mapping of QTL for the sizes of eight consecutive leaves below the tassel in maize (Zea mays L.).

PubMed

Yang, Cong; Tang, Dengguo; Qu, Jingtao; Zhang, Ling; Zhang, Lei; Chen, Zhengjie; Liu, Jian

2016-11-01

A set of RIL population was used to detect QTL associated with the sizes of eight consecutive leaves, across different environments, and ten QTL clusters were identified as main QTLs. One of the important parameters of the maize leaf architecture that affects light penetration into the canopy, leaf size, has long attracted breeders' attention for optimizing the plant type of maize and for maximizing the grain yield (GY). In this study, we used 253 RIL lines derived from a cross between B73 and SICAU1212 to investigate the leaf widths (LWs), leaf lengths (LLs), and leaf areas (LAs) of eight consecutive leaves of maize below the tassel and GY across different environments and to identify quantitative traits loci (QTLs) controlling the above-mentioned traits, using inclusive interval mapping for single-environment analysis plus a mixed-model-based composite interval mapping for joint analysis. A total of 171 and 159 putative QTLs were detected through these two mapping methods, respectively. Single-environment mapping revealed that 39 stable QTLs explained more than 10 % of the phenotypic variance, and 35 of the 39 QTLs were also detected by joint analysis. In addition, joint analysis showed that nine of the 159 QTLs exhibited significant QTL × environment interaction and 15 significant epistatic interactions were identified. Approximately 47.17 % of the QTLs for leaf architectural traits in joint analysis were concentrated in ten main chromosomal regions, namely, bins 1.07, 2.02, 3.06, 4.09, 5.01, 5.02, 5.03-5.04, 5.07, 6.07, and 8.05. This study should provide a basis for further fine-mapping of these main genetic regions and improvement of maize leaf architecture.

A Comparative Evaluation of the Mechanical Properties of Two Calcium Phosphate/Collagen Composite Materials and Their Osteogenic Effects on Adipose-Derived Stem Cells

PubMed Central

Li, Qing; Wang, Tong; Zhang, Gui-feng; Yu, Xin; Zhang, Jing; Zhou, Gang; Tang, Zhi-hui

2016-01-01

Adipose-derived stem cells (ADSCs) are ideal seed cells for use in bone tissue engineering and they have many advantages over other stem cells. In this study, two kinds of calcium phosphate/collagen composite scaffolds were prepared and their effects on the proliferation and osteogenic differentiation of ADSCs were investigated. The hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) composite scaffolds (HTPSs), which have an additional β-tricalcium phosphate, resulted in better proliferation of ADSCs and showed osteogenesis-promoting effects. Therefore, such composite scaffolds, in combination with ADSCs or on their own, would be promising for use in bone regeneration and potential clinical therapy for bone defects. PMID:27239204

Developing Pericarp of Maize: A Model to Study Arabinoxylan Synthesis and Feruloylation

PubMed Central

Chateigner-Boutin, Anne-Laure; Ordaz-Ortiz, José J.; Alvarado, Camille; Bouchet, Brigitte; Durand, Sylvie; Verhertbruggen, Yves; Barrière, Yves; Saulnier, Luc

2016-01-01

Cell walls are comprised of networks of entangled polymers that differ considerably between species, tissues and developmental stages. The cell walls of grasses, a family that encompasses major crops, contain specific polysaccharide structures such as xylans substituted with feruloylated arabinose residues. Ferulic acid is involved in the grass cell wall assembly by mediating linkages between xylan chains and between xylans and lignins. Ferulic acid contributes to the physical properties of cell walls, it is a hindrance to cell wall degradability (thus biomass conversion and silage digestibility) and may contribute to pest resistance. Many steps leading to the formation of grass xylans and their cross-linkages remain elusive. One explanation might originate from the fact that many studies were performed on lignified stem tissues. Pathways leading to lignins and feruloylated xylans share several steps, and lignin may impede the release and thus the quantification of ferulic acid. To overcome these difficulties, we used the pericarp of the maize B73 line as a model to study feruloylated xylan synthesis and crosslinking. Using Fourier-transform infra-red spectroscopy and biochemical analyses, we show that this tissue has a low lignin content and is composed of approximately 50% heteroxylans and approximately 5% ferulic acid. Our study shows that, to date, maize pericarp contains the highest level of ferulic acid reported in plant tissue. The detection of feruloylated xylans with a polyclonal antibody shows that the occurrence of these polysaccharides is developmentally regulated in maize grain. We used the genomic tools publicly available for the B73 line to study the expression of genes within families involved or suggested to be involved in the phenylpropanoid pathway, xylan formation, feruloylation and their oxidative crosslinking. Our analysis supports the hypothesis that the feruloylated moiety of xylans originated from feruloylCoA and is transferred by a member of the BAHD acyltransferase family. We propose candidate genes for functional characterization that could subsequently be targeted for grass crop breeding. PMID:27746801

Agricultural expansion as risk to endangered wildlife: Pesticide exposure in wild chimpanzees and baboons displaying facial dysplasia.

PubMed

Krief, Sabrina; Berny, Philippe; Gumisiriza, Francis; Gross, Régine; Demeneix, Barbara; Fini, Jean Baptiste; Chapman, Colin A; Chapman, Lauren J; Seguya, Andrew; Wasswa, John

2017-11-15

Prenatal exposure to environmental endocrine disruptors can affect development and induce irreversible abnormalities in both humans and wildlife. The northern part of Kibale National Park, a mid-altitude rainforest in western Uganda, is largely surrounded by industrial tea plantations and wildlife using this area (Sebitoli) must cope with proximity to human populations and their activities. The chimpanzees and baboons in this area raid crops (primarily maize) in neighboring gardens. Sixteen young individuals of the 66 chimpanzees monitored (25%) exhibit abnormalities including reduced nostrils, cleft lip, limb deformities, reproductive problems and hypopigmentation. Each pathology could have a congenital component, potentially exacerbated by environmental factors. In addition, at least six of 35 photographed baboons from a Sebitoli troop (17%) have similar severe nasal deformities. Our inquiries in villages and tea factories near Sebitoli revealed use of eight pesticides (glyphosate, cypermethrin, profenofos, mancozeb, metalaxyl, dimethoate, chlorpyrifos and 2,4-D amine). Chemical analysis of samples collected from 2014 to 2016 showed that mean levels of pesticides in fresh maize stems and seeds, soils, and river sediments in the vicinity of the chimpanzee territory exceed recommended limits. Notably, excess levels were found for total DDT and its metabolite pp'-DDE and for chlorpyrifos in fresh maize seeds and in fish from Sebitoli. Imidacloprid was detected in coated maize seeds planted at the edge the forest and in fish samples from the Sebitoli area, while no pesticides were detected in fish from central park areas. Since some of these pesticides are thyroid hormone disruptors, we postulate that excessive pesticide use in the Sebitoli area may contribute to facial dysplasia in chimpanzees and baboons through this endocrine pathway. Chimpanzees are considered as endangered by IUCN and besides their intrinsic value and status as closely related to humans, they have major economic value in Uganda via ecotourism. Identifying and limiting potential threats to their survival such be a conservation priority. Copyright © 2017 Elsevier B.V. All rights reserved.

QTL Mapping of Agronomic Waterlogging Tolerance Using Recombinant Inbred Lines Derived from Tropical Maize (Zea mays L) Germplasm

PubMed Central

Zaidi, Pervez Haider; Rashid, Zerka; Vinayan, Madhumal Thayil; Almeida, Gustavo Dias; Phagna, Ramesh Kumar; Babu, Raman

2015-01-01

Waterlogging is an important abiotic stress constraint that causes significant yield losses in maize grown throughout south and south-east Asia due to erratic rainfall patterns. The most economic option to offset the damage caused by waterlogging is to genetically incorporate tolerance in cultivars that are grown widely in the target agro-ecologies. We assessed the genetic variation in a population of recombinant inbred lines (RILs) derived from crossing a waterlogging tolerant line (CAWL-46-3-1) to an elite but sensitive line (CML311-2-1-3) and observed significant range of variation for grain yield (GY) under waterlogging stress along with a number of other secondary traits such as brace roots (BR), chlorophyll content (SPAD), % stem and root lodging (S&RL) among the RILs. Significant positive correlation of GY with BR and SPAD and negative correlation with S&RL indicated the potential use of these secondary traits in selection indices under waterlogged conditions. RILs were genotyped with 331 polymorphic single nucleotide polymorphism (SNP) markers using KASP (Kompetitive Allele Specific PCR) Platform. QTL mapping revealed five QTL on chromosomes 1, 3, 5, 7 and 10, which together explained approximately 30% of phenotypic variance for GY based on evaluation of RIL families under waterlogged conditions, with effects ranging from 520 to 640 kg/ha for individual genomic regions. 13 QTL were identified for various secondary traits associated with waterlogging tolerance, each individually explaining from 3 to 14% of phenotypic variance. Of the 22 candidate genes with known functional domains identified within the physical intervals delimited by the flanking markers of the QTL influencing GY and other secondary traits, six have previously been demonstrated to be associated with anaerobic responses in either maize or other model species. A pair of flanking SNP markers has been identified for each of the QTL and high throughput marker assays were developed to facilitate rapid introgression of waterlogging tolerance in tropical maize breeding programs. PMID:25884393

QTL mapping of agronomic waterlogging tolerance using recombinant inbred lines derived from tropical maize (Zea mays L) germplasm.

PubMed

Zaidi, Pervez Haider; Rashid, Zerka; Vinayan, Madhumal Thayil; Almeida, Gustavo Dias; Phagna, Ramesh Kumar; Babu, Raman

2015-01-01

Waterlogging is an important abiotic stress constraint that causes significant yield losses in maize grown throughout south and south-east Asia due to erratic rainfall patterns. The most economic option to offset the damage caused by waterlogging is to genetically incorporate tolerance in cultivars that are grown widely in the target agro-ecologies. We assessed the genetic variation in a population of recombinant inbred lines (RILs) derived from crossing a waterlogging tolerant line (CAWL-46-3-1) to an elite but sensitive line (CML311-2-1-3) and observed significant range of variation for grain yield (GY) under waterlogging stress along with a number of other secondary traits such as brace roots (BR), chlorophyll content (SPAD), % stem and root lodging (S&RL) among the RILs. Significant positive correlation of GY with BR and SPAD and negative correlation with S&RL indicated the potential use of these secondary traits in selection indices under waterlogged conditions. RILs were genotyped with 331 polymorphic single nucleotide polymorphism (SNP) markers using KASP (Kompetitive Allele Specific PCR) Platform. QTL mapping revealed five QTL on chromosomes 1, 3, 5, 7 and 10, which together explained approximately 30% of phenotypic variance for GY based on evaluation of RIL families under waterlogged conditions, with effects ranging from 520 to 640 kg/ha for individual genomic regions. 13 QTL were identified for various secondary traits associated with waterlogging tolerance, each individually explaining from 3 to 14% of phenotypic variance. Of the 22 candidate genes with known functional domains identified within the physical intervals delimited by the flanking markers of the QTL influencing GY and other secondary traits, six have previously been demonstrated to be associated with anaerobic responses in either maize or other model species. A pair of flanking SNP markers has been identified for each of the QTL and high throughput marker assays were developed to facilitate rapid introgression of waterlogging tolerance in tropical maize breeding programs.

Influence of Grape Seeds and Stems on Wine Composition and Astringency.

PubMed

Pascual, Olga; González-Royo, Elena; Gil, Mariona; Gómez-Alonso, Sergio; García-Romero, Esteban; Canals, Joan Miquel; Hermosín-Gutíerrez, Isidro; Zamora, Fernando

2016-08-31

The aim of this paper is to study the real influence of seeds and stems on wine composition, astringency, and bitterness. A decolored grape juice and a grape juice macerated for 4 days from the same Cabernet Sauvignon grapes were fermented with or without supplementation with 100% seeds, 300% seeds, or 100% stems. Once alcoholic fermentation had finished, the wines were analyzed and tasted. The presence of seeds and stems increased the concentration of flavan-3-ol monomers with respect to the controls. However, the seeds mainly released (+)-catechin and (-)-epicatechin, whereas the stems mainly released (+)-catechin and (+)-gallocatechin. The seeds and stems also released proanthocyanidins; those from seeds have a lower mDP and a high percentage of galloylation, whereas those from stems have a higher mDP and a relatively high percentage of prodelphinidins. The presence of seeds and stems brought about a slight but significant increase in pH and lowered titratable acidity and ethanol content. The presence of seeds boosted color intensity, whereas stems had the opposite effect. Finally, both seeds and stems increased wine astringency and bitterness.

Directing stem cell fate on hydrogel substrates by controlling cell geometry, matrix mechanics and adhesion ligand composition.

PubMed

Lee, Junmin; Abdeen, Amr A; Zhang, Douglas; Kilian, Kristopher A

2013-11-01

There is a dynamic relationship between physical and biochemical signals presented in the stem cell microenvironment to guide cell fate determination. Model systems that modulate cell geometry, substrate stiffness or matrix composition have proved useful in exploring how these signals influence stem cell fate. However, the interplay between these physical and biochemical cues during differentiation remains unclear. Here, we demonstrate a microengineering strategy to vary single cell geometry and the composition of adhesion ligands - on substrates that approximate the mechanical properties of soft tissues - to study adipogenesis and neurogenesis in adherent mesenchymal stem cells. Cells cultured in small circular islands show elevated expression of adipogenesis markers while cells that spread in anisotropic geometries tend to express elevated neurogenic markers. Arraying different combinations of matrix protein in a myriad of 2D and pseudo-3D geometries reveals optimal microenvironments for controlling the differentiation of stem cells to these "soft" lineages without the use of media supplements. © 2013 Elsevier Ltd. All rights reserved.

Deep UV autofluorescence microscopy for cell biology and tissue histology.

PubMed

Jamme, Frédéric; Kascakova, Slavka; Villette, Sandrine; Allouche, Fatma; Pallu, Stéphane; Rouam, Valérie; Réfrégiers, Matthieu

2013-07-01

Autofluorescence spectroscopy is a powerful tool for molecular histology and for following metabolic processes in biological samples as it does not require labelling. However, at the microscopic scale, it is mostly limited to visible and near infrared excitation of the samples. Several interesting and naturally occurring fluorophores can be excited in the UV and deep UV (DUV), but cannot be monitored in cellulo nor in vivo due to a lack of available microscopic instruments working in this wavelength range. To fulfil this need, we have developed a synchrotron-coupled DUV microspectrofluorimeter which is operational since 2010. An extended selection of endogenous autofluorescent probes that can be excited in DUV, including their spectral characteristics, is presented. The distribution of the probes in various biological samples, including cultured cells, soft tissues, bone sections and maize stems, is shown to illustrate the possibilities offered by this system. In this work we demonstrate that DUV autofluorescence is a powerful tool for tissue histology and cell biology. To fulfil this need, we have developed a synchrotron-coupled DUV microspectrofluorimeter which is operational since 2010. An extended selection of endogenous autofluorescent probes that can be excited in DUV, including their spectral characteristics, is presented. The distribution of the probes in various biological samples, including cultured cells, soft tissues, bone sections and maize stems, is shown to illustrate the possibilities offered by this system. In this work we demonstrate that DUV autofluorescence is a powerful tool for tissue histology and cell biology. In this work we demonstrate that DUV autofluorescence is a powerful tool for tissue histology and cell biology. © 2013 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.

Transgenic elite indica rice plants expressing CryIAc ∂-endotoxin of Bacillus thuringiensis are resistant against yellow stem borer (Scirpophaga incertulas)

PubMed Central

Nayak, Pritilata; Basu, Debabrata; Das, Sampa; Basu, Asitava; Ghosh, Dipankar; Ramakrishnan, Neeliyath A.; Ghosh, Maloy; Sen, Soumitra K.

1997-01-01

Generation of insect-resistant, transgenic crop plants by expression of the insecticidal crystal protein (ICP) gene of Bacillus thuringiensis (Bt) is a standard crop improvement approach. In such cases, adequate expression of the most appropriate ICP against the target insect pest of the crop species is desirable. It is also considered advantageous to generate Bt-transgenics with multiple toxin systems to control rapid development of pest resistance to the ICP. Larvae of yellow stem borer (YSB), Scirpophaga incertulas, a major lepidopteran insect pest of rice, cause massive losses of rice yield. Studies on insect feeding and on the binding properties of ICP to brush border membrane receptors in the midgut of YSB larvae revealed that cryIAb and cryIAc are two individually suitable candidate genes for developing YSB-resistant rice. Programs were undertaken to develop Bt-transgenic rice with these ICP genes independently in a single cultivar. A cryIAc gene was reconstructed and placed under control of the maize ubiquitin 1 promoter, along with the first intron of the maize ubiquitin 1 gene, and the nos terminator. The gene construct was delivered to embryogenic calli of IR64, an elite indica rice cultivar, using the particle bombardment method. Six highly expressive independent transgenic ICP lines were identified. Molecular analyses and insect-feeding assays of two such lines revealed that the transferred synthetic cryIAc gene was expressed stably in the T2 generation of these lines and that the transgenic rice plants were highly toxic to YSB larvae and lessened the damage caused by their feeding. PMID:9122157

[The effect of size reduction of corn silage on feed intake, milk production and milk composition of cows].

PubMed

Preissinger, W; Schwarz, F J; Kirchgessner, M

1998-01-01

In three experiments (E1, E2, E3) maize silage of different physical structure and of different stage of maturity at harvest were fed to 24 (E1), 36 (E2) or 28 (E3) dairy cows. The cows were fed individually over an experimental period of five or six weeks. The maize silages had a mean DM content of 28% (E1), 32% (E2) or 36% (E3). At the stage of harvest, the stovers and the cobs had a mean DM content of < 22% (E1, E2) or 27% (E3), 40% (E1), 46% (E2) or 57% (E3), respectively. The maize was harvested with a chopping length of 4 and 8 mm (E1, E3) and of 6 and 8 mm (E2), without corn cracking (E1) or with and without corn cracking (E2, E3). The daily feed ration consisted of ad libitum offered maize silage, 1.7 kg DM hay, soya bean meal (E2, E3) and concentrate. The different chopping length of 4 mm, 6 mm or 8 mm had no effect on the maize silage intake in E1 and E2. In E3 the daily maize silage intake increased by about 1.2 kg DM per cow at a chopping length of 4 mm in comparison to 8 mm, whereas only the treatment with the combination of 4 mm chopping length and corn cracking showed a significant increase in DMI. The corn cracking improved the milk yield significantly (E2) or in a tendency (E3) at 2.0 kg (E2) or at 1.6 kg (E2), while the variation of chopping length had no effect on milk yield. The different physical structure did not influence the milk fat content with mean values of 4.65% (E1), 4.15% (E2) and 4.10% (E3), respectively. The milk protein content decreased in E2 feeding maize silage with a chopping length of 8 mm and corn cracking; but in E1 and E3 no effect was seen on protein content with mean values of 3.66% (E1) or 3.51% (E2).

Accumulation of Cd, Cu and Zn in shoots of maize (Zea mays L.) exposed to 0.8 or 20 nM Cd during vegetative growth and the relation with xylem sap composition.

PubMed

Nguyen, C; Soulier, A J; Masson, P; Bussière, S; Cornu, J Y

2016-02-01

This work focuses on the exposure of maize plants to nanomolar concentrations of Cd, which is relevant for agricultural soils cropped with food and feed plants. Maize plants were cultivated in nutrient solution at 0.8 or 20 nM Cd during the vegetative growth stages. No significant hormesis or toxic effects of Cd were observed on maize growth, but a decrease in the allocation of Cd to shoots between the 0.8 and 20 nM Cd exposures revealed that the plants already responded to these low concentrations of Cd according to a shoot Cd excluder strategy. The Cd, Cu and Zn concentrations in shoots decreased with time as the result of an early decrease in the root/shoot ratio and of a decrease in the coefficient of allocation to aboveground for Zn and Cd at 20 nM. As a consequence, shoots of young plants were richer in micronutrients Cu and Zn but also in toxic Cd. The rate of delivery of Cd, Cu and Zn from xylem sap was successfully used to predict the time course of concentrations of Cd, Cu and Zn in the shoot. However, it overestimated the actual concentrations of Cd in the shoot, presumably because the reallocation of this trace element from shoots back to roots was not taken into account.

Comparison of stem morphology and anatomy of two alfalfa clonal lines exhibiting divergent cell wall composition.

PubMed

Gronwald, John W; Bucciarelli, Bruna

2013-08-30

In previous research, two alfalfa clonal lines (252 and 1283) were identified that exhibited environmentally stable differences in stem cell walls. Compared with stems of 1283, stems of 252 have a higher cell wall concentration and greater amounts of lignin and cellulose but reduced levels of pectic sugar residues. These results suggest greater deposition of secondary xylem and a reduction in pith in stems of 252 compared with 1283. The stem morphology and anatomy of first-cut and second-cut harvests of field-grown 1283 and 252 were examined. For both harvests, stems of 1283 were thicker and had a higher leaf/stem ratio compared with stems of 252. Stem cross-sections of both genotypes were stained for lignin, and the proportions of stem area that were pith and secondary xylem were measured using ImageJ. Stems of 252 exhibited greater deposition of secondary xylem and a reduction in pith proportion compared with stems of 1283 for the first-cut harvest, but this difference was not statistically significant for the second-cut harvest. The results indicate that the proportions of secondary xylem and pith are not environmentally stable in these two genotypes and hence cannot be the sole basis for the differences in cell wall concentration/composition. © 2012 Society of Chemical Industry.

Nanomaterials enhance osteogenic differentiation of human mesenchymal stem cells similar to a short peptide of BMP-7

PubMed Central

Lock, Jaclyn; Liu, Huinan

2011-01-01

Background Nanomaterials have unique advantages in controlling stem cell function due to their biomimetic characteristics and special biological and mechanical properties. Controlling adhesion and differentiation of stem cells is critical for tissue regeneration. Methods This in vitro study investigated the effects of nano-hydroxyapatite, nano-hydroxyapatite-polylactide- co-glycolide (PLGA) composites, and a bone morphogenetic protein (BMP-7)- derived short peptide (DIF-7c) on osteogenic differentiation of human mesenchymal stem cells (MSC). The peptide was chemically functionalized onto nano-hydroxyapatite, incorporated into a nanophase hydroxyapatite-PLGA composite or PLGA control, or directly injected into culture media. Results Unlike the PLGA control, the nano-hydroxyapatite-PLGA composites promoted adhesion of human MSC. Importantly, nano-hydroxyapatite and nano-hydroxyapatite-PLGA composites promoted osteogenic differentiation of human MSCs, comparable with direct injection of the DIF-7c peptide into culture media. Conclusion Nano-hydroxyapatite and nano-hydroxyapatite-PLGA composites provide a promising alternative in directing the adhesion and differentiation of human MSC. These nanocomposites should be studied further to clarify their effects on MSC functions and bone remodeling in vivo, eventually translating to clinical applications. PMID:22114505

Functionally redundant but dissimilar microbial communities within biogas reactors treating maize silage in co-fermentation with sugar beet silage

PubMed Central

Langer, Susanne G; Ahmed, Sharif; Einfalt, Daniel; Bengelsdorf, Frank R; Kazda, Marian

2015-01-01

Numerous observations indicate a high flexibility of microbial communities in different biogas reactors during anaerobic digestion. Here, we describe the functional redundancy and structural changes of involved microbial communities in four lab-scale continuously stirred tank reactors (CSTRs, 39°C, 12 L volume) supplied with different mixtures of maize silage (MS) and sugar beet silage (SBS) over 80 days. Continuously stirred tank reactors were fed with mixtures of MS and SBS in volatile solid ratios of 1:0 (Continuous Fermenter (CF) 1), 6:1 (CF2), 3:1 (CF3), 1:3 (CF4) with equal organic loading rates (OLR 1.25 kgVS m−3 d−1) and showed similar biogas production rates in all reactors. The compositions of bacterial and archaeal communities were analysed by 454 amplicon sequencing approach based on 16S rRNA genes. Both bacterial and archaeal communities shifted with increasing amounts of SBS. Especially pronounced were changes in the archaeal composition towards Methanosarcina with increasing proportion of SBS, while Methanosaeta declined simultaneously. Compositional shifts within the microbial communities did not influence the respective biogas production rates indicating that these communities adapted to environmental conditions induced by different feedstock mixtures. The diverse microbial communities optimized their metabolism in a way that ensured efficient biogas production. PMID:26200922

Distribution of branches in whole starches from maize mutants deficient in starch synthase III.

PubMed

Zhu, Fan; Bertoft, Eric; Seetharaman, Koushik

2014-05-21

An earlier study explored the possibility of analyzing the distribution of branches directly in native, whole starch without isolating the amylopectin component. The aim of this study was to explore if this approach can be extended to include starch mutants. Whole starches from du1 maize mutants deficient in starch synthase III (SSIII) with amylose content of ∼30-40% were characterized and compared with the wild type of the common genetic background W64A. Clusters were produced from whole starch by hydrolysis with α-amylase of Bacillus amyloliquefaciens. Their compositions of building blocks and chains were analyzed further by complete α-amylolysis and by debranching, respectively, whereafter the products were subjected to gel permeation and anion exchange chromatography. The size and structure of the clusters were compared with those of their isolated amylopectin component. Whereas the whole starch of the wild type sample had a branched structure similar to that of its amylopectin component, the results showed that the du1 mutation resulted in more singly branched building blocks in the whole starch compared to the isolated amylopectin. This suggested that amylose and/or intermediate materials in whole du1 starches likely contributed to the composition of branches. This study explored an alternative procedure to characterize the composition of branches in the whole starch without fractionating the components.

Lessons From Paired Data From exPVP Maize Lines in Agronomic Field Trials and RGB And Hyperspectral Time-Series Imaging In Controlled Environments

NASA Astrophysics Data System (ADS)

Schnable, J. C.; Pandey, P.; Ge, Y.; Xu, Y.; Qiu, Y.; Liang, Z.

2017-12-01

Maize Zea mays ssp. mays is one of three crops, along with rice and wheat, responsible for more than 1/2 of all calories consumed around the world. Increasing the yield and stress tolerance of these crops is essential to meet the growing need for food. The cost and speed of plant phenotyping is currently the largest constraint on plant breeding efforts. Datasets linking new types of high throughput phenotyping data collected from plants to the performance of the same genotypes under agronomic conditions across a wide range of environments are essential for developing new statistical approaches and computer vision based tools. A set of maize inbreds and hybrids - primarily recently off patent lines - were phenotyped using a high throughput platform at University of Nebraska-Lincoln. These lines have been previously subjected to high density genotyping, and scored for a core set of 13 phenotypes in field trials across 13 North American states in 2014, 2015, 2016, and 2017. Correlations between image-based measurements and manual measurements demonstrated the feasibility of quantifying variation in plant architecture using image data. However, we demonstrate that naive approaches to measuring traits such as biomass where are developed without integrating genotypic information can introduce nonrandom measurement errors which are confounded with variation between plant accessions. Analysis of hyperspectral image data demonstrated unique signatures from stem tissue which were not identified using aerial imagry. Integrating heritable phenotypes from high-throughput phenotyping data with field data from different environments can reveal previously unknown factors influencing yield plasticity.

QTL mapping for Mediterranean corn borer resistance in European flint germplasm using recombinant inbred lines

PubMed Central

2010-01-01

Background Ostrinia nubilalis (ECB) and Sesamia nonagrioides (MCB) are two maize stem borers which cause important losses in temperate maize production, but QTL analyses for corn borer resistance were mostly restricted to ECB resistance and maize materials genetically related (mapping populations derived from B73). Therefore, the objective of this work was to identify and characterize QTLs for MCB resistance and agronomic traits in a RILs population derived from European flint inbreds. Results Three QTLs were detected for stalk tunnel length at bins 1.02, 3.05 and 8.05 which explained 7.5% of the RILs genotypic variance. The QTL at bin 3.05 was co-located to a QTL related to plant height and grain humidity and the QTL at bin 8.05 was located near a QTL related to yield. Conclusions Our results, when compared with results from other authors, suggest the presence of genes involved in cell wall biosynthesis or fortification with effects on resistance to different corn borer species and digestibility for dairy cattle. Particularly, we proposed five candidate genes related to cell wall characteristics which could explain the QTL for stalk tunnelling in the region 3.05. However, the small proportion of genotypic variance explained by the QTLs suggest that there are also many other genes of small effect regulating MCB resistance and we conclude that MAS seems not promising for this trait. Two QTLs detected for stalk tunnelling overlap with QTLs for agronomic traits, indicating the presence of pleitropism or linkage between genes affecting resistance and agronomic traits. PMID:20230603

Abscisic acid and stress signals induce Viviparous1 expression in seed and vegetative tissues of maize.

PubMed

Cao, Xueyuan; Costa, Liliana M; Biderre-Petit, Corinne; Kbhaya, Bouchab; Dey, Nrisingha; Perez, Pascual; McCarty, Donald R; Gutierrez-Marcos, Jose F; Becraft, Philip W

2007-02-01

Viviparous1 (Vp1) encodes a B3 domain-containing transcription factor that is a key regulator of seed maturation in maize (Zea mays). However, the mechanisms of Vp1 regulation are not well understood. To examine physiological factors that may regulate Vp1 expression, transcript levels were monitored in maturing embryos placed in culture under different conditions. Expression of Vp1 decreased after culture in hormone-free medium, but was induced by salinity or osmotic stress. Application of exogenous abscisic acid (ABA) also induced transcript levels within 1 h in a dose-dependent manner. The Vp1 promoter fused to beta-glucuronidase or green fluorescent protein reproduced the endogenous Vp1 expression patterns in transgenic maize plants and also revealed previously unknown expression domains of Vp1. The Vp1 promoter is active in the embryo and aleurone cells of developing seeds and, upon drought stress, was also found in phloem cells of vegetative tissues, including cobs, leaves, and stems. Sequence analysis of the Vp1 promoter identified a potential ABA-responsive complex, consisting of an ACGT-containing ABA response element (ABRE) and a coupling element 1-like motif. Electrophoretic mobility shift assay confirmed that the ABRE and putative coupling element 1 components specifically bound proteins in embryo nuclear protein extracts. Treatment of embryos in hormone-free Murashige and Skoog medium blocked the ABRE-protein interaction, whereas exogenous ABA or mannitol treatment restored this interaction. Our data support a model for a VP1-dependent positive feedback mechanism regulating Vp1 expression during seed maturation.

Influence of Temperature on Intra- and Interspecific Resource Utilization within a Community of Lepidopteran Maize Stemborers

PubMed Central

Ntiri, Eric Siaw; Calatayud, Paul-Andre; Van Den Berg, Johnnie; Schulthess, Fritz; Le Ru, Bruno Pierre

2016-01-01

Competition or facilitation characterises intra- and interspecific interactions within communities of species that utilize the same resources. Temperature is an important factor influencing those interactions and eventual outcomes. The noctuid stemborers, Busseola fusca and Sesamia calamistis and the crambid Chilo partellus attack maize in sub-Saharan Africa. They often occur as a community of interacting species in the same field and plant at all elevations. The influence of temperature on the intra- and interspecific interactions among larvae of these species, was studied using potted maize plants exposed to varying temperatures in a greenhouse and artificial stems kept at different constant temperatures (15°C, 20°C, 25°C and 30°C) in an incubator. The experiments involved single- and multi-species infestation treatments. Survival and relative growth rates of each species were assessed. Both intra- and interspecific competitions were observed among all three species. Interspecific competition was stronger between the noctuids and the crambid than between the two noctuids. Temperature affected both survival and relative growth rates of the three species. Particularly at high temperatures, C. partellus was superior in interspecific interactions shown by higher larval survival and relative growth rates. In contrast, low temperatures favoured survival of B. fusca and S. calamistis but affected the relative growth rates of all three species. Survival and relative growth rates of B. fusca and S. calamistis in interspecific interactions did not differ significantly across temperatures. Temperature increase caused by future climate change is likely to confer an advantage on C. partellus over the noctuids in the utilization of resources (crops). PMID:26859748

Conventional and hyperspectral time-series imaging of maize lines widely used in field trials

PubMed Central

Liang, Zhikai; Pandey, Piyush; Stoerger, Vincent; Xu, Yuhang; Qiu, Yumou; Ge, Yufeng

2018-01-01

Abstract Background Maize (Zea mays ssp. mays) is 1 of 3 crops, along with rice and wheat, responsible for more than one-half of all calories consumed around the world. Increasing the yield and stress tolerance of these crops is essential to meet the growing need for food. The cost and speed of plant phenotyping are currently the largest constraints on plant breeding efforts. Datasets linking new types of high-throughput phenotyping data collected from plants to the performance of the same genotypes under agronomic conditions across a wide range of environments are essential for developing new statistical approaches and computer vision–based tools. Findings A set of maize inbreds—primarily recently off patent lines—were phenotyped using a high-throughput platform at University of Nebraska-Lincoln. These lines have been previously subjected to high-density genotyping and scored for a core set of 13 phenotypes in field trials across 13 North American states in 2 years by the Genomes 2 Fields Consortium. A total of 485 GB of image data including RGB, hyperspectral, fluorescence, and thermal infrared photos has been released. Conclusions Correlations between image-based measurements and manual measurements demonstrated the feasibility of quantifying variation in plant architecture using image data. However, naive approaches to measuring traits such as biomass can introduce nonrandom measurement errors confounded with genotype variation. Analysis of hyperspectral image data demonstrated unique signatures from stem tissue. Integrating heritable phenotypes from high-throughput phenotyping data with field data from different environments can reveal previously unknown factors that influence yield plasticity. PMID:29186425

Influence of Temperature on Intra- and Interspecific Resource Utilization within a Community of Lepidopteran Maize Stemborers.

PubMed

Ntiri, Eric Siaw; Calatayud, Paul-Andre; Van Den Berg, Johnnie; Schulthess, Fritz; Le Ru, Bruno Pierre

2016-01-01

Competition or facilitation characterises intra- and interspecific interactions within communities of species that utilize the same resources. Temperature is an important factor influencing those interactions and eventual outcomes. The noctuid stemborers, Busseola fusca and Sesamia calamistis and the crambid Chilo partellus attack maize in sub-Saharan Africa. They often occur as a community of interacting species in the same field and plant at all elevations. The influence of temperature on the intra- and interspecific interactions among larvae of these species, was studied using potted maize plants exposed to varying temperatures in a greenhouse and artificial stems kept at different constant temperatures (15°C, 20°C, 25°C and 30°C) in an incubator. The experiments involved single- and multi-species infestation treatments. Survival and relative growth rates of each species were assessed. Both intra- and interspecific competitions were observed among all three species. Interspecific competition was stronger between the noctuids and the crambid than between the two noctuids. Temperature affected both survival and relative growth rates of the three species. Particularly at high temperatures, C. partellus was superior in interspecific interactions shown by higher larval survival and relative growth rates. In contrast, low temperatures favoured survival of B. fusca and S. calamistis but affected the relative growth rates of all three species. Survival and relative growth rates of B. fusca and S. calamistis in interspecific interactions did not differ significantly across temperatures. Temperature increase caused by future climate change is likely to confer an advantage on C. partellus over the noctuids in the utilization of resources (crops).

Conventional and hyperspectral time-series imaging of maize lines widely used in field trials.

PubMed

Liang, Zhikai; Pandey, Piyush; Stoerger, Vincent; Xu, Yuhang; Qiu, Yumou; Ge, Yufeng; Schnable, James C

2018-02-01

Maize (Zea mays ssp. mays) is 1 of 3 crops, along with rice and wheat, responsible for more than one-half of all calories consumed around the world. Increasing the yield and stress tolerance of these crops is essential to meet the growing need for food. The cost and speed of plant phenotyping are currently the largest constraints on plant breeding efforts. Datasets linking new types of high-throughput phenotyping data collected from plants to the performance of the same genotypes under agronomic conditions across a wide range of environments are essential for developing new statistical approaches and computer vision-based tools. A set of maize inbreds-primarily recently off patent lines-were phenotyped using a high-throughput platform at University of Nebraska-Lincoln. These lines have been previously subjected to high-density genotyping and scored for a core set of 13 phenotypes in field trials across 13 North American states in 2 years by the Genomes 2 Fields Consortium. A total of 485 GB of image data including RGB, hyperspectral, fluorescence, and thermal infrared photos has been released. Correlations between image-based measurements and manual measurements demonstrated the feasibility of quantifying variation in plant architecture using image data. However, naive approaches to measuring traits such as biomass can introduce nonrandom measurement errors confounded with genotype variation. Analysis of hyperspectral image data demonstrated unique signatures from stem tissue. Integrating heritable phenotypes from high-throughput phenotyping data with field data from different environments can reveal previously unknown factors that influence yield plasticity. © The Authors 2017. Published by Oxford University Press.

Measurements and simulations of water transport in maize plants

NASA Astrophysics Data System (ADS)

Heinlein, Florian; Klein, Christian; Thieme, Christoph; Priesack, Eckart

2017-04-01

In Central Europe climate change will become manifest in the increase of extreme weather events like flash floods, heat waves and summer droughts, and in a shift of precipitation towards winter months. Therefore, regional water availability will alter which has an effect on future crop growth, water use efficiency and yields. To better estimate these effects accurate model descriptions of transpiration and other parts of the water balance are important. In this study, we determined transpiration of four maize plants on a field of the research station Scheyern (about 40km North of Munich) by means of sap flow measurement devices (ICQ International Pty Ltd, Australia) using the Heat-Ratio-Method: two temperature probes, 0.5 cm above and below a heater, detect a heat pulse and its speed which facilitates the calculation of sap flow. Additionally, high resolution changes of stem diameters were measured with dendrometers (DD-S, Ecomatik). The field was also situated next to an eddy covariance station which provided latent heat fluxes from the soil-plant system. We also performed terrestrial laser scans of the respective plants to extract the plant architectures. These structures serve as input for our mechanistic transpiration model simulating the water transport within the plant. This model, which has already been successfully applied to single Fagus sylvatica L. trees, was adapted to agricultural plants such as maize. The basic principle of this model is to solve a 1-D Richards equation along the graph of the single plants. A comparison between the simulations and the measurements is presented and discussed.

Exploitation of algal-bacterial associations in a two-stage biohydrogen and biogas generation process.

