Embryo density may affect embryo quality during in vitro culture in a microwell group culture dish.

PubMed

Lehner, Adam; Kaszas, Zita; Murber, Akos; Rigo, Janos; Urbancsek, Janos; Fancsovits, Peter

2017-08-01

Culturing embryos in groups is a common practice in mammalian embryology. Since the introduction of different microwell dishes, it is possible to identify oocytes or embryos individually. As embryo density (embryo-to-volume ratio) may affect the development and viability of the embryos, the purpose of this study was to assess the effect of different embryo densities on embryo quality. Data of 1337 embryos from 228 in vitro fertilization treatment cycles were retrospectively analyzed. Embryos were cultured in a 25 μl microdrop in a microwell group culture dish containing 9 microwells. Three density groups were defined: Group 1 with 2-4 (6.3-12.5 μl/embryo), Group 2 with 5-6 (4.2-5.0 μl/embryo), and Group 3 with 7-9 (2.8-3.6 μl/embryo) embryos. Proportion of good quality embryos was higher in Group 2 on both days (D2: 18.9 vs. 31.5 vs. 24.7%; p < 0.001; D3: 19.7 vs. 27.1 vs. 21.2%; p = 0.029; Group 1. vs. Group 2. vs. Group 3). Cell number on Day 3 differed between Groups 1 and 2 (6.8 ± 2.2; 7.3 ± 2.1; p = 0.004) and Groups 2 and 3 (7.3 ± 2.1 vs. 7.0 ± 2.0; p = 0.014). Culturing 5-6 embryos together in a culture volume of 25 μl may benefit embryo quality. As low egg number, position, and distance of the embryos may influence embryo quality, results should be interpreted with caution.

Occurrence and metabolism of 7-hydroxy-2-indolinone-3-acetic acid in Zea mays

NASA Technical Reports Server (NTRS)

Lewer, P.; Bandurski, R. S.

1987-01-01

7-Hydroxy-2-indolinone-3-acetic acid was identified as a catabolite of indole-3-acetic acid in germinating kernels of Zea mays and found to be present in amounts of ca 3.1 nmol/kernel. 7-Hydroxy-2-indolinone-3-acetic acid was shown to be a biosynthetic intermediate between 2-indolinone-3-acetic acid and 7-hydroxy-2-indolinone-3-acetic acid-7'-O-glucoside in both kernels and roots of Zea mays. Further metabolism of 7-hydroxy-2-[5-3H]-indolinone-3-acetic acid-7'-O-glucoside occurred to yield tritiated water plus, as yet, uncharacterized products.

Antiplasmodial activity and cytotoxicity of ethanol extract of Zea mays root

PubMed Central

Okokon, Jude Efiom; Antia, Bassey Sunday; Azare, Bala Adamu; Okokon, Patience Jude

2017-01-01

Objective: Zea mays root decoction that has been traditionally used for the treatment of malaria by various tribes in Nigeria, was evaluated for antimalarial potential against malaria parasites using in vivo and in vitro models. Materials and Methods: The root extract of Zea mays was investigated for antimalarial activity against Plasmodium berghei in mice using rodent malaria models; suppressive, prophylactic and curative tests and in vitro antiplasmodial activity against chloroquine-sensitive (Pf 3D7) and resistant (Pf INDO) strains of Plasmodium falciparum using SYBR green assay method. Median lethal dose and cytotoxic activity against HeLa and HEKS cells were assessed and phytochemical screening was also carried out using standard procedures. Results: The LD50 value of root extract was found to be 474.34 mg/kg. The crude extract (45-135 mg/kg, p.o) showed significant (p<0.05-0.001) antimalarial activity against P. berghei infection in suppressive, prophylactic and curative tests with a prolonged survival time. The crude extract also showed moderate activity against both chloroquine-sensitive (Pf 3D7) and resistant (Pf INDO) strains of P. falciparum with an IC50 value of 71.62±3.38 μg/ml (for Pf 3D7) and 63.76±4.12 μg/ml (for Pf INDO). The crude extract was not cytotoxic to the two cell lines tested with TC50 of >100 μg/ml against both HeLa and HEKS cell lines. Conclusion: These results suggest that the root extract of Zea mays possesses antimalarial activity against both chloroquine-sensitive and resistant malaria and these data justify its use in ethnomedicine to treat malaria infections. PMID:28748174

Antiplasmodial activity and cytotoxicity of ethanol extract of Zea mays root.

PubMed

Okokon, Jude Efiom; Antia, Bassey Sunday; Azare, Bala Adamu; Okokon, Patience Jude

2017-01-01

Zea mays root decoction that has been traditionally used for the treatment of malaria by various tribes in Nigeria, was evaluated for antimalarial potential against malaria parasites using in vivo and in vitro models. The root extract of Zea mays was investigated for antimalarial activity against Plasmodium berghei in mice using rodent malaria models; suppressive, prophylactic and curative tests and in vitro antiplasmodial activity against chloroquine-sensitive (Pf 3D7) and resistant (Pf INDO) strains of Plasmodium falciparum using SYBR green assay method. Median lethal dose and cytotoxic activity against HeLa and HEKS cells were assessed and phytochemical screening was also carried out using standard procedures. The LD 50 value of root extract was found to be 474.34 mg/kg. The crude extract (45-135 mg/kg, p.o) showed significant (p<0.05-0.001) antimalarial activity against P. berghei infection in suppressive, prophylactic and curative tests with a prolonged survival time. The crude extract also showed moderate activity against both chloroquine-sensitive (Pf 3D7) and resistant (Pf INDO) strains of P. falciparum with an IC 50 value of 71.62±3.38 μg/ml (for Pf 3D7) and 63.76±4.12 μg/ml (for Pf INDO). The crude extract was not cytotoxic to the two cell lines tested with TC 50 of >100 μg/ml against both HeLa and HEKS cell lines. These results suggest that the root extract of Zea mays possesses antimalarial activity against both chloroquine-sensitive and resistant malaria and these data justify its use in ethnomedicine to treat malaria infections.

Gene evolutionary trajectories and GC patterns driven by recombination in Zea mays

USDA-ARS?s Scientific Manuscript database

Recombination occurring during meiosis is critical for creating genetic variation and plays an essential role in plant evolution. In addition to creating novel gene combinations, recombination can affect genome structure through altering GC patterns. In maize (Zea mays) and other grasses, another in...

Influence of microgravity on cellular differentiation in root caps of Zea mays

NASA Technical Reports Server (NTRS)

Moore, R.; Fondren, W. M.; McClelen, C. E.; Wang, C. L.

1987-01-01

We launched imbibed seeds of Zea mays into outer space aboard the space shuttle Columbia to determine the influence of microgravity on cellular differentiation in root caps. The influence of microgravity varied with different stages of cellular differentiation. Overall, microgravity tended to 1) increase relative volumes of hyaloplasm and lipid bodies, 2) decrease the relative volumes of plastids, mitochondria, dictyosomes, and the vacuome, and 3) exert no influence on the relative volume of nuclei in cells comprising the root cap. The reduced allocation of dictyosomal volume in peripheral cells of flight-grown seedlings correlated positively with their secretion of significantly less mucilage than peripheral cells of Earth-grown seedlings. These results indicate that 1) microgravity alters the patterns of cellular differentiation and structures of all cell types comprising the root cap, and 2) the influence of microgravity on cellular differentiation in root caps of Zea mays is organelle specific.

Chromium accumulation potential of Zea mays grown under four different fertilizers.

PubMed

Dheeba, B; Sampathkumar, P; Kannan, K

2014-12-01

Chromium (Cr) contamination in soil is a growing concern in sustainable agriculture production and food safety. We performed pot experiment with chromium (30 mg/soil) to assess the accumulation potential of Zea mays and study the influence of four fertilizers, viz. Farm Yard Manure (FYM), NPK, Panchakavya (PK) and Vermicompost (VC) with respect to Cr accumulation. The oxidative stress and pigment (chlorophyll) levels were also examined. The results showed increased accumulation of chromium in both shoots and roots of Zea mays under FYM and NPK supply, and reduced with PK and VC. While the protein and pigment contents decreased in Cr treated plants, the fertilizers substantiated the loss to overcome the stress. Similarly, accumulation of Cr increased the levels of antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) indicating the enhanced damage control activity. However, these levels were relatively low in plants supplemented with fertilizers. Our results confirm that the maize can play an effective role in bioremediation of soils polluted with chromium, particularly in supplementation with fertilizers such as farm yard manure and NPK.

RAPD and Internal Transcribed Spacer Sequence Analyses Reveal Zea nicaraguensis as a Section Luxuriantes Species Close to Zea luxurians

PubMed Central

Wang, Pei; Lu, Yanli; Zheng, Mingmin; Rong, Tingzhao; Tang, Qilin

2011-01-01

Genetic relationship of a newly discovered teosinte from Nicaragua, Zea nicaraguensis with waterlogging tolerance, was determined based on randomly amplified polymorphic DNA (RAPD) markers and the internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA using 14 accessions from Zea species. RAPD analysis showed that a total of 5,303 fragments were produced by 136 random decamer primers, of which 84.86% bands were polymorphic. RAPD-based UPGMA analysis demonstrated that the genus Zea can be divided into section Luxuriantes including Zea diploperennis, Zea luxurians, Zea perennis and Zea nicaraguensis, and section Zea including Zea mays ssp. mexicana, Zea mays ssp. parviglumis, Zea mays ssp. huehuetenangensis and Zea mays ssp. mays. ITS sequence analysis showed the lengths of the entire ITS region of the 14 taxa in Zea varied from 597 to 605 bp. The average GC content was 67.8%. In addition to the insertion/deletions, 78 variable sites were recorded in the total ITS region with 47 in ITS1, 5 in 5.8S, and 26 in ITS2. Sequences of these taxa were analyzed with neighbor-joining (NJ) and maximum parsimony (MP) methods to construct the phylogenetic trees, selecting Tripsacum dactyloides L. as the outgroup. The phylogenetic relationships of Zea species inferred from the ITS sequences are highly concordant with the RAPD evidence that resolved two major subgenus clades. Both RAPD and ITS sequence analyses indicate that Zea nicaraguensis is more closely related to Zea luxurians than the other teosintes and cultivated maize, which should be regarded as a section Luxuriantes species. PMID:21525982

Elevated carbon dioxide reduces emission of herbivore induced volatiles in Zea mays

USDA-ARS?s Scientific Manuscript database

Terpene volatiles produced by sweet corn (Zea mays) upon infestation with pests such as beet armyworm (Spodoptera exigua) function as part of an indirect defense mechanism by attracting parasitoid wasps; yet little is known about the impact of atmospheric changes on this form of plant defense. To in...

Phytoremediation potential of maize (Zea mays L.) in co-contaminated soils with pentachlorophenol and cadmium.

PubMed

Hechmi, Nejla; Ben Aissa, Nadhira; Abdennaceur, Hassen; Jedidi, Naceur

2013-01-01

The ubiquitous coexistence of heavy metals and organic contaminants was increased in the polluted soil and phytoremediation as a remedial technology and management option is recommended to solve the problems of co-contamination. Growth of Zea mays L and pollutant removal ability may be influenced by interactions among mixed pollutants. Pot-culture experiments were conduced to investigate the single and interactive effect of cadmium (Cd) and pentachlorophenol (PCP) on growth of Zea mays L, PCP, and Cd removal from soil. Growth response of Zea mays L is considerably influenced by interaction of Cd and PCP, significantly declining with either Cd or PCP additions. The dissipation of PCP in soils was notably affected by interactions of Cd, PCP, and plant presence or absence. At the Pentachlorophenol in both planted and non-planted soil was greatly decreased at the end of the 10-week culture, accounting for 16-20% of initial extractable concentrations in non-planted soil and 9-14% in planted soil. With the increment of Cd level, residual pentachlorophenol in the planted soil tended to increase. The pentachlorophenol residual in the presence of high concentration of Cd was even higher in the planted soil than that in the non-planted soil.

Antimalarial and antiplasmodial activity of husk extract and fractions of Zea mays.

PubMed

Okokon, Jude E; Antia, Bassey S; Mohanakrishnan, Dinesh; Sahal, Dinkar

2017-12-01

Zea mays L. (Poacae) husk decoctions are traditionally used in the treatment of malaria by various tribes in Nigeria. To assess the antimalarial and antiplasmodial potentials of the husk extract and fractions on malaria parasites using in vivo and in vitro models. The ethanol husk extract and fractions (187-748 mg/kg, p.o.) of Zea mays were investigated for antimalarial activity against Plasmodium berghei using rodent (mice) malaria models and in vitro activity against chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of Plasmodium falciparum using the SRBR green assay method. Median lethal dose and cytotoxic activities against HeLa and HEKS cells were also carried out. The GCMS analysis of the most active fraction was carried out. The husk extract (187-748 mg/kg, p.o.) with LD 50 of 1874.83 mg/kg was found to exert significant (p < 0.05-0.001) antimalarial activity against P. berghei infection in suppressive, prophylactive and curative tests. The crude extract and fractions also exerted prominent activity against both chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of P. falciparum with the ethyl acetate fraction exerting the highest activity with IC 50 values of 9.31 ± 0.46 μg/mL (Pf 3D7) and 3.69 ± 0.66 μg/mL (Pf INDO). The crude extract and fractions were not cytotoxic to the two cell lines tested with IC 50 values of >100 μg/mL against both HeLa and HEKS cell lines. These results suggest that the husk extract/fractions of Zea mays possesses antimalarial and antiplasmodial activities and these justify its use in ethnomedicine to treat malaria infections.

Water deficit stress effects on corn (Zea mays, L.) root: shoot ratio

USDA-ARS?s Scientific Manuscript database

A study was conducted at Akron, CO, USA, on a Weld silt loam in 2004 to quantify the effects of water deficit stress on corn (Zea mays, L.) root and shoot biomass. Corn plants were grown under a range of soil bulk density and water conditions caused by previous tillage, crop rotation, and irrigation...

Preventive effect of Zea mays L. (purple waxy corn) on experimental diabetic cataract.

PubMed

Thiraphatthanavong, Paphaphat; Wattanathorn, Jintanaporn; Muchimapura, Supaporn; Wipawee, Thukham-mee; Wannanon, Panakaporn; Terdthai, Tong-un; Suriharn, Bhalang; Lertrat, Kamol

2014-01-01

Recently, substances possessing antioxidant can prevent cataractogenesis of diabetic cataract. Therefore, this study was carried out to determine the anticataract effect of Zea mays L. (purple waxy corn), a flavonoids rich plant, in experimental diabetic cataract. Enucleated rat lenses were incubated in artificial aqueous humor containing 55 mM glucose with various concentrations of Zea mays L. (purple waxy corn) ranging between 2, 10, and 50 mg/mL at room temperature for 72 h. At the end of the incubation period, the evaluation of lens opacification, MDA level, and the activities of SOD, CAT, GPx, and AR in lens were performed. The results showed that both medium and high doses of extract decreased lens opacity together with the decreased MDA level. In addition, medium dose of extract increased GPx activity while the high dose decreased AR activity. No other significant changes were observed. The purple waxy corn seeds extract is the potential candidate to protect against diabetic cataract. The mechanism of action may occur via the decreased oxidative stress and the suppression of AR. However, further research in vivo is still essential.

The homeologous Zea mays gigantea genes: characterization of expression and novel mutant alleles

USDA-ARS?s Scientific Manuscript database

The two homeologous Zea mays gigantea (gi) genes, gi1 and gi2, arose from the last genome duplication event in the maize lineage. Homologs of these genes in other species are required for correct circadian rhythms and proper regulation of growth and development. Here we characterized the expression ...

Preventive Effect of Zea mays L. (Purple Waxy Corn) on Experimental Diabetic Cataract

PubMed Central

Thiraphatthanavong, Paphaphat; Wattanathorn, Jintanaporn; Muchimapura, Supaporn; Thukham-mee, Wipawee; Wannanon, Panakaporn; Tong-un, Terdthai; Suriharn, Bhalang; Lertrat, Kamol

2014-01-01

Recently, substances possessing antioxidant can prevent cataractogenesis of diabetic cataract. Therefore, this study was carried out to determine the anticataract effect of Zea mays L. (purple waxy corn), a flavonoids rich plant, in experimental diabetic cataract. Enucleated rat lenses were incubated in artificial aqueous humor containing 55 mM glucose with various concentrations of Zea mays L. (purple waxy corn) ranging between 2, 10, and 50 mg/mL at room temperature for 72 h. At the end of the incubation period, the evaluation of lens opacification, MDA level, and the activities of SOD, CAT, GPx, and AR in lens were performed. The results showed that both medium and high doses of extract decreased lens opacity together with the decreased MDA level. In addition, medium dose of extract increased GPx activity while the high dose decreased AR activity. No other significant changes were observed. The purple waxy corn seeds extract is the potential candidate to protect against diabetic cataract. The mechanism of action may occur via the decreased oxidative stress and the suppression of AR. However, further research in vivo is still essential. PMID:24527449

Potassium fertilization mitigates the adverse effects of drought on selected Zea mays cultivars

USDA-ARS?s Scientific Manuscript database

In the present study, the role of potassium (K) in mitigating the adverse effects of drought stress (DS) on 2 maize (Zea mays L.) cultivars, ‘Shaandan 9’ (S9; drought-tolerant) and ‘Shaandan 911’ (S911; drought-sensitive), was assessed. K application increased dry matter (DM) across all growth stage...

Maize (Zea mays L.).

PubMed

Frame, Bronwyn; Warnberg, Katey; Main, Marcy; Wang, Kan

2015-01-01

Agrobacterium tumefaciens-mediated transformation is an effective method for introducing genes into maize. In this chapter, we describe a detailed protocol for genetic transformation of the maize genotype Hi II. Our starting plant material is immature embryos cocultivated with an Agrobacterium strain carrying a standard binary vector. In addition to step-by-step laboratory transformation procedures, we include extensive details in growing donor plants and caring for transgenic plants in the greenhouse.

Influence of calcium phosphate nanoparticles, Piriformospora indica and Glomus mosseae on growth of Zea mays

NASA Astrophysics Data System (ADS)

Rane, Mansi; Bawskar, Manisha; Rathod, Dnyaneshwar; Nagaonkar, Dipali; Rai, Mahendra

2015-12-01

In this study, the arbuscular mycorrhizal fungus (G. mosseae) and endosymbiont (P. indica) colonized Zea mays were treated with calcium phosphate nanoparticles (CaPNPs) and evaluated for their plant growth promotion efficiency. It was observed that CaPNPs in combination with both G. mosseae and P. indica are more potent plant growth promoter than independent combinations of CaPNPs + G. mosseae, CaPNPs + P. indica or CaPNPs alone. The fluorimetric studies of treated plants revealed that CaPNPs alone and in combination with P. indica can enhance vitality of Zea mays by improving chlorophyll a content and performance index of treated plants. Hence, we conclude that CaPNPs exhibit synergistic growth promotion, root proliferation and vitality improvement properties along with endosymbiotic and arbuscular mycorrhizal fungi, which after further field trials can be developed as a cost-effective nanofertilizer with pronounced efficiency.

Abscisic acid is not necessary for gravitropism in primary roots of Zea mays

NASA Technical Reports Server (NTRS)

Moore, R.

1990-01-01

Primary roots of Zea mays L. cv. Tx 5855 treated with fluridone are strongly graviresponsive, but have undetectable levels of abscisic acid (ABA). Primary roots of the carotenoid-deficient w-3, vp-5, and vp-7 mutants of Z. mays are also graviresponsive despite having undetectable amounts of ABA. Graviresponsive roots of untreated and wild-type seedlings contain 286 to 317 ng ABA g-1 f. wt, respectively. These results indicate that ABA is not necessary for root gravicurvature.

Construction of the third-generation Zea mays haplotype map.

PubMed

Bukowski, Robert; Guo, Xiaosen; Lu, Yanli; Zou, Cheng; He, Bing; Rong, Zhengqin; Wang, Bo; Xu, Dawen; Yang, Bicheng; Xie, Chuanxiao; Fan, Longjiang; Gao, Shibin; Xu, Xun; Zhang, Gengyun; Li, Yingrui; Jiao, Yinping; Doebley, John F; Ross-Ibarra, Jeffrey; Lorant, Anne; Buffalo, Vince; Romay, M Cinta; Buckler, Edward S; Ware, Doreen; Lai, Jinsheng; Sun, Qi; Xu, Yunbi

2018-04-01

Characterization of genetic variations in maize has been challenging, mainly due to deterioration of collinearity between individual genomes in the species. An international consortium of maize research groups combined resources to develop the maize haplotype version 3 (HapMap 3), built from whole-genome sequencing data from 1218 maize lines, covering predomestication and domesticated Zea mays varieties across the world. A new computational pipeline was set up to process more than 12 trillion bp of sequencing data, and a set of population genetics filters was applied to identify more than 83 million variant sites. We identified polymorphisms in regions where collinearity is largely preserved in the maize species. However, the fact that the B73 genome used as the reference only represents a fraction of all haplotypes is still an important limiting factor.

Construction of the third-generation Zea mays haplotype map

PubMed Central

Bukowski, Robert; Guo, Xiaosen; Lu, Yanli; Zou, Cheng; He, Bing; Rong, Zhengqin; Wang, Bo; Xu, Dawen; Yang, Bicheng; Xie, Chuanxiao; Fan, Longjiang; Gao, Shibin; Xu, Xun; Zhang, Gengyun; Li, Yingrui; Jiao, Yinping; Doebley, John F; Ross-Ibarra, Jeffrey; Lorant, Anne; Buffalo, Vince; Romay, M Cinta; Buckler, Edward S; Ware, Doreen; Lai, Jinsheng; Sun, Qi

2017-01-01

Abstract Background Characterization of genetic variations in maize has been challenging, mainly due to deterioration of collinearity between individual genomes in the species. An international consortium of maize research groups combined resources to develop the maize haplotype version 3 (HapMap 3), built from whole-genome sequencing data from 1218 maize lines, covering predomestication and domesticated Zea mays varieties across the world. Results A new computational pipeline was set up to process more than 12 trillion bp of sequencing data, and a set of population genetics filters was applied to identify more than 83 million variant sites. Conclusions We identified polymorphisms in regions where collinearity is largely preserved in the maize species. However, the fact that the B73 genome used as the reference only represents a fraction of all haplotypes is still an important limiting factor. PMID:29300887

Small kernel 1 encodes a pentatricopeptide repeat protein required for mitochondrial nad7 transcript editing and seed development in maize (Zea mays) and rice (Oryza sativa).

PubMed

Li, Xiao-Jie; Zhang, Ya-Feng; Hou, Mingming; Sun, Feng; Shen, Yun; Xiu, Zhi-Hui; Wang, Xiaomin; Chen, Zong-Liang; Sun, Samuel S M; Small, Ian; Tan, Bao-Cai

2014-09-01

RNA editing modifies cytidines (C) to uridines (U) at specific sites in the transcripts of mitochondria and plastids, altering the amino acid specified by the DNA sequence. Here we report the identification of a critical editing factor of mitochondrial nad7 transcript via molecular characterization of a small kernel 1 (smk1) mutant in Zea mays (maize). Mutations in Smk1 arrest both the embryo and endosperm development. Cloning of Smk1 indicates that it encodes an E-subclass pentatricopeptide repeat (PPR) protein that is targeted to mitochondria. Loss of SMK1 function abolishes the C → U editing at the nad7-836 site, leading to the retention of a proline codon that is edited to encode leucine in the wild type. The smk1 mutant showed dramatically reduced complex-I assembly and NADH dehydrogenase activity, and abnormal biogenesis of the mitochondria. Analysis of the ortholog in Oryza sativa (rice) reveals that rice SMK1 has a conserved function in C → U editing of the mitochondrial nad7-836 site. T-DNA knock-out mutants showed abnormal embryo and endosperm development, resulting in embryo or seedling lethality. The leucine at NAD7-279 is highly conserved from bacteria to flowering plants, and analysis of genome sequences from many plants revealed a molecular coevolution between the requirement for C → U editing at this site and the existence of an SMK1 homolog. These results demonstrate that Smk1 encodes a PPR-E protein that is required for nad7-836 editing, and this editing is critical to NAD7 function in complex-I assembly in mitochondria, and hence to embryo and endosperm development in maize and rice. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

Enhanced formation of aerenchyma and induction of a barrier to radial oxygen loss in adventitious roots of Zea nicaraguensis contribute to its waterlogging tolerance as compared with maize (Zea mays ssp. mays).

PubMed

Abiko, Tomomi; Kotula, Lukasz; Shiono, Katsuhiro; Malik, Al Imran; Colmer, Timothy David; Nakazono, Mikio

2012-09-01

Enhancement of oxygen transport from shoot to root tip by the formation of aerenchyma and also a barrier to radial oxygen loss (ROL) in roots is common in waterlogging-tolerant plants. Zea nicaraguensis (teosinte), a wild relative of maize (Zea mays ssp. mays), grows in waterlogged soils. We investigated the formation of aerenchyma and ROL barrier induction in roots of Z. nicaraguensis, in comparison with roots of maize (inbred line Mi29), in a pot soil system and in hydroponics. Furthermore, depositions of suberin in the exodermis/hypodermis and lignin in the epidermis of adventitious roots of Z. nicaraguensis and maize grown in aerated or stagnant deoxygenated nutrient solution were studied. Growth of maize was more adversely affected by low oxygen in the root zone (waterlogged soil or stagnant deoxygenated nutrient solution) compared with Z. nicaraguensis. In stagnant deoxygenated solution, Z. nicaraguensis was superior to maize in transporting oxygen from shoot base to root tip due to formation of larger aerenchyma and a stronger barrier to ROL in adventitious roots. The relationships between the ROL barrier formation and suberin and lignin depositions in roots are discussed. The ROL barrier, in addition to aerenchyma, would contribute to the waterlogging tolerance of Z. nicaraguensis. © 2012 Blackwell Publishing Ltd.

Fine mapping of a quantitative resistance gene for gray leaf spot of maize (Zea mays L.) derived from teosinte (Z. mays ssp. parviglumis)

USDA-ARS?s Scientific Manuscript database

In previous work, using near isogenic line (NIL) populations in which segments of the tesosinte (Zea mays ssp. parviglumis) genome had been introgressed into the background of the maize line B73, we had identified a QTL on chromosome 8, here called Qgls8, for gray leaf spot resistance. We identified...

Mutational effects of space flight on Zea mays seeds

NASA Technical Reports Server (NTRS)

Mei, M.; Qiu, Y.; He, Y.; Bucker, H.; Yang, C. H.

1994-01-01

The growth and development of more than 500 Zea mays seeds flown on Long Duration Exposure Facility (LDEF) were studied. Somatic mutations, including white-yellow stripes on leaves, dwarfing, change of leaf sheath color or seedling color were observed in plants developed from these seeds. When the frequency of white-yellow formation was used as the endpoint and compared with data from ground based studies, the dose to which maize seeds might be exposed during the flight was estimated to be equivalent to 635 cGy of gamma rays. Seeds from one particular holder gave a high mutation frequency and a wide mutation spectrum. White-yellow stripes on leaves were also found in some of the inbred progenies from plants displayed somatic mutation. Electron microscopy studies showed that the damage of chloroplast development in the white-yellow stripe on leaves was similar between seeds flown on LDEF and that irradiated by accelerated heavy ions on ground.

Structure of the novel monomeric glyoxalase I from Zea mays

PubMed Central

Turra, Gino L.; Agostini, Romina B.; Fauguel, Carolina M.; Presello, Daniel A.; Andreo, Carlos S.; González, Javier M.; Campos-Bermudez, Valeria A.

2015-01-01

The glyoxalase system is ubiquitous among all forms of life owing to its central role in relieving the cell from the accumulation of methylglyoxal, a toxic metabolic byproduct. In higher plants, this system is upregulated under diverse metabolic stress conditions, such as in the defence response to infection by pathogenic microorganisms. Despite their proven fundamental role in metabolic stresses, plant glyoxalases have been poorly studied. In this work, glyoxalase I from Zea mays has been characterized both biochemically and structurally, thus reporting the first atomic model of a glyoxalase I available from plants. The results indicate that this enzyme comprises a single polypeptide with two structurally similar domains, giving rise to two lateral concavities, one of which harbours a functional nickel(II)-binding active site. The putative function of the remaining cryptic active site remains to be determined. PMID:26457425

Structure of the novel monomeric glyoxalase I from Zea mays.

PubMed

Turra, Gino L; Agostini, Romina B; Fauguel, Carolina M; Presello, Daniel A; Andreo, Carlos S; González, Javier M; Campos-Bermudez, Valeria A

2015-10-01

The glyoxalase system is ubiquitous among all forms of life owing to its central role in relieving the cell from the accumulation of methylglyoxal, a toxic metabolic byproduct. In higher plants, this system is upregulated under diverse metabolic stress conditions, such as in the defence response to infection by pathogenic microorganisms. Despite their proven fundamental role in metabolic stresses, plant glyoxalases have been poorly studied. In this work, glyoxalase I from Zea mays has been characterized both biochemically and structurally, thus reporting the first atomic model of a glyoxalase I available from plants. The results indicate that this enzyme comprises a single polypeptide with two structurally similar domains, giving rise to two lateral concavities, one of which harbours a functional nickel(II)-binding active site. The putative function of the remaining cryptic active site remains to be determined.

Phytotoxic Effects of Lanthanum Oxide Nanoparticles on Maize (Zea mays L.)

NASA Astrophysics Data System (ADS)

Liu, Yinglin; Xu, Lina; Dai, Yanhui

2018-02-01

The use of lanthanum oxide nanoparticles (La2O3 NPs) in life products have increased dramatically in the past decades, which are inevitable released into natural environment. In this study, we determined the phytotoxicity of La2O3 NPs to maize (Zea mays L.) grown in one-fourth strength Hoagland solution. After being exposed for two weeks, the biomass, roots length and the relative chlorophyll content were measured. La2O3 NPs had phytotoxicity to maize at 5 mg/L. La2O3 NPs decreased shoot biomass (≥10 mg/L), the root biomass and length (≥5 mg/L). Moreover, La2O3 NPs had adverse effects on the chlorophyll content (≥10 mg/L). The decreased chlorophyll content may reduce net photosynthetic rate. This research offers vital information about the phytotoxicity of La2O3 NPs.

Identification of Teosinte (Zea mays ssp. parviglumis) alleles for resistance to southern leaf blight in near isogenic maize lines

USDA-ARS?s Scientific Manuscript database

Southern Leaf Blight [(SLB), causal agent Cochliobolus heterostrophus race O] is an important fungal disease of maize in the United States. Teosinte (Zea mays ssp. parviglumis), the wild progenitor of maize, offers a novel source of resistance alleles that may have been lost during domestication. T...

Compounds formed by treatment of corn (Zea mays) with nitrous acid.

PubMed

Archer, M C; Hansen, T J; Tannenbaum, S R

1980-01-01

Nitrohexane has been identified as a major product formed following treatment of corn (Zea mays) with nitrous acid. Preliminary evidence suggests that another compound isolated from the nitrosated corn is an unsaturated nitrolic acid. As an aid to the analysis of N-nitro compounds, we have characterized the response of a chemiluminescence detector (Thermal Energy Analyzer) as a function of pyrolysis chamber temperature for several nitrosamines and for an aliphatic C-nitroso compound, an aromatic C-nitro compound, a nitramine and an alkyl nitrite. The response-temperature profiles are valuable in distinguishing among the various compounds and in optimizing the sensitivity of the detector for use in chromatography. Other tests, including photolysis and stability toward nitrite-scavenging reagents, further aid in distinguishing among the various compounds.

Complete mitochondrial genome of Helicoverpa zea (Boddie) and expression profiles of mitochondrial-encoded genes in early and late embryos

USDA-ARS?s Scientific Manuscript database

The mitochondrial genome of the bollworm, Helicoverpa zea, was assembled using paired-end nucleotide sequence reads generated with a next-generation sequencing platform. Assembly resulted in a mitogenome of 15,348 bp with greater than 17,000-fold average coverage. Organization of the H. zea mitogen...

Occultifur kilbournensis f.a. sp. nov., a new member of the Cystobasidiales associated with maize (Zea mays) cultivation

USDA-ARS?s Scientific Manuscript database

During a study of microorganisms associated with maize (Zea mays) cultivation, yeasts were isolated from overwintered stalks, cobs and surrounding soil, which were collected from an agricultural field in south-central Illinois, USA. Predominant among isolates were two species of Cryptococcus (Cr. fl...

TOXICITY OF METHYL-TERT BYTYL ETHER (MTBE) TO PLANTS (AVENA SATIVA, ZEA MAYS, TRITICUM AESTIVUM, AND LACTUCA SATIVA)

EPA Science Inventory

Effects of Methyl tert-butyl ether (MTBE) on the germination of seeds and growth of the plant were studied in some laboratory experiments. Test plants were wild oat (Avena sative), sweet corn (Zea mays), wheat (Triticum aestivum), and lettuce (Lactuca sativa). Seed germination,...

Movement of endogenous calcium in the elongating zone of graviresponding roots of Zea mays

NASA Technical Reports Server (NTRS)

Moore, R.; Cameron, I. L.; Smith, N. K.

1989-01-01

Endogenous calcium (Ca) accumulates along the lower side of the elongating zone of horizontally oriented roots of Zea mays cv. Yellow Dent. This accumulation of Ca correlates positively with the onset of gravicurvature, and occurs in the cytoplasm, cell walls and mucilage of epidermal cells. Corresponding changes in endogenous Ca do not occur in cortical cells of the elongating zone of intact roots. These results indicate that the calcium asymmetries associated with root gravicurvature occur in the outermost layers of the root.

Flooding tolerance in interspecific introgression lines containing chromosome segments from teosinte (Zea nicaraguensis) in maize (Zea mays subsp. mays).

PubMed

Mano, Y; Omori, F

2013-10-01

Nicaraguan teosinte (Zea nicaraguensis), a species found in frequently flooded areas, provides useful germplasm for breeding flooding-tolerant maize (Z. mays subsp. mays). The objective of this study was to select flooding-tolerant lines using a library of introgression lines (ILs), each containing a chromosome segment from Z. nicaraguensis in the maize inbred line Mi29. To produce the ILs, a single F1 plant derived from a cross between maize Mi29 and Z. nicaraguensis was backcrossed to Mi29 three times, self-pollinated four times and genotyped using simple sequence repeat markers. Flooding tolerance was evaluated at the seedling stage under reducing soil conditions. By backcrossing and selfing, a series of 45 ILs were developed covering nearly the entire maize genome. Five flooding-tolerant lines were identified from among the ILs by evaluating leaf injury. Among these, line IL#18, containing a Z. nicaraguensis chromosome segment on the long arm of chromosome 4, showed the greatest tolerance to flooding, suggesting the presence of a major quantitative trait locus (QTL) in that region. The presence of the QTL was verified by examining flooding tolerance in a population segregating for the candidate region of chromosome 4. There was no significant relationship between the capacity to form constitutive aerenchyma and flooding tolerance in the ILs, indicating the presence of other factors related to flooding tolerance under reducing soil conditions. A flooding-tolerant genotype, IL#18, was identified; this genotype should be useful for maize breeding. In addition, because the chromosome segments of Z. nicaraguensis in the ILs cover nearly the entire genome and Z. nicaraguensis possesses several unique traits related to flooding tolerance, the ILs should be valuable material for additional QTL detection and the development of flooding-tolerant maize lines.

Flooding tolerance in interspecific introgression lines containing chromosome segments from teosinte (Zea nicaraguensis) in maize (Zea mays subsp. mays)

PubMed Central

Mano, Y.; Omori, F.

2013-01-01

Background and Aims Nicaraguan teosinte (Zea nicaraguensis), a species found in frequently flooded areas, provides useful germplasm for breeding flooding-tolerant maize (Z. mays subsp. mays). The objective of this study was to select flooding-tolerant lines using a library of introgression lines (ILs), each containing a chromosome segment from Z. nicaraguensis in the maize inbred line Mi29. Methods To produce the ILs, a single F1 plant derived from a cross between maize Mi29 and Z. nicaraguensis was backcrossed to Mi29 three times, self-pollinated four times and genotyped using simple sequence repeat markers. Flooding tolerance was evaluated at the seedling stage under reducing soil conditions. Key Results By backcrossing and selfing, a series of 45 ILs were developed covering nearly the entire maize genome. Five flooding-tolerant lines were identified from among the ILs by evaluating leaf injury. Among these, line IL#18, containing a Z. nicaraguensis chromosome segment on the long arm of chromosome 4, showed the greatest tolerance to flooding, suggesting the presence of a major quantitative trait locus (QTL) in that region. The presence of the QTL was verified by examining flooding tolerance in a population segregating for the candidate region of chromosome 4. There was no significant relationship between the capacity to form constitutive aerenchyma and flooding tolerance in the ILs, indicating the presence of other factors related to flooding tolerance under reducing soil conditions. Conclusions A flooding-tolerant genotype, IL#18, was identified; this genotype should be useful for maize breeding. In addition, because the chromosome segments of Z. nicaraguensis in the ILs cover nearly the entire genome and Z. nicaraguensis possesses several unique traits related to flooding tolerance, the ILs should be valuable material for additional QTL detection and the development of flooding-tolerant maize lines. PMID:23877074

Localization of lead accumulated by corn plants. [Zea mays L

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

Malone, C.; Koeppe, D.E.; Miller, R.J.

1974-01-01

Light and electron microscopic studies of corn plants (Zea mays L.) exposed to Pb in hydroponic solution showed that the roots generally accumulated a surface Pb precipitate and slowly accumulated Pb crystals in the cell walls. The root surface precipitate formed without the apparent influence of any cell organelles. In contrast, Pb taken up by roots was concentrated in dicytosome vesicles. Dicytosome vesicles containing cell wall material fused with one another to encase the Pb deposit. This encased deposit which was surrounded by a membrane migrated toward the outside of the cell where the membrane surrounding the deposit then fusedmore » with the plasmalemma. The material surrounding the deposit then fused with the cell wall. The result of this process was a concentration of Pb deposits in the cell wall outside the plasmalemma. Similar deposits were observed in stems and leaves suggesting that Pb was transported and deposited in a similar manner.« less

[Antimutagenic activity of Armoracia rusticana, Zea mays and Ficus carica plant extracts and their mixture].

PubMed

Agabeĭli, R A; Kasimova, T E

2005-01-01

Antimutagenic action of plant extracts of Armoracia rusticana, Ficus carica, Zea mays and their mixture on environmental xenobiotics has been investigated. The plant extracts and their mixture decreased the level of mutations induced by N-metil-N'-nitro-N-nitrozoguanidin (MNNG) in Vicia faba cells, chlorophyll mutations in Arabidopsis thaliana and NaF induced mutability in rat marrow cells. The studied plant extracts and their mixture demonstrate the ability to decrease the genotoxicity of environmental mutagens.

Patterns of diversity and recombination along chromosome 1 of maize (Zea mays ssp. mays L.).

PubMed Central

Tenaillon, Maud I; Sawkins, Mark C; Anderson, Lorinda K; Stack, Stephen M; Doebley, John; Gaut, Brandon S

2002-01-01

We investigate the interplay between genetic diversity and recombination in maize (Zea mays ssp. mays). Genetic diversity was measured in three types of markers: single-nucleotide polymorphisms, indels, and microsatellites. All three were examined in a sample of previously published DNA sequences from 21 loci on maize chromosome 1. Small indels (1-5 bp) were numerous and far more common than large indels. Furthermore, large indels (>100 bp) were infrequent in the population sample, suggesting they are slightly deleterious. The 21 loci also contained 47 microsatellites, of which 33 were polymorphic. Diversity in SNPs, indels, and microsatellites was compared to two measures of recombination: C (=4Nc) estimated from DNA sequence data and R based on a quantitative recombination nodule map of maize synaptonemal complex 1. SNP diversity was correlated with C (r = 0.65; P = 0.007) but not with R (r = -0.10; P = 0.69). Given the lack of correlation between R and SNP diversity, the correlation between SNP diversity and C may be driven by demography. In contrast to SNP diversity, microsatellite diversity was correlated with R (r = 0.45; P = 0.004) but not C (r = -0.025; P = 0.55). The correlation could arise if recombination is mutagenic for microsatellites, or it may be consistent with background selection that is apparent only in this class of rapidly evolving markers. PMID:12454083

Promoting Student Inquiry Using "Zea Mays" (Corn) Cultivars for Hypothesis-Driven Experimentation in a Majors Introductory Biology Course

ERIC Educational Resources Information Center

Blair, Amy C.; Peters, Brenda J.; Bendixen, Conrad W.

2014-01-01

The AAAS Vision and Change report (2011) recommends incorporating student research experiences into the biology curriculum at the undergraduate level. This article describes, in detail, how "Zea mays" (corn) cultivars were used as a model for a hypothesis-driven short-term research project in an introductory biology course at a small…

ent-Kaurane Diterpenoids with Neuroprotective Properties from Corn Silk ( Zea mays).

PubMed

Qi, Xiao-Li; Zhang, Ying-Ying; Zhao, Peng; Zhou, Le; Wang, Xiao-Bo; Huang, Xiao-Xiao; Lin, Bin; Song, Shao-Jiang

2018-05-25

Thirteen new ent-kaurane diterpenoids, stigmaydenes A-M (1-13), together with two known compounds (14, 15), were isolated from the crude extract of corn silk ( Zea mays). The structures of the compounds were confirmed by comprehensive spectroscopic analyses. The absolute configuration of compound 1 was defined by single-crystal X-ray diffraction. The absolute configurations of the compounds were also confirmed by comparison of experimental and calculated specific rotations. The compounds were evaluated for their neuroprotective effects against H 2 O 2 -induced SH-SY5Y cell injury, and compound 8 was active at 100 μM, as determined by flow cytometry (annexin V-FITC/PI staining) and Hoechst 33258 staining. The results suggested that compound 8 could protect neuronal cells from H 2 O 2 -induced injury by inhibiting apoptosis in SH-SY5Y cells.

The effect of ethylene on root growth of Zea mays seedlings

NASA Technical Reports Server (NTRS)

Whalen, M. C.; Feldman, L. J.

1988-01-01

The control of primary root growth in Zea mays cv. Merit by ethylene was examined. At applied concentrations of ethylene equal to or greater than 0.1 microliter L-1, root elongation during 24 h was inhibited. The half-maximal response occurred at 0.6 microliter L-1 and the response saturated at 6 microliters L-1. Inhibition of elongation took place within 20 min. However, after ethylene was removed, elongation recovered to control values within 15 min. Root elongation was also inhibited by green light. The inhibition caused by a 24-h exposure to ethylene was restricted to the elongating region just behind the apex, with inhibition of cortical cell elongation being the primary contributor to the effect. Based on use of 2,5-norbornadiene, a gaseous competitive inhibitor of ethylene, it was concluded that endogenous ethylene normally inhibits root elongation.

Movement of 14C-Labeled Assimilates into Kernels of Zea mays L

PubMed Central

Shannon, Jack C.; Dougherty, C. T.

1972-01-01

Invertases of the placento-chalazal and pedicel tissues are much more active than invertase from the pericarp of Zea mays L. kernels 12 to 40 days after pollination. Sucrose synthetase was not detected in the pedicel or placento-chalazal tissues. Sucrose content and percentage increased in the pedicel with advancing kernel age. Hexoses accounted for over half of the sugars extracted from the placento-chalazal tissues. These data are consistent with the hypothesis that sucrose translocated to the pedicel is hydrolyzed by acid invertase(s) prior to entry of sugar into the endosperm tissue. The placentochalazal tissue appears to be the primary site of sucrose inversion with the pedicel invertase contributing more or less to this process depending on kernel age. PMID:16657925

Antifungal-protein production in maize (Zea mays) suspension cultures.

PubMed

Perri, Fabio; Della Penna, Serena; Rufini, Francesca; Patamia, Maria; Bonito, Mariantonietta; Angiolella, Letizia; Vitali, Alberto

2009-04-01

The growing emergency due to the phenomenon of drug resistance to micro-organisms has pushed forward the search for new potential drug alternatives to those already in use. Plants represent a suitable source of new antifungal molecules, as they produce a series of defensive proteins. Among them are the PRPs (pathogenesis-related proteins), shown to be effective in vitro against human pathogens. An optimized and established cell-suspension culture of maize (Zea mays) was shown to constitutively secrete in the medium a series of PRPs comprising the antifungal protein zeamatin (P33679) with a final yield of approx. 3 mg/litre. The in-vitro-produced zeamatin possessed antifungal activity towards a clinical strain of the human pathogenic yeast Candida albicans, an activity comparable with the one reported for the same protein extracted from maize seeds. Along with zeamatin, other PRPs were expressed: a 9 kDa lipid-transfer protein, a 26 kDa xylanase inhibitor and a new antifungal protein, PR-5. A fast, two-step chromatographic procedure was set up allowing the complete purification of the proteins considered, making this cell line a valuable system for the production of potential antifungal agents in a reliable and easy way.

Chloroplasts in anther endothecium of Zea mays (Poaceae).

PubMed

Murphy, Katherine M; Egger, Rachel L; Walbot, Virginia

2015-11-01

Although anthers of Zea mays, Oryza sativa, and Arabidopsis thaliana have been studied intensively using genetic and biochemical analyses in the past 20 years, few updates to anther anatomical and ultrastructural descriptions have been reported. For example, no transmission electron microscopy (TEM) images of the premeiotic maize anther have been published. Here we report the presence of chloroplasts in maize anthers. TEM imaging, electron acceptor photosynthesis assay, in planta photon detection, microarray analysis, and light and fluorescence microscopy were used to investigate the presence of chloroplasts in the maize anther. Most cells of the maize subepidermal endothecium have starch-containing chloroplasts that do not conduct measurable photosynthesis in vitro. The maize anther contains chloroplasts in most subepidermal, endothecial cells. Although maize anthers receive sufficient light to photosynthesize in vivo and the maize anther transcribes >96% of photosynthesis-associated genes found in the maize leaf, no photosynthetic light reaction activity was detected in vitro. The endothecial cell layer should no longer be defined as a complete circle viewed transversely in anther lobes, because chloroplasts are observed only in cells directly beneath the epidermis and not those adjacent to the connective tissue. We propose that chloroplasts be a defining characteristic of differentiated endothecial cells and that nonsubepidermal endothecial cells that lack chloroplasts be defined as a separate cell type, the interendothecium. © 2015 Botanical Society of America.

Use of Zea mays L. in phytoremediation of trichloroethylene.

PubMed

Moccia, Emanuele; Intiso, Adriano; Cicatelli, Angela; Proto, Antonio; Guarino, Francesco; Iannece, Patrizia; Castiglione, Stefano; Rossi, Federico

2017-04-01

Trichloroethylene (TCE) is a chlorinated aliphatic organic compound often detected as pollutant in soils and ground water. "Green technologies" based on phytoremediation were proven to be effective to reclaim organic pollutants (e.g. TCE) and heavy metals from different environmental matrices. In this work, we use Zea mays L. for the removal of high TCE concentrations from medium cultures. In particular, we investigated a sealed bioreactor where the growth medium was contaminated with an increasing amount of TCE, in the range 55-280 mg/L; the removal capability of the maize plants was assessed by means of GC-MS and LC-MS analyses. An accurate mass balance of the system revealed that the plants were able to remove and metabolise TCE with an efficiency up to 20 %, depending on the total amount of TCE delivered in the bioreactor. Morphometric data showed that the growth of Z. mays is not significantly affected by the presence of the pollutant up to a concentration of 280 mg/L, while plants show significant alterations at higher TCE concentrations until the growth is completely inhibited for [TCE] ≃ 2000 mg/L. Finally, the presence of several TCE metabolites, including dichloroacetic and trichloroacetic acids, was detected in the roots and in the aerial part of the plants, revealing that Z. mays follows the green liver metabolic model. These results encourage further studies for the employment of this plant species in phytoremediation processes of soils and waters contaminated by TCE and, potentially, by many other chlorinated solvents.

Anti-inflammatory effects of Zea mays L. husk extracts.

PubMed

Roh, Kyung-Baeg; Kim, Hyoyoung; Shin, Seungwoo; Kim, Young-Soo; Lee, Jung-A; Kim, Mi Ok; Jung, Eunsun; Lee, Jongsung; Park, Deokhoon

2016-08-19

Zea mays L. (Z. mays) has been used for human consumption in the various forms of meal, cooking oil, thickener in sauces and puddings, sweetener in processed food and beverage products, bio-disel. However, especially, in case of husk extract of Z. mays, little is known about its anti-inflammatory effects. Therefore, in this study, the anti-inflammatory effects of Z. mays husk extract (ZMHE) and its mechanisms of action were investigated. The husks of Z. Mays were harvested in kangwondo, Korea. To assess the anti-inflammatory activities of ZMHE, we examined effects of ZMHE on nitric oxide (NO) production, and release of soluble intercellular adhesion molecule-1 (sICAM-1) and eotaxin-1. The expression level of inducible nitric oxide synthase (iNOS) gene was also determined by Western blot and luciferase reporter assays. To determine its mechanisms of action, a luciferase reporter assay for nuclear factor kappa B (NF-kB) and activator protein-1 (AP-1) was introduced. ZMHE inhibited lipopolysaccharide (LPS)-induced production of NO in RAW264.7 cells. In addition, expression of iNOS gene was reduced, as confirmed by Western blot and luciferase reporter assays. Effects of ZMHE on the AP-1 and NF-kB promoters were examined to elucidate the mechanism of its anti-inflammatory activity. Activation of AP-1 and NF-kB promoters induced by LPS was significantly reduced by ZMHE treatment. In addition, LPS-induced production of sICAM-1 and IL-4-induced production of eotaxin-1 were all reduced by ZMHE. Our results indicate that ZMHE has anti-inflammatory effects by downregulating the expression of iNOS gene and its downregulation is mediated by inhibiting NF-kB and AP-1 signaling.

Ergot Alkaloid Biosynthesis in the Maize (Zea mays) Ergot Fungus Claviceps gigantea.

PubMed

Bragg, Paige E; Maust, Matthew D; Panaccione, Daniel G

2017-12-13

Biosynthesis of the dihydrogenated forms of ergot alkaloids is of interest because many of the ergot alkaloids used as pharmaceuticals may be derived from dihydrolysergic acid (DHLA) or its precursor dihydrolysergol. The maize (Zea mays) ergot pathogen Claviceps gigantea has been reported to produce dihydrolysergol, a hydroxylated derivative of the common ergot alkaloid festuclavine. We hypothesized expression of C. gigantea cloA in a festuclavine-accumulating mutant of the fungus Neosartorya fumigata would yield dihydrolysergol because the P450 monooxygenase CloA from other fungi performs similar oxidation reactions. We engineered such a strain, and high performance liquid chromatography and liquid chromatography-mass spectrometry analyses demonstrated the modified strain produced DHLA, the fully oxidized product of dihydrolysergol. Accumulation of high concentrations of DHLA in field-collected C. gigantea sclerotia and discovery of a mutation in the gene lpsA, downstream from DHLA formation, supported our finding that DHLA rather than dihydrolysergol is the end product of the C. gigantea pathway.

[Antimutagenic activity of plant extracts from Armoracia rusticana, Ficus carica and Zea mays and peroxidase in eukaryotic cells].

PubMed

Agabeĭli, R A; Kasimova, T E; Alekperov, U K

2004-01-01

Antimutagene activity and high efficiency of antimutagene action of plant extracts from horseradish roots (Armoracia rusticana), fig brunches (Ficus carica) and mays seedlings (Zea mays) and their ability to decrease the frequency of spontaneous and induced by gamma-rays chromosome aberrations in meristematic cells of Vicia faba and marrow cells of mice have been shown. Comparative assessment of genoprotective properties of peroxidase and the studied extracts has revealed higher efficiency of antimutagene action of peroxidase.

Root graviresponsiveness and columella cell structure in carotenoid-deficient seedlings of Zea mays

NASA Technical Reports Server (NTRS)

Moore, R.; McClelen, C. E.

1985-01-01

Root graviresponsiveness in normal and carotenoid-deficient mutant seedlings of Zea mays was not significantly different. Columella cells in roots of mutant seedlings were characterized by fewer, smaller, and a reduced relative volume of plastids as compared to columella cells of normal seedlings. Plastids in columella cells of mutant seedlings possessed reduced amounts of starch. Although approximately 10 per cent of the columella cells in mutant seedlings lacked starch, their plastids were located at the bottom of the cell. These results suggest that (i) carotenoids are not necessary for root gravitropism, (ii) graviresponsiveness is not necessarily proportional to the size, number, or relative volume of plastids in columella cells, and (iii) sedimentation of plastids in columella cells may not result directly from their increased density due to starch content. Plastids in columella cells of normal and mutant seedlings were associated with bands of microtubule-like structures, suggesting that these structures may be involved in 'positioning' plastids in the cell.

Study of cell-differentiation and assembly of photosynthetic proteins during greening of etiolated Zea mays leaves using confocal fluorescence microspectroscopy at liquid-nitrogen temperature.

PubMed

Shibata, Yutaka; Katoh, Wataru; Tahara, Yukari

2013-04-01

Fluorescence microspectroscopy observations were used to study the processes of cell differentiation and assemblies of photosynthesis proteins in Zea mays leaves under the greening process. The observations were done at 78K by setting the sample in a cryostat to avoid any undesired progress of the greening process during the measurements. The lateral and axial spatial resolutions of the system were 0.64μm and 4.4μm, respectively. The study revealed the spatial distributions of protochlorophyllide (PChld) in both the 632-nm-emitting and 655-nm-emitting forms within etiolated Zea mays leaves. The sizes of the fluorescence spots attributed to the former were larger than those of the latter, validating the assignment of the former and latter to the prothylakoid and prolamellar bodies, respectively. In vivo microspectroscopy observations of mature Zea mays leaves confirmed the different photosystem II (PS I)/photosystem I (PS II) ratio between the bundle sheath (BS) and mesophyll (MS) cells, which is specific for C4-plants. The BS cells in Zea mays leaves 1h after the initiation of the greening process tended to show fluorescence spectra at shorter wavelength side (at around 679nm) than the MS cells (at around 682nm). The 679-nm-emitting chlorophyll-a form observed mainly in the BS cells was attributed to putative precursor complexes to PS I. The BS cells under 3-h greening showed higher relative intensities of the PS I fluorescence band at around 735nm, suggesting the reduced PS II amount in the BS cells in this greening stage. Copyright © 2013 Elsevier B.V. All rights reserved.

Molecular Evolution and Expansion Analysis of the NAC Transcription Factor in Zea mays

PubMed Central

Fan, Kai; Wang, Ming; Miao, Ying; Ni, Mi; Bibi, Noreen; Yuan, Shuna; Li, Feng; Wang, Xuede

2014-01-01

NAC (NAM, ATAF1, 2 and CUC2) family is a plant-specific transcription factor and it controls various plant developmental processes. In the current study, 124 NAC members were identified in Zea mays and were phylogenetically clustered into 13 distinct subfamilies. The whole genome duplication (WGD), especially an additional WGD event, may lead to expanding ZmNAC members. Different subfamily has different expansion rate, and NAC subfamily preference was found during the expansion in maize. Moreover, the duplication events might occur after the divergence of the lineages of Z. mays and S. italica, and segmental duplication seemed to be the dominant pattern for the gene duplication in maize. Furthermore, the expansion of ZmNAC members may be also related to gain and loss of introns. Besides, the restriction of functional divergence was discovered after most of the gene duplication events. These results could provide novel insights into molecular evolution and expansion analysis of NAC family in maize, and advance the NAC researches in other plants, especially polyploid plants. PMID:25369196

Pollen source effects on growth of kernel structures and embryo chemical compounds in maize.

PubMed

Tanaka, W; Mantese, A I; Maddonni, G A

2009-08-01

Previous studies have reported effects of pollen source on the oil concentration of maize (Zea mays) kernels through modifications to both the embryo/kernel ratio and embryo oil concentration. The present study expands upon previous analyses by addressing pollen source effects on the growth of kernel structures (i.e. pericarp, endosperm and embryo), allocation of embryo chemical constituents (i.e. oil, protein, starch and soluble sugars), and the anatomy and histology of the embryos. Maize kernels with different oil concentration were obtained from pollinations with two parental genotypes of contrasting oil concentration. The dynamics of the growth of kernel structures and allocation of embryo chemical constituents were analysed during the post-flowering period. Mature kernels were dissected to study the anatomy (embryonic axis and scutellum) and histology [cell number and cell size of the scutellums, presence of sub-cellular structures in scutellum tissue (starch granules, oil and protein bodies)] of the embryos. Plants of all crosses exhibited a similar kernel number and kernel weight. Pollen source modified neither the growth period of kernel structures, nor pericarp growth rate. By contrast, pollen source determined a trade-off between embryo and endosperm growth rates, which impacted on the embryo/kernel ratio of mature kernels. Modifications to the embryo size were mediated by scutellum cell number. Pollen source also affected (P < 0.01) allocation of embryo chemical compounds. Negative correlations among embryo oil concentration and those of starch (r = 0.98, P < 0.01) and soluble sugars (r = 0.95, P < 0.05) were found. Coincidently, embryos with low oil concentration had an increased (P < 0.05-0.10) scutellum cell area occupied by starch granules and fewer oil bodies. The effects of pollen source on both embryo/kernel ratio and allocation of embryo chemicals seems to be related to the early established sink strength (i.e. sink size and sink activity) of the

Enhanced plastochromanol-8 accumulation during reiterated drought in maize (Zea mays L.).

PubMed

Fleta-Soriano, Eva; Munné-Bosch, Sergi

2017-03-01

Plastochromanol-8 (PC-8) belongs to the group of tocochromanols, and together with tocopherols and carotenoids, might help protect photosystem II from photoinhibition during environmental stresses. Here, we aimed to unravel the time course evolution of PC-8 together with that of vitamin E compounds, in maize (Zea mays L.) plants exposed to reiterated drought. Measurements were performed in plants grown in a greenhouse subjected to two consecutive cycles of drought-recovery. PC-8 contents, which accounted for more than 25% of tocochromanols in maize leaves, increased progressively in response to reiterated drought stress. PC-8 contents paralleled with those of vitamin E, particularly α-tocopherol. Profiling of the stress-related phytohormones (ABA, jasmonic acid and salicylic acid) was consistent with a role of ABA in the regulation of PC-8 and vitamin E biosynthesis during drought stress. Results also suggest that PC-8 may help tocopherols prevent damage to the photosynthetic apparatus. A better knowledge of the ABA-dependent regulation of PC-8 may help us manipulate the contents of this important antioxidant in crops. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Targeted mutagenesis in Zea mays using TALENs and the CRISPR/Cas system.

PubMed

Liang, Zhen; Zhang, Kang; Chen, Kunling; Gao, Caixia

2014-02-20

Transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) systems have emerged as powerful tools for genome editing in a variety of species. Here, we report, for the first time, targeted mutagenesis in Zea mays using TALENs and the CRISPR/Cas system. We designed five TALENs targeting 4 genes, namely ZmPDS, ZmIPK1A, ZmIPK, ZmMRP4, and obtained targeting efficiencies of up to 23.1% in protoplasts, and about 13.3% to 39.1% of the transgenic plants were somatic mutations. Also, we constructed two gRNAs targeting the ZmIPK gene in maize protoplasts, at frequencies of 16.4% and 19.1%, respectively. In addition, the CRISPR/Cas system induced targeted mutations in Z. mays protoplasts with efficiencies (13.1%) similar to those obtained with TALENs (9.1%). Our results show that both TALENs and the CRISPR/Cas system can be used for genome modification in maize. Copyright © 2013. Published by Elsevier Ltd.

Response to gravity by Zea mays seedlings. I. Time course of the response

NASA Technical Reports Server (NTRS)

Bandurski, R. S.; Schulze, A.; Dayanandan, P.; Kaufman, P. B.

1984-01-01

Gravistimulation induces an asymmetric distribution of free indole-3-acetic acid (IAA) in the cortex-epidermis of the Zea mays L. cv 'Stowells Evergreen' mesocotyl within 15 minutes, the shortest time tested. IAA was measured by an isotope dilution method as the pentaflurobenzyl ester. The per cent IAA in the lower half of the mescotyl cortex was 56 to 57% at 15, 30, and 90 minutes after stimulus initiation. Curvature is detectable in the mescotyl within 3 minutes after beginning gravitropic stimulation. The rate of curvature of the mesocotyl increases during the first 60 minutes to maximum of about 30 degrees per hour. Thus, the growth asymmetry continues to increase for 45 minutes after hormone asymmetry is established. Free IAA occurs predominantly in the stele of the mesocotyl whereas esterified IAA is mainly in the mesocotyl cortex-epidermis. This compartmentation may permit determining in which tissue the hormone asymmetry arises. Current data suggest the asymmetry originated in the stele.

Acclimation improves salt stress tolerance in Zea mays plants.

PubMed

Pandolfi, Camilla; Azzarello, Elisa; Mancuso, Stefano; Shabala, Sergey

2016-08-20

Plants exposure to low level salinity activates an array of processes leading to an improvement of plant stress tolerance. Although the beneficial effect of acclimation was demonstrated in many herbaceous species, underlying mechanisms behind this phenomenon remain poorly understood. In the present study we have addressed this issue by investigating ionic mechanisms underlying the process of plant acclimation to salinity stress in Zea mays. Effect of acclimation were examined in two parallel sets of experiments: a growth experiment for agronomic assessments, sap analysis, stomatal conductance, chlorophyll content, and confocal laser scanning imaging; and a lab experiment for in vivo ion flux measurements from root tissues. Being exposed to salinity, acclimated plants (1) retain more K(+) but accumulate less Na(+) in roots; (2) have better vacuolar Na(+) sequestration ability in leaves and thus are capable of accumulating larger amounts of Na(+) in the shoot without having any detrimental effect on leaf photochemistry; and (3) rely more on Na(+) for osmotic adjustment in the shoot. At the same time, acclimation affect was not related in increased root Na(+) exclusion ability. It appears that even in a such salt-sensitive species as maize, Na(+) exclusion from uptake is of a much less importance compared with the efficient vacuolar Na(+) sequestration in the shoot. Copyright © 2016 Elsevier GmbH. All rights reserved.

Fungal and fumonisins contamination in Argentine maize (Zea mays L.) silo bags.

PubMed

Pacin, Ana M; Ciancio Bovier, Emilia; González, Héctor H L; Whitechurch, Elena M; Martínez, Elena J; Resnik, Silvia L

2009-04-08

Fumonisins in maize (Zea mays L.) grain silo bags in the conditions of three Argentine provinces were analyzed to determine how this kind of storage affects contamination and if differential storage durations or times of the year of silo bag closing and opening are factors that could modify it. Moisture content, water activity (a(w)), molds and yeasts present, and fumonisins were analyzed in 163 maize silo bags, at the moment of closing and later at opening. Storage durations ranged from 120 to 226 days. The analysis was centered on fumonisins since most samples were only contaminated with these toxins. Fumonisins, moisture content, and a(w) increased significantly, whereas mold propagules/g and yeasts CFU/g did not present significant differences between silo opening and closing. The date on which silo bags were closed and later opened, however, did affect the level of fumonisin contamination.

Root cortical aerenchyma inhibits radial nutrient transport in maize (Zea mays).

PubMed

Hu, Bo; Henry, Amelia; Brown, Kathleen M; Lynch, Jonathan P

2014-01-01

Formation of root cortical aerenchyma (RCA) can be induced by nutrient deficiency. In species adapted to aerobic soil conditions, this response is adaptive by reducing root maintenance requirements, thereby permitting greater soil exploration. One trade-off of RCA formation may be reduced radial transport of nutrients due to reduction in living cortical tissue. To test this hypothesis, radial nutrient transport in intact roots of maize (Zea mays) was investigated in two radiolabelling experiments employing genotypes with contrasting RCA. In the first experiment, time-course dynamics of phosphate loading into the xylem were measured from excised nodal roots that varied in RCA formation. In the second experiment, uptake of phosphate, calcium and sulphate was measured in seminal roots of intact young plants in which variation in RCA was induced by treatments altering ethylene action or genetic differences. In each of three paired genotype comparisons, the rate of phosphate exudation of high-RCA genotypes was significantly less than that of low-RCA genotypes. In the second experiment, radial nutrient transport of phosphate and calcium was negatively correlated with the extent of RCA for some genotypes. The results support the hypothesis that RCA can reduce radial transport of some nutrients in some genotypes, which could be an important trade-off of this trait.

Colonization of Corn, Zea mays, by the Entomopathogenic Fungus Beauveria bassiana†

PubMed Central

Wagner, Bruce L.; Lewis, Leslie C.