PubMed

Wirth, Roland; Lakatos, Gergely; Maróti, Gergely; Bagi, Zoltán; Minárovics, János; Nagy, Katalin; Kondorosi, Éva; Rákhely, Gábor; Kovács, Kornél L

2015-01-01

The growing concern regarding the use of agricultural land for the production of biomass for food/feed or energy is dictating the search for alternative biomass sources. Photosynthetic microorganisms grown on marginal or deserted land present a promising alternative to the cultivation of energy plants and thereby may dampen the 'food or fuel' dispute. Microalgae offer diverse utilization routes. A two-stage energetic utilization, using a natural mixed population of algae (Chlamydomonas sp. and Scenedesmus sp.) and mutualistic bacteria (primarily Rhizobium sp.), was tested for coupled biohydrogen and biogas production. The microalgal-bacterial biomass generated hydrogen without sulfur deprivation. Algal hydrogen production in the mixed population started earlier but lasted for a shorter period relative to the benchmark approach. The residual biomass after hydrogen production was used for biogas generation and was compared with the biogas production from maize silage. The gas evolved from the microbial biomass was enriched in methane, but the specific gas production was lower than that of maize silage. Sustainable biogas production from the microbial biomass proceeded without noticeable difficulties in continuously stirred fed-batch laboratory-size reactors for an extended period of time. Co-fermentation of the microbial biomass and maize silage improved the biogas production: The metagenomic results indicated that pronounced changes took place in the domain Bacteria, primarily due to the introduction of a considerable bacterial biomass into the system with the substrate; this effect was partially compensated in the case of co-fermentation. The bacteria living in syntrophy with the algae apparently persisted in the anaerobic reactor and predominated in the bacterial population. The Archaea community remained virtually unaffected by the changes in the substrate biomass composition. Through elimination of cost- and labor-demanding sulfur deprivation, sustainable biohydrogen production can be carried out by using microalgae and their mutualistic bacterial partners. The beneficial effect of the mutualistic mixed bacteria in O2 quenching is that the spent algal-bacterial biomass can be further exploited for biogas production. Anaerobic fermentation of the microbial biomass depends on the composition of the biogas-producing microbial community. Co-fermentation of the mixed microbial biomass with maize silage improved the biogas productivity.

Composition and dynamics of cutin and suberin biomarkers in plants and soils under agricultural use

NASA Astrophysics Data System (ADS)

María Armas-Herrera, Cecilia; Dignac, Marie-France; Rumpel, Cornelia; Arvelo, Carmen Dolores; Chabbi, Abad

2017-04-01

Cutins of plant shoots, and suberins, mostly present in roots, may act as potential biomarkers for aboveground and belowground biomass of non-woody plants. The aim of this work was to evaluate the dynamics of specific root and shoot biomarkers after land-use changes from grass to an arable land. We (i) identified and quantified specific biomarkers of cutin and suberin of three grassland species (Dactylis glomerata L., Festuca arundinacea Schreb. and Lolium perenne L.), (ii) investigated the composition of cutin and suberin in soil under different land uses (continuous and temporary grassland, arable and bare soil) of the SOERE-ACBB experimental site in Lusignan (France) and (iii) used natural 13C isotope abundances to follow the fate of cutin and suberin specific markers in soil after conversion from grassland (C3 plants) to arable land (maize, C4 plants). Our results indicated that 9-hydroxy hexadecanedioic acid and 8(9)(10),16-dihydroxy hexadecanoic acid may be used as biomarkers for aboveground biomass, whereas 1,22-docosandioic acid, 22-hydroxy docosanoic acid and 24-hydroxy tetracosanoic acid may be the most adequate belowground biomarkers for the plants investigated under the experimental conditions studied. There were marked differences in monomer composition, abundance and patterns of shoot-root allocation of these biomarkers in the plant species analysed, which demonstrates the importance to identify specific cutin and suberin biomarkers for each plant species to study the incorporation of their biomass into SOM. Cutin and suberin marker contents followed the same trends as the biomass inputs to soil: they were the highest in soils cultivated with maize and the lowest in bare soils. We found no differences in the amounts of cutin and suberin markers in soil under continuous and temporary grassland, which might indicate that the disturbance caused by conversion from grassland to cropland was transitory only. In addition, suberin marker contents decreased by 40-64 % and cutin's by 24-40 % during a 6-year bare fallow, which indicates that root markers were more sensitive than shoot markers to degradation. Changes in the 13C isotopic signatures of specific biomarkers after 6 years of maize cropping showed a higher turnover of root markers as compared to shoot biomarkers, despite the much lower root inputs from maize than from grassland plants. These findings indicate that the stabilisation of suberin in soils was more rapid but less durable than that of cutin.

Decreasing Nitrogen Fertilizer Input Had Little Effect on Microbial Communities in Three Types of Soils

PubMed Central

Yu, Hailing; Gao, Qiang; Shao, Zeqiang; Ying, Anning; Sun, Yuyang; Liu, Jingwei; Mao, Wei; Zhang, Bin

2016-01-01

In this study, we examined the influence of different nitrogen (N) application rates (0, 168, 240, 270 and 312 kg N ha-1) on soil properties, maize (Zea mays L.) yields and microbial communities of three types of soils (clay, alluvial and sandy soils). Phospholipid fatty acid analysis was used to characterize soil microbial communities. Results indicated that N fertilization significantly decreased microbial biomass in both clay and sandy soils regardless of application rate. These decreases were more likely a result of soil pH decreases induced by N fertilization, especially in the sandy soils. This is supported by structural equation modeling and redundancy analysis results. Nitrogen fertilization also led to significant changes in soil microbial community composition. However, the change differences were gradually dismissed with increase in N application rate. We also observed that N fertilization increased maize yields to the same level regardless of application rate. This suggests that farmers could apply N fertilizers at a lower rate (i.e. 168 kg N ha-1), which could achieve high maize yield on one hand while maintain soil microbial functions on the other hand. PMID:26992097

Physical and nutritional properties of buffalo meat finished on hay or maize silage-based diets.

PubMed

Cifuni, Giulia Francesca; Contò, Michela; Amici, Andrea; Failla, Sebastiana

2014-04-01

The current study examines the effect of different finishing diets (hay- vs. maize-silage on meal ration) on carcass quality, physical, chemical and sensory properties, and fatty acid profiles of buffalo meat. Twenty male Italian Mediterranean buffaloes (246 ± 9.00 kg live weight) were distributed at random into two groups at the beginning of the finishing period (368 ± 20 days). The buffaloes were offered two finishing diets: a maize silage (MS) or an alfalfa hay (AH) diet. No significant differences were found between dietary treatments for live and carcass weight. Meat chemical composition was influenced by dietary treatment. A higher fat content was detected in meat from animals finished with MS than AH (P < 0.05). Overall, the data indicated differences between the fatty acid profiles of meat as a consequence of different feeding systems. The higher fat deposition in the MS group resulted in meat with a less favorable fatty acid profile (i.e. a lower polyunsaturated/saturated fatty acid ratio and α-linolenic fatty acid content) in relation to human health compared with meat from animals fed the AH diet. © 2013 Japanese Society of Animal Science.

Behaviour of human mesenchymal stem cells on chemically synthesized HA-PCL scaffolds for hard tissue regeneration.

PubMed

D'Antò, Vincenzo; Raucci, Maria Grazia; Guarino, Vincenzo; Martina, Stefano; Valletta, Rosa; Ambrosio, Luigi

2016-02-01

Our goal was to characterize the response of human mesenchymal stem cells (hMSCs) to a novel composite scaffold for bone tissue engineering. The hydroxyapatite-polycaprolactone (HA-PCL) composite scaffolds were prepared by a sol-gel method at room temperature and the scaffold morphology was investigated by scanning electron microscopy (SEM)/energy-dispersive spectroscopy (EDS) to validate the synthesis process. The response of two different lines of hMSCs, bone-marrow-derived human mesenchymal stem cells (BMSCs) and dental pulp stem cells (DPSCs) in terms of cell proliferation and differentiation into the osteoblastic phenotype, was evaluated using Alamar blue assay, SEM, histology and alkaline phosphatase activity. Our results indicate that tissue engineering by means of composite HA-PCL scaffolds may represent a new therapeutic strategy to repair craniofacial bone defects. Copyright © 2013 John Wiley & Sons, Ltd.

Cactus stem (Opuntia ficus-indica Mill): anatomy, physiology and chemical composition with emphasis on its biofunctional properties.

PubMed

Ventura-Aguilar, Rosa Isela; Bosquez-Molina, Elsa; Bautista-Baños, Silvia; Rivera-Cabrera, Fernando

2017-12-01

Cactus stem (Opuntia ficus-indica Mill) is native to Mesoamerica and marketed in different forms such as fresh, frozen or pre-cooked. Worldwide, this vegetable is recognized for its pharmaceutical actions, including its antioxidant, diuretic, anticarcinogenic, anti-inflammatory, anti-diabetic, and anti-hypercholesterolemic properties, as well as their antiviral and antispermatogenic effects. However, not all of these properties have been associated with its chemical composition; therefore, this review aims to present and integrate information available on the physiology and anatomy of cactus stem and its chemical composition, focusing on some of the many factors that determine its biofunctionality. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Overestimation of Crop Root Biomass in Field Experiments Due to Extraneous Organic Matter

PubMed Central

Hirte, Juliane; Leifeld, Jens; Abiven, Samuel; Oberholzer, Hans-Rudolf; Hammelehle, Andreas; Mayer, Jochen

2017-01-01

Root biomass is one of the most relevant root parameters for studies of plant response to environmental change, soil carbon modeling or estimations of soil carbon sequestration. A major source of error in root biomass quantification of agricultural crops in the field is the presence of extraneous organic matter in soil: dead roots from previous crops, weed roots, incorporated above ground plant residues and organic soil amendments, or remnants of soil fauna. Using the isotopic difference between recent maize root biomass and predominantly C3-derived extraneous organic matter, we determined the proportions of maize root biomass carbon of total carbon in root samples from the Swiss long-term field trial “DOK.” We additionally evaluated the effects of agricultural management (bio-organic and conventional), sampling depth (0–0.25, 0.25–0.5, 0.5–0.75 m) and position (within and between maize rows), and root size class (coarse and fine roots) as defined by sieve mesh size (2 and 0.5 mm) on those proportions, and quantified the success rate of manual exclusion of extraneous organic matter from root samples. Only 60% of the root mass that we retrieved from field soil cores was actual maize root biomass from the current season. While the proportions of maize root biomass carbon were not affected by agricultural management, they increased consistently with soil depth, were higher within than between maize rows, and were higher in coarse (>2 mm) than in fine (≤2 and >0.5) root samples. The success rate of manual exclusion of extraneous organic matter from root samples was related to agricultural management and, at best, about 60%. We assume that the composition of extraneous organic matter is strongly influenced by agricultural management and soil depth and governs the effect size of the investigated factors. Extraneous organic matter may result in severe overestimation of recovered root biomass and has, therefore, large implications for soil carbon modeling and estimations of the climate change mitigation potential of soils. PMID:28298919

In vivo protein quality of selected cereal-based staple foods enriched with soybean proteins

PubMed Central

Acevedo-Pacheco, Laura; Serna-Saldívar, Sergio O.

2016-01-01

Background One way to diminish protein malnutrition in children is by enriching cereal-based flours for the manufacturing of maize tortillas, wheat flour tortillas, and yeast-leavened breads, which are widely consumed among low socio-economic groups. Objective The aim was to determine and compare the essential amino acid (EAA) scores, protein digestibility corrected amino acid scores (PDCAAS), and in vivo protein quality (protein digestibility, protein efficiency ratio (PER), biological values (BV), and net protein utilization (NPU) values) of regular versus soybean-fortified maize tortillas, yeast-leavened bread, and wheat flour tortillas. Design To comparatively assess differences in protein quality among maize tortillas, wheat flour tortillas, and yeast-leavened breads, EAA compositions and in vivo studies with weanling rats were performed. The experimental diets based on regular or soybean-fortified food products were compared with a casein-based diet. Food intake, weight gains, PER, dry matter and protein digestibility, BV, NPU, and PDCAAS were assessed. The soybean-fortified tortillas contained 6% of defatted soybean flour, whereas the yeast-leavened bread flour contained 4.5% of soybean concentrate. Results The soybean-fortified tortillas and bread contained higher amounts of lysine and tryptophan, which improved their EAA scores and PDCAAS. Rats fed diets based on soybean-fortified maize or wheat tortillas gained considerably more weight and had better BV and NPU values compared with counterparts fed with respective regular products. As a result, fortified maize tortillas and wheat flour tortillas improved PER from 0.73 to 1.64 and 0.69 to 1.77, respectively. The PER improvement was not as evident in rats fed the enriched yeast-leavened bread because the formulation contained sugar that decreased lysine availability possibly to Maillard reactions. Conclusions The proposed enrichment of cereal-based foods with soybean proteins greatly improved PDCAAS, animal growth, nitrogen retention, and PER primarily in both maize and wheat flour tortillas. Therefore, these foods can help to diminish protein malnutrition among children who greatly depend on cereals as the main protein dietary source. PMID:27765143

Species composition and structure of regenerated and remnant forest patches within an urban landscape

Treesearch

Wayne C. Zipperer

2002-01-01

Regenerated and remnant forest patches were inventoried in Syracuse, New York, USA to determine differences in structure, species composition, human disturbances, and landscape context. Patches had similar mean stem diameter, total stem density, and total basal areas, but differed with respect to diameter distribution, disturbance regime, landscape context, and...

Method of Manufacturing Carbon Fiber Reinforced Carbon Composite Valves

NASA Technical Reports Server (NTRS)

Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor)

1998-01-01

A method for forming a carbon composite valve for internal combustion engines is discussed. The process includes the steps of braiding carbon fiber into a rope thereby forming a cylindrically shaped valve stem portion and continuing to braid said fiber while introducing into the braiding carbon fiber rope a carbon matrix plug having an outer surface in a net shape of a valve head thereby forming a valve head portion. The said carbon matrix plug acting as a mandrel over which said carbon fiber rope is braided, said carbon fiber rope and carbon matrix plug forming a valve head portion suitable for mating with a valve seat; cutting said braided carbon valve stem portion at one end to form a valve tip and cutting said braided carbon fiber after said valve head portion to form a valve face and thus provide a composite valve preform; and densifying said preform by embedding the braided carbon in a matrix of carbon to convert said valve stem portion to a valve stem and said valve head portion to a valve head thereby providing said composite valve.

[Histocompatibility of nano-hydroxyapatite/poly-co-glycolic acid tissue engineering bone modified by mesenchymal stem cells with vascular endothelial frowth factor].

PubMed

Zhang, Minglei; Wang, Dapeng; Yin, Ruofeng

2015-10-06

To explorec Histocompatibility of nano-hydroxyapatite/poly-co-glycolic acid tissue engineering bone modified by mesenchymal stem cells with vascular endothelial frowth factor transinfected. Rat bone marrow mesenchymal stem cells (BMSCs) was separated, using BMSCs as target cells, and then vascular endothelial growth factor (VEGF) gene was transfected. Composite bone marrow mesenchymal stem cells and cells transfected with nano-hydroxyapatite (HA)/polylactic-co-glycolic acid (PLGA). The composition of cell and scaffold was observed. The blank plasmid transfection was 39.1%, 40.1% in VEGF group. The cell adhesion and growth was found on the scaffold pore wall after 5 days, and the number of adherent cells in the nano-HA/PLGA composite scaffold material basically had no significant difference in both. Although the nano-HA/PLGA scaffold material is still not fully meet the requirements of the matrix material for bone tissue engineering, but good biocompatibility, structure is its rich microporous satisfaction in material mechanics, toughening, enhanced obviously. Composition scaffold with BMSCs transfected by VEGF plasmid, the ability of angiogenesis is promoted.

Integrated metagenomics and molecular ecological network analysis of bacterial community composition during the phytoremediation of cadmium-contaminated soils by bioenergy crops.

PubMed

Chen, Zhaojin; Zheng, Yuan; Ding, Chuanyu; Ren, Xuemin; Yuan, Jian; Sun, Feng; Li, Yuying

2017-11-01

Two energy crops (maize and soybean) were used in the remediation of cadmium-contaminated soils. These crops were used because they are fast growing, have a large biomass and are good sources for bioenergy production. The total accumulation of cadmium in maize and soybean plants was 393.01 and 263.24μg pot -1 , respectively. The rhizosphere bacterial community composition was studied by MiSeq sequencing. Phylogenetic analysis was performed using 16S rRNA gene sequences. The rhizosphere bacteria were divided into 33 major phylogenetic groups according to phyla. The dominant phylogenetic groups included Proteobacteria, Acidobacteria, Actinobacteria, Gemmatimonadetes, and Bacteroidetes. Based on principal component analysis (PCA) and unweighted pair group with arithmetic mean (UPGMA) analysis, we found that the bacterial community was influenced by cadmium addition and bioenergy cropping. Three molecular ecological networks were constructed for the unplanted, soybean- and maize-planted bacterial communities grown in 50mgkg -1 cadmium-contaminated soils. The results indicated that bioenergy cropping increased the complexity of the bacterial community network as evidenced by a higher total number of nodes, the average geodesic distance (GD), the modularity and a shorter geodesic distance. Proteobacteria and Acidobacteria were the keystone bacteria connecting different co-expressed operational taxonomic units (OTUs). The results showed that bioenergy cropping altered the topological roles of individual OTUs and keystone populations. This is the first study to reveal the effects of bioenergy cropping on microbial interactions in the phytoremediation of cadmium-contaminated soils by network reconstruction. This method can greatly enhance our understanding of the mechanisms of plant-microbe-metal interactions in metal-polluted ecosystems. Copyright © 2017 Elsevier Inc. All rights reserved.

Feed intake and production parameters of lactating crossbred cows fed maize-based diets of stover, silage or quality protein silage.

PubMed

Gebrehawariat, Efrem; Tamir, Berhan; Tegegne, Azage

2010-12-01

Thirty-six Boran × Friesian dairy cows (392 ± 12 kg; mean ± SD) in early parity were used in a randomised complete block design. Cows were blocked by parity into three blocks of 12 animals and offered normal maize (NM) stover (T1), NM silage (T2) or quality protein maize (QPM) silage (T3) basal diets supplemented with a similar concentrate mix. Feed intake, body weight and condition changes and milk yield and composition were assessed. The daily intake of DM, OM, NDF and ADF for cows fed the NM stover-based diet was higher (P<0.05) than for the cows fed the NM silage and QPM silage-based diets. However, the daily intake of DOM (9.3 kg) and ME (140.8 MJ) for cows on QPM silage-based diet was higher (P<0.05) than for cows on NM stover-based diet (8.4 kg and 124.2 MJ) and NM silage-based diet (7.9 kg and 119.1 MJ). Body weight of cows was affected (P<0.05) by the diet, but diet had no effect (P>0.05) on body condition score, milk yield and milk composition. The digestible organic matter in the NM stover-based diet (724 g/kg DM) was lower (P<0.05) than that in the NM (770 g/kg DM) and QPM silage-based diet (762 g/kg DM). It was concluded that the performances of the cows on the NM silage and QPM silage diets were similar and were not superior to that of the NM stover-based diet.

Feed intake and production parameters of lactating crossbred cows fed maize-based diets of stover, silage or quality protein silage

PubMed Central

Gebrehawariat, Efrem; Tegegne, Azage

2010-01-01

Thirty-six Boran × Friesian dairy cows (392 ± 12 kg; mean ± SD) in early parity were used in a randomised complete block design. Cows were blocked by parity into three blocks of 12 animals and offered normal maize (NM) stover (T1), NM silage (T2) or quality protein maize (QPM) silage (T3) basal diets supplemented with a similar concentrate mix. Feed intake, body weight and condition changes and milk yield and composition were assessed. The daily intake of DM, OM, NDF and ADF for cows fed the NM stover-based diet was higher (P < 0.05) than for the cows fed the NM silage and QPM silage-based diets. However, the daily intake of DOM (9.3 kg) and ME (140.8 MJ) for cows on QPM silage-based diet was higher (P < 0.05) than for cows on NM stover-based diet (8.4 kg and 124.2 MJ) and NM silage-based diet (7.9 kg and 119.1 MJ). Body weight of cows was affected (P < 0.05) by the diet, but diet had no effect (P > 0.05) on body condition score, milk yield and milk composition. The digestible organic matter in the NM stover-based diet (724 g/kg DM) was lower (P < 0.05) than that in the NM (770 g/kg DM) and QPM silage-based diet (762 g/kg DM). It was concluded that the performances of the cows on the NM silage and QPM silage diets were similar and were not superior to that of the NM stover-based diet. PMID:20577806

Evaluation of stable isotope fingerprinting techniques for the assessment of the predominant methanogenic pathways in anaerobic digesters.

PubMed

Nikolausz, M; Walter, R F H; Sträuber, H; Liebetrau, J; Schmidt, T; Kleinsteuber, S; Bratfisch, F; Günther, U; Richnow, H H

2013-03-01

Laboratory biogas reactors were operated under various conditions using maize silage, chicken manure, or distillers grains as substrate. In addition to the standard process parameters, the hydrogen and carbon stable isotopic composition of biogas was analyzed to estimate the predominant methanogenic pathways as a potential process control tool. The isotopic fingerprinting technique was evaluated by parallel analysis of mcrA genes and their transcripts to study the diversity and activity of methanogens. The dominant hydrogenotrophs were Methanomicrobiales, while aceticlastic methanogens were represented by Methanosaeta and Methanosarcina at low and high organic loading rates, respectively. Major changes in the relative abundance of mcrA transcripts were observed compared to the results obtained from DNA level. In agreement with the molecular results, the isotope data suggested the predominance of the hydrogenotrophic pathway in one reactor fed with chicken manure, while both pathways were important in the other reactors. Short-term changes in the isotopic composition were followed, and a significant change in isotope values was observed after feeding a reactor digesting maize silage. This ability of stable isotope fingerprinting to follow short-term activity changes shows potential for indicating process failures and makes it a promising technology for process control.

Effect of lignin content and subunit composition on digestibility in clones of timothy (Phleum pratense L.).

PubMed

Kärkönen, Anna; Tapanila, Tarja; Laakso, Tapio; Seppänen, Mervi M; Isolahti, Mika; Hyrkäs, Maarit; Virkajärvi, Perttu; Saranpää, Pekka

2014-07-02

Lignin amount and subunit composition were analyzed from stems and leaf sheaths of timothy (Phleum pratense L.) clones of different in vitro digestibility. Lignin concentration in stems and leaf sheaths was higher in clones of low digestibility than those of high digestibility. No change in lignin concentration occurred in stems as digestibility decreased. Intriguingly, the lignin concentration was lower and the syringyl/guaiacyl (S/G) ratio was higher in stems compared to leaf sheaths at all developmental stages studied. The developmental-associated decrease in digestibility correlated with the increase in S units in lignin in stems and leaf sheaths and in the amounts of p-coumaric acid and ferulic acid residues in the cell wall of stems. Yields of copper oxidation products increased in stems during maturation indicating qualitative changes in the lignin structure. This correlated strongly with the developmentally linked decrease in digestibility. The information obtained is valuable for breeding and for DNA marker development.

Essential oil composition of stems and fruits of Caralluma europaea N.E.Br. (Apocynaceae).

PubMed

Zito, Pietro; Sajeva, Maurizio; Bruno, Maurizio; Maggio, Antonella; Rosselli, Sergio; Formisano, Carmen; Senatore, Felice

2010-01-27

The essential oil of the stems and fruits of Caralluma europaea (Guss.) N.E.Br. (Apocynaceae) from Lampedusa Island has been obtained by hydrodistillation and its composition analyzed. The analyses allowed the identification and quantification of 74 volatile compounds, of which 16 were aromatic and 58 non-aromatic. Stems and fruits contained 1.4% and 2.7% of aromatic compounds respectively, while non-aromatic were 88.3% and 88.8%. Non-aromatic hydrocarbons were the most abundant compounds in both organs, followed by fatty acids. Data showed differences in the profiles between stems and fruits which shared only eighteen compounds; stems accounted for 38 compounds while fruits for 53. Fruits showed a higher diversity especially in aromatic compounds with twelve versus four in stems. Among the volatiles identified in stems and fruits of C. europaea 26 are present in other taxa of Apocynaceae, 52 are semiochemicals for many insects, and 21 have antimicrobial activity. The possible ecological role of the volatiles found is briefly discussed.

Characterization of Siarang Dairi local corn, Regency of Dairi, North Sumatera Province

NASA Astrophysics Data System (ADS)

Nasution, L. Z.; Buri, N.

2018-05-01

Corn is one of the carbohydrate-producing plants in addition to rice and wheat which contains nutrients that can be used for humans and animals. Local plants have an important role for genetic resources and can create new varieties. So it needs to be preserved and utilized. The purpose of this research is to characterize the local maize of Siarang Dairi. This research uses qualitative method is descriptive analysis. The data collected include the quantitative and qualitative character of agronomic and morphological characters using 5 plant samples. The results showed that the local Siarang Dairi maize had a root falling percentage of 0% and the stem fall percentage of 3.07%. The high of the plant ranged from 236 - 277 cm. The length of the cob were from 16 - 19 cm with an almost homogen diameter of 4 – 4.5 cm. The uppermost form of cylindrical and cylindrical conical. Grain lengths range from 6 - 8 mm, with grain widths ranging from 5 - 9 mm, and grain thicknesses ranging from 3 - 5 mm. The top grain surface shape is jagged, round, and flat. Specific color grains are unique and varied from brown, orange and red color.

Maize transpiration in response to meteorological conditions

NASA Astrophysics Data System (ADS)

Klimešová, Jana; Stŕedová, Hana; Stŕeda, Tomáš

2013-09-01

Differences in transpiration of maize (Zea mays L.) plants in four soil moisture regimes were quantified in a pot experiment. The transpiration was measured by the "Stem Heat Balance" method. The dependence of transpiration on air temperature, air humidity, global solar radiation, soil moisture, wind speed and leaf surface temperature were quantified. Significant relationships among transpiration, global radiation and air temperature (in the first vegetation period in the drought non-stressed variant, r = 0.881**, r = 0.934**) were found. Conclusive dependence of transpiration on leaf temperature (r = 0.820**) and wind speed (r = 0.710**) was found. Transpiration was significantly influenced by soil moisture (r = 0.395**, r = 0.528**) under moderate and severe drought stress. The dependence of transpiration on meteorological factors decreased with increasing deficiency of water. Correlation between transpiration and plant dry matter weight (r = 0.997**), plant height (r = 0.973**) and weight of corn cob (r = 0.987**) was found. The results of instrumental measuring of field crops transpiration under diverse moisture conditions at a concurrent monitoring of the meteorological elements spectra are rather unique. These results will be utilized in the effort to make calculations of the evapotranspiration in computing models more accurate.

Influence of different sizes of composite femora on the biomechanical behavior of cementless hip prosthesis.

PubMed

Schmidutz, Florian; Woiczinski, Mathias; Kistler, Manuel; Schröder, Christian; Jansson, Volkmar; Fottner, Andreas

2017-01-01

For the biomechanical evaluation of cementless stems different sizes of composite femurs have been used in the literature. However, the impact of different specimen sizes on test results is unknown. To determine the potential effect of femur size the biomechanical properties of a conventional stem (CLS Spotorno) were examined in 3 different sizes (small, medium and large composite Sawbones®). Primary stability was tested under physiologically adapted dynamic loading conditions measuring 3-dimensional micromotions. For the small composite femur the dynamic load needed to be adapted since fractures occurred when reaching 1700N. Additionally, surface strain distribution was recorded before and after implantation to draw conclusions about the tendency for stress shielding. All tested sizes revealed similar micromotions only reaching a significant different level at one measurement point. The highest micromotions were observed at the tip of the stems exceeding the limit for osseous integration of 150μm. Regarding strain distribution the highest strain reduction after implantation was registered in all sizes at the level of the lesser trochanter. Specimen size seems to be a minor influence factor for biomechanical evaluation of cementless stems. However, the small composite femur is less suitable for biomechanical testing since this size failed under physiological adapted loads. For the CLS Spotorno osseous integration is unlikely at the tip of the stem and the tendency for stress shielding is the highest at the level of the lesser trochanter. Copyright © 2016 Elsevier Ltd. All rights reserved.

Transposition-mediated DNA re-replication in maize

PubMed Central

Zhang, Jianbo; Zuo, Tao; Wang, Dafang; Peterson, Thomas

2014-01-01

Every DNA segment in a eukaryotic genome normally replicates once and only once per cell cycle to maintain genome stability. We show here that this restriction can be bypassed through alternative transposition, a transposition reaction that utilizes the termini of two separate, nearby transposable elements (TEs). Our results suggest that alternative transposition during S phase can induce re-replication of the TEs and their flanking sequences. The DNA re-replication can spontaneously abort to generate double-strand breaks, which can be repaired to generate Composite Insertions composed of transposon termini flanking segmental duplications of various lengths. These results show how alternative transposition coupled with DNA replication and repair can significantly alter genome structure and may have contributed to rapid genome evolution in maize and possibly other eukaryotes. DOI: http://dx.doi.org/10.7554/eLife.03724.001 PMID:25406063

Genotype, development and tissue-derived variation of cell-wall properties in the lignocellulosic energy crop Miscanthus

DOE Office of Scientific and Technical Information (OSTI.GOV)

da Costa, Ricardo M. F.; Lee, Scott J.; Allison, Gordon G.

Species and hybrids of the genus Miscanthus contain attributes that make them front-runners among current selections of dedicated bioenergy crops. A key trait for plant biomass conversion to biofuels and biomaterials is cell-wall quality; however, knowledge of cell-wall composition and biology in Miscanthus species is limited. This study presents data on cell-wall compositional changes as a function of development and tissue type across selected genotypes, and considers implications for the development of miscanthus as a sustainable and renewable bioenergy feedstock. Cell-wall biomass was analysed for 25 genotypes, considering different developmental stages and stem vs. leaf compositional variability, by Fourier transformmore » mid-infrared spectroscopy and lignin determination. In addition, a Clostridium phytofermentans bioassay was used to assess cell-wall digestibility and conversion to ethanol. Important cell-wall compositional differences between miscanthus stem and leaf samples were found to be predominantly associated with structural carbohydrates. Lignin content increased as plants matured and was higher in stem tissues. Although stem lignin concentration correlated inversely with ethanol production, no such correlation was observed for leaves. Leaf tissue contributed significantly to total above-ground biomass at all stages, although the extent of this contribution was genotype-dependent. In conclusion, it is hypothesized that divergent carbohydrate compositions and modifications in stem and leaf tissues are major determinants for observed differences in cell-wall quality. The findings indicate that improvement of lignocellulosic feedstocks should encompass tissue-dependent variation as it affects amenability to biological conversion. For gene-trait associations relating to cell-wall quality, the data support the separate examination of leaf and stem composition, as tissue-specific traits may be masked by considering only total above-ground biomass samples, and sample variability could be mostly due to varying tissue contributions to total biomass.« less

Genotype, development and tissue-derived variation of cell-wall properties in the lignocellulosic energy crop Miscanthus

DOE PAGES

da Costa, Ricardo M. F.; Lee, Scott J.; Allison, Gordon G.; ...

2014-04-15

Species and hybrids of the genus Miscanthus contain attributes that make them front-runners among current selections of dedicated bioenergy crops. A key trait for plant biomass conversion to biofuels and biomaterials is cell-wall quality; however, knowledge of cell-wall composition and biology in Miscanthus species is limited. This study presents data on cell-wall compositional changes as a function of development and tissue type across selected genotypes, and considers implications for the development of miscanthus as a sustainable and renewable bioenergy feedstock. Cell-wall biomass was analysed for 25 genotypes, considering different developmental stages and stem vs. leaf compositional variability, by Fourier transformmore » mid-infrared spectroscopy and lignin determination. In addition, a Clostridium phytofermentans bioassay was used to assess cell-wall digestibility and conversion to ethanol. Important cell-wall compositional differences between miscanthus stem and leaf samples were found to be predominantly associated with structural carbohydrates. Lignin content increased as plants matured and was higher in stem tissues. Although stem lignin concentration correlated inversely with ethanol production, no such correlation was observed for leaves. Leaf tissue contributed significantly to total above-ground biomass at all stages, although the extent of this contribution was genotype-dependent. In conclusion, it is hypothesized that divergent carbohydrate compositions and modifications in stem and leaf tissues are major determinants for observed differences in cell-wall quality. The findings indicate that improvement of lignocellulosic feedstocks should encompass tissue-dependent variation as it affects amenability to biological conversion. For gene-trait associations relating to cell-wall quality, the data support the separate examination of leaf and stem composition, as tissue-specific traits may be masked by considering only total above-ground biomass samples, and sample variability could be mostly due to varying tissue contributions to total biomass.« less

Genotype, development and tissue-derived variation of cell-wall properties in the lignocellulosic energy crop Miscanthus.

PubMed

da Costa, Ricardo M F; Lee, Scott J; Allison, Gordon G; Hazen, Samuel P; Winters, Ana; Bosch, Maurice

2014-10-01

Species and hybrids of the genus Miscanthus contain attributes that make them front-runners among current selections of dedicated bioenergy crops. A key trait for plant biomass conversion to biofuels and biomaterials is cell-wall quality; however, knowledge of cell-wall composition and biology in Miscanthus species is limited. This study presents data on cell-wall compositional changes as a function of development and tissue type across selected genotypes, and considers implications for the development of miscanthus as a sustainable and renewable bioenergy feedstock. Cell-wall biomass was analysed for 25 genotypes, considering different developmental stages and stem vs. leaf compositional variability, by Fourier transform mid-infrared spectroscopy and lignin determination. In addition, a Clostridium phytofermentans bioassay was used to assess cell-wall digestibility and conversion to ethanol. Important cell-wall compositional differences between miscanthus stem and leaf samples were found to be predominantly associated with structural carbohydrates. Lignin content increased as plants matured and was higher in stem tissues. Although stem lignin concentration correlated inversely with ethanol production, no such correlation was observed for leaves. Leaf tissue contributed significantly to total above-ground biomass at all stages, although the extent of this contribution was genotype-dependent. It is hypothesized that divergent carbohydrate compositions and modifications in stem and leaf tissues are major determinants for observed differences in cell-wall quality. The findings indicate that improvement of lignocellulosic feedstocks should encompass tissue-dependent variation as it affects amenability to biological conversion. For gene-trait associations relating to cell-wall quality, the data support the separate examination of leaf and stem composition, as tissue-specific traits may be masked by considering only total above-ground biomass samples, and sample variability could be mostly due to varying tissue contributions to total biomass. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company.

Comparison of stem morphology and anatomy of two alfalfa clonal lines exhibiting divergent cell wall composition

USDA-ARS?s Scientific Manuscript database

In previous research, two alfalfa clonal lines (252, 1283) were identified that exhibited environmentally stable differences in stem cell walls. Compared to stems of 1283, stems of 252 have a higher cell wall concentration and greater amounts of lignin and cellulose but reduced levels of pectic suga...

Survival of Hardwood Regeneration During Prescribed Fires: The Importance of Root Development and Root Collar Location

Treesearch

Patrick Brose; David Van Lear

2004-01-01

Fire ecology studies in eastern hardwood forests usually use plot-based inventory methods and focus on sprouting stems to detect changes in vegetative composition and structure. Rarely are individual stems studied and stems that fail to sprout are usually ignored. In this study, an individual stem mortality approach was employed. Four hundred fifty stems of eight...

Consumer preferences for maize products in urban Kenya.

PubMed

De Groote, Hugo; Kimenju, Simon Chege

2012-06-01

New maize varieties have been biofortified with provitamin A, mainly a-carotene, which renders the grain yellow or orange. Unfortunately, many African consumers prefer white maize. The maize consumption patterns in Africa are, however, not known. To determine which maize products African consumers prefer to purchase and which maize preparations they prefer to eat. A survey of 600 consumers was conducted in Nairobi, Kenya, at three types of maize outlets: posho mills (small hammer mills), kiosks, and supermarkets. Clients of posho mills had lower incomes and less education than those of kiosks and supermarkets. The preferred maize product of the posho-mill clients was artisanal maize meal; the preferred product of the others was industrial maize meal. Maize is the preferred staple for lunch and dinner, eaten as a stiff porridge (ugali), followed by boiled maize and beans (githeri), regardless of socioeconomic background. For breakfast, only half the consumers prefer maize, mostly as a soft porridge (uji). This proportion is higher in low-income groups. Consumers show a strong preference for white maize over yellow, mostly for its organoleptic characteristics, and show less interest in biofortified maize. Maize is the major food staple in Nairobi, mostly eaten in a few distinct preparations. For biofortified yellow maize to be accepted, a strong public awareness campaign to inform consumers is needed, based on a sensory evaluation and the mass media, in particular on radio in the local language.

The Role of High School Racial Composition and Opportunities to Learn in Students' STEM College Participation

ERIC Educational Resources Information Center

Bottia, Martha Cecilia; Mickelson, Roslyn Arlin; Giersch, Jason; Stearns, Elizabeth; Moller, Stephanie

2018-01-01

We analyze longitudinal data from students who spent their academic careers in North Carolina (NC) public secondary schools and attended NC public universities to investigate the importance of high school racial composition and opportunities to learn in secondary school for choosing a science, technology, engineering, and mathematics (STEM) major.…

Development of pachytene FISH maps for six maize chromosomes and their integration with other maize maps for insights into genome structure variation.