2000-01-01

Light and electron microscopy were used to describe the mode of penetration by the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin into corn, Zea mays L. After inoculation with a foliar spray of conidia, germinating hyphae grew randomly across the leaf surface. Often a germ tube formed from a conidium and elongated only a short distance before terminating its growth. Not all developing hyphae on the leaf surface penetrated the cuticle. However, when penetration did occur, the penetration site(s) was randomly located, indicating that B. bassiana does not require specific topographic signals at an appropriate entry site as do some phytopathogenic fungi. Long hyphal structures were observed to follow the leaf apoplast in any direction from the point of penetration. A few hyphae were observed within xylem elements. Because vascular bundles are interconnected throughout the corn plant, this may explain how B. bassiana travels within the plant and ultimately provides overall insecticidal protection. Virulency bioassays demonstrate that B. bassiana does not lose virulence toward the European corn borer, Ostrinia nubilalis (Hübner), once it colonizes corn. This endophytic relationship between an entomopathogenic fungus and a plant suggests possibilities for biological control, including the use of indigenous fungal inocula as insecticides. PMID:10919808

Uronide Deposition Rates in the Primary Root of Zea mays1

PubMed Central

Silk, Wendy Kuhn; Walker, Robert C.; Labavitch, John

1984-01-01

The spatial distribution of the rate of deposition of uronic acids in the elongation zone of Zea mays L. Crow WF9 × Mo 17 was determined using the continuity equation with experimentally determined values for uronide density and growth velocity. In spatial terms, the uronide deposition rate has a maximum of 0.4 micrograms per millimeter per hour at s = 3.5 mm (i.e., at the location 3.5 mm from the root tip) and decreases to 0.1 mg mm−1 h−1 by s = 10 mm. In terms of a material tissue element, a tissue segment located initially from s = 2.0 to s = 2.1 mm has 0.14 μg of uronic acids and increases in both length and uronic acid content until it is 0.9 mm long and has 0.7 μg of uronide when its center is at s = 10 mm. Simulations of radioactive labeling experiments show that 15 min is the appropriate time scale for pulse determinations of deposition rate profiles in a rapidly growing corn root. PMID:16663488

Measurement of the rates of oxindole-3-acetic acid turnover, and indole-3-acetic acid oxidation in Zea mays seedlings

NASA Technical Reports Server (NTRS)

Nonhebel, H. M.; Bandurski, R. S. (Principal Investigator)

1986-01-01

Oxindole-3-acetic acid is the principal catabolite of indole-3-acetic acid in Zea mays seedlings. In this paper measurements of the turnover of oxindole-3-acetic acid are presented and used to calculate the rate of indole-3-acetic acid oxidation. [3H]Oxindole-3-acetic acid was applied to the endosperm of Zea mays seedlings and allowed to equilibrate for 24 h before the start of the experiment. The subsequent decrease in its specific activity was used to calculate the turnover rate. The average half-life of oxindole-3-acetic acid in the shoots was found to be 30 h while that in the kernels had an average half-life of 35h. Using previously published values of the pool sizes of oxindole-3-acetic acid in shoots and kernels from seedlings of the same age and variety, and grown under the same conditions, the rate of indole-3-acetic acid oxidation was calculated to be 1.1 pmol plant-1 h-1 in the shoots and 7.1 pmol plant-1 h-1 in the kernels.

Occurrence and in Vivo Biosynthesis of Indole-3-Butyric Acid in Corn (Zea mays L.) 1

PubMed Central

Ludwig-Müller, Jutta; Epstein, Ephraim

1991-01-01

Indole-3-butyric acid (IBA) was identified as an endogenous compound in leaves and roots of maize (Zea mays L.) var Inrakorn by thin layer chromatography, high-performance liquid chromatography, and gas chromatography-mass spectrometry. Its presence was also confirmed in the variety Hazera 224. Indole-3-acetic acid (IAA) was metabolized to IBA in vivo by seedlings of the two maize varieties. The reaction product was identified by thin layer chromatography, high performance liquid chromatography, and gas chromatography-mass spectrometry after incubating the corn seedlings with [14C]IAA and [13C6]IAA. The in vivo conversion of IAA to IBA and the characteristics of IBA formation in two different maize varieties of Zea mays L. (Hazera 224 and Inrakorn) were investigated. IBA-forming activity was examined in the roots, leaves, and coleoptiles of both maize varieties. Whereas in the variety Hazera 224, IBA was formed mostly in the leaves, in the variety Inrakorn, IBA synthesis was detected in the roots as well as in the leaves. A time course study of IBA formation showed that maximum activity was reached in Inrakorn after 1 hour and in Hazera after 2 hours. The pH optimum for the uptake of IAA was 6.0, and that for IBA formation was 7.0. The Km value for IBA formation was 17 micromolar for Inrakorn and 25 micromolar for Hazera 224. The results are discussed with respect to the possible functions of IBA in the plant. ImagesFigure 5 PMID:16668464

Nascent Transcription Affected by RNA Polymerase IV in Zea mays

PubMed Central

Erhard, Karl F.; Talbot, Joy-El R. B.; Deans, Natalie C.; McClish, Allison E.; Hollick, Jay B.

2015-01-01

All eukaryotes use three DNA-dependent RNA polymerases (RNAPs) to create cellular RNAs from DNA templates. Plants have additional RNAPs related to Pol II, but their evolutionary role(s) remain largely unknown. Zea mays (maize) RNA polymerase D1 (RPD1), the largest subunit of RNA polymerase IV (Pol IV), is required for normal plant development, paramutation, transcriptional repression of certain transposable elements (TEs), and transcriptional regulation of specific alleles. Here, we define the nascent transcriptomes of rpd1 mutant and wild-type (WT) seedlings using global run-on sequencing (GRO-seq) to identify the broader targets of RPD1-based regulation. Comparisons of WT and rpd1 mutant GRO-seq profiles indicate that Pol IV globally affects transcription at both transcriptional start sites and immediately downstream of polyadenylation addition sites. We found no evidence of divergent transcription from gene promoters as seen in mammalian GRO-seq profiles. Statistical comparisons identify genes and TEs whose transcription is affected by RPD1. Most examples of significant increases in genic antisense transcription appear to be initiated by 3ʹ-proximal long terminal repeat retrotransposons. These results indicate that maize Pol IV specifies Pol II-based transcriptional regulation for specific regions of the maize genome including genes having developmental significance. PMID:25653306

Graviresponsiveness of surgically altered primary roots of Zea mays

NASA Technical Reports Server (NTRS)

Maimon, E.; Moore, R.

1991-01-01

We examined the gravitropic responses of surgically altered primary roots of Zea mays to determine the route by which gravitropic inhibitors move from the root tip to the elongating zone. Horizontally oriented roots, from which a 1-mm-wide girdle of epidermis plus 2-10 layers of cortex were removed from the apex of the elongating zone, curve downward. However, curvature occurred only apical to the girdle. Filling the girdle with mucilage-like material transmits curvature beyond the girdle. Vertically oriented roots with a half-girdle' (i.e. the epidermis and 2-10 layers of the cortex removed from half of the circumference of the apex of the elongating zone) curve away from the girdle. Inserting the half-girdle at the base of the elongating zone induces curvature towards the girdle. Filling the half-circumference girdles with mucilage-like material reduced curvature significantly. Stripping the epidermis and outer 2-5 layers of cortex from the terminal 1.5 cm of one side of a primary root induces curvature towards the cut, irrespective of the root's orientation to gravity. This effect is not due to desiccation since treated roots submerged in water also curved towards their cut surface. Coating a root's cut surface with a mucilage-like substance minimizes curvature. These results suggest that the outer cell-layers of the root, especially the epidermis, play an important role in root gravicurvature, and the gravitropic signals emanating from the root tip can move apoplastically through mucilage.

Open Field Study of Some Zea mays Hybrids, Lipid Compounds and Fumonisins Accumulation

PubMed Central

Giorni, Paola; Dall’Asta, Chiara; Reverberi, Massimo; Scala, Valeria; Ludovici, Matteo; Cirlini, Martina; Galaverna, Gianni; Fanelli, Corrado; Battilani, Paola

2015-01-01

Lipid molecules are increasingly recognized as signals exchanged by organisms interacting in pathogenic and/or symbiotic ways. Some classes of lipids actively determine the fate of the interactions. Host cuticle/cell wall/membrane components such as sphingolipids and oxylipins may contribute to determining the fate of host–pathogen interactions. In the present field study, we considered the relationship between specific sphingolipids and oxylipins of different hybrids of Zea mays and fumonisin by F. verticillioides, sampling ears at different growth stages from early dough to fully ripe. The amount of total and free fumonisin differed significantly between hybrids and increased significantly with maize ripening. Oxylipins and phytoceramides changed significantly within the hybrids and decreased with kernel maturation, starting from physiological maturity. Although the correlation between fumonisin accumulation and plant lipid profile is certain, the data collected so far cannot define a cause-effect relationship but open up new perspectives. Therefore, the question—“Does fumonisin alter plant lipidome or does plant lipidome modulate fumonisin accumulation?”—is still open. PMID:26378580

Enzymatic adaptations to arsenic-induced oxidative stress in Zea mays and genotoxic effect of arsenic in root tips of Vicia faba and Zea mays.

PubMed

Duquesnoy, Isabelle; Champeau, Gabrielle Marie; Evray, Germaine; Ledoigt, Gérard; Piquet-Pissaloux, Agnès

2010-01-01

Agronomic plant species may display physiological and biochemical responses to oxidative stress caused by heavy metals and metalloids. Zea mays plants were grown hydroponically for eight days at different concentrations of As (0, 134 and 668 μM) and at different pH (4, 7 and 9). Metabolic variations in response to As toxicity were measured using physiological parameters and antioxidant enzymatic activities. A significant decrease in SOD activity was observed in the leaves and roots of Z. mays with the majority of As treatments. As decreased G-POX activity less in leaves than in roots. An increase in the concentration of As increased APX activity in leaves and roots, except As(V) at pH 4 and pH 9 in the leaves and As(III) at pH 9 in the roots, when there was a significant decrease in APX activity at low As concentrations. After exposure to As(V), CAT activity was the same as in the control. As(III) led to an increase in CAT activity in leaves and to a decrease in roots. With increasing concentrations of As(III), CAT activity increased in both leaves and roots whatever the pH. To obtain more detailed knowledge on the effects of arsenate and arsenite exposure on Vicia faba and Z. mays, root meristems were also examined. Roots were fed hydroponically with 134, 334, 534 and 668 μM arsenate or arsenite and 4 × 10(-3)M of maleic hydrazide as positive control, at three different pH. Physiological parameters, the mitotic index and micronuclei frequencies were evaluated in root meristems. At all three pH, the highest As(V) and As(III) concentrations induced a substantial modification in root colour, increased root thickness with stiffening, and reduced root length. High concentrations also caused a significant decrease in the mitotic index, and micronucleus chromosomic aberrations were observed in the root meristems of both species. 2010 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Effects of growing conditions on purple corncob (Zea mays L.) anthocyanins.

PubMed

Jing, Pu; Noriega, Victor; Schwartz, Steven J; Giusti, M Mónica

2007-10-17

Purple corn ( Zea mays L.) has been used for centuries as a natural food colorant in South America and, more recently, in Asia and Europe. However, limited information is available on the factors affecting their anthocyanin concentration and profiles. In this study, 18 purple corn samples grown under different conditions in Peru were evaluated for quantitative and qualitative anthocyanin composition as well as total phenolics. High variability was observed on monomeric anthocyanin and phenolic contents with yields ranging from 290 to 1333 mg/100 g dry weight (DW) and from 950 to 3516 mg/100 g DW, respectively, while 30.5-47.1% of the total phenolics were anthocyanins. The major anthocyanins present were cyanidin-3-glucoside, pelargonidin-3-glucoside, peonidin-3-glucoside, cyanidin-3-maloylglucoside, pelargonidin-3-maloylglucoside, and peonidin-3-maloylglucoside, and 35.6-54.0% of the anthocyanins were acylated. Potassium sources/concentrations on the soil and seedling density did not significantly affect anthocyanin composition. The growing location affected anthocyanin levels and the percentage of anthocyanins to total phenolics ( p < 0.01) and should be taken into account when choosing a material for color production.

Chelant-assisted phytoextraction and accumulation of Zn by Zea mays.

PubMed

Gheju, M; Stelescu, I

2013-10-15

Zea mays plants were exposed to soils with concentrations of Zn ranging from 64 to 1800 mg kg(-1) dw, and the efficiency of three selected chelating agents (trisodium citrate (CI), disodium oxalate (OX) and disodium dihydrogen ethylene-diamine-tetraacetate (EDTA)) in enhancing metal phytoextraction was compared. Zn concentration in plant tissues increased in conjunction with the metal concentration of the soil. EDTA was found to be the most efficient chelating amendment, increasing concentrations of Zn in shoots from 88 mg kg(-1) dw, at 64 mg kg(-1) dw soil, to 8026 mg kg(-1) dw at 1800 mg kg(-1) dw soil. The overall orders of BCFs and TFs which resulted from this study are: EDTA > H2O > OX > CI, and EDTANa2 > OX > CI > H2O, respectively. The more effective uptake of Zn by plants for the control treatment (distilled water only) than for CI and OX was attributed to the neutral or slightly alkaline pH of the two chelant irrigation solutions. Instead, EDTA had a favorable effect on Zn uptake from soil due to its additive chelating and acidifying properties. Among the three chelants, only EDTA significantly increased the Zn phytoextraction potential of Z. mays, while CI and OX induced a low metal uptake from soil by plants. Although Z. mays has a lower Zn accumulation capacity than the hyperaccumulator Thlaspi caerulescens, it could be considered as a potential phytoremediator of soils with elevated Zn concentrations, especially when metal pollution extends to depths greater than 20 cm. Copyright © 2013 Elsevier Ltd. All rights reserved.

Elevated carbon dioxide reduces emission of herbivore-induced volatiles in Zea mays.

PubMed

Block, Anna; Vaughan, Martha M; Christensen, Shawn A; Alborn, Hans T; Tumlinson, James H

2017-09-01

Terpene volatiles produced by sweet corn (Zea mays) upon infestation with pests such as beet armyworm (Spodoptera exigua) function as part of an indirect defence mechanism by attracting parasitoid wasps; yet little is known about the impact of climate change on this form of plant defence. To investigate how a central component of climate change affects indirect defence, we measured herbivore-induced volatile emissions in plants grown under elevated carbon dioxide (CO 2 ). We found that S. exigua infested or elicitor-treated Z. mays grown at elevated CO 2 had decreased emission of its major sesquiterpene, (E)-β-caryophyllene and two homoterpenes, (3E)-4,8-dimethyl-1,3,7-nonatriene and (3E,7E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene. In contrast, inside the leaves, elicitor-induced (E)-β-caryophyllene hyper-accumulated at elevated CO 2 , while levels of homoterpenes were unaffected. Furthermore, gene expression analysis revealed that the induction of terpene synthase genes following treatment was lower in plants grown at elevated CO 2 . Our data indicate that elevated CO 2 leads both to a repression of volatile synthesis at the transcriptional level and to limitation of volatile release through effects of CO 2 on stomatal conductance. These findings suggest that elevated CO 2 may alter the ability of Z. mays to utilize volatile terpenes to mediate indirect defenses. © 2017 John Wiley & Sons Ltd.

Quantitative trait loci for maysin synthesis in maize (Zea mays L.) lines selected for high silk maysin content.

PubMed

Meyer, J D F; Snook, M E; Houchins, K E; Rector, B G; Widstrom, N W; McMullen, M D

2007-06-01

Maysin is a naturally occurring C-glycosyl flavone found in maize (Zea mays L.) silk tissue that confers resistance to corn earworm (Helicoverpa zea, Boddie). Recently, two new maize populations were derived for high silk maysin. The two populations were named the exotic populations of maize (EPM) and the southern inbreds of maize (SIM). Quantitative trait locus (QTL) analysis was employed to determine which loci were responsible for elevated maysin levels in inbred lines derived from the EPM and SIM populations. The candidate genes consistent with QTL position included the p (pericarp color), c2 (colorless2), whp1 (white pollen1) and in1 (intensifier1) loci. The role of these loci in controlling high maysin levels in silks was tested by expression analysis and use of the loci as genetic markers onto the QTL populations. These studies support p, c2 and whp1, but not in1, as loci controlling maysin. Through this study, we determined that the p locus regulates whp1 transcription and that increased maysin in these inbred lines was primarily due to alleles at both structural and regulatory loci promoting increased flux through the flavone pathway by increasing chalcone synthase activity.

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.

The involvement of glucose-6-phosphatase in mucilage secretion by root cap cells of Zea mays

NASA Technical Reports Server (NTRS)

Moore, R.; McClelen, C. E.

1985-01-01

In order to determine the involvement of glucose-6-phosphatase in mucilage secretion by root cap cells, we have cytochemically localized the enzyme in columella and peripheral cells of root caps of Zea mays. Glucose-6-phosphatase is associated with the plasmalemma and cell wall of columella cells. As columella cells differentiate into peripheral cells and begin to produce and secrete mucilage, glucose-6-phosphatase staining intensifies and becomes associated with the mucilage and, to a lesser extent, the cell wall. Cells being sloughed from the cap are characterized by glucose-6-phosphatase staining being associated with the vacuole and plasmalemma. These changes in enzyme localization during cellular differentiation in root caps suggest that glucose-6-phosphatase is involved in the production and/or secretion of mucilage by peripheral cells of Z. mays.

Identification of two frataxin isoforms in Zea mays: Structural and functional studies.

PubMed

Buchensky, Celeste; Sánchez, Manuel; Carrillo, Martin; Palacios, Oscar; Capdevila, Mercè; Domínguez-Vera, Jose M; Busi, Maria V; Atrian, Sílvia; Pagani, Maria A; Gomez-Casati, Diego F

2017-09-01

Frataxin is a ubiquitous protein that plays a role in Fe-S cluster biosynthesis and iron and heme metabolism, although its molecular functions are not entirely clear. In non-photosynthetic eukaryotes, frataxin is encoded by a single gene, and the protein localizes to mitochondria. Here we report the presence of two functional frataxin isoforms in Zea mays, ZmFH-1 and ZmFH-2. We confirmed our previous findings regarding plant frataxins: both proteins have dual localization in mitochondria and chloroplasts. Physiological, biochemical and biophysical studies show some differences in the expression pattern, protection against oxidants and in the aggregation state of both isoforms, suggesting that the two frataxin homologs would play similar but not identical roles in plant cell metabolism. In addition, two specific features of plant frataxins were evidenced: their ability to form dimers and their tendency to undergo conformational change under oxygen exposure. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Calcium-regulated in vivo protein phosphorylation in Zea mays L. root tips

NASA Technical Reports Server (NTRS)

Raghothama, K. G.; Reddy, A. S.; Friedmann, M.; Poovaiah, B. W.

1987-01-01

Calcium dependent protein phosphorylation was studied in corn (Zea mays L.) root tips. Prior to in vivo protein phosphorylation experiments, the effect of calcium, ethyleneglycol-bis-(beta-aminoethyl ether)-N-N' -tetraacetic acid (EGTA) and calcium ionophore (A-23187) on phosphorus uptake was studied. Calcium increased phosphorus uptake, whereas EGTA and A-23187 decreased it. Consequently, phosphorus concentration in the media was adjusted so as to attain similar uptake in different treatments. Phosphoproteins were analyzed by two-dimensional gel electrophoresis. Distinct changes in phosphorylation were observed following altered calcium levels. Calcium depletion in root tips with EGTA and A-23187 decreased protein phosphorylation. However, replenishment of calcium following EGTA and ionophore pretreatment enhanced phosphorylation of proteins. Preloading of the root tips with 32P in the presence of EGTA and A-23187 followed by a ten minute calcium treatment, resulted in increased phosphorylation indicating the involvement of calcium, calcium and calmodulin-dependent kinases. Calmodulin antagonist W-7 was effective in inhibiting calcium-promoted phosphorylation. These studies suggest a physiological role for calcium-dependent phosphorylation in calcium-mediated processes in plants.

Phytomanagement of Cd-contaminated soils using maize (Zea mays L.) assisted by plant growth-promoting rhizobacteria.

PubMed

Moreira, Helena; Marques, Ana P G C; Franco, Albina R; Rangel, António O S S; Castro, Paula M L

2014-01-01

Zea mays (L.) is a crop widely cultivated throughout the world and can be considered suitable for phytomanagement due to its metal resistance and energetic value. In this study, the effect of two plant growth-promoting rhizobacteria, Ralstonia eutropha and Chryseobacterium humi, on growth and metal uptake of Z. mays plants in soils contaminated with up to 30 mg Cd kg(-1) was evaluated. Bacterial inoculation increased plant biomass up to 63% and led to a decrease of up to 81% in Cd shoot levels (4-88 mg Cd kg(-1)) and to an increase of up to 186% in accumulation in the roots (52-134 mg Cd kg(-1)). The rhizosphere community structure changed throughout the experiment and varied with different levels of Cd soil contamination, as revealed by molecular biology techniques. Z. mays plants inoculated with either of the tested strains may have potential application in a strategy of soil remediation, in particular short-term phytostabilization, coupled with biomass production for energy purposes.

Induction of glutathione S-Transferase in Helicoverpa zea fed cashew flour.

USDA-ARS?s Scientific Manuscript database

H. zea and other insects have evolved strategies to counteract the plant protective proteins and defensive compounds they may encounter during feeding. We sought to take advantage of this phenomenon by identifying proteins upregulated in H. zea in response to the inclusion of cashew nut flour in th...

Spatio-temporal diversification of the cell wall matrix materials in the developing stomatal complexes of Zea mays.

PubMed

Giannoutsou, E; Apostolakos, P; Galatis, B

2016-11-01

The matrix cell wall materials, in developing Zea mays stomatal complexes are asymmetrically distributed, a phenomenon appearing related to the local cell wall expansion and deformation, the establishment of cell polarity, and determination of the cell division plane. In cells of developing Zea mays stomatal complexes, definite cell wall regions expand determinately and become locally deformed. This differential cell wall behavior is obvious in the guard cell mother cells (GMCs) and the subsidiary cell mother cells (SMCs) that locally protrude towards the adjacent GMCs. The latter, emitting a morphogenetic stimulus, induce polarization/asymmetrical division in SMCs. Examination of immunolabeled specimens revealed that homogalacturonans (HGAs) with a high degree of de-esterification (2F4- and JIM5-HGA epitopes) and arabinogalactan proteins are selectively distributed in the extending and deformed cell wall regions, while their margins are enriched with rhamnogalacturonans (RGAs) containing highly branched arabinans (LM6-RGA epitope). In SMCs, the local cell wall matrix differentiation constitutes the first structural event, indicating the establishment of cell polarity. Moreover, in the premitotic GMCs and SMCs, non-esterified HGAs (2F4-HGA epitope) are preferentially localized in the cell wall areas outlining the cytoplasm where the preprophase band is formed. In these areas, the forthcoming cell plate fuses with the parent cell walls. These data suggest that the described heterogeneity in matrix cell wall materials is probably involved in: (a) local cell wall expansion and deformation, (b) the transduction of the inductive GMC stimulus, and (c) the determination of the division plane in GMCs and SMCs.

The maize (Zea mays ssp. mays var. B73) genome encodes 33 members of the purple acid phosphatase family

PubMed Central

González-Muñoz, Eliécer; Avendaño-Vázquez, Aida-Odette; Montes, Ricardo A. Chávez; de Folter, Stefan; Andrés-Hernández, Liliana; Abreu-Goodger, Cei; Sawers, Ruairidh J. H.

2015-01-01

Purple acid phosphatases (PAPs) play an important role in plant phosphorus nutrition, both by liberating phosphorus from organic sources in the soil and by modulating distribution within the plant throughout growth and development. Furthermore, members of the PAP protein family have been implicated in a broader role in plant mineral homeostasis, stress responses and development. We have identified 33 candidate PAP encoding gene models in the maize (Zea mays ssp. mays var. B73) reference genome. The maize Pap family includes a clear single-copy ortholog of the Arabidopsis gene AtPAP26, shown previously to encode both major intracellular and secreted acid phosphatase activities. Certain groups of PAPs present in Arabidopsis, however, are absent in maize, while the maize family contains a number of expansions, including a distinct radiation not present in Arabidopsis. Analysis of RNA-sequencing based transcriptome data revealed accumulation of maize Pap transcripts in multiple plant tissues at multiple stages of development, and increased accumulation of specific transcripts under low phosphorus availability. These data suggest the maize PAP family as a whole to have broad significance throughout the plant life cycle, while highlighting potential functional specialization of individual family members. PMID:26042133

A morphometric analysis of the redistribution of organelles in columella cells of horizontally-oriented roots of Zea mays

NASA Technical Reports Server (NTRS)

Moore, R.

1986-01-01

In order to determine what structural changes in graviperceptive cells are associated with onset of root gravicurvature, the redistribution of organelles in columella cells of horizontally-oriented, graviresponding roots of Zea mays has been quantified. Root gravicurvature began by 15 min after reorientation, and did not involve significant changes in the (i) volume of individual columella cells or amyloplasts, (ii) relative volume of any cellular organelle, (iii) number of amyloplasts per columella cell, or (iv) surface area of cellular location of endoplasmic reticulum. Sedimentation of amyloplasts began within 1 to 2 min after reorientation, and was characterized by an intensely staining area of cytoplasm adjacent to the sedimenting amyloplasts. By 5 min after reorientation, amyloplasts were located in the lower distal corner of columella cells, and, by 15 min after reorientation, overlaid the entire length of the lower cell wall. No consistent contact between amyloplasts and any cellular structure was detected at any stage of gravicurvature. Centrally-located nuclei initially migrated upward in columella cells of horizontally-oriented roots, after which they moved to the proximal ends of the cells by 15 min after reorientation. No significant pattern of redistribution of vacuoles, mitochondria, dictyosomes, or hyaloplasm was detected that correlated with the onset of gravicurvature. These results indicate that amyloplasts and nuclei are the only organelles whose movements correlate positively with the onset of gravicurvature by primary roots of this cultivar of Zea mays.

Final report of the safety assessment of cosmetic ingredients derived from Zea mays (corn).

PubMed

Andersen, F Alan; Bergfeld, Wilma F; Belsito, Donald V; Klaassen, Curtis D; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W

2011-05-01

Many cosmetic ingredients are derived from Zea mays (corn). While safety test data were not available for most ingredients, similarities in preparation and the resulting similar composition allowed extrapolation of safety data to all listed ingredients. Animal studies included acute toxicity, ocular and dermal irritation studies, and dermal sensitization studies. Clinical studies included dermal irritation and sensitization. Case reports were available for the starch as used as a donning agent in medical gloves. Studies of many other endpoints, including reproductive and developmental toxicity, use corn oil as a vehicle control with no reported adverse effects at levels used in cosmetics. While industry should continue limiting ingredient impurities such as pesticide residues before blending into a cosmetic formulation, the CIR Expert Panel determined that corn-derived ingredients are safe for use in cosmetics in the practices of use and concentration described in the assessment.

Oxidative damage and cell-programmed death induced in Zea mays L. by allelochemical stress.

PubMed

Ciniglia, Claudia; Mastrobuoni, Francesco; Scortichini, Marco; Petriccione, Milena

2015-05-01

The allelochemical stress on Zea mays was analyzed by using walnut husk washing waters (WHWW), a by-product of Juglans regia post-harvest process, which possesses strong allelopathic potential and phytotoxic effects. Oxidative damage and cell-programmed death were induced by WHWW in roots of maize seedlings. Treatment induced ROS burst, with excess of H2O2 content. Enzymatic activities of catalase were strongly increased during the first hours of exposure. The excess in malonildialdehyde following exposure to WHWW confirmed that oxidative stress severely damaged maize roots. Membrane alteration caused a decrease in NADPH oxidase activity along with DNA damage as confirmed by DNA laddering. The DNA instability was also assessed through sequence-related amplified polymorphism assay, thus suggesting the danger of walnut processing by-product and focusing the attention on the necessity of an efficient treatment of WHWW.

Cytochemical localization of calcium in cap cells of primary roots of Zea mays L

NASA Technical Reports Server (NTRS)

Moore, R.

1985-01-01

The cellular distribution of Ca in caps of primary roots of Zea mays was examined during the onset and early stages of gravicurvature to determine its possible role in root gravitropism. Staining becomes associated with the portion of the cell wall adjacent to the distal end of the cell after five minutes, and persists throughout the onset of gravicurvature. The outermost peripheral cells of roots oriented horizontally and vertically secrete Ca through plasmodesmata-like channels in their cell walls. Data suggest that Ca is not transported laterally through the columella tissue,but rather that the movement of Ca to the lower side of caps of horizontally-oriented roots is at least partially through and/or on the mucilage of the cap, and via an electrochemical gradient. An important role in root gravitropism is indicated for Ca secretion by peripheral cells.

Determination of stress responses induced by aluminum in maize (Zea mays).

PubMed

Vardar, Filiz; Ismailoğlu, Işil; Inan, Deniz; Unal, Meral

2011-06-01

To assess the alternative responses to aluminum toxicity, maize (Zea mays L. cv Karadeniz yıldızı) roots were exposed to different concentrations of AlCl3 (150, 300 and 450 μM). Aluminum reduced the root elongation by 39.6% in 150 μM, 44.1% in 300 μM, 50.1% in 450 μM AlCl3 after 96 h period. To correlate the root elongation with the alternative stress responses including aluminum accumulation, lipid peroxidation, mitotic abnormalities, reduction of starch content, intracellular Ca2+ accumulation, callose formation, lignin deposition and peroxidase activity, cytochemical and biochemical tests were performed. The results indicated that aluminum accumulation and lipid peroxidation were observed more densely on the root cap and the outer cortex cells. In addition to morphological deformations, cytochemical analysis displayed cellular deformations. Furthermore, mitotic abnormalities were observed such as c-mitosis, micronuclei, bi- and trinucleated cells in aluminum treated root tips. Aluminum treatment induced starch reduction, callose formation, lignin accumulation and intracellular Ca2+ increase. Moreover, the peroxidase activity increased significantly by 3, 4.4 and 7.7 times higher than in that of control after 96 h, respectively. In conclusion, aluminum is significantly stressful in maize culminating in morphological and cellular alterations.

Morphometric analysis of epidermal differentiation in primary roots of Zea mays

NASA Technical Reports Server (NTRS)

Moore, R.; Smith, H. S.

1990-01-01

Epidermal differentiation in primary roots of Zea mays was divided into six cell types based on cellular shape and cytoplasmic appearance. These six cell types are: 1) apical protoderm, located at the tip of the root pole and characterized by periclinally flattened cells; 2) cuboidal protoderm, located approximately 230 microns from the root pole and characterized by cuboidal cells; 3) tabular epidermis, located approximately 450 microns from the root pole and characterized by anticlinally flattened cells; 4) cuboidal epidermis, located approximately 900 microns from the root pole and characterized by cuboidal cells having numerous small vacuoles; 5) vacuolate cuboidal epidermis, located approximately 1,500 microns from the root pole and characterized by cuboidal cells containing several large vacuoles; and 6) columnar epidermis, located approximately 2,200 microns from the root pole (i.e., at the beginning of the zone of elongation) and characterized by elongated cells. We also used stereology to quantify the cellular changes associated with epidermal differentiation. The quiescent center and the apical protoderm have significantly different ultrastructures. The relative volume of dictyosomes increases dramatically during the early stages of epidermal differentiation. This increase correlates inversely with the amount of coverage provided by the root cap and mucilage.

Phytochemical screening, total phenolic content and phytotoxic activity of corn (Zea mays) extracts against some indicator species.

PubMed

Ahmed, Hiwa M

2018-03-01

Allelopathic effects of corn (Zea mays) extracts was studied, against seed germination and seedling growth of Phalaris minor, Helianthus annuus, Triticumaestivum, Sorghum halepense, Z. mays. Bioassay results showed that aqueous extracts of corn root and shoot, markedly affected seed germination, and other parameters compared with related controls. Preliminary phytochemical screening revealed the presence of various phytochemicals such as tannins, phlobatannins, flavonoids, terpenoids and alkaloids in both roots and shoot aqueous extracts. However, saponins were only present in the shoot aqueous extract, while in shoot ethanol extracts, only terpenoids and alkaloids were detected. Additionally, total polyphenolic (TPC) content in aqueous extracts of corn root and shoot, plus ethanol extracts of corn shoot were determined using an Ultraviolet-visible spectroscopy. Results revealed TPC content of the corn shoot aqueous extract showed the highest yield, compared to other extracts. These findings suggest that phytochemicals present in Z. mays extracts may contribute to allelopathy effect.

Salmon silk genes contribute to the elucidation of the flavone pathway in maize (Zea mays L.).

PubMed

McMullen, M D; Kross, H; Snook, M E; Cortés-Cruz, M; Houchins, K E; Musket, T A; Coe, E H

2004-01-01

We utilized maize (Zea mays L.) lines expressing the salmon silk (sm) phenotype, quantitative trait locus analysis, and analytical chemistry of flavone compounds to establish the order of undefined steps in the synthesis of the flavone maysin in maize silks. In addition to the previously described sm1 gene, we identified a second sm locus, which we designate sm2, located on the long arm of maize chromosome 2. Our data indicate that the sm1 gene encodes or controls a glucose modification enzyme and sm2 encodes or controls a rhamnosyl transferase. The order of intermediates in the late steps of maysin synthesis was established as luteolin --> isoorientin --> rhamnosylisoorientin --> maysin. Copyright 2004 The American Genetic Association

A gradient of endogenous calcium forms in mucilage of graviresponding roots of Zea mays

NASA Technical Reports Server (NTRS)

Moore, R.; Fondren, W. M.

1988-01-01

Agar blocks that contacted the upper sides of tips of horizontally-oriented roots of Zea mays contain significantly less calcium (Ca) than blocks that contacted the lower sides of such roots. This gravity-induced gradient of Ca forms prior to the onset of gravicurvature, and does not form across tips of vertically-oriented roots or roots of agravitropic mutants. These results indicate that (1) Ca can be collected from mucilage of graviresponding roots, (2) gravity induces a downward movement of endogenous Ca in mucilage overlying the root tip, (3) this gravity-induced gradient of Ca does not form across tips of agravitropic roots, and (4) formation of a Ca gradient is not a consequence of gravicurvature. These results are consistent with gravity-induced movement of Ca being a trigger for subsequent redistribution of growth effectors (e.g. auxin) that induce differential growth and gravicurvature.

Collection of gravitropic effectors from mucilage of electrotropically-stimulated roots of Zea mays L

NASA Technical Reports Server (NTRS)

Fondren, W. M.; Moore, R.

1987-01-01

We placed agar blocks adjacent to tips of electrotropically stimulated primary roots of Zea mays. Blocks placed adjacent to the anode-side of the roots for 3 h induced significant curvature when subsequently placed asymmetrically on tips of vertically-oriented roots. Curvature was always toward the side of the root unto which the agar block was placed. Agar blocks not contacting roots and blocks placed adjacent to the cathode-side of electrotropically stimulated roots did not induce significant curvature when placed asymmetrically on tips of vertically-oriented roots. Atomic absorption spectrophotometry indicated that blocks adjacent to the anode-side of electrotropically-stimulated roots contained significantly more calcium than (1) blocks not contacting roots, and (2) blocks contacting the cathode-side of roots. These results demonstrate the presence of a gradient of endogenous Ca in mucilage of electrotropically-stimulated roots (i.e. roots undergoing gravitropic-like curvature).

Depth Profiles in Maize ( Zea mays L.) Seeds Studied by Photoacoustic Spectroscopy

NASA Astrophysics Data System (ADS)

Hernández-Aguilar, C.; Domínguez-Pacheco, A.; Cruz-Orea, A.; Zepeda-Bautista, R.

2015-06-01

Photoacoustic spectroscopy (PAS) has been used to analyze agricultural seeds and can be applied to the study of seed depth profiles of these complex samples composed of different structures. The sample depth profile can be obtained through the photoacoustic (PA) signal, amplitude, and phase at different light modulation frequencies. The PA signal phase is more sensitive to changes of thermal properties in layered samples than the PA signal amplitude. Hence, the PA signal phase can also be used to characterize layers at different depths. Thus, the objective of the present study was to obtain the optical absorption spectra of maize seeds ( Zea mays L.) by means of PAS at different light modulation frequencies (17 Hz, 30 Hz, and 50 Hz) and comparing these spectra with the ones obtained from the phase-resolved method in order to separate the optical absorption spectra of seed pericarp and endosperm. The results suggest the possibility of using the phase-resolved method to obtain optical absorption spectra of different seed structures, at different depths, without damaging the seed. Thus, PAS could be a nondestructive method for characterization of agricultural seeds and thus improve quality control in the food industry.

Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by an enzyme preparation from Zea mays

NASA Technical Reports Server (NTRS)

Reinecke, D. M.; Bandurski, R. S.

1988-01-01

Indole-3-acetic acid is oxidized to oxindole-3-acetic acid by Zea mays tissue extracts. Shoot, root, and endosperm tissues have enzyme activities of 1 to 10 picomoles per hour per milligram protein. The enzyme is heat labile, is soluble, and requires oxygen for activity. Cofactors of mixed function oxygenase, peroxidase, and intermolecular dioxygenase are not stimulatory to enzymic activity. A heat-stable, detergent-extractable component from corn enhances enzyme activity 6- to 10-fold. This is the first demonstration of the in vitro enzymic oxidation of indole-3-acetic acid to oxindole-3-acetic acid in higher plants.

Development of accelerated net nitrate uptake. [Zea mays L

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

MacKown, C.T.; McClure, P.R.

1988-05-01

Upon initial nitrate exposure, net nitrate uptake rates in roots of a wide variety of plants accelerate within 6 to 8 hours to substantially greater rates. Effects of solution nitrate concentrations and short pulses of nitrate ({le}1 hour) upon nitrate-induced acceleration of nitrate uptake in maize (Zea mays L.) were determined. Root cultures of dark-grown seedlings, grown without nitrate, were exposed to 250 micromolar nitrate for 0.25 to 1 hour or to various solution nitrate concentration (10-250 micromolar) for 1 hour before returning them to a nitrate-free solution. Net nitrate uptake rates were assayed at various periods following nitrate exposuremore » and compared to rates of roots grown either in the absence of nitrate (CaSO{sub 4}-grown) or with continuous nitrate for at least 20 hours. Three hours after initial nitrate exposure, nitrate pulse treatments increased nitrate uptake rates three- to four-fold compared to the rates of CaSO{sub 4}-grown roots. When cycloheximide (5 micrograms per milliliter) was included during a 1-hour pulse with 250 micromolar nitrate, development of the accelerated nitrate uptake state was delayed. Otherwise, nitrate uptake rates reached maximum values within 6 hours before declining. Maximum rates, however, were significantly less than those of roots exposed continuously for 20, 32, or 44 hours. Pulsing for only 0.25 hour with 250 micromolar nitrate and for 1 hour with 10 micromolar caused acceleration of nitrate uptake, but the rates attained were either less than or not sustained for a duration comparable to those of roots pulsed for 1 hour with 250 micromolar nitrate. These results indicate that substantial development of nitrate-induced accelerated nitrate uptake state can be achieved by small endogenous accumulations of nitrate, which appear to moderate the activity or level of root nitrate uptake.« less

Maternal stress-associated cortisol stimulation may protect embryos from cortisol excess in zebrafish.

PubMed

Faught, Erin; Best, Carol; Vijayan, Mathilakath M

2016-02-01

Abnormal embryo cortisol level causes developmental defects and poor survival in zebrafish (Danio rerio). However, no study has demonstrated that maternal stress leads to higher embryo cortisol content in zebrafish. We tested the hypothesis that maternal stress-associated elevation in cortisol levels increases embryo cortisol content in this asynchronous breeder. Zebrafish mothers were fed cortisol-spiked food for 5 days, to mimic maternal stress, followed by daily breeding for 10 days to monitor temporal embryo cortisol content. Cortisol treatment increased mean embryo yield, but the daily fecundity was variable among the groups. Embryo cortisol content was variable in both groups over a 10-day period. A transient elevation in cortisol levels was observed in the embryos from cortisol-fed mothers only on day 3, but not on subsequent days. We tested whether excess cortisol stimulates 11βHSD2 expression in ovarian follicles as a means to regulate embryo cortisol deposition. Cortisol treatment in vitro increased 11β HSD2 levels sevenfold, and this expression was regulated by actinomycin D and cycloheximide suggesting tight regulation of cortisol levels in the ovarian follicles. We hypothesize that cortisol-induced upregulation of 11βHSD2 activity in the ovarian follicles is a mechanism restricting excess cortisol incorporation into the eggs during maternal stress.

The influence of gravity on the formation of amyloplasts in columella cells of Zea mays L

NASA Technical Reports Server (NTRS)

Moore, R.; Fondren, W. M.; Koon, E. C.; Wang, C. L.

1986-01-01

Columella (i.e., putative graviperceptive) cells of Zea mays seedlings grown in the microgravity of outer space allocate significantly less volume to putative statoliths (amyloplasts) than do columella cells of Earth-grown seedlings. Amyloplasts of flight-grown seedlings are significantly smaller than those of ground controls, as is the average volume of individual starch grains. Similarly, the relative volume of starch in amyloplasts in columella cells of flight-grown seedlings is significantly less than that of Earth-grown seedlings. Microgravity does not significantly alter the volume of columella cells, the average number of amyloplasts per columella cell, or the number of starch grains per amyloplast. These results are discussed relative to the influence of gravity on cellular and organellar structure.

Some physical properties of teosinte (Zea mays subsp. parviglumis) pollen.

PubMed

Aylor, Donald E; Baltazar, Baltazar M; Schoper, John B

2005-09-01

In parts of the world where teosinte and maize are grown in close proximity, there is concern about gene flow between them. Pollen is the primary vehicle for gene flow. Quantifying the biophysical properties of pollen, such as its settling speed and dehydration rate, is important for evaluating outcrossing potential. These properties were measured for teosinte (Zea mays subsp. parviglumis) pollen. Pollen was found to have an average settling speed of 0.165 m s(-1), which agrees well with theoretical values based on the size of the pollen grains. The conductance of the pollen wall for water was derived from the time rate of change of pollen grain size and gave an average conductance of 3.42x10(-4) m s(-1). Water potential, psi, of teosinte pollen was determined at various values of relative water content (dry-weight basis), theta, by using a thermocouple psychrometer and by allowing samples of pollen to come to vapour equilibrium with various saturated salt solutions. Non-linear regression analysis of the data yielded psi (MPa) = -4.13 theta(-1.23) (r2=0.77). Results for conductance and psi were incorporated into a model equation for the rate of water loss from pollen grains, which yielded results that agreed well (r2=0.96) with observations of water loss from pollen grains in air. The data reported here are important building blocks in a model of teosinte pollen movement and should be helpful in establishing the main factors influencing the degree and the direction of pollination between teosinte populations and between maize and teosinte.

Sugar Efflux from Maize (Zea mays L.) Pedicel Tissue 1

PubMed Central

Porter, Gregory A.; Knievel, Daniel P.; Shannon, Jack C.

1985-01-01

Sugar release from the pedicel tissue of maize (Zea mays L.) kernels was studied by removing the distal portion of the kernel and the lower endosperm, followed by replacement of the endosperm with an agar solute trap. Sugars were unloaded into the apoplast of the pedicel and accumulated in the agar trap while the ear remained attached to the maize plant. The kinetics of 14C-assimilate movement into treated versus intact kernels were comparable. The rate of unloading declined with time, but sugar efflux from the pedicel continued for at least 6 hours and in most experiments the unloading rates approximated those necessary to support normal kernel growth rates. The unloading process was challenged with a variety of buffers, inhibitors, and solutes in order to characterize sugar unloading from this tissue. Unloading was not affected by apoplastic pH or a variety of metabolic inhibitors. Although p-chloromercuribenzene sulfonic acid (PCMBS), a nonpenetrating sulfhydryl group reagent, did not affect sugar unloading, it effectively inhibited extracellular acid invertase. When the pedicel cups were pretreated with PCMBS, at least 60% of sugars unloaded from the pedicel could be identified as sucrose. Unloading was inhibited up to 70% by 10 millimolar CaCl2. Unloading was stimulated by 15 millimolar ethyleneglycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid which partially reversed the inhibitory effects of Ca2+. Based on these results, we suggest that passive efflux of sucrose occurs from the maize pedicel symplast followed by extracellular hydrolysis to hexoses. Images Fig. 1 Fig. 2 PMID:16664091

Evaluation of zinc accumulation, allocation, and tolerance in Zea mays L. seedlings: implication for zinc phytoextraction.

PubMed

Bashmakov, Dmitry I; Lukatkin, Alexander S; Anjum, Naser A; Ahmad, Iqbal; Pereira, Eduarda

2015-10-01

This work investigated the accumulation, allocation, and impact of zinc (Zn; 1.0 μM-10 mM) in maize (Zea mays L.) seedlings under simulated laboratory conditions. Z. mays exhibited no significant change in its habitus (the physical characteristics of plants) up to 10-1000 μM of Zn (vs 5-10 mM Zn). Zn tolerance evaluation, based on the root test, indicated a high tolerance of Z. mays to both low and intermediate (or relatively high) concentrations of Zn, whereas this plant failed to tolerate 10 mM Zn and exhibited a 5-fold decrease in its Zn tolerance. Contingent to Zn treatment levels, Zn hampered the growth of axial organs and brought decreases in the leaf area, water regime, and biomass accumulation. Nevertheless, at elevated levels of Zn (10 mM), Zn(2+) was stored in the root cytoplasm and inhibited both axial organ growth and water regime. However, accumulation and allocation of Zn in Z. mays roots, studied herein employing X-ray fluorimeter and histochemical methods, were close to Zn accumulator plants. Overall, the study outcomes revealed Zn tolerance of Z. mays, and also implicate its potential role in Zn phytoextraction.

Effects on the accumulation of calcium, magnesium, iron, manganese, copper and zinc of adding the two inorganic forms of selenium to solution cultures of Zea mays.

PubMed

Longchamp, M; Angeli, N; Castrec-Rouelle, M

2016-01-01

The addition of selenate or selenite to common fertilizers for crop production could be an effective way of producing selenium-rich food and feed. However, this would be feasible only if the increase in plant selenium (Se) content did not negatively influence the uptake of other essential elements. We therefore need to understand the interactions between Se and other major and trace elements during uptake by the plant. This study aimed to evaluate the influence of inorganic forms of Se on the accumulation of selected macronutrients (Ca and Mg) and micronutrients (Fe, Zn, Mn and Cu). Those essential elements are involved in the oxidative balance of cells. Zea mays seedlings were grown hydroponically in growth chambers in nutrient solutions to which we added 10, 50 or 1000 μg.L(-1) of selenate and/or selenite. Cation accumulation was significantly affected by the addition of 50 μg.L(-1) or 1000 μg.L(-1) Se, but not by the presence of 10 μg.L(-1) of Se in the nutrient solution. The highest concentration (1000 μg.L(-1)) of Se in the nutrient solution affected the accumulation of essential cations in Zea mays: selenate tended to increase the accumulation of Mg, Zn and Mn, whereas a selenate/selenite mixture tended to decrease the accumulation of Ca, Mg, Zn and Mn. Only Fe accumulation was unaffected by Se whatever its form or concentration. Selenium may also affect the distribution of cations on Zea mays. For example, levels of Mg and Zn translocation to the shoots were lower in the presence of selenite. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Biochemical characterization of a new maize (Zea mays L.) peptide growth factor.

PubMed

Rodríguez-López, Cesar David; Rodríguez-Romero, Adela; Aguilar, Raúl; de Jiménez, Estela Sánchez

2011-01-01

Coordination of cell growth and cell division is very important for living organisms in order for these to develop harmonically. The present research is concerned with the purification and characterization of a new peptide hormone, namely ZmIGF (Zea mays insulin-like growth factor), which regulates growth and cell division in maize tissues. ZmIGF is a peptide of 5.7 kDa, as determined by mass spectroscopy. It was isolated either from maize embryonic axes of 48-h germinated seeds or from embryogenic callus and purified through several chromatographic procedures to obtain a single peak as shown by Reverse Phase High-Performance Liquid Chromatography (RP-HPLC). This peptide exhibits a well defined α-helix structure by circular dichroism analysis, similar to that reported for Insulin or for Insulin-like growth factor (IGF-1). Further, ZmIGF seems to perform, in maize, a similar function to that reported for insulin or peptides from the IGF family in animals. Indeed, maize tissues stimulated either by ZmIGF or insulin showed to induce selective synthesis of ribosomal proteins as well as of DNA. Taken together, the previously mentioned data strongly suggest that plants contain a peptide hormone of the IGF family, highly conserved through evolution that regulates growth and development.

Aphrodisiac Activity of the Aqueous Crude Extract of Purple Corn ( Zea mays) in Male Rats.

PubMed

Carro-Juárez, Miguel; Rodríguez-Santiago, Magdalena G; Franco, Miguel Angel; Hueletl-Soto, María Eugenia

2017-10-01

In the present study, the aphrodisiac properties of the purple corn ( Zea mays) in male rats were analyzed. The aqueous crude extract of purple corn (at 25, 50, and 75 mg/kg) was administered to ( a) copulating male rats and ( b) anesthetized and spinal cord transected male rats. Behavioral parameters of copulatory behavior and parameters of the genital motor pattern of ejaculation previous to its inhibition, under the influence of the purple corn extract, are described. Administration of the aqueous crude extract of purple corn significantly facilitates the arousal and execution of male rat sexual behavior without significant influences on the ambulatory behavior. In addition, purple corn extract elicit a significant increase in the number of discharges of the ejaculatory motor patterns and in the total number of genital motor patterns evoked in spinal rats. The present findings show that the aqueous crude extract of purple corn possesses aphrodisiac activity.

Superoxide-responsive gene expression in Arabidopsis thaliana and Zea mays.

PubMed

Xu, Junhuan; Tran, Thu; Padilla Marcia, Carmen S; Braun, David M; Goggin, Fiona L

2017-08-01

Superoxide (O 2 - ) and other reactive oxygen species (ROS) are generated in response to numerous biotic and abiotic stresses. Different ROS have been reported to elicit different transcriptional responses in plants, and so ROS-responsive marker genes and promoter::reporter gene fusions have been proposed as indirect means of detecting ROS and discriminating among different species. However, further information about the specificity of transcriptional responses to O 2 - is needed in order to assess potential markers for this critical stress-responsive signaling molecule. Using qRT-PCR, the expression of 12 genes previously reported to be upregulated by O 2 - was measured in Arabidopsis thaliana plants exposed to elicitors of common stress-responsive ROS: methyl viologen (an inducer of O 2 - ), rose bengal (an inducer of singlet oxygen, 1 ΔO 2 ), and exogenous hydrogen peroxide (H 2 O 2 ). Surprisingly, Zinc-Finger Protein 12 (AtZAT12), which had previously been used as a reporter for H 2 O 2 , responded more strongly to O 2 - than to H 2 O 2 ; moreover, the expression of an AtZAT12 promoter-reporter fusion (AtZAT12::Luc) was enhanced by diethyldithiocarbamate, which inhibits dismutation of O 2 - to H 2 O 2 . These results suggest that AtZAT12 is transcriptionally upregulated in response to O 2 - , and that AtZAT12::Luc may be a useful biosensor for detecting O 2 - generation in vivo. In addition, transcripts encoding uncoupling proteins (AtUCPs) showed selectivity for O 2 - in Arabidopsis, and an AtUCP homolog upregulated by methyl viologen was also identified in maize (Zea mays L.), indicating that there are O 2 - -responsive members of this family in monocots. These results expand our limited knowledge of ROS-responsive gene expression in monocots, as well as O 2 - -selective responses in dicots. Copyright © 2017 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

Development, survival and fitness performance of Helicoverpa zea (Lepidoptera: Noctuidae) in MON810 Bt field corn.

PubMed

Horner, T A; Dively, G P; Herbert, D A

2003-06-01

Helicoverpa zea (Boddie) development, survival, and feeding injury in MON810 transgenic ears of field corn (Zea mays L.) expressing Bacillus thuringiensis variety kurstaki (Bt) Cry1Ab endotoxins were compared with non-Bt ears at four geographic locations over two growing seasons. Expression of Cry1Ab endotoxin resulted in overall reductions in the percentage of damaged ears by 33% and in the amount of kernels consumed by 60%. Bt-induced effects varied significantly among locations, partly because of the overall level and timing of H. zea infestations, condition of silk tissue at the time of egg hatch, and the possible effects of plant stress. Larvae feeding on Bt ears produced scattered, discontinuous patches of partially consumed kernels, which were arranged more linearly than the compact feeding patterns in non-Bt ears. The feeding patterns suggest that larvae in Bt ears are moving about sampling kernels more frequently than larvae in non-Bt ears. Because not all kernels express the same level of endotoxin, the spatial heterogeneity of toxin distribution within Bt ears may provide an opportunity for development of behavioral responses in H. zea to avoid toxin. MON810 corn suppressed the establishment and development of H. zea to late instars by at least 75%. This level of control is considered a moderate dose, which may increase the risk of resistance development in areas where MON810 corn is widely adopted and H. zea overwinters successfully. Sublethal effects of MON810 corn resulted in prolonged larval and prepupal development, smaller pupae, and reduced fecundity of H. zea. The moderate dose effects and the spatial heterogeneity of toxin distribution among kernels could increase the additive genetic variance for both physiological and behavioral resistance in H. zea populations. Implications of localized population suppression are discussed.

Intraear Compensation of Field Corn, Zea mays, from Simulated and Naturally Occurring Injury by Ear-Feeding Larvae.

PubMed

Steckel, S; Stewart, S D

2015-06-01

Ear-feeding larvae, such as corn earworm, Helicoverpa zea Boddie (Lepidoptera: Noctuidae), can be important insect pests of field corn, Zea mays L., by feeding on kernels. Recently introduced, stacked Bacillus thuringiensis (Bt) traits provide improved protection from ear-feeding larvae. Thus, our objective was to evaluate how injury to kernels in the ear tip might affect yield when this injury was inflicted at the blister and milk stages. In 2010, simulated corn earworm injury reduced total kernel weight (i.e., yield) at both the blister and milk stage. In 2011, injury to ear tips at the milk stage affected total kernel weight. No differences in total kernel weight were found in 2013, regardless of when or how much injury was inflicted. Our data suggested that kernels within the same ear could compensate for injury to ear tips by increasing in size, but this increase was not always statistically significant or sufficient to overcome high levels of kernel injury. For naturally occurring injury observed on multiple corn hybrids during 2011 and 2012, our analyses showed either no or a minimal relationship between number of kernels injured by ear-feeding larvae and the total number of kernels per ear, total kernel weight, or the size of individual kernels. The results indicate that intraear compensation for kernel injury to ear tips can occur under at least some conditions. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Genetic and cellular analysis of cross-incompatibility in Zea mays.

PubMed

Lu, Yongxian; Kermicle, Jerry L; Evans, Matthew M S

2014-03-01

Three genetic systems conferring cross-incompatibility have been described in Zea mays: Teosinte crossing barrier1-strong (Tcb1-s) found in teosinte, and Gametophyte factor1-strong (Ga1-s) and Ga2-s found in maize and teosinte. The reproductive barrier between maize and some weedy teosintes is controlled by the Tcb1-s locus. Multi-generation inheritance experiments on two independent Tcb1-s lineages show that the Tcb1-s barrier is unstable in some maize lines. Reciprocal crosses between Tcb1-s tester plants and three recombinants in the Tcb1-s mapping region demonstrate that the Tcb1-s haplotype contains separable male and female components. In vivo assays of the dynamics of pollen tube growth and pollen tube morphology during rejection of incompatible pollen in silks carrying the Tcb1-s, Ga1-s, or Ga2-s barriers showed that, in all three, pollen tube growth is slower than in compatible crosses at early stages and had ceased by 24 h after pollination. In all three crossing barrier systems, incompatible pollen tubes have clustered callose plugs in contrast to pollen tubes of compatible crosses. Incompatible pollen tubes growing in the Tcb1-s, Ga1-s, and Ga2-s silks have different morphologies: straight, curved, and kinked, respectively. The distinct morphologies suggest that these crossing barriers block incompatible pollen through different mechanisms. This study lays the foundation for cloning the Tcb1 genes and provides clues about the cellular mechanisms involved in pollen rejection in the Tcb1-s, Ga1-s, and Ga2-s crossing barriers.

Embryo Aggregation in Pig Improves Cloning Efficiency and Embryo Quality.

PubMed

Buemo, Carla Paola; Gambini, Andrés; Moro, Lucia Natalia; Hiriart, María Inés; Fernández-Martín, Rafael; Collas, Philippe; Salamone, Daniel Felipe

2016-01-01

In this study, we analyzed the effects of the cloned embryo aggregation on in vitro embryo development and embryo quality by measuring blastocyst diameter and cell number, DNA fragmentation levels and the expression of genes associated with pluripotency, apoptosis, trophoblast and DNA methylation in the porcine. Zona-free reconstructed cloned embryos were cultured in the well of the well system, placing one (1x non aggregated group) or three (3x group) embryos per microwell. Our results showed that aggregation of three embryos increased blastocyst formation rate and blastocyst diameter of cloned pig embryos. DNA fragmentation levels in 3x aggregated cloned blastocysts were significantly decreased compared to 1x blastocysts. Levels of Oct4, Klf4, Igf2, Bax and Dnmt 1 transcripts were significantly higher in aggregated embryos, whereas Nanog levels were not affected. Transcripts of Cdx2 and Bcl-xl were essentially non-detectable. Our study suggests that embryo aggregation in the porcine may be beneficial for cloned embryo development and embryo quality, through a reduction in apoptotic levels and an improvement in cell reprogramming.

Fine mapping of a quantitative resistance gene for gray leaf spot of maize (Zea mays L.) derived from teosinte (Z. mays ssp. parviglumis).

PubMed

Zhang, Xinye; Yang, Qin; Rucker, Elizabeth; Thomason, Wade; Balint-Kurti, Peter

2017-06-01

In this study we mapped the QTL Qgls8 for gray leaf spot (GLS) resistance in maize to a ~130 kb region on chromosome 8 including five predicted genes. In previous work, using near isogenic line (NIL) populations in which segments of the teosinte (Zea mays ssp. parviglumis) genome had been introgressed into the background of the maize line B73, we had identified a QTL on chromosome 8, here called Qgls8, for gray leaf spot (GLS) resistance. We identified alternate teosinte alleles at this QTL, one conferring increased GLS resistance and one increased susceptibility relative to the B73 allele. Using segregating populations derived from NIL parents carrying these contrasting alleles, we were able to delimit the QTL region to a ~130 kb (based on the B73 genome) which encompassed five predicted genes.

Comparative effectiveness of metal ions in inducing curvature of primary roots of Zea mays

NASA Technical Reports Server (NTRS)

Hasenstein, K. H.; Evans, M. L.; Stinemetz, C. L.; Moore, R.; Fondren, W. M.; Koon, E. C.; Higby, M. A.; Smucker, A. J.

1988-01-01

We used five cultivars of Zea mays (Bear Hybrid WF9 * 38MS, B73 * Missouri 17, Yellow Dent, Merit, and Great Lakes Hybrid 422) to reinvestigate the specificity of metal ions for inducing root curvature. Of 17 cations tested, 6 (Al3+, Ba2+, Ca2+, Cd2+, Cu2+, Zn2+) induced curvature. Roots curved away from Al3+, Ba2+, and Cd2+. Roots curved away from low (0.1 millimolar) concentrations of Cu2+ but toward higher (1-5 millimolar) concentrations. Roots initially curved away from Zn2+ but the direction of the subsequent curvature was unpredictable. In most cases, roots of all cultivars curved towards calcium. However, in some tests there was no response to calcium or even (especially in the cultivars Merit and B73 * Missouri 17) substantial curvature away from calcium. The results indicate that the induction of root curvature is not specific for calcium. The results are discussed relative to the possible role of calmodulin as a mediator of ion-induced root curvature.

Response of maize (Zea mays L. saccharata Sturt) to different concentration treatments of deltamethrin.

PubMed

Duran, Ragbet Ezgi; Kilic, Semra; Coskun, Yasemin

2015-10-01

The aim of this study was to investigate the effect of the deltamethrin pesticide on the biological properties of maize (Zea mays L. saccharata Sturt). Maize seeds were exposed to environmentally relevant dosages (0.01, 0.05, 0.1 and 0.5 ppm) of deltamethrin. On the 7th day of germination, morphological, anatomical and physiological responses were determined. All seedling growth characters were decreased with increasing deltamethrin levels. The most negative effect on the radicle length of maize was observed by the highest deltamethrin concentration with a 61% decrease (P <0.05). Both stomatal density and stomatal dimension reduction were caused by increasing concentrations of deltamethrin. Moreover, the pigments like chlorophyll a, chlorophyll b, total chlorophyll and caretonoids decreased with the increase in deltamethrin concentration. Conversely, anthocyanin and proline content increased in parallel with deltamethrin concentration. As a result, all morphological traits and pigments except for proline and anthocyanin were significantly reduced with an increase in pesticide concentration, compared to control (P <0.05). Copyright © 2015 Elsevier Inc. All rights reserved.

Cytochemical localization of calcium in cap cells of primary roots of Zea mays L

NASA Technical Reports Server (NTRS)

Moore, R.

1986-01-01

The distribution of calcium (Ca) in caps of vertically- and horizontally-oriented roots of Zea mays was monitored to determine its possible role in root graviresponsiveness. A modification of the antimonate precipitation procedure was used to localize Ca in situ. In vertically-oriented roots, the presumed graviperceptive (i.e., columella) cells were characterized by minimal and symmetric staining of the plasmalemma and mitochondria. No precipitate was present in plasmodesmata or cell walls. Within 5 min after horizontal reorientation, staining was associated with the portion of the cell wall adjacent to the distal end of the cell. This asymmetric staining persisted throughout the onset of gravicurvature. No staining of lateral cell walls of columella cells was observed at any stage of gravicurvature, suggesting that a lateral flow of Ca through the columella tissue of horizontally-oriented roots does not occur. The outermost peripheral cells of roots oriented horizontally and vertically secrete Ca through plasmodesmata-like structures in their cell walls. These results are discussed relative to proposed roles of root-cap Ca in root gravicurvature.

Effect of Soil Aging on the Phytoremediation Potential of Zea mays in Chromium and Benzo[a]Pyrene Contaminated Soils.

PubMed

Chigbo, Chibuike

2015-06-01

This study compared the phytoremediation potential of Zea mays in soil either aged or freshly amended with chromium (Cr) and benzo[a]pyrene (B[a]P). Z. mays showed increased shoot biomass in aged soils than in freshly spiked soils. The shoot biomass in contaminated soils increased by over 50% in aged soil when compared to freshly amended soils, and over 29% more Cr was accumulated in the shoot of Z. mays in aged soil than in freshly amended soil. Planting Z. mays in aged soil helped in the dissipation of more than 31% B[a]P than in freshly spiked soil, but in the absence of plants, there seemed to be no difference between the dissipation rates of B[a]P in freshly and aged co-contaminated soil. Z. mays seemed to enhance the simultaneous removal of Cr and B[a]P in aged soil than in freshly spiked soil and hence can be a good plant choice for phytoremediation of co-contaminated soils.

Aphrodisiac Activity of the Aqueous Crude Extract of Purple Corn (Zea mays) in Male Rats

PubMed Central

Carro-Juárez, Miguel; Rodríguez-Santiago, Magdalena G.; Franco, Miguel Angel; Hueletl-Soto, María Eugenia

2017-01-01

In the present study, the aphrodisiac properties of the purple corn (Zea mays) in male rats were analyzed. The aqueous crude extract of purple corn (at 25, 50, and 75 mg/kg) was administered to (a) copulating male rats and (b) anesthetized and spinal cord transected male rats. Behavioral parameters of copulatory behavior and parameters of the genital motor pattern of ejaculation previous to its inhibition, under the influence of the purple corn extract, are described. Administration of the aqueous crude extract of purple corn significantly facilitates the arousal and execution of male rat sexual behavior without significant influences on the ambulatory behavior. In addition, purple corn extract elicit a significant increase in the number of discharges of the ejaculatory motor patterns and in the total number of genital motor patterns evoked in spinal rats. The present findings show that the aqueous crude extract of purple corn possesses aphrodisiac activity. PMID:28508664

Development of flange and reticulate wall ingrowths in maize (Zea mays L.) endosperm transfer cells.

PubMed

Monjardino, Paulo; Rocha, Sara; Tavares, Ana C; Fernandes, Rui; Sampaio, Paula; Salema, Roberto; da Câmara Machado, Artur

2013-04-01

Maize (Zea mays L.) endosperm transfer cells are essential for kernel growth and development so they have a significant impact on grain yield. Although structural and ultrastructural studies have been published, little is known about the development of these cells, and prior to this study, there was a general consensus that they contain only flange ingrowths. We characterized the development of maize endosperm transfer cells by bright field microscopy, transmission electron microscopy, and confocal laser scanning microscopy. The most basal endosperm transfer cells (MBETC) have flange and reticulate ingrowths, whereas inner transfer cells only have flange ingrowths. Reticulate and flange ingrowths are mostly formed in different locations of the MBETC as early as 5 days after pollination, and they are distinguishable from each other at all stages of development. Ingrowth structure and ultrastructure and cellulose microfibril compaction and orientation patterns are discussed during transfer cell development. This study provides important insights into how both types of ingrowths are formed in maize endosperm transfer cells.

Asymmetric distribution of glucose and indole-3-acetyl-myo-inositol in geostimulated Zea mays seedlings

NASA Technical Reports Server (NTRS)

Momonoki, Y. S.; Bandurski, R. S. (Principal Investigator)

1988-01-01

Indole-3-acetyl-myo-inositol occurs in both the kernel and vegetative shoot of germinating Zea mays seedlings. The effect of a gravitational stimulus on the transport of [3H]-5-indole-3-acetyl-myo-inositol and [U-14C]-D-glucose from the kernel to the seedling shoot was studied. Both labeled glucose and labeled indole-3-acetyl-myo-inositol become asymmetrically distributed in the mesocotyl cortex of the shoot with more radioactivity occurring in the bottom half of a horizontally placed seedling. Asymmetric distribution of [3H]indole-3-acetic acid, derived from the applied [3H]indole-3-acetyl-myo-inositol, occurred more rapidly than distribution of total 3H-radioactivity. These findings demonstrate that the gravitational stimulus can induce an asymmetric distribution of substances being transported from kernel to shoot. They also indicate that, in addition to the transport asymmetry, gravity affects the steady state amount of indole-3-acetic acid derived from indole-3-acetyl-myo-inositol.

Root growth, secondary root formation and root gravitropism in carotenoid-deficient seedlings of Zea mays L

NASA Technical Reports Server (NTRS)

Ng, Y. K.; Moore, R.

1985-01-01

The effect of ABA on root growth, secondary-root formation and root gravitropism in seedlings of Zea mays was investigated by using Fluridone-treated seedlings and a viviparous mutant, both of which lack carotenoids and ABA. Primary roots of seedlings grown in the presence of Fluridone grew significantly slower than those of control (i.e. untreated) roots. Elongation of Fluridone-treated roots was inhibited significantly by the exogenous application of 1 mM ABA. Exogenous application of 1 micromole and 1 nmole ABA had either no effect or only a slight stimulatory effect on root elongation, depending on the method of application. The absence of ABA in Fluridone-treated plants was not an important factor in secondary-root formation in seedlings less than 9-10 d old. However, ABA may suppress secondary-root formation in older seedlings, since 11-d-old control seedlings had significantly fewer secondary roots than Fluridone-treated seedlings. Roots of Fluridone-treated and control seedlings were graviresponsive. Similar data were obtained for vp-9 mutants of Z. mays, which are phenotypically identical to Fluridone-treated seedlings. These results indicate that ABA is necessary for neither secondary-root formation nor for positive gravitropism by primary roots.