PubMed

Figueroa, Debbie M; Bass, Hank W

2012-05-01

Integrated cytogenetic pachytene fluorescence in situ hybridization (FISH) maps were developed for chromosomes 1, 3, 4, 5, 6, and 8 of maize using restriction fragment length polymorphism marker-selected Sorghum propinquum bacterial artificial chromosomes (BACs) for 19 core bin markers and 4 additional genetic framework loci. Using transgenomic BAC FISH mapping on maize chromosome addition lines of oats, we found that the relative locus position along the pachytene chromosome did not change as a function of total arm length, indicative of uniform axial contraction along the fibers during mid-prophase for tested loci on chromosomes 4 and 5. Additionally, we cytogenetically FISH mapped six loci from chromosome 9 onto their duplicated syntenic regions on chromosomes 1 and 6, which have varying amounts of sequence divergence, using sorghum BACs homologous to the chromosome 9 loci. We found that successful FISH mapping was possible even when the chromosome 9 selective marker had no counterpart in the syntenic block. In total, these 29 FISH-mapped loci were used to create the most extensive pachytene FISH maps to date for these six maize chromosomes. The FISH-mapped loci were then merged into one composite karyotype for direct comparative analysis with the recombination nodule-predicted cytogenetic, genetic linkage, and genomic physical maps using the relative marker positions of the loci on all the maps. Marker colinearity was observed between all pair-wise map comparisons, although marker distribution patterns varied widely in some cases. As expected, we found that the recombination nodule-based predictions most closely resembled the cytogenetic map positions overall. Cytogenetic and linkage map comparisons agreed with previous studies showing a decrease in marker spacing in the peri-centromeric heterochromatin region on the genetic linkage maps. In fact, there was a general trend with most loci mapping closer towards the telomere on the linkage maps than on the cytogenetic maps, regardless of chromosome number or maize inbred line source, with just some of the telomeric loci exempted. Finally and somewhat surprisingly, we observed considerable variation between the relative arm positions of loci when comparing our cytogenetic FISH map to the B73 genomic physical maps, even where comparisons were to a B73-derived cytogenetic map. This variation is more evident between different chromosome arms, but less so within a given arm, ruling out any type of inbred-line dependent global features of linear deoxyribonucleic acid compared with the meiotic fiber organization. This study provides a means for analyzing the maize genome structure by producing new connections for integrating the cytogenetic, linkage, and physical maps of maize.

High-resolution detection of adulteration of maize oil using multi-component compound-specific delta13C values of major and minor components and discriminant analysis.

PubMed

Mottram, Hazel R; Woodbury, Simon E; Rossell, J Barry; Evershed, Richard P

2003-01-01

Maize oil commands a premium price and is thus a target for adulteration with cheaper vegetable oils. Detection of this activity presents a particular challenge to the analyst because of the natural variability in the fatty acid composition of maize oils and because of their high sterol and tocopherol contents. This paper describes a method that allows detection of adulteration at concentrations of just 5% (m/m), based on the Mahalanobis distances of the principal component scores of the delta(13)C values of major and minor vegetable oil components. The method makes use of a database consisting of delta(13)C values and relative abundances of the major fatty acyl components of over 150 vegetable oils. The sterols and tocopherols of 16 maize oils and 6 potential adulterant oils were found to be depleted in (13)C by a constant amount relative to the bulk oil. Moreover, since maize oil contains particularly high levels of sterols and tocopherols, their delta(13)C values were not significantly altered when groundnut oil was added up to 20% (m/m) and it is possible to use the values for the minor components to predict the values that would be expected in a pure oil; therefore, comparison of the predicted values with those obtained experimentally allows adulteration to be detected. A refinement involved performing a discriminant analysis on the delta(13)C values of the bulk oil and the major fatty acids (16:0, 18:1 and 18:2) and using the Mahalanobis distances to determine the percentage of adulterant oil present. This approach may be refined further by including the delta(13)C values of the minor components in the discriminant analysis thereby increasing the sensitivity of the approach to concentrations at which adulteration would not be attractive economically. Copyright 2003 John Wiley & Sons, Ltd.

The effects of kale (Brassica oleracea ssp. acephala), basil (Ocimum basilicum) and thyme (Thymus vulgaris) as forage material in organic egg production on egg quality.

PubMed

Hammershøj, M; Steenfeldt, S

2012-01-01

1. In organic egg production, forage material as part of the diet for laying hens is mandatory. The purpose of the present study was to examine the effect of feeding with forage materials including maize silage, herbs or kale on egg production and various egg quality parameters of the shell, yolk colour, egg albumen, sensory properties, fatty acid and carotenoid composition of the egg yolk. 2. A total of 5 dietary treatments were tested for 5 weeks, consisting of a basal organic feed plus 120 g/hen.d of the following forage materials: 1) maize silage (control), 2) maize silage incl. 15 g/kg basil, 3) maize silage incl. 30 g/kg basil, 4) maize silage incl. 15 g/kg thyme, or 5) fresh kale leaves. Each was supplied to three replicates of 20 hens. A total of 300 hens was used. 3. Feed intake, forage intake and laying rate did not differ with treatment, but egg weight and egg mass produced increased significantly with the kale treatment. 4. The egg shell strength tended to be higher with the kale treatment, and egg yolk colour was significantly more red with the kale treatment and more yellow with basil and kale treatments. The albumen DM content and albumen gel strength were lowest with the thyme treatment. By sensory evaluation, the kale treatment resulted in eggs with less sulphur aroma, higher yolk colour score, and more sweet and less watery albumen taste. Furthermore, the eggs of the kale treatment had significantly higher lutein and β-carotene content. Also, violaxanthin, an orange xanthophyll, tended to be higher in kale and eggs from hens receiving kale. 5. In conclusion, forage material, especially basil and kale, resulted in increased egg production and eggs of high and differentiable quality.

Genetic and agronomic assessment of cob traits in corn under low and normal nitrogen management conditions.

PubMed

Jansen, Constantin; Zhang, Yongzhong; Liu, Hongjun; Gonzalez-Portilla, Pedro J; Lauter, Nick; Kumar, Bharath; Trucillo-Silva, Ignacio; Martin, Juan Pablo San; Lee, Michael; Simcox, Kevin; Schussler, Jeff; Dhugga, Kanwarpal; Lübberstedt, Thomas

2015-07-01

Exploring and understanding the genetic basis of cob biomass in relation to grain yield under varying nitrogen management regimes will help breeders to develop dual-purpose maize. With rising energy demands and costs for fossil fuels, alternative energy from renewable sources such as maize cobs will become competitive. Maize cobs have beneficial characteristics for utilization as feedstock including compact tissue, high cellulose content, and low ash and nitrogen content. Nitrogen is quantitatively the most important nutrient for plant growth. However, the influence of nitrogen fertilization on maize cob production is unclear. In this study, quantitative trait loci (QTL) have been analyzed for cob morphological traits such as cob weight, volume, length, diameter and cob tissue density, and grain yield under normal and low nitrogen regimes. 213 doubled-haploid lines of the intermated B73 × Mo17 (IBM) Syn10 population have been resequenced for 8575 bins, based on SNP markers. A total of 138 QTL were found for six traits across six trials using composite interval mapping with ten cofactors and empirical comparison-wise thresholds (P = 0.001). Despite moderate to high repeatabilities across trials, few QTL were consistent across trials and overall levels of explained phenotypic variance were lower than expected some of the cob trait × trial combinations (R (2) = 7.3-43.1 %). Variation for cob traits was less affected by nitrogen conditions than by grain yield. Thus, the economics of cob usage under low nitrogen regimes is promising.

Effects of Metal Phytoextraction Practices on the Indigenous Community of Arbuscular Mycorrhizal Fungi at a Metal-Contaminated Landfill

PubMed Central

Pawlowska, Teresa E.; Chaney, Rufus L.; Chin, Mel; Charvat, Iris

2000-01-01

Phytoextraction involves use of plants to remove toxic metals from soil. We examined the effects of phytoextraction practices with three plant species (Silene vulgaris, Thlaspi caerulescens, and Zea mays) and a factorial variation of soil amendments (either an ammonium or nitrate source of nitrogen and the presence or absence of an elemental sulfur supplement) on arbuscular mycorrhizal (AM) fungi (Glomales, Zygomycetes) at a moderately metal-contaminated landfill located in St. Paul, Minn. Specifically, we tested whether the applied treatments affected the density of glomalean spores and AM root colonization in maize. Glomalean fungi from the landfill were grouped into two morphotypes characterized by either light-colored spores (LCS) or dark-colored spores (DCS). Dominant species of the LCS morphotype were Glomus mosseae and an unidentified Glomus sp., whereas the DCS morphotype was dominated by Glomus constrictum. The density of spores of the LCS morphotype from the phytoremediated area was lower than the density of these spores in the untreated landfill soil. Within the experimental area, spore density of the LCS morphotype in the rhizosphere of mycorrhizal maize was significantly higher than in rhizospheres of nonmycorrhizal S. vulgaris or T. caerulescens. Sulfur supplement increased vesicular root colonization in maize and exerted a negative effect on spore density in maize rhizosphere. We conclude that phytoextraction practices, e.g., the choice of plant species and soil amendments, may have a great impact on the quantity and species composition of glomalean propagules as well as on mycorrhiza functioning during long-term metal-remediation treatments. PMID:10831433

A 6900-year history of landscape modification by humans in lowland Amazonia

NASA Astrophysics Data System (ADS)

Bush, M. B.; Correa-Metrio, A.; McMichael, C. H.; Sully, S.; Shadik, C. R.; Valencia, B. G.; Guilderson, T.; Steinitz-Kannan, M.; Overpeck, J. T.

2016-06-01

A sedimentary record from the Peruvian Amazon provided evidence of climate and vegetation change for the last 6900 years. Piston cores collected from the center of Lake Sauce, a 20 m deep lake at 600 m elevation, were 19.7 m in length. The fossil pollen record showed a continuously forested catchment within the period of the record, although substantial changes in forest composition were apparent. Fossil charcoal, found throughout the record, was probably associated with humans setting fires. Two fires, at c. 6700 cal BP and 4270 cal BP, appear to have been stand-replacing events possibly associated with megadroughts. The fire event at 4270 cal BP followed a drought that caused lowered lake levels for several centuries. The successional trajectories of forest recovery following these large fires were prolonged by smaller fire events. Fossil pollen of Zea mays (cultivated maize) provided evidence of agricultural activity at the site since c. 6320 cal BP. About 5150 years ago, the lake deepened and started to deposit laminated sediments. Maize agriculture reached a peak of intensity between c. 3380 and 700 cal BP. Fossil diatom data provided a proxy for lake nutrient status and productivity, both of which peaked during the period of maize cultivation. A marked change in land use was evident after c. 700 cal BP when maize agriculture was apparently abandoned at this site. Iriartea, a hyperdominant of riparian settings in western Amazonia, increased in abundance within the last 1100 years, but declined markedly at c. 1070 cal BP and again between c. 80 and -10 cal BP.

Mechanical and barrier properties of maize starch-gelatin composite films: effects of amylose content.

PubMed

Wang, Kun; Wang, Wenhang; Ye, Ran; Xiao, Jingdong; Liu, Yaowei; Ding, Junsheng; Zhang, Shaojing; Liu, Anjun

2017-08-01

In order to obtain new reinforcing bio-fillers to improve the physicochemical properties of gelatin-based films, three types of maize starch, waxy maize starch (Ap), normal starch (Ns) and high-amylose starch (Al), were incorporated into gelatin film and the resulting film properties were investigated, focusing on the impact of amylose content. The thickness, opacity and roughness of gelatin film increased depending on the amylose content along with the starch concentration. The effects of the three starches on the mechanical properties of gelatin film were governed by amylose content, starch concentration as well as environmental relative humidity (RH). At 75% RH, the presence of Al and Ns in the gelatin matrix increased the film strength but decreased its elongation, while Ap exhibited an inverse effect. Starch addition decreased the oxygen permeability of the film, with the lowest value at 20% Al and Ns. All starches, notably at 30% content, led to a decrease in the water vapor permeability of the film at 90% RH, especially Ns starch. Furthermore, the starches improved the thermal stability of the film to some extent. Fourier transform infrared spectra indicated that some weak intermolecular interactions such as hydrogen bonding occurred between gelatin and starch. Moreover, a high degree of B-type crystallinity of starch was characterized in Gel-Al film by X-ray diffraction. Tailoring the properties of gelatin film by the incorporation of different types of maize starch provides the potential to extend its applications in edible food packaging. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Simplified and representative bacterial community of maize roots

PubMed Central

Niu, Ben; Paulson, Joseph Nathaniel; Zheng, Xiaoqi; Kolter, Roberto

2017-01-01

Plant-associated microbes are important for the growth and health of their hosts. As a result of numerous prior studies, we know that host genotypes and abiotic factors influence the composition of plant microbiomes. However, the high complexity of these communities challenges detailed studies to define experimentally the mechanisms underlying the dynamics of community assembly and the beneficial effects of such microbiomes on plant hosts. In this work, from the distinctive microbiota assembled by maize roots, through host-mediated selection, we obtained a greatly simplified synthetic bacterial community consisting of seven strains (Enterobacter cloacae, Stenotrophomonas maltophilia, Ochrobactrum pituitosum, Herbaspirillum frisingense, Pseudomonas putida, Curtobacterium pusillum, and Chryseobacterium indologenes) representing three of the four most dominant phyla found in maize roots. By using a selective culture-dependent method to track the abundance of each strain, we investigated the role that each plays in community assembly on roots of axenic maize seedlings. Only the removal of E. cloacae led to the complete loss of the community, and C. pusillum took over. This result suggests that E. cloacae plays the role of keystone species in this model ecosystem. In planta and in vitro, this model community inhibited the phytopathogenic fungus Fusarium verticillioides, indicating a clear benefit to the host. Thus, combined with the selective culture-dependent quantification method, our synthetic seven-species community representing the root microbiome has the potential to serve as a useful system to explore how bacterial interspecies interactions affect root microbiome assembly and to dissect the beneficial effects of the root microbiota on hosts under laboratory conditions in the future. PMID:28275097

Simplified and representative bacterial community of maize roots.

PubMed

Niu, Ben; Paulson, Joseph Nathaniel; Zheng, Xiaoqi; Kolter, Roberto

2017-03-21

Plant-associated microbes are important for the growth and health of their hosts. As a result of numerous prior studies, we know that host genotypes and abiotic factors influence the composition of plant microbiomes. However, the high complexity of these communities challenges detailed studies to define experimentally the mechanisms underlying the dynamics of community assembly and the beneficial effects of such microbiomes on plant hosts. In this work, from the distinctive microbiota assembled by maize roots, through host-mediated selection, we obtained a greatly simplified synthetic bacterial community consisting of seven strains ( Enterobacter cloacae , Stenotrophomonas maltophilia, Ochrobactrum pituitosum, Herbaspirillum frisingense, Pseudomonas putida, Curtobacterium pusillum , and Chryseobacterium indologenes ) representing three of the four most dominant phyla found in maize roots. By using a selective culture-dependent method to track the abundance of each strain, we investigated the role that each plays in community assembly on roots of axenic maize seedlings. Only the removal of E. cloacae led to the complete loss of the community, and C. pusillum took over. This result suggests that E. cloacae plays the role of keystone species in this model ecosystem. In planta and in vitro, this model community inhibited the phytopathogenic fungus Fusarium verticillioides , indicating a clear benefit to the host. Thus, combined with the selective culture-dependent quantification method, our synthetic seven-species community representing the root microbiome has the potential to serve as a useful system to explore how bacterial interspecies interactions affect root microbiome assembly and to dissect the beneficial effects of the root microbiota on hosts under laboratory conditions in the future.

Iron and manganese oxides modified maize straw to remove tylosin from aqueous solutions.

PubMed

Yin, Yongyuan; Guo, Xuetao; Peng, Dan

2018-08-01

Maize straw modified by iron and manganese oxides was synthesized via a simple and environmentally friendly method. Three maize straw materials, the original maize straw, maize straw modified by manganese oxides and maize straw modified by iron and manganese oxides, were detected by SEM, BET, XPS, XRD and FTIR. The results showed that maize straw was successfully modified and maize straw modified by iron and manganese oxides has a larger surface area than MS. According to the experimental data, the sorption trend could conform to the pseudo-second-order kinetic model well, and the sorption ability of tylosin on sorbents followed the order of original maize straw < maize straw modified by manganese oxides < maize straw modified by iron and manganese oxides. The study indicated that manganese oxides and iron-manganese oxides could significantly enhance the sorption capacity of original maize straw. The sorption isotherm data of tylosin on original maize straw fit a linear model well, while Freundlich models were more suitable for maize straw modified by manganese oxides and maize straw modified by iron and manganese oxides. The pH, ionic strength and temperature can affect the sorption process. The sorption mechanisms of tylosin on iron and manganese oxides modified maize straw were attribute to the surface complexes, electrostatic interactions, H bonding and hydrophobic interactions. Copyright © 2018 Elsevier Ltd. All rights reserved.

A preliminary biomechanical study of a novel carbon-fibre hip implant versus standard metallic hip implants.

PubMed

Bougherara, Habiba; Zdero, Rad; Dubov, Anton; Shah, Suraj; Khurshid, Shaheen; Schemitsch, Emil H

2011-01-01

Total hip arthroplasty is a widespread surgical approach for treating severe osteoarthritis of the human hip. Aseptic loosening of standard metallic hip implants due to stress shielding and bone loss has motivated the development of new materials for hip prostheses. Numerically, a three-dimensional finite element (FE) model that mimicked hip implants was used to compare a new hip stem to two commercially available implants. The hip implants simulated were a novel CF/PA12 carbon-fibre polyamide-based composite hip stem, the Exeter hip stem (Stryker, Mahwah, NJ, USA), and the Omnifit Eon (Stryker, Mahwah, NJ, USA). A virtual axial load of 3 kN was applied to the FE model. Strain and stress distributions were computed. Experimentally, the three hip stems had their distal portions rigidly mounted and had strain gauges placed along the surface at 3 medial and 3 lateral locations. Axial loads of 3 kN were applied. Measurements of axial stiffness and strain were taken and compared to FE analysis. The overall linear correlation between FE model versus experimental strains showed reasonable results for the lines-of-best-fit for the Composite (Pearson R(2)=0.69, slope=0.82), Exeter (Pearson R(2)=0.78, slope=0.59), and Omnifit (Pearson R(2)=0.66, slope=0.45), with some divergence for the most distal strain locations. From FE analysis, the von Mises stress range for the Composite stem was much lower than that in the Omnifit and Exeter implants by 200% and 45%, respectively. The preliminary experiments showed that the Composite stem stiffness (1982 N/mm) was lower than the metallic hip stem stiffnesses (Exeter, 2460 N/mm; Omnifit, 2543 N/mm). This is the first assessment of stress, strain, and stiffness of the CF/PA12 carbon-fibre hip stem compared to standard commercially-available devices. Copyright © 2010 IPEM. Published by Elsevier Ltd. All rights reserved.

Increased soil phosphorus availability induced by faba bean root exudation stimulates root growth and phosphorus uptake in neighbouring maize.

PubMed

Zhang, Deshan; Zhang, Chaochun; Tang, Xiaoyan; Li, Haigang; Zhang, Fusuo; Rengel, Zed; Whalley, William R; Davies, William J; Shen, Jianbo

2016-01-01

Root growth is influenced by soil nutrients and neighbouring plants, but how these two drivers affect root interactions and regulate plant growth dynamics is poorly understood. Here, interactions between the roots of maize (Zea mays) and faba bean (Vicia faba) are characterized. Maize was grown alone (maize) or with maize (maize/maize) or faba bean (maize/faba bean) as competitors under five levels of phosphorus (P) supply, and with homogeneous or heterogeneous P distribution. Maize had longer root length and greater shoot biomass and P content when grown with faba bean than with maize. At each P supply rate, faba bean had a smaller root system than maize but greater exudation of citrate and acid phosphatase, suggesting a greater capacity to mobilize P in the rhizosphere. Heterogeneous P availability enhanced the root-length density of maize but not faba bean. Maize root proliferation in the P-rich patches was associated with increased shoot P uptake. Increased P availability by localized P application or by the presence of faba bean exudation stimulated root morphological plasticity and increased shoot growth in maize in the maize/faba bean mixture, suggesting that root interactions of neighbouring plants can be modified by increased P availability. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

MaizeGDB, the maize model organism database

USDA-ARS?s Scientific Manuscript database

MaizeGDB is the maize research community's database for maize genetic and genomic information. In this seminar I will outline our current endeavors including a full website redesign, the status of maize genome assembly and annotation projects, and work toward genome functional annotation. Mechanis...

Phenotypic plasticity in cell walls of maize brown midrib mutants is limited by lignin composition

PubMed Central

Vermerris, Wilfred; Sherman, Debra M.; McIntyre, Lauren M.

2010-01-01

The hydrophobic cell wall polymer lignin is deposited in specialized cells to make them impermeable to water and prevent cell collapse as negative pressure or gravitational force is exerted. The variation in lignin subunit composition that exists among different species, and among different tissues within the same species suggests that lignin subunit composition varies depending on its precise function. In order to gain a better understanding of the relationship between lignin subunit composition and the physico-chemical properties of lignified tissues, detailed analyses were performed of near-isogenic brown midrib2 (bm2), bm4, bm2-bm4, and bm1-bm2-bm4 mutants of maize. This investigation was motivated by the fact that the bm2-bm4 double mutant is substantially shorter, displays drought symptoms even when well watered, and will often not develop reproductive organs, whereas the phenotypes of the individual bm single mutants and double mutant combinations other than bm2-bm4 are only subtly different from the wild-type control. Detailed cell wall compositional analyses revealed midrib-specific reductions in Klason lignin content in the bm2, bm4, and bm2-bm4 mutants relative to the wild-type control, with reductions in both guaiacyl (G)- and syringyl (S)-residues. The cellulose content was not different, but the reduction in lignin content was compensated by an increase in hemicellulosic polysaccharides. Linear discriminant analysis performed on the compositional data indicated that the bm2 and bm4 mutations act independently of each other on common cell wall biosynthetic steps. After quantitative analysis of scanning electron micrographs of midrib sections, the variation in chemical composition of the cell walls was shown to be correlated with the thickness of the sclerenchyma cell walls, but not with xylem vessel surface area. The bm2-bm4 double mutant represents the limit of phenotypic plasticity in cell wall composition, as the bm1-bm2-bm4 and bm2-bm3-bm4 mutants did not develop into mature plants, unlike the triple mutants bm1-bm2-bm3 and bm1-bm3-bm4. PMID:20410320

Reinventing MaizeGDB

USDA-ARS?s Scientific Manuscript database

The Maize Database (MaizeDB) to the Maize Genetics and Genomics Database (MaizeGDB) turns 20 this year, and such a significant milestone must be celebrated! With the release of the B73 reference sequence and more sequenced genomes on the way, the maize community needs to address various opportunitie...

Detection of Cell Wall Chemical Variation in Zea Mays Mutants Using Near-Infrared Spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buyck, N.; Thomas, S.

Corn stover is regarded as the prime candidate feedstock material for commercial biomass conversion in the United States. Variations in chemical composition of Zea mays cell walls can affect biomass conversion process yields and economics. Mutant lines were constructed by activating a Mu transposon system. The cell wall chemical composition of 48 mutant families was characterized using near-infrared (NIR) spectroscopy. NIR data were analyzed using a multivariate statistical analysis technique called Principal Component Analysis (PCA). PCA of the NIR data from 349 maize leaf samples reveals 57 individuals as outliers on one or more of six Principal Components (PCs) atmore » the 95% confidence interval. Of these, 19 individuals from 16 families are outliers on either PC3 (9% of the variation) or PC6 (1% of the variation), the two PCs that contain information about cell wall polymers. Those individuals for which altered cell wall chemistry is confirmed with wet chemical analysis will then be subjected to fermentation analysis to determine whether or not biomass conversion process kinetics, yields and/or economics are significantly affected. Those mutants that provide indications for a decrease in process cost will be pursued further to identify the gene(s) responsible for the observed changes in cell wall composition and associated changes in process economics. These genes will eventually be incorporated into maize breeding programs directed at the development of a truly dual use crop.« less

Characterization of Femoral Component Initial Stability and Cortical Strain in a Reduced Stem-Length Design.

PubMed

Small, Scott R; Hensley, Sarah E; Cook, Paige L; Stevens, Rebecca A; Rogge, Renee D; Meding, John B; Berend, Michael E

2017-02-01

Short-stemmed femoral components facilitate reduced exposure surgical techniques while preserving native bone. A clinically successful stem should ideally reduce risk for stress shielding while maintaining adequate primary stability for biological fixation. We asked (1) how stem-length changes cortical strain distribution in the proximal femur in a fit-and-fill geometry and (2) if short-stemmed components exhibit primary stability on par with clinically successful designs. Cortical strain was assessed via digital image correlation in composite femurs implanted with long, medium, and short metaphyseal fit-and-fill stem designs in a single-leg stance loading model. Strain was compared to a loaded, unimplanted femur. Bone-implant micromotion was then compared with reduced lateral shoulder short stem and short tapered-wedge designs in cyclic axial and torsional testing. Femurs implanted with short-stemmed components exhibited cortical strain response most closely matching that of the intact femur model, theoretically reducing the potential for proximal stress shielding. In micromotion testing, no difference in primary stability was observed as a function of reduced stem length within the same component design. Our findings demonstrate that within this fit-and-fill stem design, reduction in stem length improved proximal cortical strain distribution and maintained axial and torsional stability on par with other stem designs in a composite femur model. Short-stemmed implants may accommodate less invasive surgical techniques while facilitating more physiological femoral loading without sacrificing primary implant stability. Copyright © 2016 Elsevier Inc. All rights reserved.

Radiosynthesis of 6’-Deoxy-6’[18F]Fluorosucrose via Automated Synthesis and Its Utility to Study In Vivo Sucrose Transport in Maize (Zea mays) Leaves

PubMed Central

Ying, Weijiang; Gaddam, Vikram; Harmata, Michael; Robertson, J. David; Swyers, Michael; Jurisson, Silvia S.

2015-01-01

Sugars produced from photosynthesis in leaves are transported through the phloem tissues within veins and delivered to non-photosynthetic organs, such as roots, stems, flowers, and seeds, to support their growth and/or storage of carbohydrates. However, because the phloem is located internally within the veins, it is difficult to access and to study the dynamics of sugar transport. Radioactive tracers have been extensively used to study vascular transport in plants and have provided great insights into transport dynamics. To better study sucrose partitioning in vivo, a novel radioactive analog of sucrose was synthesized through a completely chemical synthesis route by substituting fluorine-18 (half-life 110 min) at the 6’ position to generate 6’-deoxy-6’[18F]fluorosucrose (18FS). This radiotracer was then used to compare sucrose transport between wild-type maize plants and mutant plants lacking the Sucrose transporter1 (Sut1) gene, which has been shown to function in sucrose phloem loading. Our results demonstrate that 18FS is transported in vivo, with the wild-type plants showing a greater rate of transport down the leaf blade than the sut1 mutant plants. A similar transport pattern was also observed for universally labeled [U-14C]sucrose ([U-14C]suc). Our findings support the proposed sucrose phloem loading function of the Sut1 gene in maize, and additionally demonstrate that the 18FS analog is a valuable, new tool that offers imaging advantages over [U-14C]suc for studying phloem transport in plants. PMID:26024520

Influence of salt tolerant Trichoderma spp. on growth of maize (Zea mays) under different salinity conditions.

PubMed

Kumar, Krishna; Manigundan, K; Amaresan, Natarajan

2017-02-01

In the present study, a total of 70 Trichoderma spp. were isolated from the rhizosphere soils of vegetable and spice crops that were grown in Andaman and Nicobar Islands, India. Initial screening of Trichoderma spp. for salt tolerant properties showed 32 isolates were able to tolerate 10% NaCl. Furthermore, these isolates were screened for their potential plant growth-promoting characteristics such as IAA production, phosphate solubilization, and siderophore production. Among 32 isolates, nine isolates were able to produce IAA, siderophore, and solubilize phosphate. Jar trial was carried out on maize under axenic conditions at 1.67, 6.25, 11.25, 17.2, and 22.9 dS m -1 salt stress using the best nine isolates. Three isolates (TRC3, NRT2, and THB3) were effective in improving germination percentage, reducing reduction percentage of germination (RPG) and also in increasing the shoot and root length under axenic conditions. These three isolates were further tested under pot trial at 52 (sea water), 27, 15, 7, and 1.67 dS m -1 . TRC3 was found to be the most effective isolate compared to the other isolates and significantly increased the physiological parameters like shoot, root length, leaf area, total biomass, and stem and leaf fresh weight at all stress levels. Similarly, total chlorophyll content also increased by TRC3 over control. All three isolates, NRT2, TRC3, and THB3 showed lower accumulation of malondialdehyde (MDA) content whereas, proline and phenol content were higher than the uninoculated control plants under both normal and saline conditions. The results suggest that these isolates could be utilized for the alleviation of salinity stress in maize. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

MaizeGDB - Past, present, and future

USDA-ARS?s Scientific Manuscript database

The Maize Genetics and Genomics Database (MaizeGDB) turns 20 this year. This editorial outlines MaizeGDB's history and connection to the Maize Genetics Cooperation, describes key components of how the MaizeGDB interface will be completely redesigned over the course of the next two years to meet cur...

Effect of temperature on the phenology of Chilo partellus (Swinhoe) (Lepidoptera, Crambidae); simulation and visualization of the potential future distribution of C. partellus in Africa under warmer temperatures through the development of life-table parameters.

PubMed

Khadioli, N; Tonnang, Z E H; Muchugu, E; Ong'amo, G; Achia, T; Kipchirchir, I; Kroschel, J; Le Ru, B

2014-12-01

Maize (Zea mays) is a major staple food in Africa. However, maize production is severely reduced by damage caused by feeding lepidopteran pests. In East and Southern Africa, Chilo partellus is one of the most damaging cereal stem borers mainly found in the warmer lowland areas. In this study, it was hypothesized that the future distribution and abundance of C. partellus may be affected greatly by the current global warming. The temperature-dependent population growth potential of C. partellus was studied on artificial diet under laboratory conditions at six constant temperatures (15, 18, 20, 25, 28, 30, 32 and 35 °C), relative humidity of 75±5% and a photoperiod of L12:L12 h. Several non-linear models were fitted to the data to model development time, mortality and reproduction of the insect species. Cohort updating algorithm and rate summation approach were stochastically used for simulating age and stage structure populations and generate life-table parameters. For spatial analysis of the pest risk, three generic risk indices (index of establishment, generation number and activity index) were visualized in the geographical information system component of the advanced Insect Life Cycle modeling (ILCYM) software. To predict the future distribution of C. partellus we used the climate change scenario A1B obtained from WorldClim and CCAFS databases. The maps were compared with available data on the current distribution of C. partellus in Kenya. The results show that the development times of the different stages decreased with increasing temperatures ranging from 18 to 35 °C; at the extreme temperatures, 15 and 38 °C, no egg could hatch and no larvae completed development. The study concludes that C. partellus may potentially expands its range into higher altitude areas, highland tropics and moist transitional regions, with the highest maize potential where the species has not been recorded yet. This has serious implication in terms of food security since these areas produce approximately 80% of the total maize in East Africa.

Impact of Cell Wall Composition on Maize Resistance to Pests and Diseases

PubMed Central

Santiago, Rogelio; Barros-Rios, Jaime; Malvar, Rosa A.

2013-01-01

In cereals, the primary cell wall is built of a skeleton of cellulosic microfibrils embedded in a matrix of hemicelluloses and smaller amounts of pectins, glycoproteins and hydroxycinnamates. Later, during secondary wall development, p-coumaryl, coniferyl and sinapyl alcohols are copolymerized to form mixed lignins. Several of these cell wall components show a determinative role in maize resistance to pest and diseases. However, defense mechanisms are very complex and vary among the same plant species, different tissues or even the same tissue at different developmental stages. Thus, it is important to highlight that the role of the cell wall components needs to be tested in diverse genotypes and specific tissues where the feeding or attacking by the pathogen takes place. Understanding the role of cell wall constituents as defense mechanisms may allow modifications of crops to withstand pests and diseases. PMID:23535334

Antisense expression of the fasciclin-like arabinogalactan protein FLA6 gene in Populus inhibits expression of its homologous genes and alters stem biomechanics and cell wall composition in transgenic trees

PubMed Central

Wang, Haihai; Jiang, Chunmei; Wang, Cuiting; Yang, Yang; Yang, Lei; Gao, Xiaoyan; Zhang, Hongxia

2015-01-01

Fasciclin-like arabinogalactan proteins (FLAs) play important roles in the growth and development of roots, stems, and seeds in Arabidopsis. However, their biological functions in woody plants are largely unknown. In this work, we investigated the possible function of PtFLA6 in poplar. Quantitative real-time PCR, PtFLA6–yellow fluorescent protein (YFP) fusion protein subcellular localization, Western blotting, and immunohistochemical analyses demonstrated that the PtFLA6 gene was expressed specifically in the xylem of mature stem, and PtFLA6 protein was distributed ubiquitous in plant cells and accumulated predominantly in stem xylem fibres. Antisense expression of PtFLA6 in the aspen hybrid clone Poplar davidiana×Poplar bolleana reduced the transcripts of PtFLA6 and its homologous genes. Transgenic plants that showed a significant reduction in the transcripts of PtFLAs accumulated fewer PtFLA6 and arabinogalactan proteins than did the non-transgenic plants, leading to reduced stem flexural strength and stiffness. Further studies revealed that the altered stem biomechanics of transgenic plants could be attributed to the decreased cellulose and lignin composition in the xylem. In addition expression of some xylem-specific genes involved in cell wall biosynthesis was downregulated in these transgenic plants. All these results suggest that engineering the expression of PtFLA6 and its homologues could modulate stem mechanical properties by affecting cell wall composition in trees. PMID:25428999

Significant aspects on thermal degradation of hybrid biocomposite material

NASA Astrophysics Data System (ADS)

Bavan, D. Saravana; Kumar, G. C. Mohan

2013-06-01

Interest in use of bio fibers is increasing rapidly in structural and automotive applications because of few important properties such as low density, mechanical properties, renewability, biodegradation and sustainability. The present work is focused on fabricating a hybrid bio-composite material processed through compression molding technique. Natural fibers of maize and jute with bio polymeric resin of epoxidized soya bean oil are used as a matrix in obtaining a hybrid bio composite material. Thermal degradation of the prepared material is studied through Thermal gravimetric analyzer. Chemical treatment of the fibers was performed to have a better adhesion between the fibers and the matrix. The work is also surveyed on various parameters influencing the thermal properties and other aspects for a hybrid bio composite material.

Aspergillus parasiticus communities associated with sugarcane in the Rio Grande Valley of Texas: implications of global transport and host association within Aspergillus section Flavi.

PubMed

Garber, N P; Cotty, P J

2014-05-01

In the Rio Grande Valley of Texas (RGV), values of maize and cottonseed crops are significantly reduced by aflatoxin contamination. Aflatoxin contamination of susceptible crops is the product of communities of aflatoxin producers and the average aflatoxin-producing potentials of these communities influence aflatoxin contamination risk. Cropping pattern influences community composition and, thereby, the epidemiology of aflatoxin contamination. In 2004, Aspergillus parasiticus was isolated from two fields previously cropped to sugarcane but not from 23 fields without recent history of sugarcane cultivation. In 2004 and 2005, A. parasiticus composed 18 to 36% of Aspergillus section Flavi resident in agricultural soils within sugarcane-producing counties. A. parasiticus was not detected in counties that do not produce sugarcane. Aspergillus section Flavi soil communities within sugarcane-producing counties differed significantly dependent on sugarcane cropping history. Fields cropped to sugarcane within the previous 5 years had greater quantities of A. parasiticus (mean = 16 CFU/g) than fields not cropped to sugarcane (mean = 0.1 CFU/g). The percentage of Aspergillus section Flavi composed of A. parasiticus increased to 65% under continuous sugarcane cultivation and remained high the first season of rotation out of sugarcane. Section Flavi communities in fields rotated to non-sugarcane crops for 3 to 5 years were composed of <5% A. parasiticus, and fields with no sugarcane history averaged only 0.2% A. parasiticus. The section Flavi community infecting RGV sugarcane stems ranged from 95% A. parasiticus in billets prepared for commercial planting to 52% A. parasiticus in hand-collected sugarcane stems. Vegetative compatibility assays and multilocus phylogenies verified that aflatoxin contamination of raw sugar was previously attributed to similar A. parasiticus in Japan. Association of closely related A. parasiticus genotypes with sugarcane produced in Japan and RGV, frequent infection of billets by these genotypes, and the ephemeral nature of A. parasiticus in RGV soils suggests global transport with sugarcane planting material.

Chlorogenic acid and maize ear rot resistance: a dynamic study investigating Fusarium graminearum development, deoxynivalenol production, and phenolic acid accumulation.

PubMed

Atanasova-Penichon, Vessela; Pons, Sebastien; Pinson-Gadais, Laetitia; Picot, Adeline; Marchegay, Gisèle; Bonnin-Verdal, Marie-Noelle; Ducos, Christine; Barreau, Christian; Roucolle, Joel; Sehabiague, Pierre; Carolo, Pierre; Richard-Forget, Florence

2012-12-01

Fusarium graminearum is the causal agent of Gibberella ear rot and produces trichothecene mycotoxins. Basic questions remain unanswered regarding the kernel stages associated with trichothecene biosynthesis and the kernel metabolites potentially involved in the regulation of trichothecene production in planta. In a two-year field study, F. graminearum growth, trichothecene accumulation, and phenolic acid composition were monitored in developing maize kernels of a susceptible and a moderately resistant variety using quantitative polymerase chain reaction and liquid chromatography coupled with photodiode array or mass spectrometry detection. Infection started as early as the blister stage and proceeded slowly until the dough stage. Then, a peak of trichothecene accumulation occurred and infection progressed exponentially until the final harvest time. Both F. graminearum growth and trichothecene production were drastically reduced in the moderately resistant variety. We found that chlorogenic acid is more abundant in the moderately resistant variety, with levels spiking in the earliest kernel stages induced by Fusarium infection. This is the first report that precisely describes the kernel stage associated with the initiation of trichothecene production and provides in planta evidence that chlorogenic acid may play a role in maize resistance to Gibberella ear rot and trichothecene accumulation.

Using water vapor isotopes to examine evapotranspiration dynamics in corn and miscanthus reveals challenges to the technique as well as seasonal differences between crops.

NASA Astrophysics Data System (ADS)

Miller, J. N.; Bernacchi, C.