Degradation of fipronil by Stenotrophomonas acidaminiphila isolated from rhizospheric soil of Zea mays.

PubMed

Uniyal, Shivani; Paliwal, Rashmi; Sharma, R K; Rai, J P N

2016-06-01

Fipronil is a widely used insecticide in agriculture and can cause potential health hazards to non-target soil invertebrates and nearby aquatic systems. In the present study, a fipronil degrading bacterium was isolated from fipronil contaminated soil, i.e. rhizospheric zone of Zea mays. Morphological, biochemical and molecular characterization of strain indicated that it clearly belongs to Stenotrophomonas acidaminiphila (accession no. KJ396942). A three-factor Box-Behnken experimental design combined with response surface modeling was employed to predict the optimum conditions for fipronil degradation. The optimum pH, temperature and total inocula biomass for the degradation of fipronil were 7.5, 35 °C and 0.175 g L -1 , respectively. The bacterial strain was able to metabolize 25 mg L -1 fipronil with 86.14 % degradation in Dorn's broth medium under optimum conditions. Metabolites formed as a result of fipronil degradation were characterized with gas liquid chromatograph. A novel fipronil degradation pathway was proposed for S. acidaminiphila on the basis of metabolites formed. Non-sterilized soil inoculated with S. acidaminiphila was found to follow first order kinetics with a rate constant of 0.046 d -1 . Fipronil sulfone, sulfide and amide were formed as the metabolites and were degraded below the quantifiable limit after 90 days of time period. Given the high fipronil degradation observed in the present study, S. acidaminiphila may have potential for use in bioremediation of fipronil contaminated soils.

[Vasodilator effect mediated by nitric oxide of the Zea mays L (andean purple corn) hydroalcoholic extract in aortic rings of rat].

PubMed

Moreno-Loaiza, Oscar; Paz-Aliaga, Azael

2010-01-01

To evaluate the vasodilator response of the hydroalcoholic extract of Zea mays L. (Andean purple corn) and to determine if this response is mediated by nitric oxide (NO). We obtained an extract by maceration for eight days of Andean purple corn cobs in 70% ethanol and subsequent concentration of the product. Thoracic aortic rings were evaluated in an isolated organ chamber, bathed with Krebs-Hensleit solution (KH), and vasomotor activity was recorded with an isometric tension transducer. Basal contraction was produced with 120 mM KCl and then, we proceeded to determinate the vasodilator effect of 3 doses of the extract: 0.1, 0.5, and 1.0 mg/mL. We used L-NG-Nitroarginin methyl ester (L-NAME) to verify that the vasodilation depends on nitric oxide sinteasa (NOs). Then we compared the inhibition of vascular contraction after incubation for 30 minutes, with purple corn extract and captopril 10-5 M. We observed a reduction in maximum contraction (100%) to 85.25 ± 2.60%, 77.76 ± 3.23%, and 73.3 ± 4.87% for doses of 0.1, 0.5 and 1,0 mg/mL respectively. The vasodilation was inhibited by prior incubation with L-NAME. Andean purple corn extract did not inhibit vascular contraction as captopril did (reduction to 75.27 ± 8.61%). The hydroalcoholic extract of Zea mays L produces NO dependent vasodilation.

Purification and Characterization of Four β-Expansins (Zea m 1 Isoforms) from Maize Pollen1[w

PubMed Central

Li, Lian-Chao; Bedinger, Patricia A.; Volk, Carol; Jones, A. Daniel; Cosgrove, Daniel J.

2003-01-01

Four proteins with wall extension activity on grass cell walls were purified from maize (Zea mays) pollen by conventional column chromatography and high-performance liquid chromatography. Each is a basic glycoprotein (isoelectric point = 9.1–9.5) of approximately 28 kD and was identified by immunoblot analysis as an isoform of Zea m 1, the major group 1 allergen of maize pollen and member of the β-expansin family. Four distinctive cDNAs for Zea m 1 were identified by cDNA library screening and by GenBank analysis. One pair (GenBank accession nos. AY104999 and AY104125) was much closer in sequence to well-characterized allergens such as Lol p 1 and Phl p 1 from ryegrass (Lolium perenne) and Phleum pretense, whereas a second pair was much more divergent. The N-terminal sequence and mass spectrometry fingerprint of the most abundant isoform (Zea m 1d) matched that predicted for AY197353, whereas N-terminal sequences of the other isoforms matched or nearly matched AY104999 and AY104125. Highly purified Zea m 1d induced extension of a variety of grass walls but not dicot walls. Wall extension activity of Zea m 1d was biphasic with respect to protein concentration, had a broad pH optimum between 5 and 6, required more than 50 μg mL-1 for high activity, and led to cell wall breakage after only approximately 10% extension. These characteristics differ from those of α-expansins. Some of the distinctive properties of Zea m 1 may not be typical of β-expansins as a class but may relate to the specialized function of this β-expansin in pollen function. PMID:12913162

Characterization of Zea mays endosperm C-24 sterol methyltransferase: one of two types of sterol methyltransferase in higher plants.

PubMed

Grebenok, R J; Galbraith, D W; Penna, D D

1997-08-01

We report the characterization of a higher-plant C-24 sterol methyltransferase by yeast complementation. A Zea mays endosperm expressed sequence tag (EST) was identified which, upon complete sequencing, showed 46% identity to the yeast C-24 methyltransferase gene (ERG6) and 75% and 37% amino acid identity to recently isolated higher-plant sterol methyltransferases from soybean and Arabidopsis, respectively. When placed under GALA regulation, the Z. mays cDNA functionally complemented the erg6 mutation, restoring ergosterol production and conferring resistance to cycloheximide. Complementation was both plasmid-dependent and galactose-inducible. The Z. mays cDNA clone contains an open reading frame encoding a 40 kDa protein containing motifs common to a large number of S-adenosyl-L-methionine methyltransferases (SMTs). Sequence comparisons and functional studies of the maize, soybean and Arabidopsis cDNAs indicates two types of C-24 SMTs exist in higher plants.

Callose deposition during gravitropism of Zea mays and Pisum sativum and its inhibition by 2-deoxy-D-glucose

NASA Technical Reports Server (NTRS)

Jaffe, M. J.; Leopold, A. C.

1984-01-01

In etiolated corn (Zea mays L.) and etiolated pea (Pisum sativum L.) seedlings, a gravitropic stimulation induces the deposition of callose. In the corn coleoptiles this occurs within 5 min of gravity stimulation, and prior to the beginning of curvature. Both gravitropic curvature and callose deposition reach their maxima by 12 h. Within the first 2 h more callose is deposited on the upper (concave) side, but after 2-3 h, this deposition pattern is reversed. An inhibitor of protein glycosylation, 2-deoxy-D-glucose (DDG), inhibits callose production and considerably retards gravitropic bending in both species of plants. Mannose can relieve the inhibition of gravitropic bending by DDG. The pea mutant "Ageotropum", which does not respond to gravity when etiolated, also fails to produce callose in response to a gravitic stimulus. These correlations indicate that callose deposition may be a biochemical component of gravitropism in plant shoots.

Effect of a longitudinally applied voltage upon the growth of Zea mays seedlings

NASA Technical Reports Server (NTRS)

Desrosiers, M. F.; Bandurski, R. S.

1988-01-01

The electrical parameters that affect young seedling growth were investigated. Voltages ranging from 5 to 40 volts were applied longitudinally along the mesocotyl region of 4-day old Zea mays L. (cv Silver Queen) seedlings for periods of 3 or 4 hours. It was determined that: (a) making the tips of the seedlings electrically positive relative to the base strongly inhibited shoot growth at 5 volts, whereas the reverse polarity had no effect; (b) at higher voltages, making the tip of the seedlings negative caused less growth inhibition than the reverse polarity at each voltage level; (c) the higher the applied voltage the greater the degree of inhibition; and, (d) the more growth inhibition experienced by the plants the poorer, and slower, their recovery. Previous observations of a relationship between the amount of free indole-3-acetic acid in the mesocotyl cortex and the growth rate of the mesocotyl and of gravitropism-induced movement of labeled indole-3-acetic acid from the seed to the shoot lead to the prediction of a voltage-dependent gating of the movement of indole-3-acetic acid from the stele to the cortex. This provided the basis for attempting to alter the growth rate of seedlings by means of an applied voltage.

Effect of a longitudinally applied voltage upon the growth of Zea mays seedlings.

PubMed

Desrosiers, M F; Bandurski, R S

1988-01-01

The electrical parameters that affect young seedling growth were investigated. Voltages ranging from 5 to 40 volts were applied longitudinally along the mesocotyl region of 4-day old Zea mays L. (cv Silver Queen) seedlings for periods of 3 or 4 hours. It was determined that: (a) making the tips of the seedlings electrically positive relative to the base strongly inhibited shoot growth at 5 volts, whereas the reverse polarity had no effect; (b) at higher voltages, making the tip of the seedlings negative caused less growth inhibition than the reverse polarity at each voltage level; (c) the higher the applied voltage the greater the degree of inhibition; and, (d) the more growth inhibition experienced by the plants the poorer, and slower, their recovery. Previous observations of a relationship between the amount of free indole-3-acetic acid in the mesocotyl cortex and the growth rate of the mesocotyl and of gravitropism-induced movement of labeled indole-3-acetic acid from the seed to the shoot lead to the prediction of a voltage-dependent gating of the movement of indole-3-acetic acid from the stele to the cortex. This provided the basis for attempting to alter the growth rate of seedlings by means of an applied voltage.

[CONTENT OF OXIDATIVE STRESS MARKERS IN BLOOD PLASMA UNDER THE ACTION OF EXTRACTS OF GRATIOLA OFFICINALIS L., HELICHRYSUM ARENARIUM (L.) MOENCH, AND ANTHOCYANIN FORMS OF ZEA MAYS L].

PubMed

Durnova, N A; Afanas'eva, G A; Kurchatova, M N; Zaraeva, N V; Golikov, A G; Bucharskaya, A B; Golikov, A G; Bucharskaya, A B; Plastun, V O; Andreeva, N V

2015-01-01

The effect of aqueous solutions of dry ethanol extracts of Gratiola officinalis L., Helichrysum arenarium (L.) Moench, and anthocyanin forms of Zea mays L. on the dioxidin-induced lipid peroxidation in blood has been studied on rats. It is established that all these extracts are capable of reducing the amount of avera- ge-mass (AM) molecules and malonic dialdehyde (MDA) in rat blood plasma. The extract of Gratiola officinalis L. reduces the concentration of AM and MDA moleules by 43%. The extract of Helichrysum arenarium (L.) Moench reduces the concentration of AM molecules on the average by 18.66% (within 9.22 -34.81%) and MDA by 49.36% (within 34.12-79.75%). The Extract of anthocyanin forms of Zea mays L. does not reduce the concentration of AM mo- lecules, but reduces the amount of MDA in the blood of rats on average by 27.88% (within 21.58-37.82%) (p < 0.01).

Dehydration stress memory genes of Zea mays; comparison with Arabidopsis thaliana

PubMed Central

2014-01-01

Background Pre-exposing plants to diverse abiotic stresses may alter their physiological and transcriptional responses to a subsequent stress, suggesting a form of “stress memory”. Arabidopsis thaliana plants that have experienced multiple exposures to dehydration stress display transcriptional behavior suggesting “memory” from an earlier stress. Genes that respond to a first stress by up-regulating or down-regulating their transcription but in a subsequent stress provide a significantly different response define the ‘memory genes’ category. Genes responding similarly to each stress form the ‘non-memory’ category. It is unknown whether such memory responses exists in other Angiosperm lineages and whether memory is an evolutionarily conserved response to repeated dehydration stresses. Results Here, we determine the transcriptional responses of maize (Zea mays L.) plants that have experienced repeated exposures to dehydration stress in comparison with plants encountering the stress for the first time. Four distinct transcription memory response patterns similar to those displayed by A. thaliana were revealed. The most important contribution is the evidence that monocot and eudicot plants, two lineages that have diverged 140 to 200 M years ago, display similar abilities to ‘remember’ a dehydration stress and to modify their transcriptional responses, accordingly. The highly sensitive RNA-Seq analyses allowed to identify genes that function similarly in the two lineages, as well as genes that function in species-specific ways. Memory transcription patterns indicate that the transcriptional behavior of responding genes under repeated stresses is different from the behavior during an initial dehydration stress, suggesting that stress memory is a complex phenotype resulting from coordinated responses of multiple signaling pathways. Conclusions Structurally related genes displaying the same memory responses in the two species would suggest conservation

Human research cloning, embryos, and embryo-like artifacts.

PubMed

Hyun, Insoo; Jung, Kyu Won

2006-01-01

Research suggests that cloning is incapable of producing a viable embryo when it is used on primate eggs. In fact, the entity created may not qualify as an embryo at all. If the results stand, cloning avoids the moral objections typically lodged against it, and cloning is itself an "alternative source" of stem cells.

Xylem- and phloem-based transport of CuO nanoparticles in maize (Zea mays L.).

PubMed

Wang, Zhenyu; Xie, Xiaoyan; Zhao, Jian; Liu, Xiaoyun; Feng, Wenqiang; White, Jason C; Xing, Baoshan

2012-04-17

This work reports on the toxicity of CuO nanoparticles (NPs) to maize (Zea mays L.) and their transport and redistribution in the plant. CuO NPs (100 mg L(-1)) had no effect on germination, but inhibited the growth of maize seedlings; in comparison the dissolved Cu(2+) ions and CuO bulk particles had no obvious effect on maize growth. CuO NPs were present in xylem sap as examined by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS), showing that CuO NPs were transported from roots to shoots via xylem. Split-root experiments and high-resolution TEM observation further showed that CuO NPs could translocate from shoots back to roots via phloem. During this translocation, CuO NPs could be reduced from Cu (II) to Cu (I). To our knowledge, this is the first report of root-shoot-root redistribution of CuO NPs within maize. The current study provides direct evidence for the bioaccumulation and biotransformation of CuO NPs (20-40 nm) in maize, which has significant implications on the potential risk of NPs and food safety.

Evaluating Corn (Zea Mays L.) N Variability Via Remote Sensed Data

NASA Technical Reports Server (NTRS)

Sullivan, D. G.; Shaw, J. N.; Mask, P. L.; Rickman, D.; Luvall, J.; Wersinger, J. M.

2003-01-01

Transformations and losses of nitrogen (N) throughout the growing season can be costly. Methods in place to improve N management and facilitate split N applications during the growing season can be time consuming and logistically difficult. Remote sensing (RS) may be a method to rapidly assess temporal changes in crop N status and promote more efficient N management. This study was designed to evaluate the ability of three different RS platforms to predict N variability in corn (Zea mays L.) leaves during vegetative and early reproductive growth stages. Plots (15 x 15m) were established in the Coastal Plain (CP) and Appalachian Plateau (AP) physiographic regions each spring from 2000 to 2002 in a completely randomized design. Treatments consisted of four N rates (0, 56, 112, and 168 kg N/ha) applied as ammonium nitrate (NH4N03) replicated four time. Spectral measurements were acquired via spectroradiometer (lambda = 350 - 1050 nm), Airborne Terrestrial Applications Sensor (ATLAS) (lambda = 400 - 12,500 nm), and the IKONOS satellite (lambda = 450 - 900 nm). Spectroradiometer data were collected on a biweekly basis from V4 through R1. Due to the nature of - satellite and aircraft acquisitions, these data were acquired per availability. Chlorophyll meter (SPAD) and tissue N were collected as ancillary data along with each RS acquisition. Results showed vegetation indices derived from hand-held spectroradiometer measurements as early as V6-V8 were linearly related to yield and tissue N content. ATLAS data was correlated with tissue N at the AP site during the V6 stage (r2 = 0.66), but no significant relationships were observed at the CP site. No significant relationships were observed between plant N and IKONOS imagery. Using a combination of the greenness vegetation index (GNDVI) and the normalized difference vegetation index (NDVI), RS data acquired via ATLAS and the spectroradiometer could be used to evaluate tissue N variability and estimate corn yield variability

Nematode suppression and growth stimulation in corn plants (Zea mays L.) irrigated with domestic effluent.

PubMed

Barros, Kenia Kelly; do Nascimento, Clístenes Williams Araújo; Florencio, Lourdinha

2012-01-01

Treated wastewater has great potential for agricultural use due to its concentrations of nutrients and organic matter, which are capable of improving soil characteristics. Additionally, effluents can induce suppression of plant diseases caused by soil pathogens. This study evaluates the effect of irrigation with effluent in a UASB reactor on maize (Zea mays L.) development and on suppression of the diseases caused by nematodes of the genus Meloidogyne. Twelve lysimeters of 1 m(3) each were arranged in a completely randomized design, with four treatments and three replicates. The following treatments were used: T1 (W+I), irrigation with water and infestation with nematodes; T2 (W+I+NPK), irrigation with water, infestation with nematodes and fertilization with nitrogen (N), phosphorus (P) and potassium (K); T3 (E+I), irrigation with effluent and infestation with nematodes; and T4 (E+I+P), irrigation with effluent, infestation with nematodes and fertilization with phosphorus. The plants irrigated with the effluent plus the phosphorus fertilizer had better growth and productivity and were more resistant to the disease symptoms caused by the nematodes. The suppression levels may have been due to the higher levels of Zn and NO(3)(-) found in the leaf tissue of the plants irrigated with the effluent and phosphorus fertilizer.

Characterization of phenylpropanoid pathway genes within European maize (Zea mays L.) inbreds

PubMed Central

Andersen, Jeppe Reitan; Zein, Imad; Wenzel, Gerhard; Darnhofer, Birte; Eder, Joachim; Ouzunova, Milena; Lübberstedt, Thomas

2008-01-01

Background Forage quality of maize is influenced by both the content and structure of lignins in the cell wall. Biosynthesis of monolignols, constituting the complex structure of lignins, is catalyzed by enzymes in the phenylpropanoid pathway. Results In the present study we have amplified partial genomic fragments of six putative phenylpropanoid pathway genes in a panel of elite European inbred lines of maize (Zea mays L.) contrasting in forage quality traits. Six loci, encoding C4H, 4CL1, 4CL2, C3H, F5H, and CAD, displayed different levels of nucleotide diversity and linkage disequilibrium (LD) possibly reflecting different levels of selection. Associations with forage quality traits were identified for several individual polymorphisms within the 4CL1, C3H, and F5H genomic fragments when controlling for both overall population structure and relative kinship. A 1-bp indel in 4CL1 was associated with in vitro digestibility of organic matter (IVDOM), a non-synonymous SNP in C3H was associated with IVDOM, and an intron SNP in F5H was associated with neutral detergent fiber. However, the C3H and F5H associations did not remain significant when controlling for multiple testing. Conclusion While the number of lines included in this study limit the power of the association analysis, our results imply that genetic variation for forage quality traits can be mined in phenylpropanoid pathway genes of elite breeding lines of maize. PMID:18173847

Genome-Wide Comparative In Silico Analysis of the RNA Helicase Gene Family in Zea mays and Glycine max: A Comparison with Arabidopsis and Oryza sativa

PubMed Central

Huang, Jinguang; Zheng, Chengchao

2013-01-01

RNA helicases are enzymes that are thought to unwind double-stranded RNA molecules in an energy-dependent fashion through the hydrolysis of NTP. RNA helicases are associated with all processes involving RNA molecules, including nuclear transcription, editing, splicing, ribosome biogenesis, RNA export, and organelle gene expression. The involvement of RNA helicase in response to stress and in plant growth and development has been reported previously. While their importance in Arabidopsis and Oryza sativa has been partially studied, the function of RNA helicase proteins is poorly understood in Zea mays and Glycine max. In this study, we identified a total of RNA helicase genes in Arabidopsis and other crop species genome by genome-wide comparative in silico analysis. We classified the RNA helicase genes into three subfamilies according to the structural features of the motif II region, such as DEAD-box, DEAH-box and DExD/H-box, and different species showed different patterns of alternative splicing. Secondly, chromosome location analysis showed that the RNA helicase protein genes were distributed across all chromosomes with different densities in the four species. Thirdly, phylogenetic tree analyses identified the relevant homologs of DEAD-box, DEAH-box and DExD/H-box RNA helicase proteins in each of the four species. Fourthly, microarray expression data showed that many of these predicted RNA helicase genes were expressed in different developmental stages and different tissues under normal growth conditions. Finally, real-time quantitative PCR analysis showed that the expression levels of 10 genes in Arabidopsis and 13 genes in Zea mays were in close agreement with the microarray expression data. To our knowledge, this is the first report of a comparative genome-wide analysis of the RNA helicase gene family in Arabidopsis, Oryza sativa, Zea mays and Glycine max. This study provides valuable information for understanding the classification and putative functions of

Genome-wide comparative in silico analysis of the RNA helicase gene family in Zea mays and Glycine max: a comparison with Arabidopsis and Oryza sativa.

PubMed

Xu, Ruirui; Zhang, Shizhong; Huang, Jinguang; Zheng, Chengchao

2013-01-01

RNA helicases are enzymes that are thought to unwind double-stranded RNA molecules in an energy-dependent fashion through the hydrolysis of NTP. RNA helicases are associated with all processes involving RNA molecules, including nuclear transcription, editing, splicing, ribosome biogenesis, RNA export, and organelle gene expression. The involvement of RNA helicase in response to stress and in plant growth and development has been reported previously. While their importance in Arabidopsis and Oryza sativa has been partially studied, the function of RNA helicase proteins is poorly understood in Zea mays and Glycine max. In this study, we identified a total of RNA helicase genes in Arabidopsis and other crop species genome by genome-wide comparative in silico analysis. We classified the RNA helicase genes into three subfamilies according to the structural features of the motif II region, such as DEAD-box, DEAH-box and DExD/H-box, and different species showed different patterns of alternative splicing. Secondly, chromosome location analysis showed that the RNA helicase protein genes were distributed across all chromosomes with different densities in the four species. Thirdly, phylogenetic tree analyses identified the relevant homologs of DEAD-box, DEAH-box and DExD/H-box RNA helicase proteins in each of the four species. Fourthly, microarray expression data showed that many of these predicted RNA helicase genes were expressed in different developmental stages and different tissues under normal growth conditions. Finally, real-time quantitative PCR analysis showed that the expression levels of 10 genes in Arabidopsis and 13 genes in Zea mays were in close agreement with the microarray expression data. To our knowledge, this is the first report of a comparative genome-wide analysis of the RNA helicase gene family in Arabidopsis, Oryza sativa, Zea mays and Glycine max. This study provides valuable information for understanding the classification and putative functions of

Maize (Zea mays L.) performance in organically amended mine site soils.

PubMed

Oladipo, Oluwatosin Gbemisola; Olayinka, Akinyemi; Awotoye, Olusegun Olufemi

2016-10-01

Organic amendments play an important role in the eco-friendly remediation of degraded mine site soils. This study investigated the quality (essential nutrients and heavy metal content) of maize grown on organically amended soils from three active mines in Nigeria. Soil samples were collected randomly at 0-15 cm depth, air-dried and sieved. Five kg of soil were amended with poultry manure and sawdust (poultry manure only, sawdust only, poultry manure-sawdust mixtures in 3:1, 2:1 and 1:1 ratios) at 10 g kg(-1). Maize (Zea mays L.) seeds were planted and watered for two consecutive periods of 8 weeks, with the control and treatment experiments set up in the screenhouse in quadruples. Harvested tissues were weighed, dried, ground and digested. Chemical properties were determined using standard methods while atomic absorption spectrophotometry was used to determine total metal concentrations (Ca, Mg, Fe, Zn, Pb, Cd and Cu). ANOVA was used to test for significant differences among treatment groups in the various parameters. Application of poultry manure-sawdust mixtures significantly (p < 0.05) enhanced tissue dry matter yield, as well as N, P, K, and Na contents while Zn, Cd, Cu and Pb were immobilized to approximately 50-100%. Treatment with sawdust alone reduced tissue nutrient content resulting in depressed plant yield while poultry manure only though enhanced crop yield, contained higher heavy metal contents. Soil amendments comprised of poultry manure-sawdust mixtures can be effective remediation strategy for mine site soils, as these organic materials help replenish soil nutrients, immobilize heavy metals, and enhance food productivity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optical Reflectance and Fluorescence for Detecting Nitrogen Needs in Zea mays L.

NASA Technical Reports Server (NTRS)

McMurtrey, J. E.; Middleton, E. M.; Corp. L. A.; Campbell, P. K. Entcheva; Butcher, L. M.; Daughtry, C. S. T.

2003-01-01

Nitrogen (N) status in field grown corn (Zea mays L.) was assessed using spectral techniques. Passive reflectance remote sensing and, both passive and active fluorescence sensing methods were investigated. Reflectance and fluorescence methods are reported to detect changes in the primary plant pigments (chlorophylls a and b; carotenoids) in higher plant species. As a general rule, foliar chlorophyll a (Chl a) and chlorophyll b (Chl b) usually exist in approx.3:l ratio. In plants under stress, Chl b content is affected before Chl a reductions occur. For reflectance, a version of the chlorophyll absorption in reflectance index (CARI) method was tested with narrow bands from the Airborne Imaging Spectroradiometer for Applications (ASIA). CARI minimizes the effects of soil background on the signal from green canopies. A modified CARI (MCARI) was used to track total Chl a levels in the red dip of the spectrum from the corn canopy. A second MCARI was used to track the auxiliary plant pigments (Chl b and the carotenoids) in the yellow/orange/red edge part of the reflectance spectrum. The difference between these two MCARI indices detected variations in N levels across the field plot canopies using ASIA data. At the leaf level, ratios of fluorescence emissions in the blue, green, red and far-red wavelengths sensed responses that were associated with the plant pigments, and were indicative of energy transfer in the photosynthetic process. N stressed corn stands could be distinguish from those with optimally applied N with fluorescence emission spectra obtained from individual corn leaves. Both reflectance and fluorescence methods are sensitive in detecting corn N needs and may be especially powerful in monitoring crop conditions if both types of information can be combined.

Effects of Light and Temperature on the Association between Zea mays and Spirillum lipoferum1

PubMed Central

Albrecht, Stephan L.; Okon, Yaacov; Burris, Robert H.

1977-01-01

Zea mays was grown on a low N nutrient solution under 16 conditions of light and temperature in a crossed-gradient room in an attempt to determine whether or not variation in climatic conditions influences N2 fixation by the association between maize and Spirillum lipoferum. Temperatures were 28, 32, 36, and 40 C and 10 C lower at night; light intensities were 500, 1,250, 2,400, and 3,000 ft-c. Plants harvested after 94 days showed no significant benefit from association with S. lipoferum either in dry weight production or in total N content; variations in temperature and light had only a small influence on N2 fixation under the conditions tested. Measurements of total N, together with designated assumptions, indicated that less than the equivalent of 0.5 kilogram of N was fixed/hectare during the entire growing period by the maize-S. lipoferum association. Rates of C2H2 reduction by replicate root samples generally were low and variable and did not correlate with the measurements of total N. PMID:16660131

Quantification of allantoin in various Zea mays L. hybrids by RP-HPLC with UV detection.

PubMed

Maksimović, Z; Malenović, A; Jancić, B; Kovacević, N

2004-07-01

A RP-HPLC method for quantification of allantoin in silk of fifteen maize hybrids (Zea mays L., Poaceae) was described. Following extraction of the plant material with an acetone-water (7:3, VN) mixture, filtration and dilution, the extracts were analyzed without previous chemical derivatization. Separation and quantification were achieved using an Alltech Econosil C18 column under isocratic conditions at 40 degrees C. The mobile phase flow (20% methanol--80% water with 5 mM sodium laurylsulfate added at pH 2.5, adjusted with 85% orthophosphoric acid; pH of water phase was finally adjusted at 6.0 by addition of triethylamine) was maintained at 1.0 mL/min. Column effluent was monitored at 235 nm. This simple procedure afforded efficient separation and quantification of allantoin in plant material, without interference of polyphenols or other plant constituents of medium to high polarity, or similar UV absorption. Our study revealed that the silk of all investigated maize hybrids could be considered relatively rich in allantoin, covering the concentration range between 215 and 289 mg per 100 g of dry plant material.

Hydrolysis and reconjugation of gibberellin A20 glucosyl ester by seedlings of Zea mays L.

PubMed Central

Schneider, G; Jensen, E; Spray, C R; Phinney, B O

1992-01-01

The [6-2H]glucosyl ester of [17-13C,3H]gibberellin A20 (GA20) was injected into light-grown 14-day-old seedlings of normal, dwarf-1, and dwarf-5 maize (Zea mays L.). The plant material was extracted 24 h later, and the extracts were purified by solvent partitioning, column chromatography, and HPLC. 13C-labeled metabolites were identified from the purified extracts by full-scan gas chromatography/mass spectrometry and selected ion current monitoring in conjunction with Kovats retention indices. The metabolites, [13C]GA20, [13C]GA29, [13C]GA20-13-O-glucoside, and [13C]GA29-2-O-glucoside, were identified from normal, dwarf-1, and dwarf-5 seedlings. [13C]GA8 and [13C]GA8-2-O-glucoside were also identified from normal and dwarf-5 seedlings but not from dwarf-1 seedlings. The data provide definitive evidence for the endogenous hydrolysis by the seedlings of the introduced conjugate and its reconjugation to three glucosides. PMID:1518829

Comparative Effectivness of Metal Ions in Inducing Curvature of Primary Roots of Zea mays1

PubMed Central

Hasenstein, Karl Heinz; Evans, Michael L.; Stinemetz, Charles L.; Moore, Randy; Fondren, W. Mark; Koon, E. Colin; Higby, Mary A.; Smucker, Alvin J. M.

1988-01-01

We used five cultivars of Zea mays (Bear Hybrid WF9 * 38MS, B73 * Missouri 17, Yellow Dent, Merit, and Great Lakes Hybrid 422) to reinvestigate the specificity of metal ions for inducing root curvature. Of 17 cations tested, 6 (Al3+, Ba2+, Ca2+, Cd2+, Cu2+, Zn2+) induced curvature. Roots curved away from Al3+, Ba2+, and Cd2+. Roots curved away from low (0.1 millimolar) concentrations of Cu2+ but toward higher (1-5 millimolar) concentrations. Roots initially curved away from Zn2+ but the direction of the subsequent curvature was unpredictable. In most cases, roots of all cultivars curved towards calcium. However, in some tests there was no response to calcium or even (especially in the cultivars Merit and B73 * Missouri 17) substantial curvature away from calcium. The results indicate that the induction of root curvature is not specific for calcium. The results are discussed relative to the possible role of calmodulin as a mediator of ion-induced root curvature. PMID:11538239

Effects of As2O3 on DNA methylation, genomic instability, and LTR retrotransposon polymorphism in Zea mays.

PubMed

Erturk, Filiz Aygun; Aydin, Murat; Sigmaz, Burcu; Taspinar, M Sinan; Arslan, Esra; Agar, Guleray; Yagci, Semra

2015-12-01

Arsenic is a well-known toxic substance on the living organisms. However, limited efforts have been made to study its DNA methylation, genomic instability, and long terminal repeat (LTR) retrotransposon polymorphism causing properties in different crops. In the present study, effects of As2O3 (arsenic trioxide) on LTR retrotransposon polymorphism and DNA methylation as well as DNA damage in Zea mays seedlings were investigated. The results showed that all of arsenic doses caused a decreasing genomic template stability (GTS) and an increasing Random Amplified Polymorphic DNAs (RAPDs) profile changes (DNA damage). In addition, increasing DNA methylation and LTR retrotransposon polymorphism characterized a model to explain the epigenetically changes in the gene expression were also found. The results of this experiment have clearly shown that arsenic has epigenetic effect as well as its genotoxic effect. Especially, the increasing of polymorphism of some LTR retrotransposon under arsenic stress may be a part of the defense system against the stress.

Isolation and Characterization of Fipronil Degrading Acinetobacter calcoaceticus and Acinetobacter oleivorans from Rhizospheric Zone of Zea mays.

PubMed

Uniyal, Shivani; Paliwal, Rashmi; Verma, Megha; Sharma, R K; Rai, J P N

2016-06-01

An enrichment culture technique was used for the isolation of bacteria capable of utilizing fipronil as a sole source of carbon and energy. Based on morphological, biochemical characteristics and phylogenetic analysis of 16S rRNA sequence, the bacterial strains were identified as Acinetobacter calcoaceticus and Acinetobacter oleivorans. Biodegradation experiments were conducted in loamy sand soil samples fortified with fipronil (50 µg kg(-1)) and inoculated with Acinetobacter sp. cells (45 × 10(7) CFU mL(-1)) for 90 days. Soil samples were periodically analyzed by gas liquid chromatography equipped with electron capture detector. Biodegradation of fipronil fitted well with the pseudo first-order kinetics, with rate constant value between 0.041 and 0.051 days(-1). In pot experiments, fipronil and its metabolites fipronil sulfide, fipronil sulfone and fipronil amide were found below quantifiable limit in soil and root, shoot and leaves of Zea mays. These results demonstrated that A. calcoaceticus and A. oleivorans may serve as promising strains in the bioremediation of fipronil-contaminated soils.