2016-12-01

Second-generation biofuel crops are being planted at an increasing extent around the globe. Changing land use from common field crops to perennial biofuel crops such as miscanthus or switchgrass is expected to alter ecohydrology via changes in evapotranspiration (ET). However, the direction in which evapotranspiration will shift, either partitioning more moisture through soil evaporation (E) or through plant transpiration (T) is uncertain. To investigate how land conversion from maize to miscanthus affects ET partitioning we measured the isotopic composition of water vapor via continuous air sampling. We obtained continuous diurnal measurements of δ2H and δ18O for miscanthus and maize on multiple days over the course of the growing season. Water vapor isotopes drawn from two heights were measured at 2 Hz using a cavity ringdown spectrometer and partitioned into components of E and T using a simple mixing equation. Partitioning was also accomplished with a combination of sap flow sensors and soil lysimeters. Preliminary results reveal that while daily transpiration fraction can be strongly influenced by meteorological events, the whole season transpiration fraction dominates variations in ET in miscanthus fields more so than in fields of maize.

Methylenetetrahydrofolate Reductase Modulates Methyl Metabolism and Lignin Monomer Methylation in Maize.

PubMed

Wu, Zhenying; Ren, Hao; Xiong, Wangdan; Roje, Sanja; Liu, Yuchen; Su, Kunlong; Fu, Chunxiang

2018-05-30

The brown midrib2 (bm2) mutant of maize, with a modified lignin composition, contains a mutation in the methylenetetrahydrofolate reductase (MTHFR) gene. We here show that a MITE transposon insertion caused downregulation of MTHFR with accompanying decrease in 5-methyl-THF and increase in 5, 10-methylene-THF and THF in the bm2 mutant. Furthermore, MTHFR mutation did not change the content of SAM, the methyl group donor involved in the biosynthesis of guaiacyl (G) and syringyl (S) lignins, but increased the level of S-adenosyl homocysteine (SAH), the de-methylation product of SAM. Moreover, competitive inhibition of the maize caffeoyl CoA O-methyltransferase (CCoAOMT) and caffeic acid O-methyltransferase (COMT) enzyme activities by SAH was found, suggesting that SAH/SAM ratio rather than SAM concentration regulates the transmethylation reactions of lignin intermediates. Phenolic profiling revealed that caffeoyl alcohol glucose derivatives accumulated in the mutant, indicating impaired 3-O-methylation of monolignols. A remarkable increase in the unusual catechyl (C) lignin determined in the mutant demonstrates that MTHFR downregulation mainly affects G lignin biosynthesis, consistent with the observation that CCoAOMT is more sensitive to SAH inhibition than COMT. This study which uncovered a novel regulatory mechanism in lignin biosynthesis and may offer an effective approach to utilize lignocellulosic feedstocks in future.

Retrobiosynthetic nuclear magnetic resonance analysis of amino acid biosynthesis and intermediary metabolism. Metabolic flux in developing maize kernels.

PubMed

Glawischnig, E; Gierl, A; Tomas, A; Bacher, A; Eisenreich, W

2001-03-01

Information on metabolic networks could provide the basis for the design of targets for metabolic engineering. To study metabolic flux in cereals, developing maize (Zea mays) kernels were grown in sterile culture on medium containing [U-(13)C(6)]glucose or [1,2-(13)C(2)]acetate. After growth, amino acids, lipids, and sitosterol were isolated from kernels as well as from the cobs, and their (13)C isotopomer compositions were determined by quantitative nuclear magnetic resonance spectroscopy. The highly specific labeling patterns were used to analyze the metabolic pathways leading to amino acids and the triterpene on a quantitative basis. The data show that serine is generated from phosphoglycerate, as well as from glycine. Lysine is formed entirely via the diaminopimelate pathway and sitosterol is synthesized entirely via the mevalonate route. The labeling data of amino acids and sitosterol were used to reconstruct the labeling patterns of key metabolic intermediates (e.g. acetyl-coenzyme A, pyruvate, phosphoenolpyruvate, erythrose 4-phosphate, and Rib 5-phosphate) that revealed quantitative information about carbon flux in the intermediary metabolism of developing maize kernels. Exogenous acetate served as an efficient precursor of sitosterol, as well as of amino acids of the aspartate and glutamate family; in comparison, metabolites formed in the plastidic compartments showed low acetate incorporation.

Cloning and Functional Characterization of the Maize (Zea mays L.) Carotenoid Epsilon Hydroxylase Gene

PubMed Central

Sheng, Yanmin; Wang, Yingdian; Capell, Teresa; Shi, Lianxuan; Ni, Xiuzhen; Sandmann, Gerhard; Christou, Paul; Zhu, Changfu

2015-01-01

The assignment of functions to genes in the carotenoid biosynthesis pathway is necessary to understand how the pathway is regulated and to obtain the basic information required for metabolic engineering. Few carotenoid ε-hydroxylases have been functionally characterized in plants although this would provide insight into the hydroxylation steps in the pathway. We therefore isolated mRNA from the endosperm of maize (Zea mays L., inbred line B73) and cloned a full-length cDNA encoding CYP97C19, a putative heme-containing carotenoid ε hydroxylase and member of the cytochrome P450 family. The corresponding CYP97C19 genomic locus on chromosome 1 was found to comprise a single-copy gene with nine introns. We expressed CYP97C19 cDNA under the control of the constitutive CaMV 35S promoter in the Arabidopsis thaliana lut1 knockout mutant, which lacks a functional CYP97C1 (LUT1) gene. The analysis of carotenoid levels and composition showed that lutein accumulated to high levels in the rosette leaves of the transgenic lines but not in the untransformed lut1 mutants. These results allowed the unambiguous functional annotation of maize CYP97C19 as an enzyme with strong zeinoxanthin ε-ring hydroxylation activity. PMID:26030746

Volatiles produced by soil-borne endophytic bacteria increase plant pathogen resistance and affect tritrophic interactions

PubMed Central

Ton, Jurriaan; Brandenburg, Anna; Karlen, Danielle; Zopfi, Jakob; Turlings, Ted C. J.

2014-01-01

Volatile organic compounds (VOCs) released by soil microorganisms influence plant growth and pathogen resistance. Yet, very little is known about their influence on herbivores and higher trophic levels. We studied the origin and role of a major bacterial VOC, 2,3-butanediol (2,3-BD), on plant growth, pathogen and herbivore resistance, and the attraction of natural enemies in maize. One of the major contributors to 2,3-BD in the headspace of soil-grown maize seedlings was identified as Enterobacter aerogenes, an endophytic bacterium that colonizes the plants. The production of 2,3-BD by E. aerogenes rendered maize plants more resistant against the Northern corn leaf blight fungus Setosphaeria turcica. On the contrary, E. aerogenes-inoculated plants were less resistant against the caterpillar Spodoptera littoralis. The effect of 2,3-BD on the attraction of the parasitoid Cotesia marginiventris was more variable: 2,3-BD application to the headspace of the plants had no effect on the parasitoids, but application to the soil increased parasitoid attraction. Furthermore, inoculation of seeds with E. aerogenes decreased plant attractiveness, whereas inoculation of soil with a total extract of soil microbes increased parasitoid attraction, suggesting that the effect of 2,3-BD on the parasitoid is indirect and depends on the composition of the microbial community. PMID:24127750

Real-time quantitative polymerase chain reaction methods for four genetically modified maize varieties and maize DNA content in food.

PubMed

Brodmann, Peter D; Ilg, Evelyn C; Berthoud, Hélène; Herrmann, Andre

2002-01-01

Quantitative detection methods are needed for enforcement of the recently introduced labeling threshold for genetically modified organisms (GMOs) in food ingredients. This labeling threshold, which is set to 1% in the European Union and Switzerland, must be applied to all approved GMOs. Four different varieties of maize are approved in the European Union: the insect-resistant Bt176 maize (Maximizer), Btl 1 maize, Mon810 (YieldGard) maize, and the herbicide-tolerant T25 (Liberty Link) maize. Because the labeling must be considered individually for each ingredient, a quantitation system for the endogenous maize content is needed in addition to the GMO-specific detection systems. Quantitative real-time polymerase chain reaction detection methods were developed for the 4 approved genetically modified maize varieties and for an endogenous maize (invertase) gene system.

Bulk C, H, O, and fatty acid C stable isotope analyses for purity assessment of vegetable oils from the southern and northern hemispheres.

PubMed

Spangenberg, Jorge E

2016-09-06

|The carbon, hydrogen and oxygen stable isotope composition (δ 13 C, δ 2 H, and δ 18 O values) of plants and their products is linked to photosynthetic fractionation, environmental factors and agricultural practices. Therefore, they contribute to determining the purity of commercial vegetable oils and may provide information on their geographical origin. Maize, olive, sunflower, groundnut, soybean and rice oils differing in sites of growth in the southern and northern hemispheres were characterized by bulk oil stable isotope ratios (δ 13 C bulk , δ 2 H bulk , and δ 18 O bulk values), fatty acids (FAs) concentrations and δ 13 C FA values using elemental analysis/isotope ratio mass spectrometry, gas chromatography/mass spectrometry, gas chromatography/flame ionization detection and gas chromatography/combustion/isotope ratio mass spectrometry. Principal component analysis was applied to examine the inherent structure of the data. The δ 13 C bulk values of maize oils (-18.4 to -14.9 ‰) are typical for C 4 plants, and those of olive (-30.2 to -28.2 ‰), sunflower (-30.2 to -29.2 ‰), groundnut (-29.3 ‰), soybean (-30.6 ‰), and rice (-34.5 ‰) oils are typical for C 3 plants. The δ 2 H bulk values vary from -161 to -132‰ for maize oils and -171 to -109 ‰ for C 3 oils. The δ 18 O bulk values of all oils vary between 15.2 and 38.9 ‰. The major δ 13 C FA differences (>5 ‰) within plant species render the inter-C 3 -species comparison difficult. These differences are explained in terms of variations in the lipid biosynthetic pathways and blend of vegetable oils of different FA composition and δ 13 C FA values. The samples from the southern hemisphere are generally enriched in 13 C compared with those from the northern hemisphere. Differences between the southern and northern hemispheres were observed in δ 2 H (p < 0.001) and δ 18 O bulk (p = 0.129) values for all C 3 oils, and in δ 13 C 18:1 (p = 0.026) and δ 18 O bulk (p = 0.160) values for maize oils. The results of this study show that combining bulk and molecular stable isotope ratios, fatty acid compositions and their statistical analysis helps the characterization of the geographic origin of oils. This methodology can be used to detect and source impurities in valuable vegetable oils commercialized worldwide. This article is protected by copyright. All rights reserved.

[Effects of nitrogen management on maize nitrogen utilization and residual nitrate nitrogen in soil under maize/soybean and maize/sweet potato relay strip intercropping systems].

PubMed

Wang, Xiao-Chun; Yang, Wen-Yu; Deng, Xiao-Yan; Zhang, Qun; Yong, Tai-Wen; Liu, Wei-Guo; Yang, Feng; Mao, Shu-Ming

2014-10-01

A large amount of nitrogen (N) fertilizers poured into the fields severely pollute the environment. Reasonable application of N fertilizer has always been the research hotpot. The effects of N management on maize N utilization and residual nitrate N in soil under maize/soybean and maize/ sweet potato relay strip intercropping systems were reported in a field experiment in southwest China. It was found that maize N accumulation, N harvest index, N absorption efficiency, N contribution proportion after the anthesis stage in maize/soybean relay strip intercropping were increased by 6.1%, 5.4%, 4.3%, and 15.1% than under maize/sweet potato with an increase of 22.6% for maize yield after sustainable growing of maize/soybean intercropping system. Nitrate N accumulation in the 0-60 cm soil layer was 12.9% higher under maize/soybean intercropping than under maize/sweet potato intercropping. However, nitrate N concentration in the 60-120 cm soil layer when intercropped with soybean decreased by 10.3% than when intercropped with sweet potato, indicating a decrease of N leaching loss. Increasing of N application rate enhanced N accumulation of maize and decreased N use efficiency and significantly increased nitrate concentration in the soil profile except in the 60-100 cm soil layer, where no significant difference was observed with nitrogen application rate at 0 to 270 kg · hm(-2). Further application of N fertilizer significantly enhanced nitrate leaching loss. Postponing N application increased nitrate accumulation in the 60-100 cm soil layer. The results suggested that N application rates and ratio of base to top dressing had different influences on maize N concentration and nitrate N between maize/soybean and maize/sweet potato intercropping. Maize N concentration in the late growing stage, N harvest index and N use efficiency under maize/soybean intercropping increased (with N application rate at 180-270 kg · hm(-2) and ratio of base to top dressing = 3:2:5) and decreased nitrate leaching loss with yield reaching 7757 kg · hm(-2) on average. However, for maize/sweet potato, N concentration and use efficiency and maize yield increased significantly with N application rate at 180 kg · hm(-2) and ratio of base to top dressing = 5:5 than that under other treatments with yield reaching 6572 kg · hm(-2). Under these circumstances, it would be possible to realize maize high yield, high efficiency and safety of N man- agement under maize/soybean and maize/sweet potato relay strip intercropping systems.

Choosing a genome browser for a Model Organism Database: surveying the Maize community

PubMed Central

Sen, Taner Z.; Harper, Lisa C.; Schaeffer, Mary L.; Andorf, Carson M.; Seigfried, Trent E.; Campbell, Darwin A.; Lawrence, Carolyn J.

2010-01-01

As the B73 maize genome sequencing project neared completion, MaizeGDB began to integrate a graphical genome browser with its existing web interface and database. To ensure that maize researchers would optimally benefit from the potential addition of a genome browser to the existing MaizeGDB resource, personnel at MaizeGDB surveyed researchers’ needs. Collected data indicate that existing genome browsers for maize were inadequate and suggest implementation of a browser with quick interface and intuitive tools would meet most researchers’ needs. Here, we document the survey’s outcomes, review functionalities of available genome browser software platforms and offer our rationale for choosing the GBrowse software suite for MaizeGDB. Because the genome as represented within the MaizeGDB Genome Browser is tied to detailed phenotypic data, molecular marker information, available stocks, etc., the MaizeGDB Genome Browser represents a novel mechanism by which the researchers can leverage maize sequence information toward crop improvement directly. Database URL: http://gbrowse.maizegdb.org/ PMID:20627860

Chemical composition of needles and cambial activity of stems of Scots pine trees affected by air pollutants in Polish forests

Treesearch

Wojciech Dmuchowski; Ewa U. Kurczynska; Wieslaw Wloch

1998-01-01

The impact of environmental pollution is defined for the chemical composition of Scots pine (Pinus sylvestris L.) needles and cambial activity in the tree stems in Polish forests. The research investigated 20-year-old trees growing in two areas in significantly different levels of pollution. The highly polluted area was located near the Warsaw...

Storage related changes of cell wall based dietary fiber components of broccoli (Brassica oleracea var. italica) stems.

PubMed

Schäfer, Judith; Stanojlovic, Luisa; Trierweiler, Bernhard; Bunzel, Mirko

2017-03-01

Storage related changes in the cell wall composition potentially affect the texture of plant-based foods and the physiological effects of cell wall based dietary fiber components. Therefore, a detailed characterization of cell wall polysaccharides and lignins from broccoli stems was performed. Freshly harvested broccoli and broccoli stored at 20°C and 1°C for different periods of time were analyzed. Effects on dietary fiber contents, polysaccharide composition, and on lignin contents/composition were much more pronounced during storage at 20°C than at 1°C. During storage, insoluble dietary fiber contents of broccoli stems increased up to 13%. Storage related polysaccharide modifications include an increase of the portions of cellulose, xylans, and homogalacturonans and a decrease of the neutral pectic side-chains arabinans and galactans. Broccoli stem lignins are generally rich in guaiacyl units. Lignins from freshly harvested broccoli stems contain slightly larger amounts of p-hydroxyphenyl units than syringyl units. Syringyl units are predominantly incorporated into the lignin polymers during storage, resulting in increased acetyl bromide soluble lignin contents. NMR-based analysis of the interunit linkage types of broccoli stem lignins revealed comparably large portions of resinol structures for a guaiacyl rich lignin. Incorporation of syringyl units into the polymers over storage predominantly occurs through β-O-4-linkages. Copyright © 2017 Elsevier Ltd. All rights reserved.

Co-infection and disease severity of Ohio Maize dwarf mosaic virus and Maize chlorotic dwarf virus strains

USDA-ARS?s Scientific Manuscript database

Two major maize viruses have been reported in the United States: Maize dwarf mosaic virus (MDMV) and Maize chlorotic dwarf virus (MCDV). These viruses co-occur in regions where maize is grown such that co-infections are likely. Co-infection of different strains of MCDV is also observed frequently...

Sequence-Based Analysis of the Intestinal Microbiota of Sows and Their Offspring Fed Genetically Modified Maize Expressing a Truncated Form of Bacillus thuringiensis Cry1Ab Protein (Bt Maize)

PubMed Central

Buzoianu, Stefan G.; Walsh, Maria C.; Rea, Mary C.; Quigley, Lisa; O'Sullivan, Orla; Cotter, Paul D.; Ross, R. Paul; Lawlor, Peadar G.

2013-01-01

The aim was to investigate transgenerational effects of feeding genetically modified (GM) maize expressing a truncated form of Bacillus thuringiensis Cry1Ab protein (Bt maize) to sows and their offspring on maternal and offspring intestinal microbiota. Sows were assigned to either non-GM or GM maize dietary treatments during gestation and lactation. At weaning, offspring were assigned within sow treatment to non-GM or GM maize diets for 115 days, as follows: (i) non-GM maize-fed sow/non-GM maize-fed offspring (non-GM/non-GM), (ii) non-GM maize-fed sow/GM maize-fed offspring (non-GM/GM), (iii) GM maize-fed sow/non-GM maize-fed offspring (GM/non-GM), and (iv) GM maize-fed sow/GM maize-fed offspring (GM/GM). Offspring of GM maize-fed sows had higher counts of fecal total anaerobes and Enterobacteriaceae at days 70 and 100 postweaning, respectively. At day 115 postweaning, GM/non-GM offspring had lower ileal Enterobacteriaceae counts than non-GM/non-GM or GM/GM offspring and lower ileal total anaerobes than pigs on the other treatments. GM maize-fed offspring also had higher ileal total anaerobe counts than non-GM maize-fed offspring, and cecal total anaerobes were lower in non-GM/GM and GM/non-GM offspring than in those from the non-GM/non-GM treatment. The only differences observed for major bacterial phyla using 16S rRNA gene sequencing were that fecal Proteobacteria were less abundant in GM maize-fed sows prior to farrowing and in offspring at weaning, with fecal Firmicutes more abundant in offspring. While other differences occurred, they were not observed consistently in offspring, were mostly encountered for low-abundance, low-frequency bacterial taxa, and were not associated with pathology. Therefore, their biological relevance is questionable. This confirms the lack of adverse effects of GM maize on the intestinal microbiota of pigs, even following transgenerational consumption. PMID:24096421

Adipose-Derived Stem Cell Delivery into Collagen Gels Using Chitosan Microspheres

DTIC Science & Technology

2010-02-17

Porous CSM of uniform size and composition were prepared and used as a stem cell carrier. ASC were allowed to attach to the microspheres and infiltrate...and viable, could be retrieved from the spheres, and maintained expression of stem - cell -specific markers. Electron microscopic evaluation of the cell

Earthworm populations and functional traits in a land-use gradient of annual, perennial and permanent grassland systems in a heterogenic agricultural landscape

NASA Astrophysics Data System (ADS)

Emmerling, Christoph; Ruf, Thorsten

2017-04-01

Soil use is the key driving factor for the composition of the detritus food webs, for SOM quantity and quality, and related soil properties. Many studies have identified land-use change as a major driver affecting soil biodiversity, which severely influences soil functioning and the ecosystem services they deliver. The overall intention of the study was to gain insights in future trends of soil ecology in a changing land-use towards bioenergy production. Therefor we investigated earthworm responses to different land-use intensities, such as rotational cropping with maize (1G), cultivation of perennial crops (2G), like Szarvasi, Silphie, Igniscum and Miscanthus, and permanent grasslands at landscape scale in Western Germany. We analyzed species composition, individual numbers and biomass, and earthworm functional traits. We can conclude that on average the investigated earthworm parameters of the newly introduced second generation bioenergy crops took a medium position between annual maize and permanent grassland sites. In addition, the experiments clearly emphasized that some results were in a clear trend, but others were site-depended and to some extend indifferent. We will critically discuss the ecological significance of perennial land-use systems from a soil biodiversity and soil functioning point of view.

Maize opaque5 Encodes Monogalactosyldiacylglycerol Synthase and Specifically Affects Galactolipids Necessary for Amyloplast and Chloroplast Function[C][W][OA

PubMed Central

Myers, Alan M.; James, Martha G.; Lin, Qiaohui; Yi, Gibum; Stinard, Philip S.; Hennen-Bierwagen, Tracie A.; Becraft, Philip W.

2011-01-01

The maize (Zea mays) opaque5 (o5) locus was shown to encode the monogalactosyldiacylglycerol synthase MGD1. Null and point mutations of o5 that affect the vitreous nature of mature endosperm engendered an allelic series of lines with stepwise reductions in gene function. C18:3/C18:2 galactolipid abundance in seedling leaves was reduced proportionally, without significant effects on total galactolipid content. This alteration in polar lipid composition disrupted the organization of thylakoid membranes into granal stacks. Total galactolipid abundance in endosperm was strongly reduced in o5- mutants, causing developmental defects and changes in starch production such that the normal simple granules were replaced with compound granules separated by amyloplast membrane. Complete loss of MGD1 function in a null mutant caused kernel lethality owing to failure in both endosperm and embryo development. The data demonstrate that low-abundance galactolipids with five double bonds serve functions in plastid membranes that are not replaced by the predominant species with six double bonds. Furthermore, the data identify a function of amyloplast membranes in the development of starch granules. Finally, the specific changes in lipid composition suggest that MGD1 can distinguish the constituency of acyl groups on its diacylglycerol substrate based upon the degree of desaturation. PMID:21685260

Autologous Hematopoietic Stem Cell Transplantation to Prevent Antibody Mediated Rejection After Vascularized Composite Allotransplantation

DTIC Science & Technology

2017-10-01

Award Number: W81XWH-16-1-0664 TITLE: Autologous Hematopoietic Stem Cell Transplantation to Prevent Antibody-Mediated Rejection after...Annual 3. DATES COVERED 15 Sep 2016 – 14 Sep 2017 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Autologous Hematopoietic Stem Cell Transplantation to...sensitization, autologous hematopoietic stem cell transplantation, antibody mediated rejection, donor specific antibodies 16. SECURITY CLASSIFICATION OF

Essential oils and crude extracts from Chrysanthemum trifurcatum leaves, stems and roots: chemical composition and antibacterial activity.

PubMed

Sassi, Ahlem Ben; Skhiri, Fethia Harzallah; Chraief, Imed; Bourgougnon, Nathalie; Hammami, Mohamed; Aouni, Mahjoub

2014-01-01

The essential oils from the leaves, stems and roots of Chrysanthemum trifurcatum (Desf.) Batt. and Trab. var. macrocephalum (viv.) were obtained by hydrodistillation and their chemical compositions were analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS), in order to get insight into similarities and differences as to their active composition. A total of fifty compounds were identified, constituting 97.84%, 99.02% and 98.20% of total oil composition of the leaves, stems and roots, respectively. Monoterpene hydrocarbons were shown to be the main group of constituents of the leaves and stems parts in the ratio of 67.88% and 51.29%, respectively. But, the major group in the roots oil was found to be sesquiterpene hydrocarbons (70.30%). The main compounds in leaves oil were limonene (26.83%), γ-terpinene (19.68%), α-pinene (9.7%) and α-terpenyl acetate (7.16%). The stems oil, contains mainly limonene (32.91%), 4-terpenyl acetate (16.33%) and γ-terpinene (5.93%), whereas the main compounds in roots oil were α-calacorene (25.98%), α-cedrene (16.55%), β-bourbobene (14.91%), elemol (7.45%) and 2-hexenal (6.88%). The crude organic extracts of leaves, stems and roots, obtained by maceration with solvents of increasing polarity: petroleum ether, ethyl acetate and methanol, contained tannins, flavonoids and alkaloids. Meanwhile, essential oils and organic extracts were tested for antibacterial activities against eight Gram-positive and Gram-negative strains, using a microdilution method. The oil and methanolic extact from C. trifurcatum leaves showed a great potential of antibacterial effect against Bacillus subtilis and Staphylococcus epidermidis, with an IC50 range of 31.25-62.5 µg/ml.

Cuticular lipid composition, surface structure, and gene expression in Arabidopsis stem epidermis.

PubMed

Suh, Mi Chung; Samuels, A Lacey; Jetter, Reinhard; Kunst, Ljerka; Pollard, Mike; Ohlrogge, John; Beisson, Fred

2005-12-01

All vascular plants are protected from the environment by a cuticle, a lipophilic layer synthesized by epidermal cells and composed of a cutin polymer matrix and waxes. The mechanism by which epidermal cells accumulate and assemble cuticle components in rapidly expanding organs is largely unknown. We have begun to address this question by analyzing the lipid compositional variance, the surface micromorphology, and the transcriptome of epidermal cells in elongating Arabidopsis (Arabidopsis thaliana) stems. The rate of cell elongation is maximal near the apical meristem and decreases steeply toward the middle of the stem, where it is 10 times slower. During and after this elongation, the cuticular wax load and composition remain remarkably constant (32 microg/cm2), indicating that the biosynthetic flux into waxes is closely matched to surface area expansion. By contrast, the load of polyester monomers per unit surface area decreases more than 2-fold from the upper (8 microg/cm2) to the lower (3 microg/cm2) portion of the stem, although the compositional variance is minor. To aid identification of proteins involved in the biosynthesis of waxes and cutin, we have isolated epidermal peels from Arabidopsis stems and determined transcript profiles in both rapidly expanding and nonexpanding cells. This transcriptome analysis was validated by the correct classification of known epidermis-specific genes. The 15% transcripts preferentially expressed in the epidermis were enriched in genes encoding proteins predicted to be membrane associated and involved in lipid metabolism. An analysis of the lipid-related subset is presented.

Methane transport mechanisms and isotopic fractionation in emergent macrophytes of an Alaskan tundra lake

NASA Technical Reports Server (NTRS)

Chanton, Jeffrey P.; Martens, Christopher S.; Kelley, Cheryl A.; Crill, Patrick M.; Showers, William J.

1992-01-01

The stable carbon isotopic composition of methane associated with and emitted by the two dominant emergent macrophytes abundant in the many Alaskan tundra lakes, Carex rostrata and Arctophila fulva, is determined. The carbon isotopic composition of the methane was -58.6 +/- 0.5 (n=2) for Arctophila and -66.6 +/- 2.5 (n=6) for Carex. The methane emitted by these species is depleted in C-13 by 12 per mil for Arctophila and 18 per mil for Carex relative to methane withdrawn from plant stems 1-2 cm below the waterline. The results suggest more rapid transport of (C-12)H4 relative to (C-13)H4 through plants to the atmosphere. Plant stem methane concentrations ranged from 0.2 to 4.0 percent in Arctophila, with an isotopic composition of -46.1 +/- 4.3 percent (n=8). Carex stem methane concentrations ranged from 150 to 1200 ppm, with an isotopic composition of -48.3 +/- 1.4 per mil (n=3).

Comprehensive proteomic characterization of stem cell-derived extracellular matrices.

PubMed

Ragelle, Héloïse; Naba, Alexandra; Larson, Benjamin L; Zhou, Fangheng; Prijić, Miralem; Whittaker, Charles A; Del Rosario, Amanda; Langer, Robert; Hynes, Richard O; Anderson, Daniel G

2017-06-01

In the stem-cell niche, the extracellular matrix (ECM) serves as a structural support that additionally provides stem cells with signals that contribute to the regulation of stem-cell function, via reciprocal interactions between cells and components of the ECM. Recently, cell-derived ECMs have emerged as in vitro cell culture substrates to better recapitulate the native stem-cell microenvironment outside the body. Significant changes in cell number, morphology and function have been observed when mesenchymal stem cells (MSC) were cultured on ECM substrates as compared to standard tissue-culture polystyrene (TCPS). As select ECM components are known to regulate specific stem-cell functions, a robust characterization of cell-derived ECM proteomic composition is critical to better comprehend the role of the ECM in directing cellular processes. Here, we characterized and compared the protein composition of ECM produced in vitro by bone marrow-derived MSC, adipose-derived MSC and neonatal fibroblasts from different donors, employing quantitative proteomic methods. Each cell-derived ECM displayed a specific and unique matrisome signature, yet they all shared a common set of proteins. We evaluated the biological response of cells cultured on the different matrices and compared them to cells on standard TCPS. The matrices lead to differential survival and gene-expression profiles among the cell types and as compared to TCPS, indicating that the cell-derived ECMs influence each cell type in a different manner. This general approach to understanding the protein composition of different tissue-specific and cell-derived ECM will inform the rational design of defined systems and biomaterials that recapitulate critical ECM signals for stem-cell culture and tissue engineering. Copyright © 2017 Elsevier Ltd. All rights reserved.

"Omics" of maize stress response for sustainable food production: opportunities and challenges.

PubMed

Gong, Fangping; Yang, Le; Tai, Fuju; Hu, Xiuli; Wang, Wei

2014-12-01

Maize originated in the highlands of Mexico approximately 8700 years ago and is one of the most commonly grown cereal crops worldwide, followed by wheat and rice. Abiotic stresses (primarily drought, salinity, and high and low temperatures), together with biotic stresses (primarily fungi, viruses, and pests), negatively affect maize growth, development, and eventually production. To understand the response of maize to abiotic and biotic stresses and its mechanism of stress tolerance, high-throughput omics approaches have been used in maize stress studies. Integrated omics approaches are crucial for dissecting the temporal and spatial system-level changes that occur in maize under various stresses. In this comprehensive analysis, we review the primary types of stresses that threaten sustainable maize production; underscore the recent advances in maize stress omics, especially proteomics; and discuss the opportunities, challenges, and future directions of maize stress omics, with a view to sustainable food production. The knowledge gained from studying maize stress omics is instrumental for improving maize to cope with various stresses and to meet the food demands of the exponentially growing global population. Omics systems science offers actionable potential solutions for sustainable food production, and we present maize as a notable case study.

“Omics” of Maize Stress Response for Sustainable Food Production: Opportunities and Challenges

PubMed Central

Gong, Fangping; Yang, Le; Tai, Fuju; Hu, Xiuli

2014-01-01

Abstract Maize originated in the highlands of Mexico approximately 8700 years ago and is one of the most commonly grown cereal crops worldwide, followed by wheat and rice. Abiotic stresses (primarily drought, salinity, and high and low temperatures), together with biotic stresses (primarily fungi, viruses, and pests), negatively affect maize growth, development, and eventually production. To understand the response of maize to abiotic and biotic stresses and its mechanism of stress tolerance, high-throughput omics approaches have been used in maize stress studies. Integrated omics approaches are crucial for dissecting the temporal and spatial system-level changes that occur in maize under various stresses. In this comprehensive analysis, we review the primary types of stresses that threaten sustainable maize production; underscore the recent advances in maize stress omics, especially proteomics; and discuss the opportunities, challenges, and future directions of maize stress omics, with a view to sustainable food production. The knowledge gained from studying maize stress omics is instrumental for improving maize to cope with various stresses and to meet the food demands of the exponentially growing global population. Omics systems science offers actionable potential solutions for sustainable food production, and we present maize as a notable case study. PMID:25401749

Striga parasitizes transgenic hairy roots of Zea mays and provides a tool for studying plant-plant interactions

PubMed Central

2012-01-01

Background Striga species are noxious root hemi-parasitic weeds that debilitate cereal production in sub-Saharan Africa (SSA). Control options for Striga are limited and developing Striga resistant crop germplasm is regarded as the best and most sustainable control measure. Efforts to improve germplasm for Striga resistance by a non-Genetic Modification (GM) approach, for example by exploiting natural resistance, or by a GM approach are constrained by limited information on the biological processes underpinning host-parasite associations. Additionaly, a GM approach is stymied by lack of availability of candidate resistance genes for introduction into hosts and robust transformation methods to validate gene functions. Indeed, a majority of Striga hosts, the world’s most cultivated cereals, are recalcitrant to genetic transformation. In maize, the existing protocols for transformation and regeneration are tedious, lengthy, and highly genotype-specific with low efficiency of transformation. Results We used Agrobacterium rhizogenes strain K599 carrying a reporter gene construct, Green Fluorescent Protein (GFP), to generate transgenic composite maize plants that were challenged with the parasitic plant Striga hermonthica. Eighty five percent of maize plants produced transgenic hairy roots expressing GFP. Consistent with most hairy roots produced in other species, transformed maize roots exhibited a hairy root phenotype, the hallmark of A. rhizogenes mediated transformation. Transgenic hairy roots resulting from A. rhizogenes transformation were readily infected by S. hermonthica. There were no significant differences in the number and size of S. hermonthica individuals recovered from either transgenic or wild type roots. Conclusions This rapid, high throughput, transformation technique will advance our understanding of gene function in parasitic plant-host interactions. PMID:22720750

Metabolic engineering of geranic acid in maize to achieve fungal resistance is compromised by novel glycosylation patterns.

PubMed

Yang, Ting; Stoopen, Geert; Yalpani, Nasser; Vervoort, Jacques; de Vos, Ric; Voster, Alessandra; Verstappen, Francel W A; Bouwmeester, Harro J; Jongsma, Maarten A

2011-07-01

Many terpenoids are known to have antifungal properties and overexpression of these compounds in crops is a potential tool in disease control. In this study, 15 different mono- and sesquiterpenoids were tested in vitro against two major pathogenic fungi of maize (Zea mays), Colletotrichum graminicola and Fusarium graminearum. Among all tested terpenoids, geranic acid showed very strong inhibitory activity against both fungi (MIC<46 μM). To evaluate the possibility of enhancing fungal resistance in maize by overexpressing geranic acid, we generated transgenic plants with the geraniol synthase gene cloned from Lippia dulcis under the control of a ubiquitin promoter. The volatile and non-volatile metabolite profiles of leaves from transgenic and control lines were compared. The headspaces collected from intact seedlings of transgenic and control plants were not significantly different, although detached leaves of transgenic plants emitted 5-fold more geranyl acetate compared to control plants. Non-targeted LC-MS profiling and LC-MS-MS identification of extracts from maize leaves revealed that the major significantly different non-volatile compounds were 2 geranic acid derivatives, a geraniol dihexose and 4 different types of hydroxyl-geranic acid-hexoses. A geranic acid glycoside was the most abundant, and identified by NMR as geranoyl-6-O-malonyl-β-d-glucopyranoside with an average concentration of 45μM. Fungal bioassays with C. graminicola and F. graminearum did not reveal an effect of these changes in secondary metabolite composition on plant resistance to either fungus. The results demonstrate that metabolic engineering of geraniol into geranic acid can rely on the existing default pathway, but branching glycosylation pathways must be controlled to achieve accumulation of the aglycones. Copyright © 2011 Elsevier Inc. All rights reserved.

Near-Continuous Isotopic Characterization of Soil N2O Fluxes from Maize Production

NASA Astrophysics Data System (ADS)

Anex, R. P.; Francis Clar, J.

2015-12-01

Isotopomer ratios of N2O and especially intramolecular 15N site preference (SP) have been proposed as indicators of the sources of N2O and for providing insight into the contributions of different microbial processes. Current knowledge, however, is mainly based on pure culture studies and laboratory flask studies using mass spectrometric analysis. Recent development of laser spectroscopic methods has made possible high-precision, in situ measurements. We present results from a maize production field in Columbia County, Wisconsin, USA. Data were collected from the fertilized maize phase of a maize-soybean rotation. N2O mole fractions and isotopic composition were determined using an automatic gas flux measurement system comprising a set of custom-designed automatic chambers, circulating gas paths and an OA-ICOS N2O Isotope Analyzer (Los Gatos Research, Inc., Model 914-0027). The instrument system allows for up to 15 user programmable soil gas chambers. Wide dynamic range and parts-per-billion precision of OA-ICOS laser absorption instrument allows for extremely rapid estimation of N2O fluxes. Current operational settings provide measurements of N2O and its isotopes every 20 seconds with a precision of 0.1 ± 0.050 PPB. Comparison of measurements from four chambers (two between row and two in-row) show very different aggregate N2O flux, but SP values suggest similar sources from nitrifier denitrification and incomplete bacterial denitrification. SP values reported are being measured throughout the current growing season. To date, the majority of values are consistent with an origin from bacterial denitrification and coincide with periods of high water filled pore space.

Essential oil composition of two myrtus communis L. varieties grown in North Tunisia.

PubMed

Aidi Wannes, Wissem; Mhamdi, Baya; Marzouk, Brahim

2007-06-01

Two Myrtus communis varieties (var. italica and baetica) were studied in order to investigate their essential oil yield and composition. Essential oil yield varied in leaves, fruits and stems. So, in leaves, it was 0.5% for italica and 0.3% for baetica and was higher than in fruits and stems with respectively 0.1% and 0.04% for italica and 0.07% and 0.03% for baetica. The essential oil analysis performed by GC and GC/MS showed a composition characterized by a high percentage of monoterpene hydrocarbons in leaves, largely due to alpha-pinene with 51.3% for italica and 27.7% for baetica; 1,8-cineole, the alone compound of ether class, was predominant in fruits and stems with respectively 31.6% and 34.7% for italica and 19.8% and 25.8% for baetica.

Regulation of a maize HD-ZIP IV transcription factor by a non-conventional RDR2-dependent small RNA.

PubMed

Klein-Cosson, Catherine; Chambrier, Pierre; Rogowsky, Peter M; Vernoud, Vanessa

2015-03-01

Small non-coding RNAs are versatile riboregulators that control gene expression at the transcriptional or post-transcriptional level, governing many facets of plant development. Here we present evidence for the existence of a 24 nt small RNA (named small1) that is complementary to the 3' UTR of OCL1 (Outer Cell Layer1), the founding member of the maize HD-ZIP IV gene family encoding plant-specific transcription factors that are mainly involved in epidermis differentiation and specialization. The biogenesis of small1 depends on DICER-like 3 (DCL3), RNA-dependent RNA polymerase 2 (RDR2) and RNA polymerase IV, components that are usually required for RNA-dependent DNA-methylation. Unexpectedly, GFP sensor experiments in transient and stable transformation systems revealed that small1 may regulate its target at the post-transcriptional level, mainly through translational repression. This translational repression is attenuated in an rdr2 mutant background in which small1 does not accumulate. Our experiments further showed the possible involvement of a secondary stem-loop structure present in the 3' UTR of OCL1 for efficient target repression, suggesting the existence of several regulatory mechanisms affecting OCL1 mRNA stability and translation. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

Endophytic Herbaspirillum seropedicae expresses nif genes in gramineous plants.

PubMed

Roncato-Maccari, Lauren D B; Ramos, Humberto J O; Pedrosa, Fabio O; Alquini, Yedo; Chubatsu, Leda S; Yates, Marshall G; Rigo, Liu U; Steffens, Maria Berenice R; Souza, Emanuel M

2003-07-01

Abstract The interactions between maize, sorghum, wheat and rice plants and Herbaspirillum seropedicae were examined microscopically following inoculation with the H. seropedicae LR15 strain, a Nif(+) (Pnif::gusA) mutant obtained by the insertion of a gusA-kanamycin cassette into the nifH gene of the H. seropedicae wild-type strain. The expression of the Pnif::gusA fusion was followed during the association of the diazotroph with the gramineous species. Histochemical analysis of seedlings of maize, sorghum, wheat and rice grown in vermiculite showed that strain LR15 colonized root surfaces and inner tissues. In early steps of the endophytic association, H. seropedicae colonized root exudation sites, such as axils of secondary roots and intercellular spaces of the root cortex; it then occupied the vascular tissue and there expressed nif genes. The expression of nif genes occurred in roots, stems and leaves as detected by the GUS reporter system. The expression of nif genes was also observed in bacterial colonies located in the external mucilaginous root material, 8 days after inoculation. Moreover, the colonization of plant tissue by H. seropedicae did not depend on the nitrogen-fixing ability, since similar numbers of cells were isolated from roots or shoots of the plants inoculated with Nif(+) or Nif(-) strains.

Use of Maize (Zea mays L.) for phytomanagement of Cd-contaminated soils: a critical review.

PubMed

Rizwan, Muhammad; Ali, Shafaqat; Qayyum, Muhammad Farooq; Ok, Yong Sik; Zia-Ur-Rehman, Muhammad; Abbas, Zaheer; Hannan, Fakhir

2017-04-01

Maize (Zea mays L.) has been widely adopted for phytomanagement of cadmium (Cd)-contaminated soils due to its high biomass production and Cd accumulation capacity. This paper reviewed the toxic effects of Cd and its management by maize plants. Maize could tolerate a certain level of Cd in soil while higher Cd stress can decrease seed germination, mineral nutrition, photosynthesis and growth/yields. Toxicity response of maize to Cd varies with cultivar/varieties, growth medium and stress duration/extent. Exogenous application of organic and inorganic amendments has been used for enhancing Cd tolerance of maize. The selection of Cd-tolerant maize cultivar, crop rotation, soil type, and exogenous application of microbes is a representative agronomic practice to enhance Cd tolerance in maize. Proper selection of cultivar and agronomic practices combined with amendments might be successful for the remediation of Cd-contaminated soils with maize. However, there might be the risk of food chain contamination by maize grains obtained from the Cd-contaminated soils. Thus, maize cultivation could be an option for the management of low- and medium-grade Cd-contaminated soils if grain yield is required. On the other hand, maize can be grown on Cd-polluted soils only if biomass is required for energy production purposes. Long-term field trials are required, including risks and benefit analysis for various management strategies aiming Cd phytomanagement with maize.

[Contamination with genetically modified maize MON863 of processed foods on the market].

PubMed

Ohgiya, Yoko; Sakai, Masaaki; Miyashita, Taeko; Yano, Koichi

2009-06-01

Genetically modified maize MON863 (MON863), which has passed a safety examination in Japan, is commercially cultivated in the United States as a food and a resource for fuel. Maize is an anemophilous flower, which easily hybridizes. However, an official method for quantifying the content of MON863 has not been provided yet in Japan. We here examined MON863 contamination in maize-processed foods that had no labeling indicating of the use of genetically modified maize.From March 2006 to July 2008, we purchased 20 frozen maize products, 8 maize powder products, 7 canned maize products and 4 other maize processed foods. Three primer pairs named MON 863 primer, MON863-1, and M3/M4 for MON863-specific integrated cassette were used for qualitative polymerase chain reaction (PCR). A primer pair "SSIIb-3" for starch synthase gene was used to confirm the quality of extracted DNA. The starch synthase gene was detected in all samples. In qualitative tests, the MON863-specific fragments were detected in 7 (18%) maize powder products out of the 39 processed foods with all the three primer pairs.We concluded that various maize processed foods on the market were contaminated with MON863. It is important to accumulate further information on MON863 contamination in maize-processed foods that have no label indication of the use of genetically modified maize.

Antisense expression of the fasciclin-like arabinogalactan protein FLA6 gene in Populus inhibits expression of its homologous genes and alters stem biomechanics and cell wall composition in transgenic trees.

PubMed

Wang, Haihai; Jiang, Chunmei; Wang, Cuiting; Yang, Yang; Yang, Lei; Gao, Xiaoyan; Zhang, Hongxia

2015-03-01

Fasciclin-like arabinogalactan proteins (FLAs) play important roles in the growth and development of roots, stems, and seeds in Arabidopsis. However, their biological functions in woody plants are largely unknown. In this work, we investigated the possible function of PtFLA6 in poplar. Quantitative real-time PCR, PtFLA6-yellow fluorescent protein (YFP) fusion protein subcellular localization, Western blotting, and immunohistochemical analyses demonstrated that the PtFLA6 gene was expressed specifically in the xylem of mature stem, and PtFLA6 protein was distributed ubiquitous in plant cells and accumulated predominantly in stem xylem fibres. Antisense expression of PtFLA6 in the aspen hybrid clone Poplar davidiana×Poplar bolleana reduced the transcripts of PtFLA6 and its homologous genes. Transgenic plants that showed a significant reduction in the transcripts of PtFLAs accumulated fewer PtFLA6 and arabinogalactan proteins than did the non-transgenic plants, leading to reduced stem flexural strength and stiffness. Further studies revealed that the altered stem biomechanics of transgenic plants could be attributed to the decreased cellulose and lignin composition in the xylem. In addition expression of some xylem-specific genes involved in cell wall biosynthesis was downregulated in these transgenic plants. All these results suggest that engineering the expression of PtFLA6 and its homologues could modulate stem mechanical properties by affecting cell wall composition in trees. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Composite cell sheet for periodontal regeneration: crosstalk between different types of MSCs in cell sheet facilitates complex periodontal-like tissue regeneration.

PubMed

Zhang, Hao; Liu, Shiyu; Zhu, Bin; Xu, Qiu; Ding, Yin; Jin, Yan

2016-11-14

Tissue-engineering strategies based on mesenchymal stem cells (MSCs) and cell sheets have been widely used for periodontal tissue regeneration. However, given the complexity in periodontal structure, the regeneration methods using a single species of MSC could not fulfill the requirement for periodontal regeneration. We researched the interaction between the periodontal ligament stem cells (PDLSCs) and jaw bone marrow-derived mesenchymal stem cells (JBMMSCs), and constructed a composite cell sheet comprising both of the above MSCs to regenerate complex periodontium-like structures in nude mice. Our results show that by co-culturing PDLSCs and JBMMSCs, the expressions of bone and extracellular matrix (ECM)-related genes and proteins were significantly improved in both MSCs. Further investigations showed that, compared to the cell sheet using PDLSCs or JBMMSCs, the composite stem cell sheet (CSCS), which comprises these two MSCs, expressed higher levels of bone- and ECM-related genes and proteins, and generated a composite structure more similar to the native periodontal tissue physiologically in vivo. In conclusion, our results demonstrate that the crosstalk between PDLSCs and JBMMSCs in cell sheets facilitate regeneration of complex periodontium-like structures, providing a promising new strategy for physiological and functional regeneration of periodontal tissue.

Dynamics of biomass partitioning, stem gene expression, cell wall biosynthesis, and sucrose accumulation during development of Sorghum bicolor.

PubMed

McKinley, Brian; Rooney, William; Wilkerson, Curtis; Mullet, John

2016-11-01

Biomass accumulated preferentially in leaves of the sweet sorghum Della until floral initiation, then stems until anthesis, followed by panicles until grain maturity, and apical tillers. Sorghum stem RNA-seq transcriptome profiles and composition data were collected for approximately 100 days of development beginning at floral initiation. The analysis identified >200 differentially expressed genes involved in stem growth, cell wall biology, and sucrose accumulation. Genes encoding expansins and xyloglucan endotransglucosylase/hydrolases were differentially expressed in growing stem internodes. Genes encoding enzymes involved in the synthesis of cellulose, lignin, and glucuronoarabinoxylan were expressed at elevated levels in stems until approximately 7 days before anthesis and then down-regulated. CESA genes involved in primary and secondary cell wall synthesis showed different temporal patterns of expression. Following floral initiation, the level of sucrose and other non-structural carbohydrates increased to approximately 50% of the stem's dry weight. Stem sucrose accumulation was inversely correlated with >100-fold down-regulation of SbVIN1, a gene encoding a vacuolar invertase. Accumulation of stem sucrose was also correlated with cessation of leaf and stem growth at anthesis, decreased expression of genes involved in stem cell wall synthesis, and approximately 10-fold lower expression of SbSUS4, a gene encoding sucrose synthase that generates UDP-glucose from sucrose for cell wall biosynthesis. Genes for mixed linkage glucan synthesis (CSLF) and turnover were expressed at high levels in stems throughout development. Overall, the stem transcription profile resource and the genes and regulatory dynamics identified in this study will be useful for engineering sorghum stem composition for improved conversion to biofuels and bio-products. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

Phenolic compositions and antioxidant attributes of leaves and stems from three inbred varieties of Lycium chinense Miller harvested at various times.

PubMed

Liu, Shih-Chuan; Lin, Jau-Tien; Hu, Chao-Chin; Shen, Bo-Yan; Chen, Ting-Yo; Chang, Ya-Ling; Shih, Chia-Huing; Yang, Deng-Jye

2017-01-15

Antioxidant components and properties (assayed by scavenging DPPH radicals, TEAC, reducing power, and inhibiting Cu(2+)-induced human LDL oxidation) of leaves and stems from three inbred varieties of Lycium chinense Miller, namely ML01, ML02 and ML02-TY, harvested from January to April were studied. Their flavonoid and phenolic acid compositions were also analyzed by HPLC. For each variety, the leaves and stems collected in higher temperature month had higher contents of total phenol, total flavonoid and condensed tannin. Contents of these components in the samples collected in different months were in the order: April (22.3°C)>March (18.0°C)>January (15.6°C)>February (15.4°C). Antioxidant activities of the leaves and stems for all assays also showed similar trends. The samples from different varieties collected in the same month also possessed different phenolic compositions and contents and antioxidant activities. Their antioxidant activities were significantly correlated with flavonoid and phenolic contents. Copyright © 2016. Published by Elsevier Ltd.

Proximate nutritional composition of CELSS crops grown at different CO2 partial pressures

NASA Technical Reports Server (NTRS)

Wheeler, R. M.; Mackowiak, C. L.; Sager, J. C.; Knott, W. M.; Berry, W. L.

1994-01-01

Two Controlled Ecological Life Support System (CELSS) candidate crops, soybean (Glycine max) and potato (Solanum tuberosum), were grown hydroponically in controlled environments maintained at carbon dioxide (CO2) partial pressures ranging from 0.05 to 1.00 kPa (500 to 10,000 ppm at 101 kPa atmospheric pressure). Plants were harvested at maturity (90 days for soybean and 105 days for potato) and all tissues analyzed for proximate nutritional composition (i.e. protein, fat, carbohydrate, crude fiber, and ash content). Soybean seed ash and crude fiber were higher and carbohydrate was lower than values reported for field-grown seed. Potato tubers showed little difference from field-grown tubers. Crude fiber of soybean stems and leaves increased with increased CO2, as did soybean leaf protein (total nitrogen). Potato leaf and stem (combined) protein levels also increased with increased CO2, while leaf and stem carbohydrates decreased. Values for leaf and stem protein and ash were higher than values generally reported for field-grown plants for both species. Results suggest that CO2 partial pressure should have little influence on proximate composition of potato tubers or soybean seed, but that high ash and protein levels might be expected from leaves and stems of crops grown in controlled environments of a CELSS.

Global maize production, utilization, and consumption.

PubMed

Ranum, Peter; Peña-Rosas, Juan Pablo; Garcia-Casal, Maria Nieves

2014-04-01

Maize (Zea mays), also called corn, is believed to have originated in central Mexico 7000 years ago from a wild grass, and Native Americans transformed maize into a better source of food. Maize contains approximately 72% starch, 10% protein, and 4% fat, supplying an energy density of 365 Kcal/100 g and is grown throughout the world, with the United States, China, and Brazil being the top three maize-producing countries in the world, producing approximately 563 of the 717 million metric tons/year. Maize can be processed into a variety of food and industrial products, including starch, sweeteners, oil, beverages, glue, industrial alcohol, and fuel ethanol. In the last 10 years, the use of maize for fuel production significantly increased, accounting for approximately 40% of the maize production in the United States. As the ethanol industry absorbs a larger share of the maize crop, higher prices for maize will intensify demand competition and could affect maize prices for animal and human consumption. Low production costs, along with the high consumption of maize flour and cornmeal, especially where micronutrient deficiencies are common public health problems, make this food staple an ideal food vehicle for fortification. © 2014 New York Academy of Sciences. The World Health Organization retains copyright and all other rights in the manuscript of this article as submitted for publication.

Stem cell bioprinting for applications in regenerative medicine.

PubMed

Tricomi, Brad J; Dias, Andrew D; Corr, David T

2016-11-01

Many regenerative medicine applications seek to harness the biologic power of stem cells in architecturally complex scaffolds or microenvironments. Traditional tissue engineering methods cannot create such intricate structures, nor can they precisely control cellular position or spatial distribution. These limitations have spurred advances in the field of bioprinting, aimed to satisfy these structural and compositional demands. Bioprinting can be defined as the programmed deposition of cells or other biologics, often with accompanying biomaterials. In this concise review, we focus on recent advances in stem cell bioprinting, including performance, utility, and applications in regenerative medicine. More specifically, this review explores the capability of bioprinting to direct stem cell fate, engineer tissue(s), and create functional vascular networks. Furthermore, the unique challenges and concerns related to bioprinting living stem cells, such as viability and maintaining multi- or pluripotency, are discussed. The regenerative capacity of stem cells, when combined with the structural/compositional control afforded by bioprinting, provides a unique and powerful tool to address the complex demands of tissue engineering and regenerative medicine applications. © 2016 New York Academy of Sciences.

Quality Protein Maize for Africa: Closing the Protein Inadequacy Gap in Vulnerable Populations12

PubMed Central

Nuss, Emily T.; Tanumihardjo, Sherry A.

2011-01-01

Africa shares a unique relationship with maize (Zea mays). After its introduction from New World explorers, maize was quickly adopted as the cornerstone of local cuisine, especially in sub-Saharan countries. Although maize provides macro- and micronutrients required for humans, it lacks adequate amounts of the essential amino acids lysine and tryptophan. For those consuming >50% of their daily energy from maize, pandemic protein malnutrition may exist. Severe protein and energy malnutrition increases susceptibility to life-threatening diseases such as tuberculosis and gastroenteritis. A nutritionally superior maize cultivar named quality protein maize (QPM) represents nearly one-half century of research dedicated to malnutrition eradication. Compared with traditional maize types, QPM has twice the amount of lysine and tryptophan, as well as protein bioavailability that rivals milk casein. Animal and human studies suggest that substituting QPM for common maize results in improved health. However, QPM’s practical contribution to maize-subsisting populations remains unresolved. Herein, total protein and essential amino acid requirements recommended by the WHO and the Institute of Medicine were applied to estimate QPM target intake levels for young children and adults, and these were compared with mean daily maize intakes by African country. The comparisons revealed that ∼100 g QPM is required for children to maintain adequacy of lysine, the most limiting amino acid, and nearly 500 g is required for adults. This represents a 40% reduction in maize intake relative to common maize to meet protein requirements. The importance of maize in Africa underlines the potential for QPM to assist in closing the protein inadequacy gap. PMID:22332054

A few sequence polymorphisms among isolates of Maize bushy stunt phytoplasma associate with organ proliferation symptoms of infected maize plants

PubMed Central

Orlovskis, Zigmunds; Canale, Maria Cristina; Haryono, Mindia; Lopes, João Roberto Spotti

2017-01-01

Background and Aims Maize bushy stunt phytoplasma (MBSP) is a bacterial pathogen of maize (Zea mays L.) across Latin America. MBSP belongs to the 16SrI-B sub-group within the genus ‘Candidatus Phytoplasma’. MBSP and its insect vector Dalbulus maidis (Hemiptera: Cicadellidae) are restricted to maize; both are thought to have coevolved with maize during its domestication from a teosinte-like ancestor. MBSP-infected maize plants show a diversity of symptoms. and it is likely that MBSP is under strong selection for increased virulence and insect transmission on maize hybrids that are widely grown in Brazil. In this study it was investigated whether the differences in genome sequences of MBSP isolates from two maize-growing regions in South-east Brazil explain variations in symptom severity of the MBSP isolates on various maize genotypes. Methods MBSP isolates were collected from maize production fields in Guaíra and Piracicaba in South-east Brazil for infection assays. One representative isolate was chosen for de novo whole-genome assembly and for the alignment of sequence reads from the genomes of other phytoplasma isolates to detect polymorphisms. Statistical methods were applied to investigate the correlation between variations in disease symptoms of infected maize plants and MBSP sequence polymorphisms. Key Results MBSP isolates contributed consistently to organ proliferation symptoms and maize genotype to leaf necrosis, reddening and yellowing of infected maize plants. The symptom differences are associated with polymorphisms in a phase-variable lipoprotein, which is a candidate effector, and an ATP-dependent lipoprotein ABC export protein, whereas no polymorphisms were observed in other candidate effector genes. Lipoproteins and ABC export proteins activate host defence responses, regulate pathogen attachment to host cells and activate effector secretion systems in other pathogens. Conclusions Polymorphisms in two putative virulence genes among MBSP isolates from maize-growing regions in South-east Brazil are associated with variations in organ proliferation symptoms of MBSP-infected maize plants. PMID:28069632

Behavior of N-ethyl perfluorooctane sulfonamido acetic acid (N-EtFOSAA) in biosolids amended soil-plant microcosms of seven plant species: Accumulation and degradation.

PubMed

Wen, Bei; Pan, Ying; Shi, Xiaoli; Zhang, Hongna; Hu, Xiaoyu; Huang, Honglin; Lv, Jitao; Zhang, Shuzhen

2018-06-13

Perfluorooctane sulfonate (PFOS) precursors have been found extensively in sewage sludge and biosolids-amended soils. The degradation of these precursors are regarded as a significant source of PFOS in the environment. In this study, the accumulation of N-ethyl perfluorooctane sulfonamido acetic acid (N-EtFOSAA) in the plants of seven species, namely alfalfa, lettuce, maize, mung bean, radish, ryegrass, and soybean from biosolids-amended soil, and the degradation kinetics of N-EtFOSAA in soil-plant microcosms were evaluated over 60 days. N-EtFOSAA was found in the roots of all plant species, while was not in stems and leaves. The root concentration factors of N-EtFOSAA ranged 0.52-1.37 (pmol/g root )/(pmol/g soil ). Stepwise multiple regression analysis was used to elucidate the accumulation of N-EtFOSAA in the roots of plants. The results showed that the root protein and lipid contents explain 85.0% of the variation in root N-EtFOSAA levels (P < 0.05). Four degradation products, including N-ethyl perfluorooctane sulfonamide (N-EtFOSA), perfluorooctane sulfonamide acetate (FOSAA), perfluorooctane sulfonamide (FOSA) and PFOS were found in soils and plant roots, stems and leaves, indicating the degradation of N-EtFOSAA in soil-plant system. Degradation kinetics fitted a first-order kinetic model well. Degradation rate constants of N-EtFOSAA in the microcosms with plants ranged 0.063-0.165 d -1 , which was 1.40-3.6 times higher than those without plants. Degradation rate constant of maize was relatively higher than those of other plant species. The results is the first to reveal N-EtFOSAA accumulation in plants and degradation in soil-plant microcosms. Copyright © 2018. Published by Elsevier B.V.

Effect of different kinds of crop residues on aggregate-protected soil organic matter fractions.

NASA Astrophysics Data System (ADS)

Huisz, A.

2009-04-01

Organic matter content of soils determines many important soil properties, such as soil structure, fertility and water-management. To improve its fertility and quality, returning different kinds of organic matter to soil has a long historical tradition. Ameliorating of soil and enhancing its fertility by enhancing its carbon stock with organic matter incorporation (like farmyard manure, crop residues or green manure) are general practices, but the extent of the amelioration depends much on several factors such as quantity, quality of the used organic matters. Quality of soil organic matters is affected by their chemical build-up, which differs by their origin (i.e. plant species); and their decomposability is affected by particle-size, protection by soil aggregates and the extent of their association to mineral surfaces. In our paper we investigated the effect of three different kinds of organic matter incorporation on aggregate-protected organic matter fractions: (1) Maize stem (M), (2) Wheat straw (W), and (3) Maize stem & Wheat straw (MW). Our samples were originated from Keszthely, Western Hungary, where the texture of the investigated soil is Sandy loam, the type of soil is Eutric Cambisol (soil type FAO), or Alfisol (soil type USDA). SOM fractions might be isolated and measured by physical fractionation of soil (Cambardella and Elliott (1992), Jensen et al. (1992)). Firstly, microaggregates were separated according to their particle-size with physical fractionation (i.e. wet sieving) (Six et al. (2000a)). Each sample was pre-treated by capillary wetting and was sieved for 2 min in an analytic sieve shaker machine with the following aperture sizes: 2 mm, 250 μm, 53 μm. Therefore 4 fractions were resulted: (1) the >2000 μm large macro-, (2) the 250-2000 μm small macro-, (3) the 53-250 μm microaggregates, and (4) the

Maize GO annotation—methods, evaluation, and review (maize-GAMER)

USDA-ARS?s Scientific Manuscript database

We created a new high-coverage, robust, and reproducible functional annotation of maize protein-coding genes based on Gene Ontology (GO) term assignments. Whereas the existing Phytozome and Gramene maize GO annotation sets only cover 41% and 56% of maize protein-coding genes, respectively, this stu...

Mining natural variation for maize improvement: Selection on phenotypes and genes

USDA-ARS?s Scientific Manuscript database

Maize is highly genetically and phenotypically diverse. Tropical maize and teosinte are important genetic resources that harbor unique alleles not found in temperate maize hybrids. To access these resources, breeders must be able to extract favorable unique alleles from tropical maize and teosinte f...

Compositional variability of nutrients and phytochemicals in corn after processing.

PubMed

Prasanthi, P S; Naveena, N; Vishnuvardhana Rao, M; Bhaskarachary, K

2017-04-01

The result of various process strategies on the nutrient and phytochemical composition of corn samples were studied. Fresh and cooked baby corn, sweet corn, dent corn and industrially processed and cooked popcorn, corn grits, corn flour and corn flakes were analysed for the determination of proximate, minerals, xanthophylls and phenolic acids content. This study revealed that the proximate composition of popcorn is high compared to the other corn products analyzed while the mineral composition of these maize products showed higher concentration of magnesium, phosphorus, potassium and low concentration of calcium, manganese, zinc, iron, copper, and sodium. Popcorn was high in iron, zinc, copper, manganese, sodium, magnesium and phosphorus. The xanthophylls lutein and zeaxanthin were predominant in the dent corn and the total polyphenolic content was highest in dent corn while the phenolic acids distribution was variable in different corn products. This study showed preparation and processing brought significant reduction of xanthophylls and polyphenols.

Metabolic pathway resources at MaizeGDB

USDA-ARS?s Scientific Manuscript database

Two maize metabolic networks are available at MaizeGDB: MaizeCyc (http://maizecyc.maizegdb.org, also at Gramene) and CornCyc (http://corncyc.maizegdb.org, also at the Plant Metabolic Network). MaizeCyc was developed by Gramene, and CornCyc by the Plant Metabolic Network, both in collaboration with M...

Viruses in maize and Johnsongrass in southern Ohio

USDA-ARS?s Scientific Manuscript database

Two major maize viruses in the United States, Maize dwarf mosaic virus and Maize chlorotic dwarf virus, were first described in Southern Ohio and surrounding regions in the 1960s when they were major problems in maize (Zea mays L.) production. Planting resistant varieties and changing cultural prac...

MaizeGDB: Curation and outreach go hand-in-hand

USDA-ARS?s Scientific Manuscript database

This is a brief synopsis of the formal and informal interactions among MaizeGDB (www.maizegdb.org) and maize researchers; and among MaizeGDB and other stakeholders, especially the MaizeGDB Working Group and farmers growing this important crop. Particular note is made of the efficacy in distribution ...

MaizeGDB: enabling access to basic, translational, and applied research information

USDA-ARS?s Scientific Manuscript database

MaizeGDB is the Maize Genetics and Genomics Database (available online at http://www.maizegdb.org). The MaizeGDB project is not simply an online database and website but rather an information service to maize researchers that supports customized data access and analysis needs to individual research...

Breeder survey, tools, and resources to visualize diversity and pedigree relationships at MaizeGDB

USDA-ARS?s Scientific Manuscript database

In collaboration with maize researchers, the MaizeGDB Team prepared a survey to identify breeder needs for visualizing pedigrees, diversity data, and haplotypes, and distributed it to the maize community on behalf of the Maize Genetics Executive Committee (Summer 2015). We received 48 responses from...

Potential subchronic food safety of the stacked trait transgenic maize GH5112E-117C in Sprague-Dawley rats.

PubMed

Han, Shiwen; Zou, Shiying; He, Xiaoyun; Huang, Kunlun; Mei, Xiaohong

2016-08-01

The food safety of stacked trait genetically modified (GM) maize GH5112E-117C containing insect-resistance gene Cry1Ah and glyphosate-resistant gene G2-aroA was evaluated in comparison to non-GM Hi-II maize fed to Sprague-Dawley rats during a 90-day subchronic feeding study. Three different dietary concentrations (12.5, 25 and 50 %, w/w) of the GM maize were used or its corresponding non-GM maize. No biologically significant differences in the animals' clinical signs, body weights, food consumption, hematology, clinical chemistry, organ weights and histopathology were found between the stacked trait GM maize groups, and the non-GM maize groups. The results of the 90-day subchronic feeding study demonstrated that the stacked trait GM maize GH5112E-117C is as safe as the conventional non-GM maize Hi-II.

Maize-Pathogen Interactions: An Ongoing Combat from a Proteomics Perspective.

PubMed

Pechanova, Olga; Pechan, Tibor

2015-11-30

Maize (Zea mays L.) is a host to numerous pathogenic species that impose serious diseases to its ear and foliage, negatively affecting the yield and the quality of the maize crop. A considerable amount of research has been carried out to elucidate mechanisms of maize-pathogen interactions with a major goal to identify defense-associated proteins. In this review, we summarize interactions of maize with its agriculturally important pathogens that were assessed at the proteome level. Employing differential analyses, such as the comparison of pathogen-resistant and susceptible maize varieties, as well as changes in maize proteomes after pathogen challenge, numerous proteins were identified as possible candidates in maize resistance. We describe findings of various research groups that used mainly mass spectrometry-based, high through-put proteomic tools to investigate maize interactions with fungal pathogens Aspergillus flavus, Fusarium spp., and Curvularia lunata, and viral agents Rice Black-streaked Dwarf Virus and Sugarcane Mosaic Virus.

Maize-Pathogen Interactions: An Ongoing Combat from a Proteomics Perspective

PubMed Central

Pechanova, Olga; Pechan, Tibor

2015-01-01

Maize (Zea mays L.) is a host to numerous pathogenic species that impose serious diseases to its ear and foliage, negatively affecting the yield and the quality of the maize crop. A considerable amount of research has been carried out to elucidate mechanisms of maize-pathogen interactions with a major goal to identify defense-associated proteins. In this review, we summarize interactions of maize with its agriculturally important pathogens that were assessed at the proteome level. Employing differential analyses, such as the comparison of pathogen-resistant and susceptible maize varieties, as well as changes in maize proteomes after pathogen challenge, numerous proteins were identified as possible candidates in maize resistance. We describe findings of various research groups that used mainly mass spectrometry-based, high through-put proteomic tools to investigate maize interactions with fungal pathogens Aspergillus flavus, Fusarium spp., and Curvularia lunata, and viral agents Rice Black-streaked Dwarf Virus and Sugarcane Mosaic Virus. PMID:26633370

Identification of Genetic Differentiation between Waxy and Common Maize by SNP Genotyping

PubMed Central

Hao, Derong; Zhang, Zhenliang; Cheng, Yujing; Chen, Guoqing; Lu, Huhua; Mao, Yuxiang; Shi, Mingliang; Huang, Xiaolan; Zhou, Guangfei; Xue, Lin

2015-01-01

Waxy maize (Zea mays L. var. ceratina) is an important vegetable and economic crop that is thought to have originated from cultivated flint maize and most recently underwent divergence from common maize. In this study, a total of 110 waxy and 110 common maize inbred lines were genotyped with 3072 SNPs to evaluate the genetic diversity, population structure, and linkage disequilibrium decay as well as identify putative loci that are under positive selection. The results revealed abundant genetic diversity in the studied panel and that genetic diversity was much higher in common than in waxy maize germplasms. Principal coordinate analysis and neighbor-joining cluster analysis consistently classified the 220 accessions into two major groups and a mixed group with mixed ancestry. Subpopulation structure in both waxy and common maize sets were associated with the germplasm origin and corresponding heterotic groups. The LD decay distance (1500–2000 kb) in waxy maize was lower than that in common maize. Fourteen candidate loci were identified as under positive selection between waxy and common maize at the 99% confidence level. The information from this study can assist waxy maize breeders by enhancing parental line selection and breeding program design. PMID:26566240

Host Status of Five Weed Species and Their Effects on Pratylenchus zeae Infestation of Maize.

PubMed

Jordaan, E M; De Waele, D

1988-10-01

The host suitability of five of the most common weed species occurring in maize (Zea mays L.) fields in South Africa to Pratylenchus zeae was tested. Based on the number of nematodes per root unit, mealie crotalaria (Crotalaria sphaerocarpa) was a good host; goose grass (Eleusine indica), common pigweed (Amaranthus hybridus), and thorn apple (Datura stramonium) were moderate hosts; and khaki weed (Tagetes minuta) was a poor host. Only the root residues of khaki weed suppressed the P. zeae infestation of subsequently grown maize. When goose grass, khaki weed, and mealie crotalaria were grown in association with maize in soil infested with P. zeae, goose grass and khaki weed severely suppressed maize root development; this resulted in a low number of nematodes per maize root system and a high number of nematodes per maize root unit. Mealie crotalaria did not restrict maize root growth and did not affect nematode densities per maize root system or maize root unit. Special attention should be given to the control of mealie crotalaria, which is a good host for P. zeae, and goose grass, which, in addition to its ability to compete with maize, is also a suitable host for P. zeae.

Host Status of Five Weed Species and Their Effects on Pratylenchus zeae Infestation of Maize

PubMed Central

Jordaan, Elizabeth M.; De Waele, D.

1988-01-01

The host suitability of five of the most common weed species occurring in maize (Zea mays L.) fields in South Africa to Pratylenchus zeae was tested. Based on the number of nematodes per root unit, mealie crotalaria (Crotalaria sphaerocarpa) was a good host; goose grass (Eleusine indica), common pigweed (Amaranthus hybridus), and thorn apple (Datura stramonium) were moderate hosts; and khaki weed (Tagetes minuta) was a poor host. Only the root residues of khaki weed suppressed the P. zeae infestation of subsequently grown maize. When goose grass, khaki weed, and mealie crotalaria were grown in association with maize in soil infested with P. zeae, goose grass and khaki weed severely suppressed maize root development; this resulted in a low number of nematodes per maize root system and a high number of nematodes per maize root unit. Mealie crotalaria did not restrict maize root growth and did not affect nematode densities per maize root system or maize root unit. Special attention should be given to the control of mealie crotalaria, which is a good host for P. zeae, and goose grass, which, in addition to its ability to compete with maize, is also a suitable host for P. zeae. PMID:19290263

The Importance of Maize Management on Dung Beetle Communities in Atlantic Forest Fragments

PubMed Central

Campos, Renata Calixto; Hernández, Malva Isabel Medina

2015-01-01

Dung beetle community structures changes due to the effects of destruction, fragmentation, isolation and decrease in tropical forest area, and therefore are considered ecological indicators. In order to assess the influence of type of maize cultivated and associated maize management on dung beetle communities in Atlantic Forest fragments surrounded by conventional and transgenic maize were evaluated 40 Atlantic Forest fragments of different sizes, 20 surrounded by GM maize and 20 surrounded by conventional maize, in February 2013 and 2014 in Southern Brazil. After applying a sampling protocol in each fragment (10 pitfall traps baited with human feces or carrion exposed for 48 h), a total of 3454 individuals from 44 species were captured: 1142 individuals from 38 species in GM maize surrounded fragments, and 2312 from 42 species in conventional maize surrounded fragments. Differences in dung beetle communities were found between GM and conventional maize communities. As expected for fragmented areas, the covariance analysis showed a greater species richness in larger fragments under both conditions; however species richness was greater in fragments surrounded by conventional maize. Dung beetle structure in the forest fragments was explained by environmental variables, fragment area, spatial distance and also type of maize (transgenic or conventional) associated with maize management techniques. In Southern Brazil’s scenario, the use of GM maize combined with associated agricultural management may be accelerating the loss of diversity in Atlantic Forest areas, and consequently, important ecosystem services provided by dung beetles may be lost. PMID:26694874

The Importance of Maize Management on Dung Beetle Communities in Atlantic Forest Fragments.

PubMed

Campos, Renata Calixto; Hernández, Malva Isabel Medina

2015-01-01

Dung beetle community structures changes due to the effects of destruction, fragmentation, isolation and decrease in tropical forest area, and therefore are considered ecological indicators. In order to assess the influence of type of maize cultivated and associated maize management on dung beetle communities in Atlantic Forest fragments surrounded by conventional and transgenic maize were evaluated 40 Atlantic Forest fragments of different sizes, 20 surrounded by GM maize and 20 surrounded by conventional maize, in February 2013 and 2014 in Southern Brazil. After applying a sampling protocol in each fragment (10 pitfall traps baited with human feces or carrion exposed for 48 h), a total of 3454 individuals from 44 species were captured: 1142 individuals from 38 species in GM maize surrounded fragments, and 2312 from 42 species in conventional maize surrounded fragments. Differences in dung beetle communities were found between GM and conventional maize communities. As expected for fragmented areas, the covariance analysis showed a greater species richness in larger fragments under both conditions; however species richness was greater in fragments surrounded by conventional maize. Dung beetle structure in the forest fragments was explained by environmental variables, fragment area, spatial distance and also type of maize (transgenic or conventional) associated with maize management techniques. In Southern Brazil's scenario, the use of GM maize combined with associated agricultural management may be accelerating the loss of diversity in Atlantic Forest areas, and consequently, important ecosystem services provided by dung beetles may be lost.

All STEM fields are not created equal: People and things interests explain gender disparities across STEM fields

PubMed Central

Su, Rong; Rounds, James

2015-01-01

The degree of women's underrepresentation varies by STEM fields. Women are now overrepresented in social sciences, yet only constitute a fraction of the engineering workforce. In the current study, we investigated the gender differences in interests as an explanation for the differential distribution of women across sub-disciplines of STEM as well as the overall underrepresentation of women in STEM fields. Specifically, we meta-analytically reviewed norm data on basic interests from 52 samples in 33 interest inventories published between 1964 and 2007, with a total of 209,810 male and 223,268 female respondents. We found gender differences in interests to vary largely by STEM field, with the largest gender differences in interests favoring men observed in engineering disciplines (d = 0.83–1.21), and in contrast, gender differences in interests favoring women in social sciences and medical services (d = −0.33 and −0.40, respectively). Importantly, the gender composition (percentages of women) in STEM fields reflects these gender differences in interests. The patterns of gender differences in interests and the actual gender composition in STEM fields were explained by the people-orientation and things-orientation of work environments, and were not associated with the level of quantitative ability required. These findings suggest potential interventions targeting interests in STEM education to facilitate individuals' ability and career development and strategies to reform work environments to better attract and retain women in STEM occupations. PMID:25762964

All STEM fields are not created equal: People and things interests explain gender disparities across STEM fields.

PubMed

Su, Rong; Rounds, James

2015-01-01

The degree of women's underrepresentation varies by STEM fields. Women are now overrepresented in social sciences, yet only constitute a fraction of the engineering workforce. In the current study, we investigated the gender differences in interests as an explanation for the differential distribution of women across sub-disciplines of STEM as well as the overall underrepresentation of women in STEM fields. Specifically, we meta-analytically reviewed norm data on basic interests from 52 samples in 33 interest inventories published between 1964 and 2007, with a total of 209,810 male and 223,268 female respondents. We found gender differences in interests to vary largely by STEM field, with the largest gender differences in interests favoring men observed in engineering disciplines (d = 0.83-1.21), and in contrast, gender differences in interests favoring women in social sciences and medical services (d = -0.33 and -0.40, respectively). Importantly, the gender composition (percentages of women) in STEM fields reflects these gender differences in interests. The patterns of gender differences in interests and the actual gender composition in STEM fields were explained by the people-orientation and things-orientation of work environments, and were not associated with the level of quantitative ability required. These findings suggest potential interventions targeting interests in STEM education to facilitate individuals' ability and career development and strategies to reform work environments to better attract and retain women in STEM occupations.

Biological activities and chemical composition of the stems and roots of Helichrysum oligocephalum DC grown in Iran.

PubMed

Esmaeili, Akbar

2013-05-01

Helichrysum has long been used medicinally, proving to be beneficial in treatment of acne, asthma, bronchitis and circulatory problems, and lymphatic system diseases. The objective of this research was to study the antioxidant and antibacterial activities and chemical composition of the compounds derived from the stems and roots of cultivated H. oligocephalum using gas chromatography (GC) and gas chromatography-mass spectroscopy (GC-MS). The primary components found in the stem oil were ortho-vanillin (51.0%) and carvacrol (16.0%), and those found in the root oil were 1,8-cineole (30.6%) and isobornyl acetate (13.9%). Stem and root oils of H. oligocephalum demonstrated antibacterial activity, particularly in relation to Gram-positive bacteria. In a β-carotene/linoleic acid bleaching assay, the root oil of H. oligocephalum demonstrated an antioxidant effect. Antioxidant capacity measured with 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was 1205.0 for the stem oil and 722.8 μg/ml for the root oil.