Zea mays, Stigma maydis prevents and extenuates acetaminophen-perturbed oxidative onslaughts in rat hepatocytes.

PubMed

Saheed, Sabiu; Frans Hendrik, O'Neill; Tom, Ashafa Anofi Omotayo

2016-11-01

Zea mays L. (Poaceae) Stigma maydis is an underutilized product of corn cultivation finding therapeutic applications in oxidative stress-related disorders. This study investigated its aqueous extract against acetaminophen (APAP)-perturbed oxidative insults in rat hepatocytes. Hepatotoxic rats were orally pre- and post-treated with the extract (at 200 and 400 mg/kg body weight) and vitamin C (200 mg/kg body weight), respectively, for 14 days. Liver function, antioxidative and histological analyses were thereafter evaluated. The APAP-induced marked (p < 0.05) increases in the activities of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, gamma glutamyl transferase and the concentrations of bilirubin, oxidized glutathione, protein carbonyls, malondialdehyde, conjugated dienes, lipid hydroperoxides and fragmented DNA were dose-dependently extenuated in the extract-treated animals. The extract also significantly (p < 0.05) improved the reduced activities of superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase as well as total protein, albumin and glutathione concentrations in the hepatotoxic rats. These improvements may be attributed to the bioactive constituents as revealed by the gas chromatography-mass spectrometric chromatogram of the extract. The observed effects compared favourably with vitamin C and are informative of hepatoprotective and antioxidative attributes of the extract and were further supported by the histological analysis. The data from the present findings suggest that Stigma maydis aqueous extract is capable of preventing and ameliorating APAP-mediated oxidative hepatic damage via enhancement of antioxidant defence systems.

Phytoremediation for co-contaminated soils of chromium and benzo[a]pyrene using Zea mays L.

PubMed

Chigbo, Chibuike; Batty, Lesley

2014-02-01

A greenhouse experiment was carried out to investigate the single effect of benzo[a]pyrene (B[a]P) or chromium (Cr) and the joint effect of Cr-B[a]P on the growth of Zea mays, its uptake and accumulation of Cr, and the dissipation of B[a]P over 60 days. Results showed that single or joint contamination of Cr and B[a]P did not affect the plant growth relative to control treatments. However, the occurrence of B[a]P had an enhancing effect on the accumulation and translocation of Cr. The accumulation of Cr in shoot of plant significantly increased by ≥ 79 % in 50 mg kg(-1) Cr-B[a]P (1, 5, and 10 mg kg(-1)) treatments and by ≥ 86 % in 100 mg kg(-1) Cr-B[a]P (1, 5, and 10 mg kg(-1)) treatments relative to control treatments. The presence of plants did not enhance the dissipation of B[a]P in lower (1and 5 mg kg(-1)) B[a]P contaminated soils; however, over 60 days of planting Z. mays seemed to enhance the dissipation of B[a]P by over 60 % in 10 mg kg(-1) single contaminated soil and by 28 to 41 % in 10 mg kg(-1)B[a]P co-contaminated soil. This suggests that Z. mays might be a useful plant for the remediation of Cr-B[a]P co-contaminated soil.

Influence of electrical fields and asymmetric application of mucilage on curvature of primary roots of Zea mays

NASA Technical Reports Server (NTRS)

Marcum, H.; Moore, R.

1990-01-01

Primary roots of Zea mays cv. Yellow Dent growing in an electric field curve towards the anode. Roots treated with EDTA and growing in electric field do not curve. When root cap mucilage is applied asymmetrically to tips of vertically-oriented roots, the roots curve toward the mucilage. Roots treated with EDTA curve toward the side receiving mucilage and toward blocks containing 10 mM CaCl2, but not toward "empty" agar blocks or the cut surfaces of severed root tips. These results suggest that 1) free calcium (Ca) is necessary for root electrotropism, 2) mucilage contains effector(s) that induce gravitropiclike curvature, and 3) mucilage can replace gravitropic effectors chelated by EDTA. These results are consistent with the hypothesis that the downward movement of gravitropic effectors to the lower sides of tips of horizontally-oriented roots occurs at least partially in the apoplast.

Bacillus ciccensis sp. nov., isolated from maize (Zea mays L.) seeds.

PubMed

Liu, Yang; Li, Nannan; Eom, Mi Kyung; Schumann, Peter; Zhang, Xin; Cao, Yanhua; Ge, Yuanyuan; Xiao, Ming; Zhao, Jiuran; Cheng, Chi; Kim, Song-Gun

2017-11-01

Two Gram-stain-positive bacterial strains, designated as 5L6 T and 6L6, isolated from seeds of hybrid maize (Zea mays L., Jingke 968) were investigated using a polyphasic taxonomic approach. The cells were aerobic, motile, endospore-forming and rod-shaped. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolates were recognized as a species of the genus Bacillus, to which the five closest neighbours are Bacillus solani FJAT-18043 T (99.8 % similarity), Bacillus horneckiae DSM 23495 T (97.7 %), Bacillus eiseniae A1-2 T (97.4 %), Bacillus kochii WCC 4582 T (97.1 %) and Bacillus purgationiresistens DS22 T (97.0 %). The DNA G+C content of strain 5L6 T was 37.4 mol%. Its polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The predominant respiratory quinone was MK-7 and the major fatty acids were iso-C15 : 0, anteiso-C15 : 0, iso-C16 : 0, iso-C14 : 0, anteiso-C17 : 0 and C16 : 1 ω7c alcohol. The cell-wall peptidoglycan contained ornithine, serine, aspartic acid, glutamic acid and alanine while diaminopimelic acid could not be detected. Strains 5L6 T and 6L6 were clearly distinguished from the type strains of related validly named species using phylogenetic analysis, DNA-DNA hybridization, fatty acid analysis, peptidoglycan analysis and comparison of a range of physiological and biochemical characteristics. The genotypic and phenotypic data show that strains 5L6 T and 6L6 represent a novel species of the genus Bacillus, for which the name Bacillusciccensis sp. nov. is proposed. The type strain is 5L6 T (=KCTC 33663 T =CICC 23855 T =DSM 104513 T ).

Hydrogen sulphide improves adaptation of Zea mays seedlings to iron deficiency

PubMed Central

Chen, Juan; Wu, Fei-Hua; Shang, Yu-Ting; Wang, Wen-Hua; Hu, Wen-Jun; Simon, Martin; Liu, Xiang; Shangguan, Zhou-Ping; Zheng, Hai-Lei

2015-01-01

Hydrogen sulphide (H2S) is emerging as a potential molecule involved in physiological regulation in plants. However, whether H2S regulates iron-shortage responses in plants is largely unknown. Here, the role of H2S in modulating iron availability in maize (Zea mays L. cv Canner) seedlings grown in iron-deficient culture solution is reported. The main results are as follows: Firstly, NaHS, a donor of H2S, completely prevented leaf interveinal chlorosis in maize seedlings grown in iron-deficient culture solution. Secondly, electron micrographs of mesophyll cells from iron-deficient maize seedlings revealed plastids with few photosynthetic lamellae and rudimentary grana. On the contrary, mesophyll chloroplasts appeared completely developed in H2S-treated maize seedlings. Thirdly, H2S treatment increased iron accumulation in maize seedlings by changing the expression levels of iron homeostasis- and sulphur metabolism-related genes. Fourthly, phytosiderophore (PS) accumulation and secretion were enhanced by H2S treatment in seedlings grown in iron-deficient solution. Indeed, the gene expression of ferric-phytosiderophore transporter (ZmYS1) was specifically induced by iron deficiency in maize leaves and roots, whereas their abundance was decreased by NaHS treatment. Lastly, H2S significantly enhanced photosynthesis through promoting the protein expression of ribulose-1,5-bisphosphate carboxylase large subunit (RuBISCO LSU) and phosphoenolpyruvate carboxylase (PEPC) and the expression of genes encoding RuBISCO large subunit (RBCL), small subunit (RBCS), D1 protein (psbA), and PEPC in maize seedlings grown in iron-deficient solution. These results indicate that H2S is closely related to iron uptake, transport, and accumulation, and consequently increases chlorophyll biosynthesis, chloroplast development, and photosynthesis in plants. PMID:26208645

Hydrogen sulphide improves adaptation of Zea mays seedlings to iron deficiency.

PubMed

Chen, Juan; Wu, Fei-Hua; Shang, Yu-Ting; Wang, Wen-Hua; Hu, Wen-Jun; Simon, Martin; Liu, Xiang; Shangguan, Zhou-Ping; Zheng, Hai-Lei

2015-11-01

Hydrogen sulphide (H2S) is emerging as a potential molecule involved in physiological regulation in plants. However, whether H2S regulates iron-shortage responses in plants is largely unknown. Here, the role of H2S in modulating iron availability in maize (Zea mays L. cv Canner) seedlings grown in iron-deficient culture solution is reported. The main results are as follows: Firstly, NaHS, a donor of H2S, completely prevented leaf interveinal chlorosis in maize seedlings grown in iron-deficient culture solution. Secondly, electron micrographs of mesophyll cells from iron-deficient maize seedlings revealed plastids with few photosynthetic lamellae and rudimentary grana. On the contrary, mesophyll chloroplasts appeared completely developed in H2S-treated maize seedlings. Thirdly, H2S treatment increased iron accumulation in maize seedlings by changing the expression levels of iron homeostasis- and sulphur metabolism-related genes. Fourthly, phytosiderophore (PS) accumulation and secretion were enhanced by H2S treatment in seedlings grown in iron-deficient solution. Indeed, the gene expression of ferric-phytosiderophore transporter (ZmYS1) was specifically induced by iron deficiency in maize leaves and roots, whereas their abundance was decreased by NaHS treatment. Lastly, H2S significantly enhanced photosynthesis through promoting the protein expression of ribulose-1,5-bisphosphate carboxylase large subunit (RuBISCO LSU) and phosphoenolpyruvate carboxylase (PEPC) and the expression of genes encoding RuBISCO large subunit (RBCL), small subunit (RBCS), D1 protein (psbA), and PEPC in maize seedlings grown in iron-deficient solution. These results indicate that H2S is closely related to iron uptake, transport, and accumulation, and consequently increases chlorophyll biosynthesis, chloroplast development, and photosynthesis in plants. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Rate of dehydration of corn (Zea mays L.) pollen in the air.

PubMed

Aylor, Donald E

2003-10-01

The water content of corn (Zea mays L.) pollen directly affects its dispersal in the atmosphere through its effect on settling speed and viability. Therefore, the rate of water loss from pollen after being shed from the anther is an important component of a model to predict effective pollen transport distances in the atmosphere. The rate of water loss from corn pollen in air was determined using two methods: (1) by direct weighing of samples containing approximately 5 x 10(4) grains, and (2) by microscopic measurement of the change in size of individual grains. The conductance of the pollen wall to water loss was derived from the time rate of change of pollen mass or pollen grain size. The two methods gave average conductance values of 0.026 and 0.027 cm s-1, respectively. In other experiments, the water potential, psi, of corn pollen was determined at various values of relative water content (dry weight basis), either by using a thermocouple psychrometer or by allowing samples of pollen to come to vapour equilibrium with various saturated salt solutions. Non-linear regression analysis of the data yielded psi (MPa) = -3.218 theta(-1.35) (r2 = 0.94; for -298 < or = psi < or = -1 MPa). This result was incorporated into a model differential equation for the rate of water loss from pollen. The model agreed well (r2 approximately 0.98) with the observed time-course of the decrease of water content of pollen grains exposed to a range of temperature and humidity conditions.

Expression profiling of selected glutathione transferase genes in Zea mays (L.) seedlings infested with cereal aphids.

PubMed

Sytykiewicz, Hubert; Chrzanowski, Grzegorz; Czerniewicz, Paweł; Sprawka, Iwona; Łukasik, Iwona; Goławska, Sylwia; Sempruch, Cezary

2014-01-01

The purpose of this report was to evaluate the expression patterns of selected glutathione transferase genes (gst1, gst18, gst23 and gst24) in the tissues of two maize (Zea mays L.) varieties (relatively resistant Ambrozja and susceptible Tasty Sweet) that were colonized with oligophagous bird cherry-oat aphid (Rhopalosiphum padi L.) or monophagous grain aphid (Sitobion avenae L.). Simultaneously, insect-triggered generation of superoxide anion radicals (O2•-) in infested Z. mays plants was monitored. Quantified parameters were measured at 1, 2, 4, 8, 24, 48 and 72 h post-initial aphid infestation (hpi) in relation to the non-infested control seedlings. Significant increases in gst transcript amounts were recorded in aphid-stressed plants in comparison to the control seedlings. Maximal enhancement in the expression of the gst genes in aphid-attacked maize plants was found at 8 hpi (gst23) or 24 hpi (gst1, gst18 and gst24) compared to the control. Investigated Z. mays cultivars formed excessive superoxide anion radicals in response to insect treatments, and the highest overproduction of O2•- was noted 4 or 8 h after infestation, depending on the aphid treatment and maize genotype. Importantly, the Ambrozja variety could be characterized as having more profound increments in the levels of gst transcript abundance and O2•- generation in comparison with the Tasty Sweet genotype.

Selection of inbred maize (Zea mays L.) progenies by topcrosses conducted in contrasting environments.

PubMed

Rodrigues, C S; Pacheco, C A P; Guedes, M L; Pinho, R G V; Castro, C R

2016-09-23

The aim of this study was to identify inbred progenies of S 0:1 maize (Zea mays L.) plants that were efficient at a low level of technology and responsive at a high level of technology through the use of topcrosses. Two contrasting environments were created using two levels of base fertilization and topdressing, so that the levels of nitrogen, phosphorus, and potassium were applied four times higher in one environment than in the other. We used S 0:1 progenies derived from commercial hybrids in topcrosses with two testers (an elite line from the flint heterotic group and an elite line from the dent heterotic group). The progenies and three controls were evaluated in an augmented block design in Nossa Senhora das Dores, SE, Brazil in the 2010 crop season. The average grain yield in the high-technological level was 21.44% greater than that in the low-technological level. There were no changes in progeny behavior in the two technological levels for grain yield. The testers did not differ in the average grain yield of the progenies at the two technological levels. Therefore, it is possible to select progenies derived from commercial hybrids that have an efficient response to fertilization.

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

Proteus mirabilis alleviates zinc toxicity by preventing oxidative stress in maize (Zea mays) plants.

PubMed

Islam, Faisal; Yasmeen, Tahira; Riaz, Muhammad; Arif, Muhammad Saleem; Ali, Shafaqat; Raza, Syed Hammad

2014-12-01

Plant-associated bacteria can have beneficial effects on the growth and health of their host. However, the role of plant growth promoting bacteria (PGPR), under metal stress, has not been widely investigated. The present study investigated the possible mandatory role of plant growth promoting rhizobacteria in protecting plants from zinc (Zn) toxicity. The exposure of maize plants to 50µM zinc inhibited biomass production, decreased chlorophyll, total soluble protein and strongly increased accumulation of Zn in both root and shoot. Similarly, Zn enhanced hydrogen peroxide, electrolyte leakage and lipid peroxidation as indicated by malondaldehyde accumulation. Pre-soaking with novel Zn tolerant bacterial strain Proteus mirabilis (ZK1) isolated zinc (Zn) contaminated soil, alleviated the negative effect of Zn on growth and led to a decrease in oxidative injuries caused by Zn. Furthermore, strain ZK1 significantly enhanced the activities of catalase, guaiacol peroxidase, superoxide dismutase and ascorbic acid but lowered the Proline accumulation in Zn stressed plants. The results suggested that the inoculation of Zea mays plants with P. mirabilis during an earlier growth period could be related to its plant growth promoting activities and avoidance of cumulative damage upon exposure to Zn, thus reducing the negative consequences of oxidative stress caused by heavy metal toxicity. Copyright © 2014 Elsevier Inc. All rights reserved.

Effect of a Longitudinally Applied Voltage Upon the Growth of Zea mays Seedlings 1

PubMed Central

Desrosiers, Mark F.; Bandurski, Robert S.

1988-01-01

The electrical parameters that affect young seedling growth were investigated. Voltages ranging from 5 to 40 volts were applied longitudinally along the mesocotyl region of 4-day old Zea mays L. (cv Silver Queen) seedlings for periods of 3 or 4 hours. It was determined that: (a) making the tips of the seedlings electrically positive relative to the base strongly inhibited shoot growth at 5 volts, whereas the reverse polarity had no effect; (b) at higher voltages, making the tip of the seedlings negative caused less growth inhibition than the reverse polarity at each voltage level; (c) the higher the applied voltage the greater the degree of inhibition; and, (d) the more growth inhibition experienced by the plants the poorer, and slower, their recovery. Previous observations of a relationship between the amount of free indole-3-acetic acid in the mesocotyl cortex and the growth rate of the mesocotyl and of gravitropism-induced movement of labeled indole-3-acetic acid from the seed to the shoot lead to the prediction of a voltage-dependent gating of the movement of indole-3-acetic acid from the stele to the cortex. This provided the basis for attempting to alter the growth rate of seedlings by means of an applied voltage. Images Fig. 1 PMID:11537877

The short-term response of Arabidopsis thaliana (C3) and Zea mays (C4) chloroplasts to red and far red light.

PubMed

Zienkiewicz, Maksymilian; Drożak, Anna; Wasilewska, Wioleta; Bacławska, Ilona; Przedpełska-Wąsowicz, Ewa; Romanowska, Elżbieta

2015-12-01

Light quality has various effects on photochemistry and protein phosphorylation in Zea mays and Arabidopsis thaliana thylakoids due to different degrees of light penetration across leaves and redox status in chloroplasts. The effect of the spectral quality of light (red, R and far red, FR) on the function of thylakoid proteins in Zea mays and Arabidopsis thaliana was investigated. It was concluded that red light stimulates PSII activity in A. thaliana thylakoids and in maize bundle sheath (BS) thylakoids, but not in mesophyll (M) thylakoids. The light quality did not change PSI activity in M thylakoids of maize. FR used after a white light period increased PSI activity significantly in maize BS and only slightly in A. thaliana thylakoids. As shown by blue native (BN)-PAGE followed by SDS-PAGE, proteins were differently phosphorylated in the thylakoids, indicating their different functions. FR light increased dephosphorylation of LHCII proteins in A. thaliana thylakoids, whereas in maize, dephosphorylation did not occur at all. The rate of phosphorylation was higher in maize BS than in M thylakoids. D1 protein phosphorylation increased in maize and decreased in A. thaliana upon irradiation with both R and growth light (white light, W). Light variations did not change the level of proteins in thylakoids. Our data strongly suggest that response to light quality is a species-dependent phenomenon. We concluded that the maize chloroplasts were differently stimulated, probably due to different degrees of light penetration across the leaf and thereby the redox status in the chloroplasts. These acclimation changes induced by light quality are important in the regulation of chloroplast membrane flexibility and thus its function.

Influence of microgravity on root-cap regeneration and the structure of columella cells in Zea mays

NASA Technical Reports Server (NTRS)

Moore, R.; McClelen, C. E.; Fondren, W. M.; Wang, C. L.

1987-01-01

We launched imbibed seeds and seedlings of Zea mays into outer space aboard the space shuttle Columbia to determine the influence of microgravity on 1) root-cap regeneration, and 2) the distribution of amyloplasts and endoplasmic reticulum (ER) in the putative statocytes (i.e., columella cells) of roots. Decapped roots grown on Earth completely regenerated their caps within 4.8 days after decapping, while those grown in microgravity did not regenerate caps. In Earth-grown seedlings, the ER was localized primarily along the periphery of columella cells, and amyloplasts sedimented in response to gravity to the lower sides of the cells. Seeds germinated on Earth and subsequently launched into outer space had a distribution of ER in columella cells similar to that of Earth-grown controls, but amyloplasts were distributed throughout the cells. Seeds germinated in outer space were characterized by the presence of spherical and ellipsoidal masses of ER and randomly distributed amyloplasts in their columella cells. These results indicate that 1) gravity is necessary for regeneration of the root cap, 2) columella cells can maintain their characteristic distribution of ER in microgravity only if they are exposed previously to gravity, and 3) gravity is necessary to distribute the ER in columella cells of this cultivar of Z. mays.

Ammonia Assimilation in Zea mays L. Infected with a Vesicular-Arbuscular Mycorrhizal Fungus Glomus fasciculatum.

PubMed

Cliquet, J. B.; Stewart, G. R.

1993-03-01

To investigate nitrogen assimilation and translocation in Zea mays L. colonized by the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus fasciculatum (Thax. sensu Gerd.), we measured key enzyme activities, 15N incorporation into free amino acids, and 15N translocation from roots to shoots. Glutamine synthetase and nitrate reductase activities were increased in both roots and shoots compared with control plants, and glutamate dehydrogenase activity increased in roots only. In the presence of [15N]ammonium, glutamine amide was the most heavily labeled product. More label was incorporated into amino acids in VAM plants. The kinetics of 15N labeling and effects of methionine sulfoximine on distribution of 15N-labeled products were entirely consistent with the operation of the glutamate synthase cycle. No evidence was found for ammonium assimilation via glutamate dehydrogenase. 15N translocation from roots to shoots through the xylem was higher in VAM plants compared with control plants. These results establish that, in maize, VAM fungi increase ammonium assimilation, glutamine production, and xylem nitrogen translocation. Unlike some ectomycorrhizal fungi, VAM fungi do not appear to alter the pathway of ammonium assimilation in roots of their hosts.

Determination of the genotoxic effects of Convolvulus arvensis extracts on corn (Zea mays L.) seeds.

PubMed

Sunar, Serap; Yildirim, Nalan; Aksakal, Ozkan; Agar, Guleray

2013-06-01

In this research, the methanolic extracts of Convolvulus arvensis were tested for genotoxic and inhibitor activity on the total soluble protein content and the genomic template stability against corn Zea mays L. seed. The methanol extracts of leaf, stem and root of C. arvensis were diluted to 50, 75 and 100 μl concentrations and applied to corn seed. The total soluble protein and genomic template stability results were compared with the control. The results showed that especially 100 μl extracts of diluted leaf, stem and root had a strong inhibitory activity on the genomic template stability. The changes occurred in random amplification of polymorphic DNA (RAPD) profiles of C. arvensis extract treatment included variation in band intensity, loss of bands and appearance of new bands compared with control. Also, the results obtained from this study revealed that the increase in the concentrations of C. arvensis extract increased the total soluble protein content in maize. The results suggested that RAPD analysis and total protein analysis could be applied as a suitable biomarker assay for the detection of genotoxic effects of plant allelochemicals.

Overexpression of Arabidopsis Molybdenum Cofactor Sulfurase Gene Confers Drought Tolerance in Maize (Zea mays L.)

PubMed Central

Zhang, Jiachang; Xiao, Yitao; Yue, Yuesen; Duan, Liusheng; Zhang, Mingcai; Li, Zhaohu

2013-01-01

Abscisic acid (ABA) is a key component of the signaling system that integrates plant adaptive responses to abiotic stress. Overexpression of Arabidopsis molybdenum cofactor sulfurase gene (LOS5) in maize markedly enhanced the expression of ZmAO and aldehyde oxidase (AO) activity, leading to ABA accumulation and increased drought tolerance. Transgenic maize (Zea mays L.) exhibited the expected reductions in stomatal aperture, which led to decreased water loss and maintenance of higher relative water content (RWC) and leaf water potential. Also, transgenic maize subjected to drought treatment exhibited lower leaf wilting, electrolyte leakage, malondialdehyde (MDA) and H2O2 content, and higher activities of antioxidative enzymes and proline content compared to wild-type (WT) maize. Moreover, overexpression of LOS5 enhanced the expression of stress-regulated genes such as Rad 17, NCED1, CAT1, and ZmP5CS1 under drought stress conditions, and increased root system development and biomass yield after re-watering. The increased drought tolerance in transgenic plants was associated with ABA accumulation via activated AO and expression of stress-related gene via ABA induction, which sequentially induced a set of favorable stress-related physiological and biochemical responses. PMID:23326325

Overexpression of Arabidopsis molybdenum cofactor sulfurase gene confers drought tolerance in maize (Zea mays L.).

PubMed

Lu, Yao; Li, Yajun; Zhang, Jiachang; Xiao, Yitao; Yue, Yuesen; Duan, Liusheng; Zhang, Mingcai; Li, Zhaohu

2013-01-01

Abscisic acid (ABA) is a key component of the signaling system that integrates plant adaptive responses to abiotic stress. Overexpression of Arabidopsis molybdenum cofactor sulfurase gene (LOS5) in maize markedly enhanced the expression of ZmAO and aldehyde oxidase (AO) activity, leading to ABA accumulation and increased drought tolerance. Transgenic maize (Zea mays L.) exhibited the expected reductions in stomatal aperture, which led to decreased water loss and maintenance of higher relative water content (RWC) and leaf water potential. Also, transgenic maize subjected to drought treatment exhibited lower leaf wilting, electrolyte leakage, malondialdehyde (MDA) and H(2)O(2) content, and higher activities of antioxidative enzymes and proline content compared to wild-type (WT) maize. Moreover, overexpression of LOS5 enhanced the expression of stress-regulated genes such as Rad 17, NCED1, CAT1, and ZmP5CS1 under drought stress conditions, and increased root system development and biomass yield after re-watering. The increased drought tolerance in transgenic plants was associated with ABA accumulation via activated AO and expression of stress-related gene via ABA induction, which sequentially induced a set of favorable stress-related physiological and biochemical responses.

Myo-inositol esters of indole-3-acetic acid are endogenous components of Zea mays L. shoot tissue

NASA Technical Reports Server (NTRS)

Chisnell, J. R.

1984-01-01

Indole-3-acetyl-myo-inositol esters have been demonstrated to be endogenous components of etiolated Zea mays shoots tissue. This was accomplished by comparison of the putative compounds with authentic, synthetic esters. The properties compared were liquid and gas-liquid chromatographic retention times and the 70-ev mass spectral fragmentation pattern of the pentaacetyl derivative. The amount of indole-3-acetyl-myo-inositol esters in the shoots was determined to be 74 nanomoles per kilogram fresh weight as measured by isotope dilution, accounting for 19% of the ester indole-3-acetic acid of the shoot. This work is the first characterization of an ester conjugate of indole-3-acetate acid from vegetative shoot tissue using multiple chromatographic properties and mass spectral identification. The kernel and the seedling shoot both contain indole-3-acetyl-myo-inositol esters, and these esters comprise approximately the same percentage of the total ester content of the kernel and of the shoot.

Down-Regulation of ZmEXPB6 (Zea mays β-Expansin 6) Protein Is Correlated with Salt-mediated Growth Reduction in the Leaves of Z. mays L.

PubMed Central

Geilfus, Christoph-Martin; Ober, Dietrich; Eichacker, Lutz A.; Mühling, Karl Hermann; Zörb, Christian

2015-01-01

The salt-sensitive crop Zea mays L. shows a rapid leaf growth reduction upon NaCl stress. There is increasing evidence that salinity impairs the ability of the cell walls to expand, ultimately inhibiting growth. Wall-loosening is a prerequisite for cell wall expansion, a process that is under the control of cell wall-located expansin proteins. In this study the abundance of those proteins was analyzed against salt stress using gel-based two-dimensional proteomics and two-dimensional Western blotting. Results show that ZmEXPB6 (Z. mays β-expansin 6) protein is lacking in growth-inhibited leaves of salt-stressed maize. Of note, the exogenous application of heterologously expressed and metal-chelate-affinity chromatography-purified ZmEXPB6 on growth-reduced leaves that lack native ZmEXPB6 under NaCl stress partially restored leaf growth. In vitro assays on frozen-thawed leaf sections revealed that recombinant ZmEXPB6 acts on the capacity of the walls to extend. Our results identify expansins as a factor that partially restores leaf growth of maize in saline environments. PMID:25750129

Characterization and Transposon Mutagenesis of the Maize (Zea mays) Pho1 Gene Family

PubMed Central

Salazar-Vidal, M. Nancy; Acosta-Segovia, Edith; Sánchez-León, Nidia; Ahern, Kevin R.; Brutnell, Thomas P.; Sawers, Ruairidh J. H.

2016-01-01

Phosphorus is an essential nutrient for all plants, but also one of the least mobile, and consequently least available, in the soil. Plants have evolved a series of molecular, metabolic and developmental adaptations to increase the acquisition of phosphorus and to maximize the efficiency of use within the plant. In Arabidopsis (Arabidopsis thaliana), the AtPHO1 protein regulates and facilitates the distribution of phosphorus. To investigate the role of PHO1 proteins in maize (Zea mays), the B73 reference genome was searched for homologous sequences, and four genes identified that were designated ZmPho1;1, ZmPho1;2a, ZmPho1;2b and ZmPho1;3. ZmPho1;2a and ZmPho1;2b are the most similar to AtPHO1, and represent candidate co-orthologs that we hypothesize to have been retained following whole genome duplication. Evidence was obtained for the production of natural anti-sense transcripts associated with both ZmPho1;2a and ZmPho1;2b, suggesting the possibility of regulatory crosstalk between paralogs. To characterize functional divergence between ZmPho1;2a and ZmPho1;2b, a program of transposon mutagenesis was initiated using the Ac/Ds system, and, here, we report the generation of novel alleles of ZmPho1;2a and ZmPho1;2b. PMID:27648940

Towards efficient photosynthesis: overexpression of Zea mays phosphoenolpyruvate carboxylase in Arabidopsis thaliana.

PubMed

Kandoi, Deepika; Mohanty, Sasmita; Govindjee; Tripathy, Baishnab C

2016-12-01

Plants with C4 photosynthesis are efficient in carbon assimilation and have an advantage over C3 photosynthesis. In C4 photosynthesis, the primary CO 2 fixation is catalyzed by phosphoenolpyruvate carboxylase (PEPC). Here, we show that overexpression of Zea mays PEPC cDNA, under the control of 35 S promoter, in Arabidopsis thaliana resulted in ~7-10 fold higher protein abundance and ~7-10 fold increase in PEPC activity in the transgenic lines than that in the vector control. We suggest that overexpression of PEPC played an anaplerotic role to increase the supply of 4-carbon carboxylic acids, which provided carbon skeletons for increased amino acid and protein synthesis. Higher protein content must have been responsible for increased metabolic processes including chlorophyll biosynthesis, photosynthesis, and respiration. Consequently, the PEPC-overexpressed transgenic plants had higher chlorophyll content, enhanced electron transport rate (ETR), lower non-photochemical quenching (NPQ) of chlorophyll a fluorescence, and a higher performance index (PI) than the vector control. Consistent with these observations, the rate of CO 2 assimilation, the starch content, and the dry weight of PEPC-overexpressed plants increased by 14-18 %, 10-18 %, and 6.5-16 %, respectively. Significantly, transgenics were tolerant to salt stress as they had increased ability to synthesize amino acids, including the osmolyte proline. NaCl (150 mM)-treated transgenic plants had higher variable to maximum Chl a fluorescence (F v /F m ) ratio, higher PI, higher ETR, and lower NPQ than the salt-treated vector controls. These results suggest that expression of C4 photosynthesis enzyme(s) in a C3 plant can improve its photosynthetic capacity with enhanced tolerance to salinity stress.

β-aminobutyric acid mediated drought stress alleviation in maize (Zea mays L.).

PubMed

Shaw, Arun K; Bhardwaj, Pardeep K; Ghosh, Supriya; Roy, Sankhajit; Saha, Suman; Sherpa, Ang R; Saha, Samir K; Hossain, Zahed

2016-02-01

The present study highlights the role of β-aminobutyric acid (BABA) in alleviating drought stress effects in maize (Zea mays L.). Chemical priming was imposed by pretreating 1-week-old plants with 600 μM BABA prior to applying drought stress. Specific activities of key antioxidant enzymes and metabolites (ascorbate and glutathione) levels of ascorbate-glutathione cycle were studied to unravel the priming-induced modulation of plant defense system. Furthermore, changes in endogenous ABA and JA concentrations as well as mRNA expressions of key genes involved in their respective biosynthesis pathways were monitored in BABA-primed (BABA+) and non-primed (BABA-) leaves of drought-challenged plants to better understand the mechanistic insights into the BABA-induced hormonal regulation of plant response to water-deficit stress. Accelerated stomatal closure, high relative water content, and less membrane damage were observed in BABA-primed leaves under water-deficit condition. Elevated APX and SOD activity in non-primed leaves found to be insufficient to scavenge all H2O2 and O2 (·-) resulting in oxidative burst as evident after histochemical staining with NBT and DAB. A higher proline accumulation in non-primed leaves also does not give much protection against drought stress. Increased GR activity supported with the enhanced mRNA and protein expressions might help the BABA-primed plants to maintain a high GSH pool essential for sustaining balanced redox status to counter drought-induced oxidative stress damages. Hormonal analysis suggests that in maize, BABA-potentiated drought tolerance is primarily mediated through JA-dependent pathway by the activation of antioxidant defense systems while ABA biosynthesis pathway also plays an important role in fine-tuning of drought stress response.

Involvement of an antioxidant defense system in the adaptive response to cadmium in maize seedlings (Zea mays L.).

PubMed

Xu, Xianghua; Liu, Cuiying; Zhao, Xiaoyan; Li, Renying; Deng, Wenjing

2014-11-01

Chemical and biological analyses were used to investigate the growth response and antioxidant defense mechanism of maize seedlings (Zea mays L.) grown in soils with 0-100 mg kg(-1) Cd. Results showed that maize seedlings have strong abilities to accumulate and tolerate high concentrations of Cd. For soil with 50 mg kg(-1) Cd, the Cd contents in roots and shoots of maize seedlings are as large as 295.6 and 153.0 mg kg(-1) DW, respectively, without visible symptoms of toxicity. Lower soil Cd concentrations lead to a decrease in reduced glutathione (GSH) content in leaves of maize seedlings, whereas higher soil Cd concentrations resulted in an increase in the activities of superoxide dismutase, guaiacol peroxidase, catalase, and ascorbate peroxidase. Maize seedlings have strong capacities to adapt to low concentrations of Cd by consuming GSH and to develop an antioxidative enzyme system to defend against high-Cd stress.

Expression Profiling of Selected Glutathione Transferase Genes in Zea mays (L.) Seedlings Infested with Cereal Aphids

PubMed Central

Sytykiewicz, Hubert; Chrzanowski, Grzegorz; Czerniewicz, Paweł; Sprawka, Iwona; Łukasik, Iwona; Goławska, Sylwia; Sempruch, Cezary

2014-01-01

The purpose of this report was to evaluate the expression patterns of selected glutathione transferase genes (gst1, gst18, gst23 and gst24) in the tissues of two maize (Zea mays L.) varieties (relatively resistant Ambrozja and susceptible Tasty Sweet) that were colonized with oligophagous bird cherry-oat aphid (Rhopalosiphum padi L.) or monophagous grain aphid (Sitobion avenae L.). Simultaneously, insect-triggered generation of superoxide anion radicals (O2 •−) in infested Z. mays plants was monitored. Quantified parameters were measured at 1, 2, 4, 8, 24, 48 and 72 h post-initial aphid infestation (hpi) in relation to the non-infested control seedlings. Significant increases in gst transcript amounts were recorded in aphid-stressed plants in comparison to the control seedlings. Maximal enhancement in the expression of the gst genes in aphid-attacked maize plants was found at 8 hpi (gst23) or 24 hpi (gst1, gst18 and gst24) compared to the control. Investigated Z. mays cultivars formed excessive superoxide anion radicals in response to insect treatments, and the highest overproduction of O2 •− was noted 4 or 8 h after infestation, depending on the aphid treatment and maize genotype. Importantly, the Ambrozja variety could be characterized as having more profound increments in the levels of gst transcript abundance and O2 •− generation in comparison with the Tasty Sweet genotype. PMID:25365518

Transport and metabolism of indole-3-acetyl-myo-inositol-galactoside in seedlings of Zea mays

NASA Technical Reports Server (NTRS)

Komoszynski, M.; Bandurski, R. S.

1986-01-01

Indole-3-acetyl-myo-inositol galactoside labeled with 3H in the indole and 14C in the galactose moieties was applied to kernels of 5 day old germinating seedlings of Zea mays. Indole-3-acetyl-myo-inositol galactoside was not transported into either the shoot or root tissue as the intact molecule but was instead hydrolyzed to yield [3H]indole-3-acetyl-myo-inositol and [3H]indole-3-acetic acid which were then transported to the shoot with little radioactivity going to the root. With certain assumption concerning the equilibration of applied [3H]indole-3-acetyl-myo-inositol-[U-14C]galactose with the endogenous pool, it may be concluded that indole-3-acetyl-myo-inositol galactoside in the endosperm supplies about 2 picomoles per plant per hour of indole-3-acetyl-myo-inositol and 1 picomole per plant per hour of indole-3-acetic acid to the shoot and thus is comparable to indole-3-acetyl-myo-inositol as a source of indole-acetic acid for the shoot. Quantitative estimates of the amount of galactose in the kernels suggest that [3H]indole-3-acetyl-myo-inositol-[14C]galactose is hydrolyzed after the compound leaves the endosperm but before it reaches the shoot. In addition, [3H]indole-3-acetyl-myo-inositol-[14C]galactose supplies appreciable amounts of 14C to the shoot and both 14C and 3H to an uncharacterized insoluble fraction of the endosperm.

Differential Expression of Superoxide Dismutase Genes in Aphid-Stressed Maize (Zea mays L.) Seedlings

PubMed Central

Sytykiewicz, Hubert

2014-01-01

The aim of this study was to compare the expression patterns of superoxide dismutase genes (sod2, sod3.4, sod9 and sodB) in seedling leaves of the Zea mays L. Tasty Sweet (susceptible) and Ambrozja (relatively resistant) cultivars infested with one of two hemipteran species, namely monophagous Sitobion avenae F. (grain aphid) or oligophagous Rhopalosiphum padi L. (bird cherry-oat aphid). Secondarily, aphid-elicited alternations in the antioxidative capacity towards DPPH (1,1-diphenyl-2-picrylhydrazyl) radical in insect-stressed plants were evaluated. Comprehensive comparison of expression profiles of the four sod genes showed that both insect species evoked significant upregulation of three genes sod2, sod3.4 and sod9). However, aphid infestation affected non-significant fluctuations in expression of sodB gene in seedlings of both maize genotypes. The highest levels of transcript accumulation occurred at 8 h (sod2 and sod3.4) or 24 h (sod9) post-infestation, and aphid-induced changes in the expression of sod genes were more dramatic in the Ambrozja cultivar than in the Tasty Sweet variety. Furthermore, bird cherry-oat aphid colonization had a more substantial impact on levels of DPPH radical scavenging activity in infested host seedlings than grain aphid colonization. Additionally, Ambrozja plants infested by either hemipteran species showed markedly lower antioxidative capacity compared with attacked Tasty Sweet plants. PMID:24722734

Differential expression of superoxide dismutase genes in aphid-stressed maize (Zea mays L.) seedlings.

PubMed

Sytykiewicz, Hubert

2014-01-01

The aim of this study was to compare the expression patterns of superoxide dismutase genes (sod2, sod3.4, sod9 and sodB) in seedling leaves of the Zea mays L. Tasty Sweet (susceptible) and Ambrozja (relatively resistant) cultivars infested with one of two hemipteran species, namely monophagous Sitobion avenae F. (grain aphid) or oligophagous Rhopalosiphum padi L. (bird cherry-oat aphid). Secondarily, aphid-elicited alternations in the antioxidative capacity towards DPPH (1,1-diphenyl-2-picrylhydrazyl) radical in insect-stressed plants were evaluated. Comprehensive comparison of expression profiles of the four sod genes showed that both insect species evoked significant upregulation of three genes sod2, sod3.4 and sod9). However, aphid infestation affected non-significant fluctuations in expression of sodB gene in seedlings of both maize genotypes. The highest levels of transcript accumulation occurred at 8 h (sod2 and sod3.4) or 24 h (sod9) post-infestation, and aphid-induced changes in the expression of sod genes were more dramatic in the Ambrozja cultivar than in the Tasty Sweet variety. Furthermore, bird cherry-oat aphid colonization had a more substantial impact on levels of DPPH radical scavenging activity in infested host seedlings than grain aphid colonization. Additionally, Ambrozja plants infested by either hemipteran species showed markedly lower antioxidative capacity compared with attacked Tasty Sweet plants.

Significance of diazotrophic plant growth-promoting Herbaspirillum sp. GW103 on phytoextraction of Pband Zn by Zea mays L.

PubMed

Praburaman, Loganathan; Park, Sung-Hee; Cho, Min; Lee, Kui-Jae; Ko, Jeong-Ae; Han, Sang-Sub; Lee, Sang-Hyun; Kamala-Kannan, Seralathan; Oh, Byung-Taek

2017-01-01

Microbe-assisted phytoremediation has been considered a promising measure for the remediation of heavy metal-polluted soil. The aim of this study was to assess the effect of diazotrophic plant growth-promoting Herbaspirillum sp. GW103 on growth and lead (Pb) and zinc (Zn) accumulation in Zea mays L. The strain GW103 exhibited plant growth-promoting traits such as indole-3-acetic acid, siderophores, and 1-aminocyclopropane-1-carboxylic deaminase. Treatment of Z. mays L. plants with GW103 significantly increased 19, 31, and 52% of plant biomass and 10, 50, and 126% of chlorophyll a contents in Pb, Zn, and Pb + Zn-amended soils, respectively. Similarly, the strain GW103 significantly increased Pb and Zn accumulation in shoots and roots of Z. mays L., which were 77 and 25% in Pb-amended soil, 42 and 73% in Zn-amended soil, and 27 and 84% in Pb + Zn-amended soil. Furthermore, addition of GW103 increased 8, 12, and 7% of total protein content, catalase, and superoxide dismutase levels, respectively, in Z. mays L. plants. The results pointed out that isolate GW103 could potentially reduce the phytotoxicity of metals and increase Pb and Zn accumulation in Z. mays L. plant.

Fiber optic light-scattering measurement system for evaluation of embryo viability: light-scattering characteristics from live mouse embryo

NASA Astrophysics Data System (ADS)

Itoh, Harumi; Arai, Tsunenori; Kikuchi, Makoto

1997-06-01

We measured angular distribution of the light scattering from live mouse embryo with 632.8nm in wavelength to evaluate the embryo viability. We aim to measure the mitochondrial density in human embryo which have relation to the embryo viability. We have constructed the light scattering measurement system to detect the mitochondrial density non-invasively. We have employed two optical fibers for the illumination and sensing to change the angle between these fibers. There were two dips on the scattering angular distribution from the embryo. These dips existed on 30 and 85 deg. We calculated the scattering angular pattern by Mie theory to fit the measured scattering estimated scattering size and density. The best fitting was obtained when the particle size and density were 0.9 micrometers and 1010 particles per ml, respectively. These values coincided with the approximated values of mitochondrial in the embryo. The measured light scattering may mainly originated from mitochondria in spite of the existence of the various scattering particles in the embryo. Since our simple scattering measurement may offer the mitochondrial density in the embryo, it might become the practical method of human embryo on in vitro fertilization-embryo transfer.

Studies on the individual and combined diuretic effects of four Vietnamese traditional herbal remedies (Zea mays, Imperata cylindrica, Plantago major and Orthosiphon stamineus).

PubMed

Doan, D D; Nguyen, N H; Doan, H K; Nguyen, T L; Phan, T S; van Dau, N; Grabe, M; Johansson, R; Lindgren, G; Stjernström, N E

1992-06-01

Herbal remedies are widely used in Vietnam alongside modern drugs. We assessed the diuretic effect of four traditional Vietnamese herbal remedies from Zea mays, Imperata cylindrica, Plantago major and Orthosiphon stamineus, all claimed to produce an increase of diuresis. No influence was recorded for the 12- and 24-h urine output or on the sodium excretion for any of the drugs when tested under standardized conditions in a placebo controlled double-blind crossover model. The present study indicates the need for critical review of the present recommendations regarding therapy with plant materials in countries relying on empiric traditions.

Laboratory techniques for human embryos.

PubMed

Geber, Selmo; Sales, Liana; Sampaio, Marcos A C

2002-01-01

This review is concerned with laboratory techniques needed for assisted conception, particularly the handling of gametes and embryos. Such methods are being increasingly refined. Successive stages of fertilization and embryogenesis require especial care, and often involve the use of micromanipulative methods for intracytoplasmic sperm injection (ICSI) or preimplantation genetic diagnosis. Embryologists must take responsibility for gamete collection and preparation, and for deciding on the means of insemination or ICSI. Embryos must be assessed in culture, during the 1-cell, cleaving and morula/blastocyst stages, and classified according to quality. Co-culture methods may be necessary. The best embryos for transfer must be selected and loaded into the transfer catheter. Embryos not transferred must be cryopreserved, which demands the correct application of current methods of media preparation, seeding and the correct speed for cooling and warming. Before too long, methods of detecting abnormal embryos and avoiding their transfer may become widespread.

Zea mays Annexins Modulate Cytosolic Free Ca2+ and Generate a Ca2+-Permeable Conductance[W

PubMed Central

Laohavisit, Anuphon; Mortimer, Jennifer C.; Demidchik, Vadim; Coxon, Katy M.; Stancombe, Matthew A.; Macpherson, Neil; Brownlee, Colin; Hofmann, Andreas; Webb, Alex A.R.; Miedema, Henk; Battey, Nicholas H.; Davies, Julia M.

2009-01-01

Regulation of reactive oxygen species and cytosolic free calcium ([Ca2+]cyt) is central to plant function. Annexins are small proteins capable of Ca2+-dependent membrane binding or membrane insertion. They possess structural motifs that could support both peroxidase activity and calcium transport. Here, a Zea mays annexin preparation caused increases in [Ca2+]cyt when added to protoplasts of Arabidopsis thaliana roots expressing aequorin. The pharmacological profile was consistent with annexin activation (at the extracellular plasma membrane face) of Arabidopsis Ca2+-permeable nonselective cation channels. Secreted annexins could therefore modulate Ca2+ influx. As maize annexins occur in the cytosol and plasma membrane, they were incorporated at the intracellular face of lipid bilayers designed to mimic the plasma membrane. Here, they generated an instantaneously activating Ca2+-permeable conductance at mildly acidic pH that was sensitive to verapamil and Gd3+ and had a Ca2+-to-K+ permeability ratio of 0.36. These results suggest that cytosolic annexins create a Ca2+ influx pathway directly, particularly during stress responses involving acidosis. A maize annexin preparation also demonstrated in vitro peroxidase activity that appeared independent of heme association. In conclusion, this study has demonstrated that plant annexins create Ca2+-permeable transport pathways, regulate [Ca2+]cyt, and may function as peroxidases in vitro. PMID:19234085

A two-dimensional microscale model of gas exchange during photosynthesis in maize (Zea mays L.) leaves.

PubMed

Retta, Moges; Ho, Quang Tri; Yin, Xinyou; Verboven, Pieter; Berghuijs, Herman N C; Struik, Paul C; Nicolaï, Bart M

2016-05-01

CO2 exchange in leaves of maize (Zea mays L.) was examined using a microscale model of combined gas diffusion and C4 photosynthesis kinetics at the leaf tissue level. Based on a generalized scheme of photosynthesis in NADP-malic enzyme type C4 plants, the model accounted for CO2 diffusion in a leaf tissue, CO2 hydration and assimilation in mesophyll cells, CO2 release from decarboxylation of C4 acids, CO2 fixation in bundle sheath cells and CO2 retro-diffusion from bundle sheath cells. The transport equations were solved over a realistic 2-D geometry of the Kranz anatomy obtained from light microscopy images. The predicted responses of photosynthesis rate to changes in ambient CO2 and irradiance compared well with those obtained from gas exchange measurements. A sensitivity analysis showed that the CO2 permeability of the mesophyll-bundle sheath and airspace-mesophyll interfaces strongly affected the rate of photosynthesis and bundle sheath conductance. Carbonic anhydrase influenced the rate of photosynthesis, especially at low intercellular CO2 levels. In addition, the suberin layer at the exposed surface of the bundle sheath cells was found beneficial in reducing the retro-diffusion. The model may serve as a tool to investigate CO2 diffusion further in relation to the Kranz anatomy in C4 plants. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Impaired phloem loading in zmsweet13a,b,c sucrose transporter triple knock-out mutants in Zea mays.

PubMed

Bezrutczyk, Margaret; Hartwig, Thomas; Horschman, Marc; Char, Si Nian; Yang, Jinliang; Yang, Bing; Frommer, Wolf B; Sosso, Davide

2018-04-01

Crop yield depends on efficient allocation of sucrose from leaves to seeds. In Arabidopsis, phloem loading is mediated by a combination of SWEET sucrose effluxers and subsequent uptake by SUT1/SUC2 sucrose/H + symporters. ZmSUT1 is essential for carbon allocation in maize, but the relative contribution to apoplasmic phloem loading and retrieval of sucrose leaking from the translocation path is not known. Here we analysed the contribution of SWEETs to phloem loading in maize. We identified three leaf-expressed SWEET sucrose transporters as key components of apoplasmic phloem loading in Zea mays L. ZmSWEET13 paralogues (a, b, c) are among the most highly expressed genes in the leaf vasculature. Genome-edited triple knock-out mutants were severely stunted. Photosynthesis of mutants was impaired and leaves accumulated high levels of soluble sugars and starch. RNA-seq revealed profound transcriptional deregulation of genes associated with photosynthesis and carbohydrate metabolism. Genome-wide association study (GWAS) analyses may indicate that variability in ZmSWEET13s correlates with agronomical traits, especifically flowering time and leaf angle. This work provides support for cooperation of three ZmSWEET13s with ZmSUT1 in phloem loading in Z. mays. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Three Groups of Transposable Elements with Contrasting Copy Number Dynamics and Host Responses in the Maize (Zea mays ssp. mays) Genome

PubMed Central

Diez, Concepcion M.; Meca, Esteban; Tenaillon, Maud I.; Gaut, Brandon S.

2014-01-01

Most angiosperm nuclear DNA is repetitive and derived from silenced transposable elements (TEs). TE silencing requires substantial resources from the plant host, including the production of small interfering RNAs (siRNAs). Thus, the interaction between TEs and siRNAs is a critical aspect of both the function and the evolution of plant genomes. Yet the co-evolutionary dynamics between these two entities remain poorly characterized. Here we studied the organization of TEs within the maize (Zea mays ssp mays) genome, documenting that TEs fall within three groups based on the class and copy numbers. These groups included DNA elements, low copy RNA elements and higher copy RNA elements. The three groups varied statistically in characteristics that included length, location, age, siRNA expression and 24∶22 nucleotide (nt) siRNA targeting ratios. In addition, the low copy retroelements encompassed a set of TEs that had previously been shown to decrease expression within a 24 nt siRNA biogenesis mutant (mop1). To investigate the evolutionary dynamics of the three groups, we estimated their abundance in two landraces, one with a genome similar in size to that of the maize reference and the other with a 30% larger genome. For all three accessions, we assessed TE abundance as well as 22 nt and 24 nt siRNA content within leaves. The high copy number retroelements are under targeted similarly by siRNAs among accessions, appear to be born of a rapid bust of activity, and may be currently transpositionally dead or limited. In contrast, the lower copy number group of retrolements are targeted more dynamically and have had a long and ongoing history of transposition in the maize genome. PMID:24743518

[Systematically induced effects of Tetranychus cinnabarinus infestation on chemical defense in Zea mays inbred lines].

PubMed

Zhu, Yu-xi; Yang, Qun-fang; Huang, Yu-bi; Li, Qing

2015-09-01

In the present study, we investigated the systematically induced production of defense-related compounds, including DIMBOA, total phenol, trypsin inhibitors (TI) and chymotrypsin inhibitor (CI), by Tetranychus cinnabarinus infestation in Zea mays. The first leaves of two corn in-bred line seedlings, the mite-tolerant line ' H1014168' and the mite-sensitive line 'H1014591', were sucked by T. cinnabarinus adult female for seven days, and then the contents of DIMBOA, total phenol, TI and CI were measured in the second leaf and in the roots, respectively. Results showed that as compared to the unsucked control, all contents of DIMBOA, total phenol, TI and CI induced by T. cinnabarinus sucking were significantly higher in the second leaf of both inbred lines as well as in the roots of the mite-tolerant 'H1014168'. However, in the roots of 'H1014591', these defense compounds had different trends, where there was a higher induction of TI and a lower level of total phenol than that of the healthy control, while had almost no difference in DIMBOA and CI. These findings suggested that the infestation of T. cinnabarinus could systematically induce accumulation of defense-related compounds, and this effect was stronger in the mite-tolerant inbred line than in the mite-sensitive inbred line.

Correlations between gravitropic curvature and auxin movement across gravistimulated roots of Zea mays

NASA Technical Reports Server (NTRS)

Young, L. M.; Evans, M. L.; Hertel, R.

1990-01-01

We compared the kinetics of auxin redistribution across the caps of primary roots of 2-day-old maize (Zea mays, cv Merit) seedlings with the time course of gravitropic curvature. [3H] indoleacetic acid was applied to one side of the cap in an agar donor and radioactivity moving across the cap was collected in an agar receiver applied to the opposite side. Upon gravistimulation the roots first curved upward slightly, then returned to the horizontal and began curving downward, reaching a final angle of about 67 degrees. Movement of label across the caps of gravistimulated roots was asymmetric with preferential downward movement (ratio downward/upward = ca. 1.6, radioactivity collected during the 90 min following beginning of gravistimulation). There was a close correlation between the development of asymmetric auxin movement across the root cap and the rate of curvature, with both values increasing to a maximum and then declining as the roots approached the final angle of curvature. In roots preadapted to gravity (alternate brief stimulation on opposite flanks over a period of 1 hour) the initial phase of upward curvature was eliminated and downward bending began earlier than for controls. The correlation between asymmetric auxin movement and the kinetics of curvature also held in comparisons between control and preadapted roots. Both downward auxin transport asymmetry and downward curvature occurred earlier in preadapted roots than in controls. These findings are consistent with suggestions that the root cap is not only the site of perception but also the location of the initial redistribution of effectors that ultimately leads to curvature.

Arabidopsis mitochondrial protein slow embryo development1 is essential for embryo development

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

Ju, Yan; Liu, Chunying; Lu, Wenwen

The plant seeds formation are crucial parts in reproductive process in seed plants as well as food source for humans. Proper embryo development ensure viable seed formation. Here, we showed an Arabidopsis T-DNA insertion mutant slow embryo development1 (sed1) which exhibited retarded embryogenesis, led to aborted seeds. Embryo without SED1 developed slower compared to normal one and could be recognized at early globular stage by its white appearance. In later development stage, storage accumulated poorly with less protein and lipid body production. In vitro culture did not rescue albino embryo. SED1 encoded a protein targeted to mitochondria. Transmission electron microscopic analysismore » revealed that mitochondria developed abnormally, and more strikingly plastid failed to construct grana in time in sed1/sed1 embryo. These data indicated that SED1 is indispensable for embryogenesis in Arabidopsis, and the mitochondria may be involved in the regulation of many aspects of seed development. -- Highlights: •Arabidopsis SED1 is essential for embryo development. •The sed1 embryo accumulates less storage and has abnormal ultrastructure. •SED1 localizes to the mitochondrion.« less

Growth and graviresponsiveness of primary roots of Zea mays seedlings deficient in abscisic acid and gibberellic acid

NASA Technical Reports Server (NTRS)

Moore, R.; Dickey, K.

1985-01-01

The objective of this research was to determine if gibberellic acid (GA) and/or abscisic acid (ABA) are necessary for graviresponsiveness by primary roots of Zea mays. To accomplish this objective we measured the growth and graviresponsiveness of primary roots of seedlings in which the synthesis of ABA and GA was inhibited collectively and individually by genetic and chemical means. Roots of seedlings treated with Fluridone (an inhibitor of ABA biosynthesis) and Ancymidol (an inhibitor of GA biosynthesis) were characterized by slower growth rates but not significantly different gravicultures as compared to untreated controls. Gravicurvatures of primary roots of d-5 mutants (having undetectable levels of GA) and vp-9 mutants (having undectable levels of ABA) were not significantly different from those of wild-type seedlings. Roots of seedlings in which the biosynthesis of ABA and GA was collectively inhibited were characterized by gravicurvatures not significantly different for those of controls. These results (1) indicate that drastic reductions in the amount of ABA and GA in Z. mays seedlings do not significantly alter root graviresponsiveness, (2) suggest that neither ABA nor GA is necessary for root gravicurvature, and (3) indicate that root gravicurvature is not necessarily proportional to root elongation.

Accumulation of Hydrocarbons by Maize (Zea mays L.) in Remediation of Soils Contaminated with Crude Oil.

PubMed

Liao, Changjun; Xu, Wending; Lu, Guining; Liang, Xujun; Guo, Chuling; Yang, Chen; Dang, Zhi

2015-01-01

This study has investigated the use of screened maize for remediation of soil contaminated with crude oil. Pots experiment was carried out for 60 days by transplanting maize seedlings into spiked soils. The results showed that certain amount of crude oil in soil (≤2 147 mg·kg(-1)) could enhance the production of shoot biomass of maize. Higher concentration (6 373 mg·kg(-1)) did not significantly inhibit the growth of plant maize (including shoot and root). Analysis of plant shoot by GC-MS showed that low molecular weight polycyclic aromatic hydrocarbons (PAHs) were detected in maize tissues, but PAHs concentration in the plant did not increase with higher concentration of crude oil in soil. The reduction of total petroleum hydrocarbon in planted soil was up to 52.21-72.84%, while that of the corresponding controls was only 25.85-34.22% in two months. In addition, data from physiological and biochemical indexes demonstrated a favorable adaptability of maize to crude oil pollution stress. This study suggested that the use of maize (Zea mays L.) was a good choice for remediation of soil contaminated with petroleum within a certain range of concentrations.

Down-regulation of ZmEXPB6 (Zea mays β-expansin 6) protein is correlated with salt-mediated growth reduction in the leaves of Z. mays L.

PubMed

Geilfus, Christoph-Martin; Ober, Dietrich; Eichacker, Lutz A; Mühling, Karl Hermann; Zörb, Christian

2015-05-01

The salt-sensitive crop Zea mays L. shows a rapid leaf growth reduction upon NaCl stress. There is increasing evidence that salinity impairs the ability of the cell walls to expand, ultimately inhibiting growth. Wall-loosening is a prerequisite for cell wall expansion, a process that is under the control of cell wall-located expansin proteins. In this study the abundance of those proteins was analyzed against salt stress using gel-based two-dimensional proteomics and two-dimensional Western blotting. Results show that ZmEXPB6 (Z. mays β-expansin 6) protein is lacking in growth-inhibited leaves of salt-stressed maize. Of note, the exogenous application of heterologously expressed and metal-chelate-affinity chromatography-purified ZmEXPB6 on growth-reduced leaves that lack native ZmEXPB6 under NaCl stress partially restored leaf growth. In vitro assays on frozen-thawed leaf sections revealed that recombinant ZmEXPB6 acts on the capacity of the walls to extend. Our results identify expansins as a factor that partially restores leaf growth of maize in saline environments. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Epigenetic variation, inheritance, and parent-of-origin effects of cytosine methylation in maize (Zea mays).

PubMed

Lauria, Massimiliano; Piccinini, Sara; Pirona, Raul; Lund, Gertrud; Viotti, Angelo; Motto, Mario

2014-03-01

Pure epigenetic variation, or epigenetic variation that is independent of genetic context, may provide a mechanism for phenotypic variation in the absence of DNA mutations. To estimate the extent of pure epigenetic variation within and across generations and to identify the DNA regions targeted, a group of eight plants derived from a highly inbred line of maize (Zea mays) was analyzed by the methylation-sensitive amplified polymorphism (MSAP) technique. We found that cytosine methylation (mC) differences among individuals accounted for up to 7.4% of CCGG sites investigated by MSAP. Of the differentially methylated fragments (DMFs) identified in the S0 generation, ∼12% were meiotically inherited for at least six generations. We show that meiotically heritable mC variation was consistently generated for an average of 0.5% CCGG sites per generation and that it largely occurred somatically. We provide evidence that mC variation can be established and inherited in a parent-of-origin manner, given that the paternal lineage is more prone to both forward and reverse mC changes. The molecular characterization of selected DMFs revealed that the variation was largely determined by CG methylation changes that map within gene regions. The expression analysis of genes overlapping with DMFs did not reveal an obvious correlation between mC variation and transcription, reinforcing the idea that the primary function of gene-body methylation is not to control gene expression. Because this study focuses on epigenetic variation in field-grown plants, the data presented herein pertain to spontaneous epigenetic changes of the maize genome in a natural context.

Epigenetic Variation, Inheritance, and Parent-of-Origin Effects of Cytosine Methylation in Maize (Zea mays)

PubMed Central

Lauria, Massimiliano; Piccinini, Sara; Pirona, Raul; Lund, Gertrud; Viotti, Angelo; Motto, Mario

2014-01-01

Pure epigenetic variation, or epigenetic variation that is independent of genetic context, may provide a mechanism for phenotypic variation in the absence of DNA mutations. To estimate the extent of pure epigenetic variation within and across generations and to identify the DNA regions targeted, a group of eight plants derived from a highly inbred line of maize (Zea mays) was analyzed by the methylation-sensitive amplified polymorphism (MSAP) technique. We found that cytosine methylation (mC) differences among individuals accounted for up to 7.4% of CCGG sites investigated by MSAP. Of the differentially methylated fragments (DMFs) identified in the S0 generation, ∼12% were meiotically inherited for at least six generations. We show that meiotically heritable mC variation was consistently generated for an average of 0.5% CCGG sites per generation and that it largely occurred somatically. We provide evidence that mC variation can be established and inherited in a parent-of-origin manner, given that the paternal lineage is more prone to both forward and reverse mC changes. The molecular characterization of selected DMFs revealed that the variation was largely determined by CG methylation changes that map within gene regions. The expression analysis of genes overlapping with DMFs did not reveal an obvious correlation between mC variation and transcription, reinforcing the idea that the primary function of gene-body methylation is not to control gene expression. Because this study focuses on epigenetic variation in field-grown plants, the data presented herein pertain to spontaneous epigenetic changes of the maize genome in a natural context. PMID:24374354

A novel Zea mays ssp. mexicana L. MYC-type ICE-like transcription factor gene ZmmICE1, enhances freezing tolerance in transgenic Arabidopsis thaliana.

PubMed

Lu, Xiang; Yang, Lei; Yu, Mengyuan; Lai, Jianbin; Wang, Chao; McNeil, David; Zhou, Meixue; Yang, Chengwei

2017-04-01

The annual Zea mays ssp. mexicana L., a member of the teosinte group, is a close wild relative of maize and thus can be effectively used in maize improvement. In this study, an ICE-like gene, ZmmICE1, was isolated from a cDNA library of RNA-Seq from cold-treated seedling tissues of Zea mays ssp. mexicana L. The deduced protein of ZmmICE1 contains a highly conserved basic helix-loop-helix (bHLH) domain and C-terminal region of ICE-like proteins. The ZmmICE1 protein localizes to the nucleus and shows sumoylation when expressed in an Escherichia coli reconstitution system. In addition, yeast one hybrid assays indicated that ZmmICE1 has transactivation activities. Moreover, ectopic expression of ZmmICE1 in the Arabidopsis ice1-2 mutant increased freezing tolerance. The ZmmICE1 overexpressed plants showed lower electrolyte leakage (EL), reduced contents of malondialdehyde (MDA). The expression of downstream cold related genes of Arabidopsis C-repeat-binding factors (AtCBF1, AtCBF2 and AtCBF3), cold-responsive genes (AtCOR15A and AtCOR47), kinesin-1 member gene (AtKIN1) and responsive to desiccation gene (AtRD29A) was significantly induced when compared with wild type under low temperature treatment. Taken together, these results indicated that ZmmICE1 is the homolog of Arabidopsis inducer of CBF expression genes (AtICE1/2) and plays an important role in the regulation of freezing stress response. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Single-embryo transfer versus multiple-embryo transfer.

PubMed

Gerris, Jan

2009-01-01

Despite the progress made in assisted reproductive technology, live birth rates remain disappointingly low. Multiple-embryo transfer has been an accepted practice with which to increase the success rate. This has led to a higher incidence of multiple-order births compared with natural conception, which not only increase the risk of mortality and morbidity to both mother and children but are also associated with social and economic consequences. Elective single-embryo transfer (eSET) was developed in an effort to increase singleton pregnancies in assisted reproduction. Studies comparing eSET with multiple-embryo transfer highlight the benefit of this approach and suggest that, with careful patient selection and the transfer of good-quality embryos, the risk of a multiple-order pregnancy can be reduced without significantly decreasing live birth rates. Although the use of eSET has gradually increased in clinical practice, its acceptance has been limited by factors such as availability of funding and awareness of the procedure. An open discussion of eSET is warranted in an effort to enable a broader understanding by physicians and patients of the merits of this approach. Ultimately, eSET may provide a more cost-effective, potentially safer approach to patients undergoing assisted reproduction technology.

9 CFR 98.16 - The embryo collection unit.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false The embryo collection unit. 98.16... CERTAIN ANIMAL EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos From Regions Where Rinderpest or Foot-and-Mouth Disease Exists § 98.16 The embryo collection unit. Ruminant and swine embryos may be...

9 CFR 98.16 - The embryo collection unit.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false The embryo collection unit. 98.16... CERTAIN ANIMAL EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos From Regions Where Rinderpest or Foot-and-Mouth Disease Exists § 98.16 The embryo collection unit. Ruminant and swine embryos may be...

9 CFR 98.16 - The embryo collection unit.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false The embryo collection unit. 98.16... CERTAIN ANIMAL EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos From Regions Where Rinderpest or Foot-and-Mouth Disease Exists § 98.16 The embryo collection unit. Ruminant and swine embryos may be...