Methane production through anaerobic digestion of various energy crops grown in sustainable crop rotations.

PubMed

Amon, Thomas; Amon, Barbara; Kryvoruchko, Vitaliy; Machmüller, Andrea; Hopfner-Sixt, Katharina; Bodiroza, Vitomir; Hrbek, Regina; Friedel, Jürgen; Pötsch, Erich; Wagentristl, Helmut; Schreiner, Matthias; Zollitsch, Werner

2007-12-01

Biogas production is of major importance for the sustainable use of agrarian biomass as renewable energy source. Economic biogas production depends on high biogas yields. The project aimed at optimising anaerobic digestion of energy crops. The following aspects were investigated: suitability of different crop species and varieties, optimum time of harvesting, specific methane yield and methane yield per hectare. The experiments covered 7 maize, 2 winter wheat, 2 triticale varieties, 1 winter rye, and 2 sunflower varieties and 6 variants with permanent grassland. In the course of the vegetation period, biomass yield and biomass composition were measured. Anaerobic digestion was carried out in eudiometer batch digesters. The highest methane yields of 7500-10200 m(N)(3)ha(-1) were achieved from maize varieties with FAO numbers (value for the maturity of the maize) of 300 to 600 harvested at "wax ripeness". Methane yields of cereals ranged from 3200 to 4500 m(N)(3)ha(-1). Cereals should be harvested at "grain in the milk stage" to "grain in the dough stage". With sunflowers, methane yields between 2600 and 4550 m(N)(3)ha(-1) were achieved. There were distinct differences between the investigated sunflower varieties. Alpine grassland can yield 2700-3500 m(N)(3)CH(4)ha(-1). The methane energy value model (MEVM) was developed for the different energy crops. It estimates the specific methane yield from the nutrient composition of the energy crops. Energy crops for biogas production need to be grown in sustainable crop rotations. The paper outlines possibilities for optimising methane yield from versatile crop rotations that integrate the production of food, feed, raw materials and energy. These integrated crop rotations are highly efficient and can provide up to 320 million t COE which is 96% of the total energy demand of the road traffic of the EU-25 (the 25 Member States of the European Union).

Effects of application of corn straw on soil microbial community structure during the maize growing season.

PubMed

Lu, Ping; Lin, Yin-Hua; Yang, Zhong-Qi; Xu, Yan-Peng; Tan, Fei; Jia, Xu-Dong; Wang, Miao; Xu, De-Rong; Wang, Xi-Zhuo

2015-01-01

This study investigated the influence of corn straw application on soil microbial communities and the relationship between such communities and soil properties in black soil. The crop used in this study was maize (Zea mays L.). The five treatments consisted of applying a gradient (50, 100, 150, and 200%) of shattered corn straw residue to the soil. Soil samples were taken from May through September during the 2012 maize growing season. The microbial community structure was determined using phospholipid fatty acid (PLFA) analysis. Our results revealed that the application of corn straw influenced the soil properties and increased the soil organic carbon and total nitrogen. Applying corn straw to fields also influenced the variation in soil microbial biomass and community composition, which is consistent with the variations found in soil total nitrogen (TN) and soil respiration (SR). However, the soil carbon-to-nitrogen ratio had no effect on soil microbial communities. The abundance of PLFAs, TN, and SR was higher in C1.5 than those in other treatments, suggesting that the soil properties and soil microbial community composition were affected positively by the application of corn straw to black soil. A Principal Component Analysis indicated that soil microbial communities were different in the straw decomposition processes. Moreover, the soil microbial communities from C1.5 were significantly different from those of CK (p < 0.05). We also found a high ratio of fungal-to-bacterial PLFAs in black soil and significant variations in the ratio of monounsaturated-to-branched fatty acids with different straw treatments that correlated with SR (p < 0.05). These results indicated that the application of corn straw positively influences soil properties and soil microbial communities and that these properties affect these communities. The individual PLFA signatures were sensitive indicators that reflected the changes in the soil environment condition. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Brittle stalk 2 encodes a putative glycosylphosphatidylinositol-anchored protein that affects mechanical strength of maize tissues by altering the composition and structure of secondary cell walls.

PubMed

Ching, Ada; Dhugga, Kanwarpal S; Appenzeller, Laura; Meeley, Robert; Bourett, Timothy M; Howard, Richard J; Rafalski, Antoni

2006-10-01

A spontaneous maize mutant, brittle stalk-2 (bk2-ref), exhibits dramatically reduced tissue mechanical strength. Reduction in mechanical strength in the stalk tissue was highly correlated with a reduction in the amount of cellulose and an uneven deposition of secondary cell wall material in the subepidermal and perivascular sclerenchyma fibers. Cell wall accounted for two-thirds of the observed reduction in dry matter content per unit length of the mutant stalk in comparison to the wildtype stalk. Although the cell wall composition was significantly altered in the mutant in comparison to the wildtype stalks, no compensation by lignin and cell wall matrix for reduced cellulose amount was observed. We demonstrate that Bk2 encodes a Cobra-like protein that is homologous to the rice Bc1 protein. In the bk2-ref gene, a 1 kb transposon-like element is inserted in the beginning of the second exon, disrupting the open reading frame. The Bk2 gene was expressed in the stalk, husk, root, and leaf tissues, but not in the embryo, endosperm, pollen, silk, or other tissues with comparatively few or no secondary cell wall containing cells. The highest expression was in the isolated vascular bundles. In agreement with its role in secondary wall formation, the expression pattern of the Bk2 gene was very similar to that of the ZmCesA10, ZmCesA11, and ZmCesA12 genes, which are known to be involved in secondary wall formation. We have isolated an independent Mutator-tagged allele of bk2, referred to as bk2-Mu7, the phenotype of which is similar to that of the spontaneous mutant. Our results demonstrate that mutations in the Bk2 gene affect stalk strength in maize by interfering with the deposition of cellulose in the secondary cell wall in fiber cells.

Carbon Fiber Reinforced Carbon Composite Valve for an Internal Combustion Engine

NASA Technical Reports Server (NTRS)

Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor)

1999-01-01

A carbon fiber reinforced carbon composite valve for internal combustion engines and the like formed of continuous carbon fibers throughout the valve's stem and head is disclosed. The valve includes braided carbon fiber material over axially aligned unidirectional carbon fibers forming a valve stem; the braided and unidirectional carbon fibers being broomed out at one end of the valve stem forming the shape of the valve head; the valve-shaped structure being densified and rigidized with a matrix of carbon containing discontinuous carbon fibers: and the finished valve being treated to resist oxidation. Also disclosed is a carbon matrix plug containing continuous and discontinuous carbon fibers and forming a net-shape valve head acting as a mandrel over which the unidirectional and braided carbon fibers are formed according to textile processes. Also disclosed are various preform valves and processes for making finished and preform carbon fiber reinforced carbon composite valves.

SPRUCE S1 Bog Tree Basal Area and Understory Community Composition Assessed in the Southern and Northern Ends of the S1 Bog

DOE Data Explorer

Iversen, C. M. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A; Garrett, A. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A; Martin, A. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A; Turetsky, M. R. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A; Norby, R. J. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A; Childs, J. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A; Ontl, T. A. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A

2017-01-01

The composition and cover of woody and understory species, along with the timing of stem growth, were characterized near minirhizotron installations at the south and north ends of the S1 bog in order to understand the relationship between root dynamics and the surrounding plant communities. There are three data streams: (1) Woody species basal area -- the number, basal area, and distance from the center point of all trees within a 5-m radius of each minirhizotron pair, which were quantified in 2011, (2) Understory cover -- the understory vascular plant community composition and percent cover, which were surveyed in 1 m2 areas at four cardinal directions adjacent to each pair of minirhizotrons in June 2011, and (3) Stem growth -- the basal area increment (stem growth) of nearby trees, which was quantified using automated or manual dendrobands in 2011 and 2012, respectively.

Surveying the Maize community for their diversity and pedigree visualization needs to prioritize tool development and curation

PubMed Central

Braun, Bremen L.; Schott, David A.; Portwood, II, John L.; Schaeffer, Mary L.; Harper, Lisa C.; Gardiner, Jack M.; Cannon, Ethalinda K.; Andorf, Carson M.

2017-01-01

Abstract The Maize Genetics and Genomics Database (MaizeGDB) team prepared a survey to identify breeders’ needs for visualizing pedigrees, diversity data and haplotypes in order to prioritize tool development and curation efforts at MaizeGDB. The survey was distributed to the maize research community on behalf of the Maize Genetics Executive Committee in Summer 2015. The survey garnered 48 responses from maize researchers, of which more than half were self-identified as breeders. The survey showed that the maize researchers considered their top priorities for visualization as: (i) displaying single nucleotide polymorphisms in a given region for a given list of lines, (ii) showing haplotypes for a given list of lines and (iii) presenting pedigree relationships visually. The survey also asked which populations would be most useful to display. The following two populations were on top of the list: (i) 3000 publicly available maize inbred lines used in Romay et al. (Comprehensive genotyping of the USA national maize inbred seed bank. Genome Biol, 2013;14:R55) and (ii) maize lines with expired Plant Variety Protection Act (ex-PVP) certificates. Driven by this strong stakeholder input, MaizeGDB staff are currently working in four areas to improve its interface and web-based tools: (i) presenting immediate progenies of currently available stocks at the MaizeGDB Stock pages, (ii) displaying the most recent ex-PVP lines described in the Germplasm Resources Information Network (GRIN) on the MaizeGDB Stock pages, (iii) developing network views of pedigree relationships and (iv) visualizing genotypes from SNP-based diversity datasets. These survey results can help other biological databases to direct their efforts according to user preferences as they serve similar types of data sets for their communities. Database URL: https://www.maizegdb.org PMID:28605768

Diversification, phylogeny and evolution of auxin response factor (ARF) family: insights gained from analyzing maize ARF genes.

PubMed

Wang, Yijun; Deng, Dexiang; Shi, Yating; Miao, Nan; Bian, Yunlong; Yin, Zhitong

2012-03-01

Auxin response factors (ARFs), member of the plant-specific B3 DNA binding superfamily, target specifically to auxin response elements (AuxREs) in promoters of primary auxin-responsive genes and heterodimerize with Aux/IAA proteins in auxin signaling transduction cascade. In previous research, we have isolated and characterized maize Aux/IAA genes in whole-genome scale. Here, we report the comprehensive analysis of ARF genes in maize. A total of 36 ARF genes were identified and validated from the B73 maize genome through an iterative strategy. Thirty-six maize ARF genes are distributed in all maize chromosomes except chromosome 7. Maize ARF genes expansion is mainly due to recent segmental duplications. Maize ARF proteins share one B3 DNA binding domain which consists of seven-stranded β sheets and two short α helixes. Twelve maize ARFs with glutamine-rich middle regions could be as activators in modulating expression of auxin-responsive genes. Eleven maize ARF proteins are lack of homo- and heterodimerization domains. Putative cis-elements involved in phytohormones and light signaling responses, biotic and abiotic stress adaption locate in promoters of maize ARF genes. Expression patterns vary greatly between clades and sister pairs of maize ARF genes. The B3 DNA binding and auxin response factor domains of maize ARF proteins are primarily subjected to negative selection during selective sweep. The mixed selective forces drive the diversification and evolution of genomic regions outside of B3 and ARF domains. Additionally, the dicot-specific proliferation of ARF genes was detected. Comparative genomics analysis indicated that maize, sorghum and rice duplicate chromosomal blocks containing ARF homologs are highly syntenic. This study provides insights into the distribution, phylogeny and evolution of ARF gene family.

Development and evaluation of geochemical methods for the sourcing of archaeological maize

USGS Publications Warehouse

Benson, L.V.; Taylor, Howard E.; Peterson, K.A.; Shattuck, B.D.; Ramotnik, C.A.; Stein, J.R.

2008-01-01

Strontium (Sr)-isotope values on bone from deer mice pairs from 12 field sites in the Chaco Canyon area, New Mexico, were compared with isotope values of synthetic soil waters from the same fields. The data indicate that mice obtain Sr from near-surface sources and that soil samples collected at depths ranging from 25 to 95 cm contain Sr that is more accessible to the deep roots of maize; thus, synthetic soil solutions provide better data for the sourcing of archaeological maize. However, the Sr-isotope composition of mice may be more valuable in sourcing archaeological remains of animals such as rabbit, turkey, and deer. In a separate study, five Native American maize (Zea mays L. ssp. mays) accessions grown out at New Mexico State University Agricultural Science Center, Farmington, New Mexico were used to determine if soil-water metal pairs partition systematically into cobs and kernels. The sampled maize included landraces from three Native American groups (Acoma, Hopi, Zuni) that still occupy the Four Corners area. Two cobs each were picked from 10 plants of each landrace. Partitioning of the Ba/Mn, Ba/Sr, Ca/Sr, and K/Rb metal pairs from the soil water to the cob appears to behave in a systematic fashion. In addition, 51 rare earth element (REE) pairs also appear to systematically partition from the soil water into cobs; however, the ratios of the REE dissolved in the soil waters are relatively invariant; therefore, the distribution coefficients that describe the partitioning of REE from the soil water to the cob may not apply to archeological cobs grown under chemically heterogeneous conditions. Partitioning of Ba/Rb, Ba/Sr, Mg/P, and Mn/P metal pairs from the soil water to kernels also behaves in a systematic fashion. Given that modern Native American landraces were grown under optimal environmental conditions that may not have been duplicated by prehistoric Native Americans, the distribution coefficients obtained in this study should be used with caution. ?? 2007 Elsevier Ltd. All rights reserved.

MaizeGDB: Global support for maize research through open access information [abstract

USDA-ARS?s Scientific Manuscript database

MaizeGDB is the open-access global repository for maize genetic and genomic information – from single genes that determine nutritional quality to whole genome-scale data for complex traits including yield and drought tolerance. The data and tools at MaizeGDB enable researchers from Ethiopia to Ghan...

Surveying the maize community for their diversity and pedigree visualization needs to prioritize tool development and curation

USDA-ARS?s Scientific Manuscript database

The Maize Genetics and Genomics Database (MaizeGDB) team prepared a survey to identify breeders’ needs for visualizing pedigrees, diversity data, and haplotypes in order to prioritize tool development and curation efforts at MaizeGDB. The survey was distributed to the maize research community on beh...

Maize lethal necrosis (MLN), an emerging threat to maize-based food security in sub-Saharan Africa

USDA-ARS?s Scientific Manuscript database

In sub-Saharan Africa, maize is a staple food and key determinant of food security for smallholder farming communities. Pest and disease outbreaks are key constraints to maize productivity. In September 2011, a serious disease outbreak, later diagnosed as maize lethal necrosis (MLN), was reported on...

A selfish gene governing pollen-pistil compatibility confers reproductive isolation between maize relatives.

PubMed

Kermicle, Jerry L

2006-01-01

Some populations of maize's closest relatives, the annual teosintes of Mexico, are unreceptive to maize pollen. When present in the pistil (silk and ovary) a number of maize genes discriminate against or exclude pollen not carrying the same allele. An analogous gene Tcb1-s was found in some teosinte populations but not in sympatric or parapatric maize. It was polymorphic among populations of teosinte growing wild, but regularly present in populations growing in intimate association with maize as a weed. Introduction of Tcb1-s into maize substantially to fully restored compatibility with Tcb1-s carrying teosintes. Although Tcb1-s pollen can fertilize tcb1 tcb1 maize, it is at a competitive disadvantage relative to tcb1 pollen. Hence, the influence of Tcb1-s on crossability is bidirectional. In the absence of maize, Tcb1-s can increase in teosinte populations without improving their fitness. In the presence of maize, Tcb1-s appears to have been co-opted to provide reproductive isolation for adaptation to a cultivated habitat.

Defense Priming and Jasmonates: A Role for Free Fatty Acids in Insect Elicitor-Induced Long Distance Signaling

PubMed Central

Li, Ting; Cofer, Tristan; Engelberth, Marie; Engelberth, Jurgen

2016-01-01

Green leaf volatiles (GLV) prime plants against insect herbivore attack resulting in stronger and faster signaling by jasmonic acid (JA). In maize this response is specifically linked to insect elicitor (IE)-induced signaling processes, which cause JA accumulation not only around the damage site, but also in distant tissues, presumably through the activation of electrical signals. Here, we present additional data further characterizing these distal signaling events in maize. Also, we describe how exposure to GLV increases free fatty acid (fFA) levels in maize seedlings, but also in other plants, and how increased fFA levels affect IE-induced JA accumulation. Increased fFA, in particular α-linolenic acid (LnA), caused a significant increase in JA accumulation after IE treatment, while JA induced by mechanical wounding (MW) alone was not affected. We also identified treatments that significantly decreased certain fFA level including simulated wind and rain. In such treated plants, IE-induced JA accumulation was significantly reduced when compared to un-moved control plants, while MW-induced JA accumulation was not significantly affected. Since only IE-induced JA accumulation was altered by changes in the fFA composition, we conclude that changing levels of fFA affect primarily IE-induced signaling processes rather than serving as a substrate for JA. PMID:27135225

Cell Wall Modifications in Maize Pulvini in Response to Gravitational Stress1[W][OA

PubMed Central

Zhang, Qisen; Pettolino, Filomena A.; Dhugga, Kanwarpal S.; Rafalski, J. Antoni; Tingey, Scott; Taylor, Jillian; Shirley, Neil J.; Hayes, Kevin; Beatty, Mary; Abrams, Suzanne R.; Zaharia, L. Irina; Burton, Rachel A.; Bacic, Antony; Fincher, Geoffrey B.

2011-01-01

Changes in cell wall polysaccharides, transcript abundance, metabolite profiles, and hormone concentrations were monitored in the upper and lower regions of maize (Zea mays) pulvini in response to gravistimulation, during which maize plants placed in a horizontal position returned to the vertical orientation. Heteroxylan levels increased in the lower regions of the pulvini, together with lignin, but xyloglucans and heteromannan contents decreased. The degree of substitution of heteroxylan with arabinofuranosyl residues decreased in the lower pulvini, which exhibited increased mechanical strength as the plants returned to the vertical position. Few or no changes in noncellulosic wall polysaccharides could be detected on the upper side of the pulvinus, and crystalline cellulose content remained essentially constant in both the upper and lower pulvinus. Microarray analyses showed that spatial and temporal changes in transcript profiles were consistent with the changes in wall composition that were observed in the lower regions of the pulvinus. In addition, the microarray analyses indicated that metabolic pathways leading to the biosynthesis of phytohormones were differentially activated in the upper and lower regions of the pulvinus in response to gravistimulation. Metabolite profiles and measured hormone concentrations were consistent with the microarray data, insofar as auxin, physiologically active gibberellic acid, and metabolites potentially involved in lignin biosynthesis increased in the elongating cells of the lower pulvinus. PMID:21697508

Effect of replacing maize grain and soybean meal with a xylose-treated wheat grain on feed intake and performance of dairy cows.

PubMed

Benninghoff, Jens; Hamann, Gregor; Steingaß, Herbert; Romberg, Franz-Josef; Landfried, Karl; Südekum, Karl-Heinz

2017-06-01

This study evaluated wheat grain which was treated with xylose in aqueous Ca-Mg lignosulphonate solution at elevated temperatures (WeiPass®) in order to reduce ruminal degradation of starch and crude protein. The two tested isoenergetic and isonitrogenous diets contained on dry matter (DM) basis either 16% maize grain and 6.4% soybean meal (Diet CON) or 17.8% xylose-treated wheat and 4.6% soybean meal (Diet Wheat). Thirty-six German Holstein dairy cows were assigned to one of the two groups according to parity, body weight after calving, and milk yield during the previous lactation. Data collection started at 21 d before the expected calving date until 120 d in milk. The average of DM intake, energy-corrected milk (ECM) yield, and milk fat and protein yields (all given as kg/d) were 18.9, 28.7, 1.25, and 1.02 for Diet CON and 19.3, 32.5, 1.36, and 1.11 for Diet Wheat, respectively. Only ECM and milk protein yields were greater (p < 0.05) for cows receiving Diet Wheat. In conclusion, the xylose-treated wheat grain can replace maize grain and part of soybean meal in diets for lactating dairy cows and may be an alternative feedstuff depending on overall ration composition and availability and costs of grain sources.

A new QTL for resistance to Fusarium ear rot in maize.

PubMed

Li, Zhi-Min; Ding, Jun-Qiang; Wang, Rui-Xia; Chen, Jia-Fa; Sun, Xiao-Dong; Chen, Wei; Song, Wei-Bin; Dong, Hua-Fang; Dai, Xiao-Dong; Xia, Zong-Liang; Wu, Jian-Yu

2011-11-01

Understanding the inheritance of resistance to Fusarium ear rot is a basic prerequisite for an efficient resistance breeding in maize. In this study, 250 recombinant inbred lines (RILs) along with their resistant (BT-1) and susceptible (N6) parents were planted in Zhengzhou with three replications in 2007 and 2008. Each line was artificially inoculated using the nail-punch method. Significant genotypic variation in response to Fusarium ear rot was detected in both years. Based on a genetic map containing 207 polymorphic simple sequence repeat (SSR) markers with average genetic distances of 8.83 cM, the ear rot resistance quantitative trait loci (QTL) were analyzed by composite interval mapping with a mixed model (MCIM) across the environments. In total, four QTL were detected on chromosomes 3, 4, 5, and 6. The resistance allele at each of these four QTL was contributed by resistant parent BT-1, and accounted for 2.5-10.2% of the phenotypic variation. However, no significant epistasis interaction effect was detected after a two-dimensional genome scan. Among the four QTL, one QTL with the largest effect on chromosome 4 (bin 4.06) can be suggested to be a new locus for resistance to Fusarium ear rot, which broadens the genetic base for resistance to the disease and can be used for further genetic improvement in maize-breeding programs.

Dynamic variation of the microbial community structure during the long-time mono-fermentation of maize and sugar beet silage

PubMed Central

Klang, Johanna; Theuerl, Susanne; Szewzyk, Ulrich; Huth, Markus; Tölle, Rainer; Klocke, Michael

2015-01-01

This study investigated the development of the microbial community during a long-term (337 days) anaerobic digestion of maize and sugar beet silage, two feedstocks that significantly differ in their chemical composition. For the characterization of the microbial dynamics, the community profiling method terminal restriction fragment length polymorphism (TRFLP) in combination with a cloning-sequencing approach was applied. Our results revealed a specific adaptation of the microbial community to the supplied feedstocks. Based on the high amount of complex compounds, the anaerobic conversion rate of maize silage was slightly lower compared with the sugar beet silage. It was demonstrated that members from the phylum Bacteroidetes are mainly involved in the degradation of low molecular weight substances such as sugar, ethanol and acetate, the main compounds of the sugar beet silage. It was further shown that species of the genus Methanosaeta are highly sensitive against sudden stress situations such as a strong decrease in the ammonium nitrogen (NH4+-N) concentration or a drop of the pH value. In both cases, a functional compensation by members of the genera Methanoculleus and/or Methanosarcina was detected. However, the overall biomass conversion of both feedstocks proceeded efficiently as a steady state between acid production and consumption was recorded, which further resulted in an equal biogas yield. PMID:25712194

Occurrence of maize detritus and a transgenic insecticidal protein (Cry1Ab) within the stream network of an agricultural landscape

PubMed Central

Tank, Jennifer L.; Rosi-Marshall, Emma J.; Royer, Todd V.; Whiles, Matt R.; Griffiths, Natalie A.; Frauendorf, Therese C.; Treering, David J.

2010-01-01

Widespread planting of maize throughout the agricultural Midwest may result in detritus entering adjacent stream ecosystems, and 63% of the 2009 US maize crop was genetically modified to express insecticidal Cry proteins derived from Bacillus thuringiensis. Six months after harvest, we conducted a synoptic survey of 217 stream sites in Indiana to determine the extent of maize detritus and presence of Cry1Ab protein in the stream network. We found that 86% of stream sites contained maize leaves, cobs, husks, and/or stalks in the active stream channel. We also detected Cry1Ab protein in stream-channel maize at 13% of sites and in the water column at 23% of sites. We found that 82% of stream sites were adjacent to maize fields, and Geographical Information Systems analyses indicated that 100% of sites containing Cry1Ab-positive detritus in the active stream channel had maize planted within 500 m during the previous crop year. Maize detritus likely enters streams throughout the Corn Belt; using US Department of Agriculture land cover data, we estimate that 91% of the 256,446 km of streams/rivers in Iowa, Illinois, and Indiana are located within 500 m of a maize field. Maize detritus is common in low-gradient stream channels in northwestern Indiana, and Cry1Ab proteins persist in maize leaves and can be measured in the water column even 6 mo after harvest. Hence, maize detritus, and associated Cry1Ab proteins, are widely distributed and persistent in the headwater streams of a Corn Belt landscape. PMID:20876106

Occurrence of maize detritus and a transgenic insecticidal protein (Cry1Ab) within the stream network of an agricultural landscape.

PubMed

Tank, Jennifer L; Rosi-Marshall, Emma J; Royer, Todd V; Whiles, Matt R; Griffiths, Natalie A; Frauendorf, Therese C; Treering, David J

2010-10-12

Widespread planting of maize throughout the agricultural Midwest may result in detritus entering adjacent stream ecosystems, and 63% of the 2009 US maize crop was genetically modified to express insecticidal Cry proteins derived from Bacillus thuringiensis. Six months after harvest, we conducted a synoptic survey of 217 stream sites in Indiana to determine the extent of maize detritus and presence of Cry1Ab protein in the stream network. We found that 86% of stream sites contained maize leaves, cobs, husks, and/or stalks in the active stream channel. We also detected Cry1Ab protein in stream-channel maize at 13% of sites and in the water column at 23% of sites. We found that 82% of stream sites were adjacent to maize fields, and Geographical Information Systems analyses indicated that 100% of sites containing Cry1Ab-positive detritus in the active stream channel had maize planted within 500 m during the previous crop year. Maize detritus likely enters streams throughout the Corn Belt; using US Department of Agriculture land cover data, we estimate that 91% of the 256,446 km of streams/rivers in Iowa, Illinois, and Indiana are located within 500 m of a maize field. Maize detritus is common in low-gradient stream channels in northwestern Indiana, and Cry1Ab proteins persist in maize leaves and can be measured in the water column even 6 mo after harvest. Hence, maize detritus, and associated Cry1Ab proteins, are widely distributed and persistent in the headwater streams of a Corn Belt landscape.

Growth dynamics and cytoskeleton organization during stem maturation and gravity-induced stem bending in Zea mays L

NASA Technical Reports Server (NTRS)

Collings, D. A.; Winter, H.; Wyatt, S. E.; Allen, N. S.; Davies, E. (Principal Investigator)

1998-01-01

Characterization of gravitropic bending in the maize stem pulvinus, a tissue that functions specifically in gravity responses, demonstrates that the pulvinus is an ideal system for studying gravitropism. Gravistimulation during the second of three developmental phases of the pulvinus induces a gradient of cell elongation across the non-growing cells of the pulvinus, with the most elongation occurring on the lower side. This cell elongation is spatially and temporally separated from normal internodal cell elongation. The three characterized growth phases in the pulvinus correspond closely to a specialized developmental sequence in which structural features typical of cells not fully matured are retained while cell maturation occurs in surrounding internodal and nodal tissue. For example, the lignification of supporting tissue and rearrangement of transverse microtubules to oblique that occur in the internode when cell elongation ceases are delayed for up to 10 d in the adjacent cells of the pulvinus, and only occurs as a pulvinus loses its capacity to respond to gravistimulation. Gravistimulation does not modify this developmental sequence. Neither wall lignification nor rearrangement of transverse microtubules occurs in the rapidly elongating lower side or non-responsive upper side of the pulvinus until the pulvinus loses the capacity to bend further. Gravistimulation does, however, lead to the formation of putative pit fields within the expanding cells of the pulvinus.

A multiplex PCR method of detecting recombinant DNAs from five lines of genetically modified maize.

PubMed

Matsuoka, T; Kuribara, H; Akiyama, H; Miura, H; Goda, Y; Kusakabe, Y; Isshiki, K; Toyoda, M; Hino, A

2001-02-01

Seven lines of genetically modified (GM) maize have been authorized in Japan as foods and feeds imported from the USA. We improved a multiplex PCR method described in the previous report in order to distinguish the five lines of GM maize. Genomic DNA was extracted from GM maize with a silica spin column kit, which could reduce experimental time and improve safety in the laboratory and potentially in the environment. We sequenced recombinant DNA (r-DNA) introduced into GM maize, and re-designed new primer pairs to increase the specificity of PCR to distinguish five lines of GM maize by multiplex PCR. A primer pair for the maize intrinsic zein gene (Ze1) was also designed to confirm the presence of amplifiable maize DNA. The lengths of PCR products using these six primer pairs were different. The Ze1 and the r-DNAs from the five lines of GM maize were qualitatively detected in one tube. The specific PCR bands were distinguishable from each other on the basis of the expected length. The r-DNA could be detected from maize samples containing 0.5% of each of the five lines of GM maize. The sensitivity would be acceptable to secure the verification of non-GMO materials and to monitor the reliability of the labeling system.

Sequence Resources at MaizeGDB with Emphasis on POPcorn: A Project Portal for Corn

USDA-ARS?s Scientific Manuscript database

MaizeGDB is the maize research community’s centralized, long-term repository for genetic and genomic information about the crop plant and model organism Zea mays ssp. mays. The MaizeGDB team endeavors to meet the needs of the maize research community based on feedback and guidance. Recent work has f...

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Certified seed potatoes, and seed corn or maize... Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification as seed potatoes under subheading 0701.10.00, as seed corn (maize) under subheading 1005.10...

Diverse chromosomal locations of quantitative trait loci for tolerance to maize chlorotic mottle in five maize populations

USDA-ARS?s Scientific Manuscript database

The recent rapid emergence of maize lethal necrosis (MLN), caused by coinfection of maize with maize chlorotic mottle virus (MCMV) and a second virus usually from the family Potyviridae, is causing extensive losses for farmers in East Africa, Southeast Asia and South America. Although the genetic ba...

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 19 Customs Duties 1 2011-04-01 2011-04-01 false Certified seed potatoes, and seed corn or maize... Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification as seed potatoes under subheading 0701.10.00, as seed corn (maize) under subheading 1005.10...

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 19 Customs Duties 1 2014-04-01 2014-04-01 false Certified seed potatoes, and seed corn or maize... Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification as seed potatoes under subheading 0701.10.00, as seed corn (maize) under subheading 1005.10...

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 19 Customs Duties 1 2013-04-01 2013-04-01 false Certified seed potatoes, and seed corn or maize... Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification as seed potatoes under subheading 0701.10.00, as seed corn (maize) under subheading 1005.10...

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 19 Customs Duties 1 2012-04-01 2012-04-01 false Certified seed potatoes, and seed corn or maize... Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification as seed potatoes under subheading 0701.10.00, as seed corn (maize) under subheading 1005.10...

Bioactive gel-glasses with distinctly different compositions: Bioactivity, viability of stem cells and antibiofilm effect against Streptococcus mutans.

PubMed

Siqueira, Renato L; Maurmann, Natasha; Burguêz, Daniela; Pereira, Daniela P; Rastelli, Alessandra N S; Peitl, Oscar; Pranke, Patricia; Zanotto, Edgar D

2017-07-01

In this study, an evaluation was performed to determine the in vitro bioactivity, viability of stem cells, and antibiofilm effect against Streptococcus mutans of two bioactive gel-glass 60SiO 2 -36CaO-4P 2 O 5 (BG-A) and 80SiO 2 -15CaO-5P 2 O 5 (BG-B) compositions. Both materials were bioactive and undergo the formation of hydroxycarbonate apatite (HCA) on their surfaces when immersed in simulated body fluid (SBF) after 12h, but the BG-A composition showed a more significant formation rate. The pH variation of the samples during the test in SBF indicated that an abrupt change had occurred for the BG-A composition within the first few hours, and the pH was subsequently maintained over time, supporting its stronger antibacterial effects against S. mutans. For the in vitro viability test using mesenchymal stem cells (MSCs), the BG-B showed significantly higher cell viability compared to the BG-A composition at concentrations of 0.125, 1.25 and 12.50mg/mL for 2days. These results indicated that the higher solubility of the BG-A glass favors bioactivity and antibacterial effects. However, as a result of rapid degradation, the increase in the concentration of ions in the cell culture medium was not favorable for cell proliferation. Thus, by varying the composition of glasses, and consequently their dissolution rate, it is possible to favor bioactivity, antimicrobial activity or stem cell proliferation for a particular application of interest. Copyright © 2017 Elsevier B.V. All rights reserved.

Fabrication of Composite Material Using Gettou Fiber by Injection Molding

NASA Astrophysics Data System (ADS)

Setsuda, Roy; Fukumoto, Isao; Kanda, Yasuyuki

This study investigated the mechanical properties of composite using gettou (shell ginger) fiber as reinforcement fabricated from injection molding. Gettou fiber is a natural fiber made from gettou, a subtropical plant that is largely abundant in Okinawa, Japan. We used the stem part of gettou plant and made the gettou fiber by crushing the stem. The composite using gettou fiber contributed to low shrinkage ratio, high bending strength and high flexural modulus. The mechanical strength of composite using long gettou fiber showed higher value than composite using short gettou fiber. Next, because gettou is particularly known for its anti-mold characteristic, we investigated the characteristic in gettou plastic composite. The composite was tested against two molds: aspergillius niger and penicillium funiculosum. The 60% gettou fiber plastic composite was found to satisfy the JISZ2801 criterion. Finally, in order to predict the flexural modulus of composite using gettou fiber by Halpin-Tsai equation, the tensile elastic modulus of single gettou fiber was measured. The tendency of the experimental results of composite using gettou fiber was in good agreement with Halpin-Tsai equation.

Global Maize Trade and Food Security: Implications from a Social Network Model

PubMed Central

Wu, Felicia; Guclu, Hasan

2013-01-01

In this study, we developed a social network model of the global trade of maize: one of the most important food, feed, and industrial crops worldwide, and critical to food security. We used this model to analyze patterns of maize trade among nations, and to determine where vulnerabilities in food security might arise if maize availability were decreased due to factors such as diversion to non-food uses, climatic factors, or plant diseases. Using data on imports and exports from the United Nations Commodity Trade Statistics Database for each year from 2000 to 2009 inclusive, we summarized statistics on volumes of maize trade between pairs of nations for 217 nations. There is evidence of market segregation among clusters of nations; with three prominent clusters representing Europe, Brazil and Argentina, and the United States. The United States is by far the largest exporter of maize worldwide, while Japan and the Republic of Korea are the largest maize importers. In particular, the star-shaped cluster of the network that represents US maize trade to other nations indicates the potential for food security risks because of the lack of trade these other nations conduct with other maize exporters. If a scenario arose in which US maize could not be exported in as large quantities, maize supplies in many nations could be jeopardized. We discuss this in the context of recent maize ethanol production and its attendant impacts on food prices elsewhere worldwide. PMID:23656551

Global maize trade and food security: implications from a social network model.

PubMed

Wu, Felicia; Guclu, Hasan

2013-12-01

In this study, we developed a social network model of the global trade of maize: one of the most important food, feed, and industrial crops worldwide, and critical to food security. We used this model to analyze patterns of maize trade among nations, and to determine where vulnerabilities in food security might arise if maize availability was decreased due to factors such as diversion to nonfood uses, climatic factors, or plant diseases. Using data on imports and exports from the U.N. Commodity Trade Statistics Database for each year from 2000 to 2009 inclusive, we summarized statistics on volumes of maize trade between pairs of nations for 217 nations. There is evidence of market segregation among clusters of nations; with three prominent clusters representing Europe, Brazil and Argentina, and the United States. The United States is by far the largest exporter of maize worldwide, whereas Japan and the Republic of Korea are the largest maize importers. In particular, the star-shaped cluster of the network that represents U.S. maize trade to other nations indicates the potential for food security risks because of the lack of trade these other nations conduct with other maize exporters. If a scenario arose in which U.S. maize could not be exported in as large quantities, maize supplies in many nations could be jeopardized. We discuss this in the context of recent maize ethanol production and its attendant impacts on food prices elsewhere worldwide. © 2013 Society for Risk Analysis.

A Bilayer Construct Controls Adipose-Derived Stem Cell Differentiation into Endothelial Cells and Pericytes without Growth Factor Stimulation

DTIC Science & Technology

2011-01-01

A Bilayer Construct Controls Adipose-Derived Stem Cell Differentiation into Endothelial Cells and Pericytes Without Growth Factor Stimulation...Ph.D.3 This work describes the differentiation of adipose-derived mesenchymal stem cells (ASC) in a composite hy- drogel for use as a vascularized...tissue from a single population of ASC. This work underscores the importance of the extracellular matrix in controlling stem cell phenotype. It is our

Maize variety and method of production

DOEpatents

Pauly, Markus; Hake, Sarah; Kraemer, Florian J

2014-05-27

The disclosure relates to a maize plant, seed, variety, and hybrid. More specifically, the disclosure relates to a maize plant containing a Cal-1 allele, whose expression results in increased cell wall-derived glucan content in the maize plant. The disclosure also relates to crossing inbreds, varieties, and hybrids containing the Cal-1 allele to produce novel types and varieties of maize plants.

Analysis of recombination QTLs, segregation distortion, and epistasis for fitness in maize multiple populations using ultra-high-density markers

USDA-ARS?s Scientific Manuscript database

Understanding the maize genomic features would be useful for the study of genetic diversity and evolution and for maize breeding. Here, we used two maize nested association mapping (NAM) populations separately derived in China (CN-NAM) and the US (US-NAM) to explore the maize genomic features. The t...

How are arbuscular mycorrhizal associations related to maize growth performance during short-term cover crop rotation?

PubMed

Higo, Masao; Takahashi, Yuichi; Gunji, Kento; Isobe, Katsunori

2018-03-01

Better cover crop management options aiming to maximize the benefits of arbuscular mycorrhizal fungi (AMF) to subsequent crops are largely unknown. We investigated the impact of cover crop management methods on maize growth performance and assemblages of AMF colonizing maize roots in a field trial. The cover crop treatments comprised Italian ryegrass, wheat, brown mustard and fallow in rotation with maize. The diversity of AMF communities among cover crops used for maize management was significantly influenced by the cover crop and time course. Cover crops did not affect grain yield and aboveground biomass of subsequent maize but affected early growth. A structural equation model indicated that the root colonization, AMF diversity and maize phosphorus uptake had direct strong positive effects on yield performance. AMF variables and maize performance were related directly or indirectly to maize grain yield, whereas root colonization had a positive effect on maize performance. AMF may be an essential factor that determines the success of cover crop rotational systems. Encouraging AMF associations can potentially benefit cover cropping systems. Therefore, it is imperative to consider AMF associations and crop phenology when making management decisions. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Monitoring of Bt11 and Bt176 genetically modified maize in food sold commercially in Brazil from 2005 to 2007.

PubMed

Dinon, Andréia Z; Bosco, Kenia T; Arisi, Ana Carolina M

2010-07-01

The first genetically modified (GM) maize lines were approved for trading in Brazil after December 2007 and they were T25, MON810, Bt11, NK603 and GA21. The polymerase chain reaction (PCR) method was employed to monitor the presence of Bt11 and nested PCR was used to detect the presence of Bt176 in 81 maize-derived products (maize flour, corn meal, maize flour flakes and polenta) that were sold in Brazilian market from 2005 to 2007, before the release of GM maize in Brazil. The PCR detection limit for Bt11 was 10 g kg(-1) and for nested PCR of Bt176 it was 1 g kg(-1). All Brazilian samples analyzed showed no positive signal for these GM maize events. Bt11 and Bt176 GM maize lines were not detected by specific PCR in 81 maize-derived food samples sold in Brazil from 2005 to 2007, before the commercial release of GM maize in Brazil. These Brazilian food industries were in compliance with the rules stipulated by the current legislation with respect to consumer requirements about GMO labeling.

Occupational Rhinoconjunctivitis due to Maize in a Snack Processor: A Cross-Reactivity Study Between Lipid Transfer Proteins From Different Cereals and Peach.

PubMed

Guillen, Daiana; Barranco, Pilar; Palacín, Arantxa; Quirce, Santiago

2014-09-01

We report the case of a snack processor who developed occupational rhinoconjunctivitis due to maize brand exposure during the extrusion process, and who experienced abdominal pain upon drinking beer. The allergens implicated and the cross-reactivity between non-specific lipid transfer proteins (LTPs) from different cereals and peach were investigated. Skin prick tests and specific IgE to cereal flours, pulmonary functions tests and specific conjunctival and inhalation challenges to maize extract were performed. In vitro studies included IgE immunoblotting and ELISA inhibition assays. Skin prick tests with maize flour, maize brand and wheat flour extracts were positive, whereas serum specific IgE was positive only to maize flour. Specific inhalation challenge (SIC) to maize flour did not elicit an asthmatic reaction; however, conjunctival challenge test with the same extract was positive. Patient's serum recognized IgE-binding bands in the maize and beer extracts corresponding to LTPs. In the ELISA inhibition assays, a significant degree of allergenic cross-reactivity was found between maize and beer LTPs, whereas no cross-reactivity was observed between maize LTP and wheat and peach LTPs.

Pollen-Mediated Gene Flow in Maize: Implications for Isolation Requirements and Coexistence in Mexico, the Center of Origin of Maize.

PubMed

Baltazar, Baltazar M; Castro Espinoza, Luciano; Espinoza Banda, Armando; de la Fuente Martínez, Juan Manuel; Garzón Tiznado, José Antonio; González García, Juvencio; Gutiérrez, Marco Antonio; Guzmán Rodríguez, José Luis; Heredia Díaz, Oscar; Horak, Michael J; Madueño Martínez, Jesús Ignacio; Schapaugh, Adam W; Stojšin, Duška; Uribe Montes, Hugo Raúl; Zavala García, Francisco

2015-01-01

Mexico, the center of origin of maize (Zea mays L.), has taken actions to preserve the identity and diversity of maize landraces and wild relatives. Historically, spatial isolation has been used in seed production to maintain seed purity. Spatial isolation can also be a key component for a strategy to minimize pollen-mediated gene flow in Mexico between transgenic maize and sexually compatible plants of maize conventional hybrids, landraces, and wild relatives. The objective of this research was to generate field maize-to-maize outcrossing data to help guide coexistence discussions in Mexico. In this study, outcrossing rates were determined and modeled from eight locations in six northern states, which represent the most economically important areas for the cultivation of hybrid maize in Mexico. At each site, pollen source plots were planted with a yellow-kernel maize hybrid and surrounded by plots with a white-kernel conventional maize hybrid (pollen recipient) of the same maturity. Outcrossing rates were then quantified by assessing the number of yellow kernels harvested from white-kernel hybrid plots. The highest outcrossing values were observed near the pollen source (12.9% at 1 m distance). The outcrossing levels declined sharply to 4.6, 2.7, 1.4, 1.0, 0.9, 0.5, and 0.5% as the distance from the pollen source increased to 2, 4, 8, 12, 16, 20, and 25 m, respectively. At distances beyond 20 m outcrossing values at all locations were below 1%. These trends are consistent with studies conducted in other world regions. The results suggest that coexistence measures that have been implemented in other geographies, such as spatial isolation, would be successful in Mexico to minimize transgenic maize pollen flow to conventional maize hybrids, landraces and wild relatives.

Pollen-Mediated Gene Flow in Maize: Implications for Isolation Requirements and Coexistence in Mexico, the Center of Origin of Maize

PubMed Central

Gutiérrez, Marco Antonio; Guzmán Rodríguez, José Luis; Horak, Michael J.; Madueño Martínez, Jesús Ignacio; Schapaugh, Adam W.; Stojšin, Duška; Uribe Montes, Hugo Raúl

2015-01-01

Mexico, the center of origin of maize (Zea mays L.), has taken actions to preserve the identity and diversity of maize landraces and wild relatives. Historically, spatial isolation has been used in seed production to maintain seed purity. Spatial isolation can also be a key component for a strategy to minimize pollen-mediated gene flow in Mexico between transgenic maize and sexually compatible plants of maize conventional hybrids, landraces, and wild relatives. The objective of this research was to generate field maize-to-maize outcrossing data to help guide coexistence discussions in Mexico. In this study, outcrossing rates were determined and modeled from eight locations in six northern states, which represent the most economically important areas for the cultivation of hybrid maize in Mexico. At each site, pollen source plots were planted with a yellow-kernel maize hybrid and surrounded by plots with a white-kernel conventional maize hybrid (pollen recipient) of the same maturity. Outcrossing rates were then quantified by assessing the number of yellow kernels harvested from white-kernel hybrid plots. The highest outcrossing values were observed near the pollen source (12.9% at 1 m distance). The outcrossing levels declined sharply to 4.6, 2.7, 1.4, 1.0, 0.9, 0.5, and 0.5% as the distance from the pollen source increased to 2, 4, 8, 12, 16, 20, and 25 m, respectively. At distances beyond 20 m outcrossing values at all locations were below 1%. These trends are consistent with studies conducted in other world regions. The results suggest that coexistence measures that have been implemented in other geographies, such as spatial isolation, would be successful in Mexico to minimize transgenic maize pollen flow to conventional maize hybrids, landraces and wild relatives. PMID:26162097

Significant accumulation of C(4)-specific pyruvate, orthophosphate dikinase in a C(3) plant, rice.

PubMed

Fukayama, H; Tsuchida, H; Agarie, S; Nomura, M; Onodera, H; Ono, K; Lee, B H; Hirose, S; Toki, S; Ku, M S; Makino, A; Matsuoka, M; Miyao, M

2001-11-01

The C(4)-Pdk gene encoding the C(4) enzyme pyruvate, orthophosphate dikinase (PPDK) of maize (Zea mays cv Golden Cross Bantam) was introduced into the C(3) plant, rice (Oryza sativa cv Kitaake). When the intact maize C(4)-Pdk gene, containing its own promoter and terminator sequences and exon/intron structure, was introduced, the PPDK activity in the leaves of some transgenic lines was greatly increased, in one line reaching 40-fold over that of wild-type plants. In a homozygous line, the PPDK protein accounted for 35% of total leaf-soluble protein or 16% of total leaf nitrogen. In contrast, introduction of a chimeric gene containing the full-length cDNA of the maize PPDK fused to the maize C(4)-Pdk promoter or the rice Cab promoter only increased PPDK activity and protein level slightly. These observations suggest that the intron(s) or the terminator sequence of the maize gene, or a combination of both, is necessary for high-level expression. In maize and transgenic rice plants carrying the intact maize gene, the level of transcript in the leaves per copy of the maize C(4)-Pdk gene was comparable, and the maize gene was expressed in a similar organ-specific manner. These results suggest that the maize C(4)-Pdk gene behaves in a quantitatively and qualitatively similar way in maize and transgenic rice plants. The activity of the maize PPDK protein expressed in rice leaves was light/dark regulated as it is in maize. This is the first reported evidence for the presence of an endogenous PPDK regulatory protein in a C(3) plant.

In vivo bone regeneration with injectable chitosan/hydroxyapatite/collagen composites and mesenchymal stem cells

NASA Astrophysics Data System (ADS)

Huang, Zhi; Chen, Yan; Feng, Qing-Ling; Zhao, Wei; Yu, Bo; Tian, Jing; Li, Song-Jian; Lin, Bo-Miao

2011-09-01

For reconstruction of irregular bone defects, injectable biomaterials are more appropriate than the preformed biomaterials. We herein develop a biomimetic in situ-forming composite consisting of chitosan (CS) and mineralized collagen fibrils (nHAC), which has a complex hierarchical structure similar to natural bone. The CS/nHAC composites with or without mesenchymal stem cells (MSCs) are injected into cancellous bone defects at the distal end of rabbit femurs. Defects are assessed by radiographic, histological diagnosis and Raman microscopy until 12 weeks. The results show that MSCs improve the biocompatibility of CS/nHAC composites and enhance new bone formation in vivo at 12 weeks. It can be concluded that the injectable CS/nHAC composites combined with MSCs may be a novel method for reconstruction of irregular bone defects.

Comparative evaluation of the sperm characteristics and morphology of adult Wistar rats fed either low or normal protein-energy diets and orally dosed with aqueous Cuscuta australis extracts.

PubMed

Omirinde, J O; Ozegbe, P C; Oyeyemi, M O

2014-06-19

Cuscuta australis (C. australis) seed and stem are commonly used as dietary supplements in a maize-meal, "Ogi", by the local population for the management of male and female reproductive dysfunctions. This study, as a part of on-going efforts, therefore, evaluated and compared the effects of Low Protein-energy (LP) and Normal Protein-energy (NP) diets on the sperm morphology and characteristics of adult Wistar rats orally dosed aqueous extracts of C. australis seed (LPSE and NPSE) and stem (LPST and NPST), 300 mg of extract/kg body weight of rat/day, for seven days. The control groups (LPWA and NPWA) received vehicle, water. Live-dead ratio and percentage of sperms with curved tail were significantly decreased (p<0.01) in the NPST relative to the NPWA, LPWA, LPST, NPSE and LPSE. Total abnormal sperm counts, acephalic sperms and tailless head sperms were significantly decreased (p<0.001, p<0.05 and p<0.001, respectively) in the LPST and NPST relative to LPSE, NPSE, LPWA and NPWA. The LPSE, LPST and NPST showed significantly decreased (p<0.05) percentages of sperms with either bent mid-piece or curved mid-piece relative to the LPWA. Significantly decreased (p<0.05) percentage of sperms with curved mid-piece was also observed in the NPSE relative to LPWA. Protein-energy diet significantly influenced (at least p<0.05) the effect of each extract on sperm motility and percentage of sperms with curved tail. Stem extract significantly decreased (p<0.01) the percentages of acephalic sperms and tailless head sperms. Diet-stem extract interaction significantly influenced (p<0.05) live-dead ratio. Our data suggest that orally administered aqueous extracts of C. australis generally enhanced the sperm morphology and characteristics of the male Wistar rat and that the stem extract maintained sperm morphology better than the seed extract. It also showed that the stem extract decreased live-dead ratio and that the efficacy of orally administered aqueous C. australis stem extract may be affected by variations in dietary protein-energy levels.

Mechanical properties and solubility in water of corn starch-collagen composite films: Effect of starch type and concentrations.

PubMed

Wang, Kun; Wang, Wenhang; Ye, Ran; Liu, Anjun; Xiao, Jingdong; Liu, Yaowei; Zhao, Yana

2017-02-01

This study investigated the possibility of enhancing the properties of collagen with three different maize starches: waxy maize starch, normal starch, and high amylose starch. Scanning electron microscopy images revealed that starch-collagen films had a rougher surface compared to pure collagen films which became smoother upon heating. Amylose starch and normal starch increased the tensile strength of unheated collagen films in both dry and wet states, while all starches increased tensile strength of collagen film by heating. Depending upon the amylose content and starch concentrations, film solubility in water decreased with the addition of starch. DSC thermograms demonstrated that addition of all starches improved the thermal stability of the collagen film. Moreover, X-ray diffraction results indicated that except for high amylose starch, the crystallinity of both starch and collagen was significantly decreased when subject to heating. FTIR spectra indicated that intermolecular interactions between starch and collagen were enhanced upon heating. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Nitrogen status diagnosis and yield prediction of spring maize after green manure incorporation by using a digital camera].

PubMed

Bai, Jin-Shun; Cao, Wei-Dong; Xiong, Jing; Zeng, Nao-Hua; Shimizu, Katshyoshi; Rui, Yu-Kui

2013-12-01

In order to explore the feasibility of using the image processing technology to diagnose the nitrogen status and to predict the maize yield, a field experiment with different nitrogen rates with green manure incorporation was conducted. Maize canopy digital images over a range of growth stages were captured by digital camera. Maize nitrogen status and the relationships between image color indices derived by digital camera for maize at different growth stages and maize nitrogen status indicators were analyzed. These digital camera sourced image color indices at different growth stages for maize were also regressed with maize grain yield at maturity. The results showed that the plant nitrogen status for maize was improved by green manure application. The leaf chlorophyll content (SPAD value), aboveground biomass and nitrogen uptake for green manure treatments at different maize growth stages were all higher than that for chemical fertilization treatments. The correlations between spectral indices with plant nitrogen indicators for maize affected by green manure application were weaker than that affected by chemical fertilization. And the correlation coefficients for green manure application were ranged with the maize growth stages changes. The best spectral indices for diagnosis of plant nitrogen status after green manure incorporation were normalized blue value (B/(R+G+B)) at 12-leaf (V12) stage and normalized red value (R/(R+G+B)) at grain-filling (R4) stage individually. The coefficients of determination based on linear regression were 0. 45 and 0. 46 for B/(R+G+B) at V12 stage and R/(R+G+B) at R4 stage respectively, acting as a predictor of maize yield response to nitrogen affected by green manure incorporation. Our findings suggested that digital image technique could be a potential tool for in-season prediction of the nitrogen status and grain yield for maize after green manure incorporation when the suitable growth stages and spectral indices for diagnosis were selected.

Comparative diversity of arthropods on Bt maize and non-Bt maize in two different cropping systems in South Africa.

PubMed

Truter, J; Van Hamburg, H; Van Den Berg, J

2014-02-01

The biodiversity of an agroecosystem is not only important for its intrinsic value but also because it influences ecological functions that are vital for crop production in sustainable agricultural systems and the surrounding environment. A concern about genetically modified (GM) crops is the potential negative impact that such crops could have on diversity and abundance of nontarget organisms, and subsequently on ecosystem functions. Therefore, it is essential to assess the potential environmental risk of the release of a GM crop and to study its effect on species assemblages within that ecosystem. Assessment of the impact of Bt maize on the environment is hampered by the lack of basic checklists of species present in maize agroecosystems. The aims of the study were to compile a checklist of arthropods that occur on maize in South Africa and to compare the diversity and abundance of arthropods and functional groups on Bt maize and non-Bt maize. Collections of arthropods were carried out during two growing seasons on Bt maize and non-Bt maize plants at two localities. Three maize fields were sampled per locality during each season. Twenty plants, each of Bt maize and non-Bt maize, were randomly selected from the fields at each site. The arthropods collected during this study were classified to morphospecies level and grouped into the following functional groups: detritivores, herbivores, predators, and parasitoids. Based on feeding strategy, herbivores and predators were further divided into sucking herbivores or predators (piercing-sucking mouthparts) and chewing herbivores or predators (chewing mouthparts). A total of 8,771 arthropod individuals, comprising 288 morphospecies and presenting 20 orders, were collected. Results from this short-term study indicated that abundance and diversity of arthropods in maize and the different functional guilds were not significantly affected by Bt maize, either in terms of diversity or abundance.

Transcript Profiling of Two Alfalfa Genotypes with Contrasting Cell Wall Composition in Stems Using a Cross-Species Platform: Optimizing Analysis by Masking Biased Probes

USDA-ARS?s Scientific Manuscript database

The stem cell walls of alfalfa [Medicago sativa (L.) ssp. sativa] genotype 252 have high cellulose and lignin concentrations, while stem cell walls of genotype 1283 have low cellulose and lignin concentrations. The GeneChip® Medicago Genome Array, developed for Medicago truncatula, is a suitable pla...

Radiological study on newly developed composite corn advance lines in Malaysia

NASA Astrophysics Data System (ADS)

Adekunle Olatunji, Michael; Bemigho Uwatse, Onosohwo; Uddin Khandaker, Mayeen; Amin, Y. M.; Faruq, G.

2014-12-01

Owing to population growth, there has been high demand for food across the world, and hence, different agricultural activities such as use of phosphate fertilizers, recycling of organic matters, etc, have been deployed to increase crop yields. In Malaysia, a total of nine composite corn advance lines have been developed at the Institute of Biological Sciences, University of Malaya and are being grown under different conditions with a bid to meet the average daily human need for energy and fiber intake. To this end, the knowledge of radioactivity levels in these corn advance lines are of paramount importance for the estimation of possible radiological hazards due to its consumption. Hence, the radioactivity concentrations of 226Ra, 228Ra and 40K in the corn have been determined using HPGe γ-ray spectrometry. The activity concentrations in the corn ranged from 0.05 to 19.18 Bq kg-1 for 226Ra, from 0.10 to 3.22 Bq kg-1 for 228Ra and from 26.4 to 129 Bq kg-1 for 40K. In order to ascertain the radiological safety of the population regarding maize consumption, the daily intakes of these radionuclides as well as the annual effective dose were estimated. The total effective dose obtained due to the ingestion of radionuclides via maize consumption is 15.39 μSv y-1, which is less than the international recommendations.

High Density Linkage Map Construction and Mapping of Yield Trait QTLs in Maize (Zea mays) Using the Genotyping-by-Sequencing (GBS) Technology

PubMed Central

Su, Chengfu; Wang, Wei; Gong, Shunliang; Zuo, Jinghui; Li, Shujiang; Xu, Shizhong

2017-01-01

Increasing grain yield is the ultimate goal for maize breeding. High resolution quantitative trait loci (QTL) mapping can help us understand the molecular basis of phenotypic variation of yield and thus facilitate marker assisted breeding. The aim of this study is to use genotyping-by-sequencing (GBS) for large-scale SNP discovery and simultaneous genotyping of all F2 individuals from a cross between two varieties of maize that are in clear contrast in yield and related traits. A set of 199 F2 progeny derived from the cross of varieties SG-5 and SG-7 were generated and genotyped by GBS. A total of 1,046,524,604 reads with an average of 5,258,918 reads per F2 individual were generated. This number of reads represents an approximately 0.36-fold coverage of the maize reference genome Zea_mays.AGPv3.29 for each F2 individual. A total of 68,882 raw SNPs were discovered in the F2 population, which, after stringent filtering, led to a total of 29,927 high quality SNPs. Comparative analysis using these physically mapped marker loci revealed a higher degree of synteny with the reference genome. The SNP genotype data were utilized to construct an intra-specific genetic linkage map of maize consisting of 3,305 bins on 10 linkage groups spanning 2,236.66 cM at an average distance of 0.68 cM between consecutive markers. From this map, we identified 28 QTLs associated with yield traits (100-kernel weight, ear length, ear diameter, cob diameter, kernel row number, corn grains per row, ear weight, and grain weight per plant) using the composite interval mapping (CIM) method and 29 QTLs using the least absolute shrinkage selection operator (LASSO) method. QTLs identified by the CIM method account for 6.4% to 19.7% of the phenotypic variation. Small intervals of three QTLs (qCGR-1, qKW-2, and qGWP-4) contain several genes, including one gene (GRMZM2G139872) encoding the F-box protein, three genes (GRMZM2G180811, GRMZM5G828139, and GRMZM5G873194) encoding the WD40-repeat protein, and one gene (GRMZM2G019183) encoding the UDP-Glycosyltransferase. The work will not only help to understand the mechanisms that control yield traits of maize, but also provide a basis for marker-assisted selection and map-based cloning in further studies. PMID:28533786

[Effects of reduced N application rate on yield and nutrient uptake and utilization in maize-soybean relay strip intercropping system].

PubMed

Yong, Tai-Wen; Liu, Xiao-Ming; Wen-Yu, Liu; Su, Ben-Ying; Song, Chun; Yang, Feng; Wang, Xiao-Chun; Yang, Wen-Yu

2014-02-01

A field experiment with three N application rates (0, 180, 240 N kg x hm(-2), representing zero, reduced and conventional N application, respectively) and three planting patterns (maize monoculture, soybean monoculture and maize-soybean relay strip intercropping) was conducted to reveal the effects of cropping patterns and N application rates on yield, nutrient uptake and nitrogen use efficiency of maize and soybean. The results showed that the grain yield, N, P and K uptake and harvest index of the intercropped maize reduced slightly compared with the monoculture maize, however these indices of the intercropped soybean increased significantly compared with the monoculture. With the increase in nitrogen fertilizer application, the excellence of relay strip intercropping was weakened in the maize-soybean intercropping system. The grain yield, economic coefficient, N, P and K uptake, harvest index, N agronomy efficiency and N uptake efficiency of maize and soybean increased significantly at the reduced nitrogen rate (180 N kg x hm(-2)), but the rate of soil N contribution declined, compared with the conventional rate of N application by local farmers (240 N kg x hm(-2)). In the reduced nitrogen rate treatment, total soil N and P contents of the maize strip reduced, whereas the total soil N, P and K contents of soybean strip and the total K content of maize strip increased compared with the zero N application treatment. With the reduced N application, the annual total grain yield, N, P and K uptake of above-ground biomass in the maize-soybean relay strip intercropping system were higher than in the monoculture, and the land equivalent ratio (LER) was 2.28. N uptake efficiency of maize in the relay strip intercropping system was 20.2% higher than in the maize monoculture, and the index of soybean was 30.5% lower than in the monoculture. The rate of soil N contribution in the relay strip intercropping system was 20.0% and 8.8% lower than in the maize and soybean monoculture, respectively. The reduced N application in the maize-soybean relay strip intercropping system was helpful to promote annual grain yield and improve N utilization efficiency.

Life-History Traits of Spodoptera frugiperda Populations Exposed to Low-Dose Bt Maize

PubMed Central

Sousa, Fernanda F.; Mendes, Simone M.; Santos-Amaya, Oscar F.; Araújo, Octávio G.; Oliveira, Eugenio E.

2016-01-01

Exposure to Bacillus thuringiensis (Bt) toxins in low- and moderate-dose transgenic crops may induce sublethal effects and increase the rate of Bt resistance evolution, potentially compromising control efficacy against target pests. We tested this hypothesis using the fall armyworm Spodoptera frugiperda, a major polyphagous lepidopteran pest relatively tolerant to Bt notorious for evolving field-relevant resistance to single-gene Bt maize. Late-instar larvae were collected from Bt Cry1Ab and non-Bt maize fields in five locations in Brazil, and their offspring was compared for survival, development, and population growth in rearing environment without and with Cry1Ab throughout larval development. Larval survival on Cry1Ab maize leaves varied from 20 to 80% among the populations. Larvae reared on Cry1Ab maize had seven-day delay in development time in relation to control larvae, and such delay was shorter in offspring of armyworms from Cry1Ab maize. Population growth rates were 50–70% lower for insects continuously exposed to Cry1Ab maize relative to controls, showing the population-level effect of Cry1Ab, which varied among the populations and prior exposure to Cry1Ab maize in the field. In three out of five populations, armyworms derived from Bt maize reared on Cry1Ab maize showed higher larval weight, faster larval development and better reproductive performance than the armyworms derived from non-Bt maize, and one of these populations showed better performance on both Cry1Ab and control diets, indicating no fitness cost of the resistance trait. Altogether, these results indicate that offspring of armyworms that developed on field-grown, single-gene Bt Cry1Ab maize had reduced performance on Cry1Ab maize foliage in two populations studied, but in other three populations, these offspring had better overall performance on the Bt maize foliage than that of the armyworms from non-Bt maize fields, possibly because of Cry1Ab resistance alleles in these populations. Implications of these findings for resistance management of S. frugiperda in Bt crops are discussed. PMID:27243977

Life-History Traits of Spodoptera frugiperda Populations Exposed to Low-Dose Bt Maize.

PubMed

Sousa, Fernanda F; Mendes, Simone M; Santos-Amaya, Oscar F; Araújo, Octávio G; Oliveira, Eugenio E; Pereira, Eliseu J G

2016-01-01

Exposure to Bacillus thuringiensis (Bt) toxins in low- and moderate-dose transgenic crops may induce sublethal effects and increase the rate of Bt resistance evolution, potentially compromising control efficacy against target pests. We tested this hypothesis using the fall armyworm Spodoptera frugiperda, a major polyphagous lepidopteran pest relatively tolerant to Bt notorious for evolving field-relevant resistance to single-gene Bt maize. Late-instar larvae were collected from Bt Cry1Ab and non-Bt maize fields in five locations in Brazil, and their offspring was compared for survival, development, and population growth in rearing environment without and with Cry1Ab throughout larval development. Larval survival on Cry1Ab maize leaves varied from 20 to 80% among the populations. Larvae reared on Cry1Ab maize had seven-day delay in development time in relation to control larvae, and such delay was shorter in offspring of armyworms from Cry1Ab maize. Population growth rates were 50-70% lower for insects continuously exposed to Cry1Ab maize relative to controls, showing the population-level effect of Cry1Ab, which varied among the populations and prior exposure to Cry1Ab maize in the field. In three out of five populations, armyworms derived from Bt maize reared on Cry1Ab maize showed higher larval weight, faster larval development and better reproductive performance than the armyworms derived from non-Bt maize, and one of these populations showed better performance on both Cry1Ab and control diets, indicating no fitness cost of the resistance trait. Altogether, these results indicate that offspring of armyworms that developed on field-grown, single-gene Bt Cry1Ab maize had reduced performance on Cry1Ab maize foliage in two populations studied, but in other three populations, these offspring had better overall performance on the Bt maize foliage than that of the armyworms from non-Bt maize fields, possibly because of Cry1Ab resistance alleles in these populations. Implications of these findings for resistance management of S. frugiperda in Bt crops are discussed.

Row Ratios of Intercropping Maize and Soybean Can Affect Agronomic Efficiency of the System and Subsequent Wheat

PubMed Central

Zhang, Yitao; Liu, Jian; Zhang, Jizong; Liu, Hongbin; Liu, Shen; Zhai, Limei; Wang, Hongyuan; Lei, Qiuliang; Ren, Tianzhi; Yin, Changbin

2015-01-01

Intercropping is regarded as an important agricultural practice to improve crop production and environmental quality in the regions with intensive agricultural production, e.g., northern China. To optimize agronomic advantage of maize (Zea mays L.) and soybean (Glycine max L.) intercropping system compared to monoculture of maize, two sequential experiments were conducted. Experiment 1 was to screening the optimal cropping system in summer that had the highest yields and economic benefits, and Experiment 2 was to identify the optimum row ratio of the intercrops selected from Experiment 1. Results of Experiment 1 showed that maize intercropping with soybean (maize || soybean) was the optimal cropping system in summer. Compared to conventional monoculture of maize, maize || soybean had significant advantage in yield, economy, land utilization ratio and reducing soil nitrate nitrogen (N) accumulation, as well as better residual effect on the subsequent wheat (Triticum aestivum L.) crop. Experiment 2 showed that intercropping systems reduced use of N fertilizer per unit land area and increased relative biomass of intercropped maize, due to promoted photosynthetic efficiency of border rows and N utilization during symbiotic period. Intercropping advantage began to emerge at tasseling stage after N topdressing for maize. Among all treatments with different row ratios, alternating four maize rows with six soybean rows (4M:6S) had the largest land equivalent ratio (1.30), total N accumulation in crops (258 kg ha-1), and economic benefit (3,408 USD ha-1). Compared to maize monoculture, 4M:6S had significantly lower nitrate-N accumulation in soil both after harvest of maize and after harvest of the subsequent wheat, but it did not decrease yield of wheat. The most important advantage of 4M:6S was to increase biomass of intercropped maize and soybean, which further led to the increase of total N accumulation by crops as well as economic benefit. In conclusion, alternating four maize rows with six soybean rows was the optimum row ratio in maize || soybean system, though this needs to be further confirmed by pluri-annual trials. PMID:26061566

Aflatoxin Regulations in a Network of Global Maize Trade

PubMed Central

Wu, Felicia; Guclu, Hasan

2012-01-01

Worldwide, food supplies often contain unavoidable contaminants, many of which adversely affect health and hence are subject to regulations of maximum tolerable levels in food. These regulations differ from nation to nation, and may affect patterns of food trade. We soughtto determine whether there is an association between nations' food safety regulations and global food trade patterns, with implications for public health and policymaking. We developed a network model of maize trade around the world. From maize import/export data for 217 nations from 2000–2009, we calculated basic statistics on volumes of trade; then examined how regulations of aflatoxin, a common contaminant of maize, are similar or different between pairs of nations engaging in significant amounts of maize trade. Globally, market segregation appears to occur among clusters of nations. The United States is at the center of one cluster; European countries make up another cluster with hardly any maize trade with the US; and Argentina, Brazil, and China export maize all over the world. Pairs of nations trading large amounts of maize have very similar aflatoxin regulations: nations with strict standards tend to trade maize with each other, while nations with more relaxed standards tend to trade maize with each other. Rarely among the top pairs of maize-trading nations do total aflatoxin standards (standards based on the sum of the levels of aflatoxins B1, B2, G1, and G2) differ by more than 5 µg/kg. These results suggest that, globally, separate maize trading communities emerge; and nations tend to trade with other nations that have very similar food safety standards. PMID:23049773

Early competition shapes maize whole-plant development in mixed stands

PubMed Central

Evers, Jochem B.

2014-01-01

Mixed cropping is practised widely in developing countries and is gaining increasing interest for sustainable agriculture in developed countries. Plants in intercrops grow differently from plants in single crops, due to interspecific plant interactions, but adaptive plant morphological responses to competition in mixed stands have not been studied in detail. Here the maize (Zea mays) response to mixed cultivation with wheat (Triticum aestivum) is described. Evidence is provided that early responses of maize to the modified light environment in mixed stands propagate throughout maize development, resulting in different phenotypes compared with pure stands. Photosynthetically active radiation (PAR), red:far-red ratio (R:FR), leaf development, and final organ sizes of maize grown in three cultivation systems were compared: pure maize, an intercrop with a small distance (25cm) between maize and wheat plants, and an intercop with a large distance (44cm) between the maize and the wheat. Compared with maize in pure stands, maize in the mixed stands had lower leaf and collar appearance rates, increased blade and sheath lengths at low ranks and smaller sizes at high ranks, increased blade elongation duration, and decreased R:FR and PAR at the plant base during early development. Effects were strongest in the treatment with a short distance between wheat and maize strips. The data suggest a feedback between leaf initiation and leaf emergence at the plant level and coordination between blade and sheath growth at the phytomer level. A conceptual model, based on coordination rules, is proposed to explain the development of the maize plant in pure and mixed stands. PMID:24307719

Maize databases

USDA-ARS?s Scientific Manuscript database

This chapter is a succinct overview of maize data held in the species-specific database MaizeGDB (the Maize Genomics and Genetics Database), and selected multi-species data repositories, such as Gramene/Ensembl Plants, Phytozome, UniProt and the National Center for Biotechnology Information (NCBI), ...

Maize flour fortification in Africa: markets, feasibility, coverage, and costs.

PubMed

Fiedler, John L; Afidra, Ronald; Mugambi, Gladys; Tehinse, John; Kabaghe, Gladys; Zulu, Rodah; Lividini, Keith; Smitz, Marc-Francois; Jallier, Vincent; Guyondet, Christophe; Bermudez, Odilia

2014-04-01

The economic feasibility of maize flour and maize meal fortification in Kenya, Uganda, and Zambia is assessed using information about the maize milling industry, households' purchases and consumption levels of maize flour, and the incremental cost and estimated price impacts of fortification. Premix costs comprise the overwhelming share of incremental fortification costs and vary by 50% in Kenya and by more than 100% across the three countries. The estimated incremental cost of maize flour fortification per metric ton varies from $3.19 in Zambia to $4.41 in Uganda. Assuming all incremental costs are passed onto the consumer, fortification in Zambia would result in at most a 0.9% increase in the price of maize flour, and would increase annual outlays of the average maize flour-consuming household by 0.2%. The increases for Kenyans and Ugandans would be even less. Although the coverage of maize flour fortification is not likely to be as high as some advocates have predicted, fortification is economically feasible, and would reduce deficiencies of multiple micronutrients, which are significant public health problems in each of these countries. © 2013 New York Academy of Sciences.

Contributions of Zea mays subspecies mexicana haplotypes to modern maize.

PubMed

Yang, Ning; Xu, Xi-Wen; Wang, Rui-Ru; Peng, Wen-Lei; Cai, Lichun; Song, Jia-Ming; Li, Wenqiang; Luo, Xin; Niu, Luyao; Wang, Yuebin; Jin, Min; Chen, Lu; Luo, Jingyun; Deng, Min; Wang, Long; Pan, Qingchun; Liu, Feng; Jackson, David; Yang, Xiaohong; Chen, Ling-Ling; Yan, Jianbing

2017-11-30

Maize was domesticated from lowland teosinte (Zea mays ssp. parviglumis), but the contribution of highland teosinte (Zea mays ssp. mexicana, hereafter mexicana) to modern maize is not clear. Here, two genomes for Mo17 (a modern maize inbred) and mexicana are assembled using a meta-assembly strategy after sequencing of 10 lines derived from a maize-teosinte cross. Comparative analyses reveal a high level of diversity between Mo17, B73, and mexicana, including three Mb-size structural rearrangements. The maize spontaneous mutation rate is estimated to be 2.17 × 10 -8 ~3.87 × 10 -8 per site per generation with a nonrandom distribution across the genome. A higher deleterious mutation rate is observed in the pericentromeric regions, and might be caused by differences in recombination frequency. Over 10% of the maize genome shows evidence of introgression from the mexicana genome, suggesting that mexicana contributed to maize adaptation and improvement. Our data offer a rich resource for constructing the pan-genome of Zea mays and genetic improvement of modern maize varieties.

Evaluation of multi-scale mineralized collagen-polycaprolactone composites for bone tissue engineering.

PubMed

Weisgerber, D W; Erning, K; Flanagan, C L; Hollister, S J; Harley, B A C

2016-08-01

A particular challenge in biomaterial development for treating orthopedic injuries stems from the need to balance bioactive design criteria with the mechanical and geometric constraints governed by the physiological wound environment. Such trade-offs are of particular importance in large craniofacial bone defects which arise from both acute trauma and chronic conditions. Ongoing efforts in our laboratory have demonstrated a mineralized collagen biomaterial that can promote human mesenchymal stem cell osteogenesis in the absence of osteogenic media but that possesses suboptimal mechanical properties in regards to use in loaded wound sites. Here we demonstrate a multi-scale composite consisting of a highly bioactive mineralized collagen-glycosaminoglycan scaffold with micron-scale porosity and a polycaprolactone support frame (PCL) with millimeter-scale porosity. Fabrication of the composite was performed by impregnating the PCL support frame with the mineral scaffold precursor suspension prior to lyophilization. Here we evaluate the mechanical properties, permeability, and bioactivity of the resulting composite. Results indicated that the PCL support frame dominates the bulk mechanical response of the composite resulting in a 6000-fold increase in modulus compared to the mineral scaffold alone. Similarly, the incorporation of the mineral scaffold matrix into the composite resulted in a higher specific surface area compared to the PCL frame alone. The increased specific surface area in the collagen-PCL composite promoted increased initial attachment of porcine adipose derived stem cells versus the PCL construct. Copyright © 2016 Elsevier Ltd. All rights reserved.

78 FR 21603 - Change in Bank Control Notices; Acquisitions of Shares of a Bank or Bank Holding Company

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-11

..., LP, Mexicio City, Mexico and Rogelio Barrenechea Banzalez, Mexico City, Mexico; Constructora Maiz Mier, S.A. de C.V, Jose Sebastian Maiz Garcia, Carlos Francisco Maiz Garcia and Ricardo Javier Maiz...

MaizeCyc: Metabolic networks in maize

USDA-ARS?s Scientific Manuscript database

MaizeCyc is a catalog of known and predicted metabolic and transport pathways that enables plant researchers to graphically represent the metabolome of maize (Zea mays), thereby supporting integrated systems-biology analysis. Supported analyses include molecular and genetic/phenotypic profiling (e.g...

Field trials to evaluate the effects of transgenic cry1le maize on the community characteristics of arthropod natural enemies

USDA-ARS?s Scientific Manuscript database

Possible non-target effects of transgenic cry1Ie gene maize exerts on natural enemy community biodiversity in the field is unresolved. In the present study, a 2-yr study of transgenic cry1Ie gene maize (Event IE09S034, Bt maize) and its near isoline (Zong 31, non-Bt maize) on natural enemy community...

Screening and Selection of Maize to Enhance Associative Bacterial Nitrogen Fixation 1

PubMed Central

Ela, Stephen W.; Anderson, Mary Ann; Brill, Winston J.

1982-01-01

The ability of maize (corn, Zea mays L.) to support bacterial nitrogen fixation in or on maize roots has been increased, through screening and selection. Isotopic N fixed from 15N2 was found on the roots. The nitrogen-fixing association was found in germplasm from tropical maize, but this activity can be transferred to maize currently used in midwestern United States agriculture. PMID:16662718

Alfalfa (Medicago sativa L.)/maize (Zea mays L.) intercropping provides a feasible way to improve yield and economic incomes in farming and pastoral areas of northeast China.

PubMed

Sun, Baoru; Peng, Yi; Yang, Hongyu; Li, Zhijian; Gao, Yingzhi; Wang, Chao; Yan, Yuli; Liu, Yanmei

2014-01-01

Given the growing challenges to food and eco-environmental security as well as sustainable development of animal husbandry in the farming and pastoral areas of northeast China, it is crucial to identify advantageous intercropping modes and some constraints limiting its popularization. In order to assess the performance of various intercropping modes of maize and alfalfa, a field experiment was conducted in a completely randomized block design with five treatments: maize monoculture in even rows, maize monoculture in alternating wide and narrow rows, alfalfa monoculture, maize intercropped with one row of alfalfa in wide rows and maize intercropped with two rows of alfalfa in wide rows. Results demonstrate that maize monoculture in alternating wide and narrow rows performed best for light transmission, grain yield and output value, compared to in even rows. When intercropped, maize intercropped with one row of alfalfa in wide rows was identified as the optimal strategy and the largely complementary ecological niches of alfalfa and maize were shown to account for the intercropping advantages, optimizing resource utilization and improving yield and economic incomes. These findings suggest that alfalfa/maize intercropping has obvious advantages over monoculture and is applicable to the farming and pastoral areas of northeast China.

Determination of carotenoids in yellow maize, the effects of saponification and food preparations.

PubMed

Muzhingi, Tawanda; Yeum, Kyung-Jin; Russell, Robert M; Johnson, Elizabeth J; Qin, Jian; Tang, Guangwen

2008-05-01

Maize is an important staple food consumed by millions of people in many countries. Yellow maize naturally contains carotenoids which not only provide provitamin A carotenoids but also xanthophylls, which are known to be important for eye health. This study was aimed at 1) evaluating the effect of saponification during extraction of yellow maize carotenoids, 2) determining the major carotenoids in 36 genotypes of yellow maize by high-performance liquid chromatography with a C30 column, and 3) determining the effect of cooking on the carotenoid content of yellow maize. The major carotenoids in yellow maize were identified as all-trans lutein, cis-isomers of lutein, all-trans zeaxanthin, alpha- and beta-cryptoxanthin, all-trans beta-carotene, 9-cis beta-carotene, and 13-cis beta-carotene. Our results indicated that carotenoid extraction without saponification showed a significantly higher yield than that obtained using saponification. Results of the current study indicate that yellow maize is a good source of provitamin A carotenoids and xanthophylls. Cooking by boiling yellow maize at 100 degrees C for 30 minutes increased the carotenoid concentration, while baking at 450 degrees F for 25 minutes decreased the carotenoid concentrations by almost 70% as compared to the uncooked yellow maize flour.

Alfalfa (Medicago sativa L.)/Maize (Zea mays L.) Intercropping Provides a Feasible Way to Improve Yield and Economic Incomes in Farming and Pastoral Areas of Northeast China

PubMed Central

Sun, Baoru; Peng, Yi; Yang, Hongyu; Li, Zhijian; Gao, Yingzhi; Wang, Chao; Yan, Yuli; Liu, Yanmei

2014-01-01

Given the growing challenges to food and eco-environmental security as well as sustainable development of animal husbandry in the farming and pastoral areas of northeast China, it is crucial to identify advantageous intercropping modes and some constraints limiting its popularization. In order to assess the performance of various intercropping modes of maize and alfalfa, a field experiment was conducted in a completely randomized block design with five treatments: maize monoculture in even rows, maize monoculture in alternating wide and narrow rows, alfalfa monoculture, maize intercropped with one row of alfalfa in wide rows and maize intercropped with two rows of alfalfa in wide rows. Results demonstrate that maize monoculture in alternating wide and narrow rows performed best for light transmission, grain yield and output value, compared to in even rows. When intercropped, maize intercropped with one row of alfalfa in wide rows was identified as the optimal strategy and the largely complementary ecological niches of alfalfa and maize were shown to account for the intercropping advantages, optimizing resource utilization and improving yield and economic incomes. These findings suggest that alfalfa/maize intercropping has obvious advantages over monoculture and is applicable to the farming and pastoral areas of northeast China. PMID:25329376

Prevalence of genetically modified rice, maize, and soy in Saudi food products.

PubMed

Elsanhoty, Rafaat M; Al-Turki, A I; Ramadan, Mohamed Fawzy

2013-10-01

Qualitative and quantitative DNA-based methods were applied to detect genetically modified foods in samples from markets in the Kingdom of Saudi Arabia. Two hundred samples were collected from Al-Qassim, Riyadh, and Mahdina in 2009 and 2010. GMOScreen 35S and NOS test kits for the detection of genetically modified organism varieties in samples were used. The positive results obtained from GMOScreen 35S and NOS were identified using specific primer pairs. The results indicated that all rice samples gave negative results for the presence of 35S and NOS terminator. About 26 % of samples containing soybean were positive for 35S and NOS terminator and 44 % of samples containing maize were positive for the presence of 35S and/or NOS terminator. The results showed that 20.4 % of samples was positive for maize line Bt176, 8.8 % was positive for maize line Bt11, 8.8 % was positive for maize line T25, 5.9 % was positive for maize line MON 810, and 5.9 % was positive for StarLink maize. Twelve samples were shown to contain <3 % of genetically modified (GM) soy and 6 samples >10 % of GM soy. Four samples containing GM maize were shown to contain >5 % of GM maize MON 810. Four samples containing GM maize were shown to contain >1 % of StarLink maize. Establishing strong regulations and certified laboratories to monitor GM foods or crops in Saudi market is recommended.

A laboratory assessment of the potential effect of Cry1Ab/Cry2Aj-containing Bt maize pollen on Folsomia candida by toxicological and biochemical analyses.

PubMed

Zhang, Bing; Yang, Yan; Zhou, Xiang; Shen, Ping; Peng, Yufa; Li, Yunhe

2017-03-01

The common soil arthropod Folsomia candida can survive well when fed only maize pollen and thus may be exposed to insecticidal proteins by ingesting insect-resistant genetically engineered maize pollen containing Bacillus thuringiensis (Bt) proteins when being released into the soil. Laboratory experiments were conducted to assess the potential effects of Cry1Ab/Cry2Aj-producing transgenic Bt maize (Shuangkang 12-5) pollen on F. candida fitness. Survival, development, and the reproduction were not significantly reduced when F. candida fed on Bt maize pollen rather than on non-Bt maize pollen, but these parameters were significantly reduced when F. candida fed on non-Bt maize pollen containing the protease inhibitor E-64 at 75 μg/g pollen. The intrinsic rate of increase (r m ) was not significantly reduced when F. candida fed on Bt maize pollen but was significantly reduced when F. candida fed on non-Bt maize pollen containing E-64. The activities of antioxidant-related enzymes in F. candida were not significantly affected when F. candida fed on Bt maize pollen but were significantly increased when F. candida fed on non-Bt pollen containing E-64. The results demonstrate that consumption of Bt maize pollen containing Cry1Ab/Cry2Aj has no lethal or sublethal effects on F. candida. Copyright © 2017 Elsevier Ltd. All rights reserved.

Resistance of Tripsacorn-introgressed maize lines to Sitophilus zeamais

USDA-ARS?s Scientific Manuscript database

The maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), is one of the major pests of maize worldwide. We tested one Tripsacorn-introgressed inbred maize line and 42 hybrid combinations between eleven public inbred lines and 16 different Tripsacorn-introgressed inbreds for resis...

MaizeGDB: The Maize Genetics and Genomics Database.

USDA-ARS?s Scientific Manuscript database

MaizeGDB is the community database for biological information about the crop plant Zea mays. Genomic, genetic, sequence, gene product, functional characterization, literature reference, and person/organization contact information are among the datatypes stored at MaizeGDB. At the project’s website...

Formation of an ascorbate-apatite composite layer on titanium.

PubMed

Ito, Atsuo; Sogo, Yu; Ebihara, Yuko; Onoguchi, Masahiro; Oyane, Ayako; Ichinose, Noboru

2007-09-01

An ascorbate-apatite composite layer was successfully formed on NaOH- and heat-treated titanium by coprecipitating L-ascorbic acid phosphate and low-crystalline apatite in a supersaturated calcium phosphate solution at 37 degrees C for 48 h. The supersaturated calcium phosphate solutions used have chemical compositions attainable by mixing infusion fluids officially approved for clinical use. The amount of immobilized L-ascorbic acid phosphate ranged from 1.0 to 2.3 microg mm(-2), which is most likely to be sufficient for the in vitro osteogenic differentiation of mesenchymal stem cells on titanium. Since ascorbate is important for the collagen synthesis and subsequent osteogenesis of mesenchymal stem cells, titanium coated with the ascorbate-apatite composite layer would be useful as a scaffold in bone tissue engineering and as a bone substitute.

Novel and lost forests in the Upper Midwestern United States, from new estimates of settlement-era composition, stem density, and biomass

USGS Publications Warehouse

Goring, Simon; Mladenoff, David J.; Cogbill, Charles; Record, Sydne; Paciorek, Christopher J.; Dietze, Michael C.; Dawson, Andria; Matthes, Jaclyn; McLachlan, Jason S.; Williams, John W.

2016-01-01

EuroAmerican land-use and its legacies have transformed forest structure and composition across the United States (US). More accurate reconstructions of historical states are critical to understanding the processes governing past, current, and future forest dynamics. Here we present new gridded (8x8km) reconstructions of pre-settlement (1800s) forest composition and structure from the upper Midwestern US (Minnesota, Wisconsin, and most of Michigan), using 19th Century Public Land Survey System (PLSS), with estimates of relative composition, above-ground biomass, stem density, and basal area for 28 tree types. This mapping is more robust than past efforts, using spatially varying correction factors to accommodate sampling design, azimuthal censoring, and biases in tree selection.

Genetic Mapping of the Leaf Number above the Primary Ear and Its Relationship with Plant Height and Flowering Time in Maize.

PubMed

Cui, Min; Jia, Bo; Liu, Huanhuan; Kan, Xin; Zhang, Yu; Zhou, Ronghua; Li, Zhipeng; Yang, Liang; Deng, Dexiang; Yin, Zhitong

2017-01-01

The leaf number above the primary ear (LA) is a major contributing factor to plant architecture in maize. The yield of leafy maize, which has extra LA compared to normal maize, is higher than normal maize in some regions. One major concern is that increasing LA may be accompanied by increased plant height and/or flowering time. Using an F 2:3 population comprising 192 families derived from a leafy maize line and a normal maize line, an association population comprising 437 inbred maize lines, and a pair of near-isogenic maize lines, we mapped the quantitative trait loci (QTL) associated with LA and assessed its genetic relationship with flowering time and plant height. Ten QTL with an additive and dominant effect, 18 pairs of interacting QTL in the F 2:3 population and seventeen significant SNPs in the association population were detected for LA. Two major QTL, qLA3-4 and qLA7-1 , were repeatedly detected and explained a large proportion of the phenotypic variation. The qLA3-4 was centered on lfy1 , which is a dominant gene underlying extra leaves above the ear in leafy maize. Four LA QTL were found to overlap with flowering time and/or plant height, which suggested that these QTL might have a pleiotropic effect. The pleiotropy of the lfy1 locus on LA, flowering time and plant height were validated by near-isogenic line analysis. These results enhance our understanding of the genetic architecture affecting maize LA and the development of maize hybrids with increased LA.

Exploring karyotype diversity of Argentinian Guaraní maize landraces: Relationship among South American maize

PubMed Central

Poggio, Lidia

2018-01-01

In Argentina there are two different centers of maize diversity, the Northeastern (NEA) and the Northwestern (NWA) regions of the country. In NEA, morphological studies identified 15 landraces cultivated by the Guaraní communities in Misiones Province. In the present study we analyzed the karyotype diversity of 20 populations of Guaraní maize landraces through classical and molecular cytogenetic analyses. Our results demonstrate significant intra and inter-populational variation in the percentage, number, size, chromosome position and frequencies of the heterochromatic blocks, which are called knobs. Knob sequence analysis (180-bp and TR-1) did not show significant differences among Guaraní populations. B chromosomes were not detected, and abnormal 10 (AB10) chromosomes were found with low frequency (0.1≥f ≤0.40) in six populations. Our results allowed karyotypic characterization of each analyzed population, defining for the first time the chromosomal constitution of maize germplasm from NEA. The multivariate analysis (PCoA and UPGMA) of karyotype parameters allowed the distinction between two populations groups: the Popcorn and the Floury maize populations. These results are in agreement with previously published microsatellite and morphological/phenological studies. Finally, we compared our karyotype results with those previously reported for NWA and Central Region of South America maize. Our data suggest that there are important differences between maize from NEA and NWA at the karyotype level, supporting the hypothesis that there are two pathways of input of South America maize. Our results also confirm the existence of two centers of diversification of Argentinian native maize, NWA and NEA. This work contributes new knowledge about maize diversity, which is relevant for future plans to improve commercial maize, and for conservation of agrobiodiversity. PMID:29879173

Exploring karyotype diversity of Argentinian Guaraní maize landraces: Relationship among South American maize.

PubMed

Realini, María Florencia; Poggio, Lidia; Cámara Hernández, Julián; González, Graciela Esther

2018-01-01

In Argentina there are two different centers of maize diversity, the Northeastern (NEA) and the Northwestern (NWA) regions of the country. In NEA, morphological studies identified 15 landraces cultivated by the Guaraní communities in Misiones Province. In the present study we analyzed the karyotype diversity of 20 populations of Guaraní maize landraces through classical and molecular cytogenetic analyses. Our results demonstrate significant intra and inter-populational variation in the percentage, number, size, chromosome position and frequencies of the heterochromatic blocks, which are called knobs. Knob sequence analysis (180-bp and TR-1) did not show significant differences among Guaraní populations. B chromosomes were not detected, and abnormal 10 (AB10) chromosomes were found with low frequency (0.1≥f ≤0.40) in six populations. Our results allowed karyotypic characterization of each analyzed population, defining for the first time the chromosomal constitution of maize germplasm from NEA. The multivariate analysis (PCoA and UPGMA) of karyotype parameters allowed the distinction between two populations groups: the Popcorn and the Floury maize populations. These results are in agreement with previously published microsatellite and morphological/phenological studies. Finally, we compared our karyotype results with those previously reported for NWA and Central Region of South America maize. Our data suggest that there are important differences between maize from NEA and NWA at the karyotype level, supporting the hypothesis that there are two pathways of input of South America maize. Our results also confirm the existence of two centers of diversification of Argentinian native maize, NWA and NEA. This work contributes new knowledge about maize diversity, which is relevant for future plans to improve commercial maize, and for conservation of agrobiodiversity.

Lack of Detectable Allergenicity in Genetically Modified Maize Containing “Cry” Proteins as Compared to Native Maize Based on In Silico & In Vitro Analysis

PubMed Central

Mathur, Chandni; Kathuria, Pooran C.; Dahiya, Pushpa; Singh, Anand B.

2015-01-01

Background Genetically modified, (GM) crops with potential allergens must be evaluated for safety and endogenous IgE binding pattern compared to native variety, prior to market release. Objective To compare endogenous IgE binding proteins of three GM maize seeds containing Cry 1Ab,1Ac,1C transgenic proteins with non GM maize. Methods An integrated approach of in silico & in vitro methods was employed. Cry proteins were tested for presence of allergen sequence by FASTA in allergen databases. Biochemical assays for maize extracts were performed. Specific IgE (sIgE) and Immunoblot using food sensitized patients sera (n = 39) to non GM and GM maize antigens was performed. Results In silico approaches, confirmed for non sequence similarity of stated transgenic proteins in allergen databases. An insignificant (p> 0.05) variation in protein content between GM and non GM maize was observed. Simulated Gastric Fluid (SGF) revealed reduced number of stable protein fractions in GM then non GM maize which might be due to shift of constituent protein expression. Specific IgE values from patients showed insignificant difference in non GM and GM maize extracts. Five maize sensitized cases, recognized same 7 protein fractions of 88-28 kD as IgE bindng in both GM and non-GM maize, signifying absence of variation. Four of the reported IgE binding proteins were also found to be stable by SGF. Conclusion Cry proteins did not indicate any significant similarity of >35% in allergen databases. Immunoassays also did not identify appreciable differences in endogenous IgE binding in GM and non GM maize. PMID:25706412

Bacterial Diversity and Mycotoxin Reduction During Maize Fermentation (Steeping) for Ogi Production

PubMed Central

Okeke, Chiamaka A.; Ezekiel, Chibundu N.; Nwangburuka, Cyril C.; Sulyok, Michael; Ezeamagu, Cajethan O.; Adeleke, Rasheed A.; Dike, Stanley K.; Krska, Rudolf

2015-01-01

Bacterial diversity and community structure of two maize varieties (white and yellow) during fermentation/steeping for ogi production, and the influence of spontaneous fermentation on mycotoxin reduction in the gruel were studied. A total of 142 bacterial isolates obtained at 24–96 h intervals were preliminarily identified by conventional microbiological methods while 60 selected isolates were clustered into 39 OTUs consisting of 15 species, 10 genera, and 3 phyla by 16S rRNA sequence analysis. Lactic acid bacteria constituted about 63% of all isolated bacteria and the genus Pediococcus dominated (white maize = 84.8%; yellow maize = 74.4%). Pediococcus acidilactici and Lactobacillus paraplantarum were found at all steeping intervals of white and yellow maize, respectively, while P. claussenii was present only at the climax stage of steeping white maize. In both maize varieties, P. pentosaceus was found at 24–72 h. Mycotoxin concentrations (μg/kg) in the unsteeped grains were: white maize (aflatoxin B1 = 0.60; citrinin = 85.8; cyclopiazonic acid = 23.5; fumonisins (B1/B2/B3) = 68.4–483; zearalenone = 3.3) and yellow maize (aflatoxins (B1/B2/M1) = 22.7–513; citrinin = 16,800; cyclopiazonic acid = 247; fumonisins (B1/B2/B3) = 252–1,586; zearalenone = 205). Mycotoxins in both maize varieties were significantly (p < 0.05) reduced across steeping periods. This study reports for the first time: (a) the association of L. paraplantarum, P. acidilactici, and P. claussenii with ogi production from maize, (b) citrinin occurrence in Nigerian maize and ogi, and (c) aflatoxin M1, citrinin and cyclopiazonic acid degradation/loss due to fermentation in traditional cereal-based fermented food. PMID:26697001

The Asian corn borer Ostrinia furnacalis feeding increases the direct and indirect defense of mid-whorl stage commercial maize in the field.

PubMed

Guo, Jingfei; Qi, Jinfeng; He, Kanglai; Wu, Jianqiang; Bai, Shuxiong; Zhang, Tiantao; Zhao, Jiuran; Wang, Zhenying

2018-05-13

The Asian corn borer (Ostrinia furnacalis Guenée) is a destructive pest of maize (Zea mays L.). Despite large-scale commercial maize production, little is known about the defensive responses of field-grown commercial maize to O. furnacalis herbivory, and how these responses result in direct and indirect defense against this pest. To elucidate the maize transcriptome response to O. furnacalis feeding, leaves of maize hybrid Jingke968 were infested with O. furnacalis for 0, 2, 4, 12 and 24 h. O. furnacalis feeding elicited stronger and more rapid changes in the defense-related gene expression (i.e. after 2 h), and more differentially expressed genes (DEGs) were up-regulated than down-regulated at all times post induction (i.e. 2, 4, 12 and 24 h) in the O. furnacalis pre-infested maize plants. KEGG pathway analysis indicated that the DEGs in the O. furnacalis pre-infested maize are involved in benzoxazinoids, phytohormones, volatiles, and other metabolic pathways related to maize resistance to herbivores. In addition, the maize leaves previously infested by O. furnacalis for 24 h showed an obvious inhibition of the subsequent O. furnacalis performance, and maize volatiles induced by O. furnacalis feeding for 24 and 48 h attracted the parasitic wasp, Macrocentrus cingulum Brischke. The increased direct and indirect defenses induced by O. furnacalis feeding were correlated with O. furnacalis-induced phytohormones, benzoxazinoids, and volatiles. Together, our findings provide new insights into how commercial maize orchestrates its transcriptome and metabolome to directly and indirectly defend against O. furnacalis at the mid-whorl stage in the field. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Oat and ryegrass silage for small-scale dairy systems in the highlands of central Mexico.

PubMed

Celis-Alvarez, Maria Danaee; López-González, Felipe; Martínez-García, Carlos Galdino; Estrada-Flores, Julieta Gertrudis; Arriaga-Jordán, Carlos Manuel

2016-08-01

This study investigated the effects of the inclusion of oat-ryegrass silage (ORGS) in combination with maize silage (MSLG) in four treatments: T1 = 100 % ORGS, T2 = 67 % ORGS/33 % MSLG, T3 = 67 % ORGS/33 % MSLG, and T4 = 100 % MSLG to milking cows on continuous grazing with 4.7 kg DM of commercial dairy concentrate 18 % CP. Daily milk yield and composition, live weight, body condition score, and chemical composition of feeds were recorded during the last 4 days of the experimental periods. Feeding costs were calculated by partial budgets. Eight Holstein lactating cows were used in a replicated 4 × 4 Latin square, with 14-day periods. There were no statistical differences (P > 0.05) for milk yield (mean 15.5 ± 5.0 kg/day/cow) or composition (mean milk fat 34.6 ± 4.4 g/kg, protein 32.4 ± 3.1 g/kg, lactose 46.9 ± 1.6 g/kg), milk urea nitrogen (11.3 ± 2.1 mg/dl), live weight (434 ± 38 kg), or body condition score (2.4 ± 0.15). The silage cost of ORGS was 2.5 times higher than MSLG, so the feeding cost in T1 was 26 % higher per kilogram of milk than for T4, with T2 and T3 as intermediates. ORGS can be a substitute to maize silage in the proportions studied, although feeding costs were higher.

Role of HSP101 in the stimulation of nodal root development from the coleoptilar node by light and temperature in maize (Zea mays L.) seedlings.

PubMed

López-Frías, Guillermo; Martínez, Luz María; Ponce, Georgina; Cassab, Gladys I; Nieto-Sotelo, Jorge

2011-08-01

Nodal roots (NRs) constitute the prevalent root system of adult maize plants. NRs emerge from stem nodes located below or above ground, and little is known about their inducing factors. Here, it is shown that precocious development of NRs at the coleoptilar node (NRCNs) occurred in maize seedlings when: (i) dark grown and stimulated by the concurrent action of a single light shock of low intensity white light (2 μmol m(-2) s(-1)) and a single heat shock; (ii) grown under a photoperiod of low intensity light (0.1 μmol m(-2) s(-1)); or (iii) grown in the dark under a thermoperiod (28 °C/34 °C). The light shock effects were synergistic with heat shock and with the photoperiod, whereas the thermoperiodical and photoperiodical effects were additive. Dissection of the primary root or the root cap, to mimic the fatal consequences of severe heat shock, caused negligible effects on NRCN formation, indicating that the shoot is directly involved in perception of the heat shock-inducible signal that triggered NRCN formation. A comparison between hsp101-m5::Mu1/hsp101-m5::Mu1 and Hsp101/Hsp101 seedlings indicated that the heat shock protein 101 (HSP101) chaperone inhibited NRCN formation in the light and in the dark. Stimulation of precocious NRCN formation by light and heat shocks was affected by genetic background and by the stage of seedling development. HSP101 protein levels increased in the coleoptilar node of induced wild-type plants, particularly in the procambial region, where NRCN formation originated. The adaptive relevance of development of NRCNs in response to these environmental cues and hypothetical mechanisms of regulation by HSP101 are discussed. © 2011 The Author(s).

Study Progress on Tissue Culture of Maize Mature Embryo

NASA Astrophysics Data System (ADS)

Wang, Hongzhen; Cheng, Jun; Cheng, Yanping; Zhou, Xioafu

It has been paid more and more attention on maize tissue culture as it is a basic work in maize genetic transformation, especially huge breakthrough has been made in maize tissue culture utilizing mature embryos as explants in the recent years. This paper reviewed the study progress on maize tissue culture and plant regeneration utilizing mature embryos as explants from callus induction, subculture, plant regeneration and browning reduction and so on.

Characterization and competitive ability of non-aflatoxigenic Aspergillus flavus isolated from the maize agro-ecosystem in Argentina as potential aflatoxin biocontrol agents.

PubMed

Alaniz Zanon, María Silvina; Clemente, María Paz; Chulze, Sofía Noemí

2018-07-20

Aspergillus flavus is an opportunistic pathogen and may produce aflatoxins in maize, one of the most important crops in Argentina. A promising strategy to reduce aflatoxin accumulation is the biological control based on competitive exclusion. In order to select potential biocontrol agents among isolates from the maize growing region in Argentina, a total of 512 A. flavus strains were isolated from maize kernels and soil samples. Thirty-six per cent of the isolates from maize kernels did not produce detectable levels of aflatoxins, while 73% of the isolates from soil were characterized as non-aflatoxin producers. Forty percent and 49% of the isolates from maize kernels and soil samples, respectively, were not producers of cyclopiazonic acid (CPA). Sclerotia morphology was evaluated using Czapek Dox media. Eighty-six per cent of the isolates from maize kernels and 85% of the isolates from soil samples were L sclerotia morphotype (average diameter > 400 μm). The remaining isolates did not produce sclerotia. All isolates had MAT 1-1 idiomorph. The competitive ability of 9 non aflatoxigenic strains, 4 CPA(+) and 5 CPA(-), was evaluated in co-inoculations of maize kernels with an aflatoxigenic strain. All evaluated strains significantly (p < 0.05) reduced aflatoxin contamination in maize kernels. The aflatoxin B 1 (AFB 1 ) reduction ranged from 6 to 60%. The strain A. flavus ARG5/30 isolated from maize kernels would be a good candidate as a potential biocontrol agent to be used in maize, since it was characterized as neither aflatoxin nor CPA producer, morphotype L, MAT 1-1 idiomorph, and reduced AFB 1 content in maize kernels by 59%. This study showed the competitive ability of potential aflatoxin biocontrol agents to be evaluated under field trials in a maize agro-ecosystem in Argentina. Copyright © 2018 Elsevier B.V. All rights reserved.

Dynamics of maize carbon contribution to soil organic carbon in association with soil type and fertility level.

PubMed

Pei, Jiubo; Li, Hui; Li, Shuangyi; An, Tingting; Farmer, John; Fu, Shifeng; Wang, Jingkuan

2015-01-01

Soil type and fertility level influence straw carbon dynamics in the agroecosystems. However, there is a limited understanding of the dynamic processes of straw-derived and soil-derived carbon and the influence of the addition of straw carbon on soil-derived organic carbon in different soils associated with different fertility levels. In this study, we applied the in-situ carborundum tube method and 13C-labeled maize straw (with and without maize straw) at two cropland (Phaeozem and Luvisol soils) experimental sites in northeast China to quantify the dynamics of maize-derived and soil-derived carbon in soils associated with high and low fertility, and to examine how the addition of maize carbon influences soil-derived organic carbon and the interactions of soil type and fertility level with maize-derived and soil-derived carbon. We found that, on average, the contributions of maize-derived carbon to total organic carbon in maize-soil systems during the experimental period were differentiated among low fertility Luvisol (from 62.82% to 42.90), high fertility Luvisol (from 53.15% to 30.00%), low fertility Phaeozem (from 58.69% to 36.29%) and high fertility Phaeozem (from 41.06% to 16.60%). Furthermore, the addition of maize carbon significantly decreased the remaining soil-derived organic carbon in low and high fertility Luvisols and low fertility Phaeozem before two months. However, the increasing differences in soil-derived organic carbon between both soils with and without maize straw after two months suggested that maize-derived carbon was incorporated into soil-derived organic carbon, thereby potentially offsetting the loss of soil-derived organic carbon. These results suggested that Phaeozem and high fertility level soils would fix more maize carbon over time and thus were more beneficial for protecting soil-derived organic carbon from maize carbon decomposition.

Dynamics of Maize Carbon Contribution to Soil Organic Carbon in Association with Soil Type and Fertility Level

PubMed Central

Pei, Jiubo; Li, Hui; Li, Shuangyi; An, Tingting; Farmer, John; Fu, Shifeng; Wang, Jingkuan

2015-01-01

Soil type and fertility level influence straw carbon dynamics in the agroecosystems. However, there is a limited understanding of the dynamic processes of straw-derived and soil-derived carbon and the influence of the addition of straw carbon on soil-derived organic carbon in different soils associated with different fertility levels. In this study, we applied the in-situ carborundum tube method and 13C-labeled maize straw (with and without maize straw) at two cropland (Phaeozem and Luvisol soils) experimental sites in northeast China to quantify the dynamics of maize-derived and soil-derived carbon in soils associated with high and low fertility, and to examine how the addition of maize carbon influences soil-derived organic carbon and the interactions of soil type and fertility level with maize-derived and soil-derived carbon. We found that, on average, the contributions of maize-derived carbon to total organic carbon in maize-soil systems during the experimental period were differentiated among low fertility Luvisol (from 62.82% to 42.90), high fertility Luvisol (from 53.15% to 30.00%), low fertility Phaeozem (from 58.69% to 36.29%) and high fertility Phaeozem (from 41.06% to 16.60%). Furthermore, the addition of maize carbon significantly decreased the remaining soil-derived organic carbon in low and high fertility Luvisols and low fertility Phaeozem before two months. However, the increasing differences in soil-derived organic carbon between both soils with and without maize straw after two months suggested that maize-derived carbon was incorporated into soil-derived organic carbon, thereby potentially offsetting the loss of soil-derived organic carbon. These results suggested that Phaeozem and high fertility level soils would fix more maize carbon over time and thus were more beneficial for protecting soil-derived organic carbon from maize carbon decomposition. PMID:25774529

Quantitative disease resistance: dissection and adoption in maize

USDA-ARS?s Scientific Manuscript database

Maize is the world’s most widely cultivated crop, providing food, feed, and biofuel. Maize production is constantly threatened by the presence of devastating pathogens worldwide. Characterization of the genetic components underlying disease resistance is a major research area in maize which is highl...

MaizeGDB: New tools and resource

USDA-ARS?s Scientific Manuscript database

MaizeGDB, the USDA-ARS genetics and genomics database, is a highly curated, community-oriented informatics service to researchers focused on the crop plant and model organism Zea mays. MaizeGDB facilitates maize research by curating, integrating, and maintaining a database that serves as the central...

Biodegradable composite scaffolds: a strategy to modulate stem cell behaviour.

PubMed

Armentano, Ilaria; Fortunati, Elena; Mattioli, Samantha; Rescignano, Nicolatta; Kenny, José M

2013-04-01

The application of new biomaterial technologies offers the potential to direct the stem cell fate, targeting the delivery of cells and reducing immune rejection, thereby supporting the development of regenerative medicine. Cells respond to their surrounding structure and with nanostructures exhibit unique proliferative and differentiation properties. This review presents the relevance, the promising perspectives and challenges of current biodegradable composite scaffolds in terms of material properties, processing technology and surface modification, focusing on significant recent patents in these fields. It has been reported how biodegradable porous composite scaffolds can be engineered with initial properties that reproduce the anisotropy, viscoelasticity, tension-compression non-linearity of different tissues by introducing specific nanostructures. Moreover the modulation of electrical, morphological, surface and topographic scaffold properties enables specific stem cell response. Recent advances in nanotechnology have allowed to engineer novel biomaterials with these complexity levels. Understanding the specific biological response triggered by various aspects of the fibrous environment is important in guiding the design and engineering of novel substrates that mimic the native cell matrix interactions in vivo.

The Effect of Pollination on Cd Phytoextraction From Soil by Maize (Zea mays L.).

PubMed

Xu, Wending; Lu, Guining; Wang, Rui; Guo, Chuling; Liao, Changjun; Yi, Xiaoyun; Dang, Zhi

2015-01-01

A pot experiment was conducted to investigate the effects of pollination on cadmium (Cd) phytoextraction from soil by mature maize plants. The results showed that the unpollinated maize plants accumulated 50% more Cd than that of the pollinated plants, even though the dry weight of the former plants was 15% less than that of the latter plants. The Cd accumulation in root and leaf of the unpollinated maize plant was 0.47 and 0.89 times higher than that of the pollinated plant, respectively. The Cd concentration in the cob was significantly decreased because of pollination. Preventing pollination is a promising approach for enhancing the effectiveness of phytoextraction in Cd-contaminated soils by maize. This study suggested that in low Cd-contaminated soil pollination should be encouraged because accumulation of Cd in maize grains is very little and maize seeds can bring farmers economic benefits, while in high Cd-contaminated soil, inhibition of pollination can be applied to enhance phytoextraction of Cd from soil by maize plant.

Preparation of acetylated waxy, normal, and high-amylose maize starches with intermediate degrees of substitution in aqueous solution and their properties.

PubMed

Luo, Zhi-Gang; Shi, Yong-Cheng

2012-09-19

Acetylated waxy, normal, and high-amylose maize starches with intermediate degrees of substitution (DS) were prepared in aqueous solution with 20% (w/w) sodium hydroxide as a catalyst. The level of DS was in the order high-amylose maize starch > waxy maize starch > normal maize starch. Settling volume indicated that during the early reaction, normal maize starch swelled to a lesser extent compared with waxy and high-amylose maize starches. The settling volume of all three starches increased initially but decreased after long reaction time. Aggregation of granules was observed as DS increased. The A-type X-ray diffraction pattern of acetylated normal and waxy maize starches weakened as DS increased, whereas the diffraction peaks disappeared in acetylated high-amylose starch when DS was 0.95. Low DS promoted the swelling of the starches in water, but at high DS, the starches became more hydrophobic and the peak viscosity of acetylated starches decreased.

Response of Main Maize Varieties to Water Stress and Comprehensive Evaluation in Hebei Province

NASA Astrophysics Data System (ADS)

Yue, Haiwang; Chen, Shuping; Bu, Junzhou; Wei, Jianwei; Peng, Haicheng; Li, Yuan; Li, Chunjie; Xie, Junliang

2018-01-01

Drought is a serious threat to maize production in Hebei province. Planting drought resistant maize varieties is an effective measure to solve drought in arid and less rain areas. Drought resistance in maize is controlled by many genes, and multiple indexes should be used for comprehensive evaluation (Campos H et al.2004). In the arid rain shed, using 34 maize varieties to promote crop production compared to the drought resistance test. The experiment was conducted with two treatments of drought stress (irrigation only at seedling stage) and normal irrigation, and 12 agronomic traits related to drought resistance of maize were determined. The results showed that drought had significant effects on maize yield and main agronomic characters. Under drought stress, plant height, ear length, bare tip, ear row number, row grains, 1000-kernel weight, ASI index can be used as identification index of drought resistance of maize in different period. The results indicated that the variety with strong drought resistance is Zhongdi175, the worst drought resistance is Woyu964.

Corn and culture in central andean prehistory.

PubMed

Johannessen, S; Hastorf, C A

1989-05-12

The prehistoric development and spread of domesticated maize varieties in the highlands of Peru, unlike the drier coastal deserts, is little known because ancient maize remains in this area survive mainly as fragments, kernels, and cob parts. An analysis of fragmented charred maize from prehistoric households (A.D.450 to 1500) in the Mantaro Valley reveals a developmental sequence of maize varieties for Highland Peru. The evidence indicates an adoption of large-kernelled maize varieties beginning in the Late Intermediate (A.D. 1000). This is centuries later than a similar change in maize, associated with the Wari expansion, that occurred in coastal areas, and indicates minimal Wari impact in the Mantaro Valley.

Advances in Maize Transformation Technologies and Development of Transgenic Maize

PubMed Central

Yadava, Pranjal; Abhishek, Alok; Singh, Reeva; Singh, Ishwar; Kaul, Tanushri; Pattanayak, Arunava; Agrawal, Pawan K.

2017-01-01

Maize is the principal grain crop of the world. It is also the crop where genetic engineering has been employed to a great extent to improve its various traits. The ability to transform maize is a crucial step for application of gene technology in maize improvement. There have been constant improvements in the maize transformation technologies over past several years. The choice of genotype and the explant material to initiate transformation and the different types of media to be used in various stages of tissue culture can have significant impact on the outcomes of the transformation efforts. Various methods of gene transfer, like the particle bombardment, protoplast transformation, Agrobacterium-mediated, in planta transformation, etc., have been tried and improved over years. Similarly, various selection systems for retrieval of the transformants have been attempted. The commercial success of maize transformation and transgenic development is unmatched by any other crop so far. Maize transformation with newer gene editing technologies is opening up a fresh dimension in transformation protocols and work-flows. This review captures the various past and recent facets in improvement in maize transformation technologies and attempts to present a comprehensive updated picture of the current state of the art in this area. PMID:28111576

Advances in Maize Transformation Technologies and Development of Transgenic Maize.

PubMed

Yadava, Pranjal; Abhishek, Alok; Singh, Reeva; Singh, Ishwar; Kaul, Tanushri; Pattanayak, Arunava; Agrawal, Pawan K

2016-01-01

Maize is the principal grain crop of the world. It is also the crop where genetic engineering has been employed to a great extent to improve its various traits. The ability to transform maize is a crucial step for application of gene technology in maize improvement. There have been constant improvements in the maize transformation technologies over past several years. The choice of genotype and the explant material to initiate transformation and the different types of media to be used in various stages of tissue culture can have significant impact on the outcomes of the transformation efforts. Various methods of gene transfer, like the particle bombardment, protoplast transformation, Agrobacterium -mediated, in planta transformation, etc., have been tried and improved over years. Similarly, various selection systems for retrieval of the transformants have been attempted. The commercial success of maize transformation and transgenic development is unmatched by any other crop so far. Maize transformation with newer gene editing technologies is opening up a fresh dimension in transformation protocols and work-flows. This review captures the various past and recent facets in improvement in maize transformation technologies and attempts to present a comprehensive updated picture of the current state of the art in this area.