9 CFR 98.16 - The embryo collection unit.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false The embryo collection unit. 98.16... CERTAIN ANIMAL EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos From Regions Where Rinderpest or Foot-and-Mouth Disease Exists § 98.16 The embryo collection unit. Ruminant and swine embryos may be...

9 CFR 98.16 - The embryo collection unit.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false The embryo collection unit. 98.16... CERTAIN ANIMAL EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos From Regions Where Rinderpest or Foot-and-Mouth Disease Exists § 98.16 The embryo collection unit. Ruminant and swine embryos may be...

Late steps of egg cell differentiation are accelerated by pollination in Zea mays L.

PubMed

Mól, R; Idzikowska, K; Dumas, C; Matthys-Rochon, E

2000-04-01

Egg cells were analysed cytologically during the female receptivity period in maize (Zea mays L., line A 188). Three classes of egg cell were distinguished: type A--small, non-vacuolated cells with a central nucleus; type B--larger cells with small vacuoles surrounding the perinuclear cytoplasm located in the middle of the cell; type C--big cells with a large apical vacuole and the mid-basal perinuclear cytoplasm. The less-dense cytoplasm of the vacuolated egg cells usually contained numerous cup- or bell-shaped mitochondria. The three egg types appear to correspond to three late stages of egg cell differentiation. The frequencies of each of the three egg types were monitored in developing maize ears before and after pollination. In young ears, with the silks just extending out of the husks, small A-type cells were found in about 86% of ovules. Their frequency decreased to about 58% at the optimum silk length, remained unchanged in non-pollinated ears, and fell to 16% at the end of the female receptivity period. However, after pollination and before fertilisation the frequency of these cells decreased to about 33%, and the larger vacuolated egg cells (types B and C) prevailed. At various stages of the receptivity period, pollination accelerated changes in the egg population, increasing the number of ovules bearing larger, vacuolated egg cells. Experiments with silk removal demonstrated that putative pollination signals act immediately after pollen deposition and are not species-specific.

Directly dated starch residues document early formative maize (Zea mays L.) in tropical Ecuador

PubMed Central

Zarrillo, Sonia; Pearsall, Deborah M.; Raymond, J. Scott; Tisdale, Mary Ann; Quon, Dugane J.

2008-01-01

The study of maize (Zea mays L.) domestication has advanced from questions of its origins to the study—and debate—of its dietary role and the timing of its dispersal from Mexico. Because the investigation of maize's spread is hampered by poor preservation of macrobotanical remains in the Neotropics, research has focused on microbotanical remains whose contexts are often dated by association, leading some to question the dates assigned. Furthermore, some scholars have argued that maize was not introduced to southwestern Ecuador until ≈4150–3850 calendar years before the present (cal B.P.), that it was used first and foremost as a fermented beverage in ceremonial contexts, and that it was not important in everyday subsistence, challenging previous studies based on maize starch and phytoliths. To further investigate these questions, we analyzed every-day cooking vessels, food-processing implements, and sediments for starch and phytoliths from an archaeological site in southwestern Ecuador constituting a small Early Formative village. Employing a new technique to recover starch granules from charred cooking-pot residues we show that maize was present, cultivated, and consumed here in domestic contexts by at least 5300–4950 cal B.P. Directly dating the residues by accelerator mass spectrometry (AMS) radiocarbon measurement, our results represent the earliest direct dates for maize in Early Formative Ecuadorian sites and provide further support that, once domesticated ≈9000 calendar years ago, maize spread rapidly from southwestern Mexico to northwestern South America. PMID:18362336

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

The effect and fate of water-soluble carbon nanodots in maize (Zea mays L.).

PubMed

Chen, Jing; Dou, Runzhi; Yang, Zhongzhou; Wang, Xiaoping; Mao, Chuanbin; Gao, Xiang; Wang, Li

2016-08-01

In this study, the toxicity of water-soluble carbon nanodots (C-dots) to maize (Zea mays L.) and their uptake and transport in plants were investigated. After exposed in sand matrix amended with 0-2000 mg/L C-dots for 4 weeks, we found that the phytotoxicity of C-dots was concentration-dependent. C-dots at 250 and 500 mg/L showed no toxicity to maize. However, 1000 and 2000 mg/L C-dots significantly reduced the fresh weight of root by 57% and 68%, and decreased the shoot fresh weight by 38% and 72%, respectively. Moreover, in maize roots, the exposure of C-dots at 2000 mg/L significantly increased the H2O2 content and lipid peroxidation (6.5 and 1.65 times higher, respectively), as well as, the antioxidant enzymes activities, up to 2, 1.5, 1.9 and 1.9 times higher for catalase, ascorbate peroxidase, guaiacol peroxidase and superoxide dismutase, respectively. On the other hand, C-dots were observed in detached root-cap cells, cortex and vascular bundle of roots and mesophyll cells of leaves through fluorescence microscopy analysis, suggesting that C-dots were absorbed and translocated systemically in maize. Remarkably, a certain amount of C-dots were excreted out from leaf blade. To our knowledge, this is the first study combined phenotypic observation with physiologic responses and bioaccumulation and translocation analysis of C-dots to investigate their effect and fate in maize.

Mitochondrial DNA content in embryo culture medium is significantly associated with human embryo fragmentation.

PubMed

Stigliani, S; Anserini, P; Venturini, P L; Scaruffi, P

2013-10-01

approach we are proposing may provide a novel, non-invasive, objective tool for embryo quality grading. The correlation between a high mtDNA concentration and the fragmentation rate of embryos is suggestive that fragments are mainly anuclear cytoplasmatic debris arising during cleavage. Therefore, blastomere shaping as an early event during in vitro development may play a homeostatic role and be related to embryo competence. This project was funded by Merck Serono (Grant for Fertility Innovation 2011). The sponsor had no role in study design, data collection, data analysis, data interpretation and writing of the paper. Authors declare no conflicts of interest. ClinicalTrials.gov Identifier: NCT01397136.

Degradation of some representative polycyclic aromatic hydrocarbons by the water-soluble protein extracts from Zea mays L. cv PR32-B10.

PubMed

Barone, Roberto; de Biasi, Margherita-Gabriella; Piccialli, Vincenzo; de Napoli, Lorenzo; Oliviero, Giorgia; Borbone, Nicola; Piccialli, Gennaro

2016-10-01

The ability of the water-soluble protein extracts from Zea mais L. cv. PR32-B10 to degrade some representative polycyclic aromatic hydrocarbons (PAHs), has been evaluated. Surface sterilized seeds of corn (Zea mais L. Pioneer cv. PR32-B10) were hydroponically cultivated in a growth chamber under no-stressful conditions. The water-soluble protein extracts isolated from maize tissues showed peroxidase, polyphenol oxidase and catalase activities. Incubation of the extracts with naphthalene, fluorene, phenanthrene and pyrene, led to formation of oxidized and/or degradation products. GC-MS and TLC monitoring of the processes showed that naphthalene, phenanthrene, fluorene and pyrene underwent 100%, 78%, 92% and 65% oxidative degradation, respectively, after 120 min. The chemical structure of the degradation products were determined by (1)H NMR and ESI-MS spectrometry. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nonomuraea zeae sp. nov., isolated from the rhizosphere of corn (Zea mays L.).

PubMed

Shen, Yue; Jia, Feiyu; Liu, Chongxi; Li, Jiansong; Guo, Siyu; Zhou, Shuyu; Wang, Xiangjing; Xiang, Wensheng

2016-06-01

A novel actinobacterium, designated strain NEAU-ND5T, was isolated from the rhizosphere of corn (Zea mays L.) collected in Heilongjiang Province, north-east China, and characterized using a polyphasic approach. 16S rRNA gene sequence analysis showed that strain NEAU-ND5T was a member of the genus Nonomuraea, with highest sequence similarities to Nonomuraea jabiensis A4036T (98.29 %), Nonomuraea rosea GW12687T (98.25 %), Nonomuraea candida HMC10T (98.22 %), Nonomuraea rhizophila YIM 67092T (98.04 %) and Nonomuraea kuesteri NRRL B-24325T (98.04 %). Similarities to other type strains of the genus Nonomuraea were lower than 98 %. Morphological and chemotaxonomic properties of strain NEAU-ND5T were also consistent with the description of the genus Nonomuraea. The cell wall contained meso-diaminopimelic acid and the whole-cell sugars were glucose, ribose and madurose. The phospholipid profile consisted of diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, hydroxy-phosphatidylmonomethylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The major menaquinones were MK-9(H4), MK-9(H2) and MK-9(H0). The predominant cellular fatty acids were iso-C16:0 and 10-methyl C17:0. A combination of DNA-DNA hybridization results and some phenotypic characteristics demonstrated that strain NEAU-ND5T was clearly distinguished from its closely related Nonomuraea species. Consequently, it is concluded that strain NEAU-ND5T represents a novel species of the genus Nonomuraea, for which the name Nonomuraea zeae sp. nov. is proposed. The type strain is NEAU-ND5T (=CGMCC 4.7280T=DSM 100528T).

Determination of genotoxic effects of boron and zinc on Zea mays using protein and random amplification of polymorphic DNA analyses.

PubMed

Erturk, Filiz Aygun; Nardemir, Gokce; Hilal, A Y; Arslan, Esra; Agar, Guleray

2015-11-01

In this research, we aimed to determine genotoxic effects of boron (B) and zinc (Zn) on Zea mays by using total soluble protein content and random amplification of polymorphic DNA (RAPD) analyses. For the RAPD analysis, 16 RAPD primers were found to produce unique polymorphic band profiles on treated maize seedlings. With increased Zn and B concentrations, increased polymorphism rate was observed, while genomic template stability and total soluble protein content decreased. The treatment with Zn was more effective than that of B groups on the levels of total proteins. The obtained results from this study revealed that the total soluble protein levels and RAPD profiles were performed as endpoints of genotoxicity and these analyses can offer useful biomarker assays for the evaluation of genotoxic effects on Zn and B polluted plants. © The Author(s) 2013.

Differential antimicrobial activity of silver nanoparticles to bacteria Bacillus subtilis and Escherichia coli, and toxicity to crop plant Zea mays and beneficial B. subtilis-inoculated Z. mays

NASA Astrophysics Data System (ADS)

Doody, Michael A.; Wang, Dengjun; Bais, Harsh P.; Jin, Yan

2016-10-01

As silver nanoparticles (AgNPs) have become increasingly used in commercial antimicrobial agents and industrial and military products, concerns are increasing over their broad environmental and health impacts and risks because they are finding their way to the environment. This study was designed to quantify the antimicrobial activity of citrate-coated AgNPs (c-AgNPs; transmission electron microscope size of 44.9 ± 7.2 nm) to two species of bacteria, i.e., Gram-positive Bacillus subtilis and Gram-negative Escherichia coli, and toxicity to a major crop plant Zea mays and beneficial bacteria-inoculated plant (i.e., B. subtilis-inoculated Z. mays symbiont). Our results reveal that the exposure of c-AgNPs significantly inhibited bacteria growth and altered their growth kinetics. Z. mays experienced significant sublethal effects including reduced root length and biomass, and hyper-accumulation of Ag in roots. The beneficial interactions between B. subtilis and Z. mays were weakened as well because both species suffered sublethal effects. Potential mechanisms leading to the antimicrobial activity and toxicity of c-AgNPs to the bacteria, plant, and plant-bacteria symbiont examined in this study were discussed. Taken together, our findings advance the current knowledge of AgNPs antimicrobial property or toxicity to bacteria, crop plant, and beneficial plant-bacteria symbiotic interaction, which is a critical component for NPs environmental impact and risk assessment.

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.

Computational Study on Substrate Specificity of a Novel Cysteine Protease 1 Precursor from Zea mays

PubMed Central

Liu, Huimin; Chen, Liangcheng; Li, Quan; Zheng, Mingzhu; Liu, Jingsheng

2014-01-01

Cysteine protease 1 precursor from Zea mays (zmCP1) is classified as a member of the C1A family of peptidases (papain-like cysteine protease) in MEROPS (the Peptidase Database). The 3D structure and substrate specificity of the zmCP1 is still unknown. This study is the first one to build the 3D structure of zmCP1 by computer-assisted homology modeling. In order to determine the substrate specificity of zmCP1, docking study is used for rapid and convenient analysis of large populations of ligand–enzyme complexes. Docking results show that zmCP1 has preference for P1 position and P2 position for Arg and a large hydrophobic residue (such as Phe). Gly147, Gly191, Cys189, and Asp190 are predicted to function as active residues at the S1 subsite, and the S2 subsite contains Leu283, Leu193, Ala259, Met194, and Ala286. SIFt results indicate that Gly144, Arg268, Trp308, and Ser311 play important roles in substrate binding. Then Molecular Mechanics-Poisson-Boltzmann Surface Area (MM-PBSA) method was used to explain the substrate specificity for P1 position of zmCp1. This study provides insights into the molecular basis of zmCP1 activity and substrate specificity. PMID:24921705

Gut transcription in Helicoverpa zea is dynamically altered in response to baculovirus infection

USDA-ARS?s Scientific Manuscript database

The Helicoverpa zea transcriptome was analyzed 24 hours after H. zea larvae fed on artificial diet laced with Helicoverpa zea single nucleopolyhedrovirus (HzSNPV). Significant differential regulation of 1,139 putative genes (P<0.05 T-test with Benjamini and Hochberg False Discovery Rate) was detect...

Transcriptomic Profiling of the Maize (Zea mays L.) Leaf Response to Abiotic Stresses at the Seedling Stage.

PubMed

Li, Pengcheng; Cao, Wei; Fang, Huimin; Xu, Shuhui; Yin, Shuangyi; Zhang, Yingying; Lin, Dezhou; Wang, Jianan; Chen, Yufei; Xu, Chenwu; Yang, Zefeng

2017-01-01

Abiotic stresses, including drought, salinity, heat, and cold, negatively affect maize ( Zea mays L.) development and productivity. To elucidate the molecular mechanisms of resistance to abiotic stresses in maize, RNA-seq was used for global transcriptome profiling of B73 seedling leaves exposed to drought, salinity, heat, and cold stress. A total of 5,330 differentially expressed genes (DEGs) were detected in differential comparisons between the control and each stressed sample, with 1,661, 2,019, 2,346, and 1,841 DEGs being identified in comparisons of the control with salinity, drought, heat, and cold stress, respectively. Functional annotations of DEGs suggested that the stress response was mediated by pathways involving hormone metabolism and signaling, transcription factors (TFs), very-long-chain fatty acid biosynthesis and lipid signaling, among others. Of the obtained DEGs (5,330), 167 genes are common to these four abiotic stresses, including 10 up-regulated TFs (five ERFs, two NACs, one ARF, one MYB, and one HD-ZIP) and two down-regulated TFs (one b-ZIP and one MYB-related), which suggested that common mechanisms may be initiated in response to different abiotic stresses in maize. This study contributes to a better understanding of the molecular mechanisms of maize leaf responses to abiotic stresses and could be useful for developing maize cultivars resistant to abiotic stresses.

Expression Patterns of Genes Involved in Ascorbate-Glutathione Cycle in Aphid-Infested Maize (Zea mays L.) Seedlings

PubMed Central

Sytykiewicz, Hubert

2016-01-01

Reduced forms of ascorbate (AsA) and glutathione (GSH) are among the most important non-enzymatic foliar antioxidants in maize (Zea mays L.). The survey was aimed to evaluate impact of bird cherry-oat aphid (Rhopalosiphum padi L.) or grain aphid (Sitobion avenae F.) herbivory on expression of genes related to ascorbate-glutathione (AsA-GSH) cycle in seedlings of six maize varieties (Ambrozja, Nana, Tasty Sweet, Touran, Waza, Złota Karłowa), differing in resistance to the cereal aphids. Relative expression of sixteen maize genes encoding isoenzymes of ascorbate peroxidase (APX1, APX2, APX3, APX4, APX5, APX6, APX7), monodehydroascorbate reductase (MDHAR1, MDHAR2, MDHAR3, MDHAR4), dehydroascorbate reductase (DHAR1, DHAR2, DHAR3) and glutathione reductase (GR1, GR2) was quantified. Furthermore, effect of hemipterans’ attack on activity of APX, MDHAR, DHAR and GR enzymes, and the content of reduced and oxidized ascorbate and glutathione in maize plants were assessed. Seedling leaves of more resistant Z. mays varieties responded higher elevations in abundance of target transcripts. In addition, earlier and stronger aphid-triggered changes in activity of APX, MDHAR, DHAR and GR enzymes, and greater modulations in amount of the analyzed antioxidative metabolites were detected in foliar tissues of highly resistant Ambrozja genotype in relation to susceptible Tasty Sweet plants. PMID:26907270

Seed priming with KNO3 mediates biochemical processes to inhibit lead toxicity in maize (Zea mays L.).

PubMed

Nawaz, Fahim; Naeem, Muhammad; Akram, Asim; Ashraf, Muhammad Y; Ahmad, Khawaja S; Zulfiqar, Bilal; Sardar, Hasan; Shabbir, Rana N; Majeed, Sadia; Shehzad, Muhammad A; Anwar, Irfan

2017-11-01

Accumulation of lead (Pb) in agricultural soils has become a major factor for reduced crop yields and poses serious threats to humans consuming agricultural products. The present study investigated the effects of KNO 3 seed priming (0 and 0.5% KNO 3 ) on growth of maize (Zea mays L.) seedlings exposed to Pb toxicity (0, 1300 and 2550 mg kg -1 Pb). Pb exposure markedly reduced the growth of maize seedlings and resulted in higher Pb accumulation in roots than shoots. Pretreatment of seeds with KNO 3 significantly improved the germination percentage and increased physiological indices. A stimulating effect of KNO 3 seed priming was also observed on pigments (chlorophyll a, b, total chlorophyll and carotenoid contents) of Pb-stressed plants. Low translocation of Pb from roots to shoots caused an increased accumulation of total free amino acids and higher activities of catalase, peroxidase, superoxide dismutase and ascorbate peroxidase in roots as compared to shoot, which were further enhanced by exogenous KNO 3 supply to prevent Pb toxicity. Maize accumulates more Pb in roots than shoot at early growth stages. Priming of seeds with KNO 3 prevents Pb toxicity, which may be exploited to improve seedling establishment in crop species grown under Pb contaminated soils. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Expression Patterns of Genes Involved in Ascorbate-Glutathione Cycle in Aphid-Infested Maize (Zea mays L.) Seedlings.

PubMed

Sytykiewicz, Hubert

2016-02-23

Reduced forms of ascorbate (AsA) and glutathione (GSH) are among the most important non-enzymatic foliar antioxidants in maize (Zea mays L.). The survey was aimed to evaluate impact of bird cherry-oat aphid (Rhopalosiphum padi L.) or grain aphid (Sitobion avenae F.) herbivory on expression of genes related to ascorbate-glutathione (AsA-GSH) cycle in seedlings of six maize varieties (Ambrozja, Nana, Tasty Sweet, Touran, Waza, Złota Karłowa), differing in resistance to the cereal aphids. Relative expression of sixteen maize genes encoding isoenzymes of ascorbate peroxidase (APX1, APX2, APX3, APX4, APX5, APX6, APX7), monodehydroascorbate reductase (MDHAR1, MDHAR2, MDHAR3, MDHAR4), dehydroascorbate reductase (DHAR1, DHAR2, DHAR3) and glutathione reductase (GR1, GR2) was quantified. Furthermore, effect of hemipterans' attack on activity of APX, MDHAR, DHAR and GR enzymes, and the content of reduced and oxidized ascorbate and glutathione in maize plants were assessed. Seedling leaves of more resistant Z. mays varieties responded higher elevations in abundance of target transcripts. In addition, earlier and stronger aphid-triggered changes in activity of APX, MDHAR, DHAR and GR enzymes, and greater modulations in amount of the analyzed antioxidative metabolites were detected in foliar tissues of highly resistant Ambrozja genotype in relation to susceptible Tasty Sweet plants.

Endometrial preparation for women undergoing embryo transfer with frozen embryos or embryos derived from donor oocytes.

PubMed

Glujovsky, Demián; Pesce, Romina; Fiszbajn, Gabriel; Sueldo, Carlos; Hart, Roger J; Ciapponi, Agustín

2010-01-20

If a fresh embryo, assisted reproductive technology procedure cycle is unsuccessful and there are frozen embryos available, a frozen-thawed embryo transfer is performed. In some specific cases women may undergo oocyte donation treatment. In both situations the endometrium is primed by the administration of estrogen and progesterone. To prevent the possibility of spontaneous ovulation, gonadotropin-releasing hormone (GnRH) agonists are frequently used. To evaluate the most effective endometrial preparation for women undergoing transfer with frozen embryos or embryos from donor oocytes with regard to the subsequent live birth rate. We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE, LILACS, and abstracts of reproductive societies' meetings (from inception). No language restrictions were applied. Experts in the field were contacted. Randomised controlled trials evaluating endometrial preparation in women undergoing fresh donor cycles and frozen embryo transfers. Two review authors independently applied the inclusion criteria, assessed trial risk of bias, and extracted data. Twenty two randomised controlled trials were included. Five studies analysed the use of a GnRH agonist versus control. No significant benefit was demonstrated when using GnRH agonists. No evidence of statistically significant benefit was found for one GnRH agonist over another, or vaginal over intramuscular progesterone administration. No difference in pregnancy rate was demonstrated when no treatment was compared to aspirin, steroids, ovarian stimulation, or human chorionic gonadotropin (hCG) prior to embryo transfer, although using hCG several times before the oocyte retrieval decreases the pregnancy rate. Finally, when oocyte recipients were studied further, starting progesterone on the day of oocyte pick-up (OPU) or the day after OPU produced a significantly higher

Influence of sub-lethal crude oil concentration on growth, water relations and photosynthetic capacity of maize (Zea mays L.) plants.

PubMed

Athar, Habib-Ur-Rehman; Ambreen, Sarah; Javed, Muhammad; Hina, Mehwish; Rasul, Sumaira; Zafar, Zafar Ullah; Manzoor, Hamid; Ogbaga, Chukwuma C; Afzal, Muhammad; Al-Qurainy, Fahad; Ashraf, Muhammad

2016-09-01

Maize tolerance potential to oil pollution was assessed by growing Zea mays in soil contaminated with varying levels of crude oil (0, 2.5 and 5.0 % v/w basis). Crude oil contamination reduced soil microflora which may be beneficial to plant growth. It was observed that oil pollution caused a remarkable decrease in biomass, leaf water potential, turgor potential, photosynthetic pigments, quantum yield of photosystem II (PSII) (Fv/Fm), net CO2 assimilation rate, leaf nitrogen and total free amino acids. Gas exchange characteristics suggested that reduction in photosynthetic rate was mainly due to metabolic limitations. Fast chlorophyll a kinetic analysis suggested that crude oil damaged PSII donor and acceptor sides and downregulated electron transport as well as PSI end electron acceptors thereby resulting in lower PSII efficiency in converting harvested light energy into biochemical energy. However, maize plants tried to acclimate to moderate level of oil pollution by increasing root diameter and root length relative to its shoot biomass, to uptake more water and mineral nutrients.

Evidence for maize (Zea mays) in the Late Archaic (3000–1800 B.C.) in the Norte Chico region of Peru

PubMed Central

Haas, Jonathan; Creamer, Winifred; Huamán Mesía, Luis; Goldstein, David; Reinhard, Karl; Rodríguez, Cindy Vergel

2013-01-01

For more than 40 y, there has been an active discussion over the presence and economic importance of maize (Zea mays) during the Late Archaic period (3000–1800 B.C.) in ancient Peru. The evidence for Late Archaic maize has been limited, leading to the interpretation that it was present but used primarily for ceremonial purposes. Archaeological testing at a number of sites in the Norte Chico region of the north central coast provides a broad range of empirical data on the production, processing, and consumption of maize. New data drawn from coprolites, pollen records, and stone tool residues, combined with 126 radiocarbon dates, demonstrate that maize was widely grown, intensively processed, and constituted a primary component of the diet throughout the period from 3000 to 1800 B.C. PMID:23440194

Nastic response of maize (Zea mays L.) coleoptiles during clinostat rotation.

PubMed

Nick, P; Schafer, E

1989-08-01

Rotation of unstimulated maize (Zea mays L.) seedlings on a horizontal clinostat is accompanied by a strong bending response of the coleoptiles towards the caryopsis, yielding curvatures exceding 100 degrees. The corresponding azimuthal distribution shows two peaks, each of which is displayed by 30 degrees from the symmetry axis connecting the shortest coleoptile and caryopsis cross sections. It is argued that this spatial pattern is not the result of two independent bending preferences, but caused by a one-peaked distribution encountering an obstacle in its central part and thus being split into the two subpeaks. The existence of one preferential direction justifies considering this response to be a nastic movement. Its time course consists of an early negative phase (coleoptiles bend away from the caryopsis) followed 2 h later by a long-lasting positive bending towards the caryopsis. In light-interaction experiments, fluence-response curves for different angles between blue light and the direction of the nastic response were measured. These experiments indicate that blue light interacts with the nastic response at two levels: (i) phototonic inhibition, and (ii) addition of nastic and phototropic curvatures. It is concluded that phototropic and phototonic transduction bifurcate before the formation of phototropic transverse polarity. The additivity of nastic and phototropic responses was followed at the population level. At the level of the individual seedling, one observes, in the case of phototropic induction opposing nastic movement, three distinct responses: either strong phototropism, or nastic bending, or an "avoidance" response which involves strong curvature perpendicular to the stimulation plane. With time the nastic bending becomes increasingly stable against opposing phototropic stimulation. This can be seen from a growing proportion of seedlings exhibiting nastic bending when light is applied at variable intervals after the onset of clinostat rotation

Potentially toxic elements in foodcrops: Triticum aestivum L., Zea mays L.

NASA Astrophysics Data System (ADS)

Bini, Claudio; Fontana, Silvia; Squizzato, Stefania; Minello, Fabiola; Fornasier, Flavio; Wahsha, Mohammad

2013-04-01

Soil is the basis of the ecosystems and of our system of food production. Crops can uptake heavy metals and potentially toxic elements from the soil and store them in the roots or translocate them to the aerial parts. Excessive content of these elements in edible parts can produce toxic effects and, through the food chain and food consumption, result in a potential hazard for human health. In this study soils and plants (spring wheat, Triticum aestivum L. and maize, Zea mays L.) from a tannery district in North-East Italy were analyzed to determine pedological characters, soil microbial indicators and the content of some major and micro-nutrients and potentially toxic elements (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, P, Pb, S, Zn, V). The soils of the area are moderately polluted; Cr is the most important inorganic contaminant, followed by Ni, Cu and V. Factor analysis evidenced that the contaminants are in part anthropogenic and in part geogenic. Major anthropogenic origin was detected for Cr, Ni (from industrial activities), Zn, Cu, Cd (from agriculture practices). Biological Absorption Coefficient (BAC) from soil to plant roots and Translocation factor (TF) within the plant were calculated; major nutrients (K, P, S) and some micronutrients (Cu, Zn, Mg, Mn) are easily absorbed and translocated, whilst other nutrients (Ca, Fe) and potentially toxic elements or micronutrients (Al, Cd, Cr, Ni, Pb, V) are not accumulated in the seeds of the two considered species. However, the two edible species proved differently able to absorb and translocate elements, and this suggests to consider separately every species as potential PHEs transporter to the food chain and to humans. Cr concentrations in seeds and other aerial parts (stem and leaves) of the examined plants are higher than the values found for the same species and for other cereals grown on unpolluted soils. Comparing the Cr levels in edible parts with recommended dietary intake, besides other possible Cr sources

Optimization of anaerobic digestion of a mixture of Zea mays and Miscanthus sacchariflorus silages with various pig manure dosages.

PubMed

Bułkowska, K; Pokój, T; Klimiuk, E; Gusiatin, Z M

2012-12-01

Digestion of crop silage (Zea mays L. and Miscanthus sacchariflorus) with 0%, 7.5%, 12.5% and 25% pig manure as co-substrate was performed in continuous stirred-tank reactors, for a constant hydraulic retention time of 45 d and organic load rate of 2.1 g L(-1)d(-1). A matrix of correlations between biogas/methane production and parameters of anaerobic digestion was created in order to estimate process stability. The values of the correlation coefficients indicated that the most stable anaerobic digestion was achieved using 7.5% and 12.5% pig manure. In contrast, the positive correlation between ammonium and volatile fatty acids (r=0.8698, p<0.001) at 25% pig manure showed process instability. Compared to crop silage alone, pig manure favored the production of biogas and methane; the highest production rates were obtained with 12.5% pig manure. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of Cadmium Stress on Non-enzymatic Antioxidant and Nitric Oxide Levels in Two Varieties of Maize (Zea mays).

PubMed

Akinyemi, Ayodele Jacob; Faboya, Oluwabamise Lekan; Olayide, Israel; Faboya, Opeyemi Ayodeji; Ijabadeniyi, Tosin

2017-06-01

Cadmium (Cd) is one of the most toxic heavy metals that inhibit physiological processes of plants. Hence, the present study sought to investigate the effect of cadmium-contaminated seeds from two varieties of maize (Zea mays) on non-enzymatic antioxidant and nitric oxide levels. Seeds of yellow and white maize were exposed to different concentrations of Cd (0, 1, 3 and 5 ppm) for two weeks. The results from this study revealed that both varieties of maize bio-accumulate Cd in leaves in a dose-dependent manner. In addition, Cd exposure caused a significant (p < 0.05) decrease in total phenolic, GSH and nitric oxide (NO) levels at the highest concentration tested when compared with control. Therefore, the observed decrease in NO and endogenous antioxidant status by Cd treatment in maize plants could suggest some possible mechanism of action for Cd-induced oxidative stress and counteracting effect of the plants against Cd toxicity.

Influence Of Coal Combustion Flue Gas Desulfurization Waste On Element Uptake By Maize (Zea Mays L.)

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

ANNA, KNOX

2005-01-10

A greenhouse study was conducted to determine the effect of coal combustion flue gas desulfurization (FGD) waste from a coal combustion electric power facility on element uptake by maize (Zea mays L.). Unweathered FGD was applied to an Orangeburg Series (Typic Paleudult) soil with an initial soil pH salt of 4.90. The FGD was added at 0, 1, 2, 4, 6, 8, and 10 per cent by weight. The test plant, maize, was harvested after 6 weeks of growth. Within 56 days of the FGD application, all rates of FGD significantly increased pH in the soil and the soil leachatemore » above 6.0. The elemental concentration of the maize tissues indicated a characteristic elevation of B, Se, Mo, and As. However, no visual symptoms of toxicity of B or other elements in plants were observed. Increasing level of FGD caused a steady decline in dry weight, with the highest treatment producing plants which had approximately half the biomass of the control plants. Due to elevated concentrations of B and other elements and due to adverse yield effects measured on plants, unweathered FGD would not be a suitable amendment for 6-week old maize on this soil.« less

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

[3H]Indole-3-acetyl-myo-inositol hydrolysis by extracts of Zea mays L. vegetative tissue

NASA Technical Reports Server (NTRS)

Hall, P. J.; Bandurski, R. S.

1986-01-01

[3H]Indole-3-acetyl-myo-inositol was hydrolyzed by buffered extracts of acetone powders prepared from 4 day shoots of dark grown Zea mays L. seedlings. The hydrolytic activity was proportional to the amount of extract added and was linear for up to 6 hours at 37 degrees C. Boiled or alcohol denatured extracts were inactive. Analysis of reaction mixtures by high performance liquid chromatography demonstrated that not all isomers of indole-3-acetyl-myo-inositol were hydrolyzed at the same rate. Buffered extracts of acetone powders were prepared from coleoptiles and mesocotyls. The rates of hydrolysis observed with coleoptile extracts were greater than those observed with mesocotyl extracts. Active extracts also catalyzed the hydrolysis of esterase substrates such as alpha-naphthyl acetate and the methyl esters of indoleacetic acid and naphthyleneacetic acid. Attempts to purify the indole-3-acetyl-myo-inositol hydrolyzing activity by chromatographic procedures resulted in only slight purification with large losses of activity. Chromatography over hydroxylapatite allowed separation of two enzymically active fractions, one of which catalyzed the hydrolysis of both indole-3-acetyl-myo-inositol and esterase substrates. With the other enzymic hydrolysis of esterase substrates was readily demonstrated, but no hydrolysis of indole-3-acetyl-myo-inositol was ever detected.

A Network Approach of Gene Co-expression in the Zea mays/Aspergillus flavus Pathosystem to Map Host/Pathogen Interaction Pathways.

PubMed

Musungu, Bryan M; Bhatnagar, Deepak; Brown, Robert L; Payne, Gary A; OBrian, Greg; Fakhoury, Ahmad M; Geisler, Matt

2016-01-01

A gene co-expression network (GEN) was generated using a dual RNA-seq study with the fungal pathogen Aspergillus flavus and its plant host Zea mays during the initial 3 days of infection. The analysis deciphered novel pathways and mapped genes of interest in both organisms during the infection. This network revealed a high degree of connectivity in many of the previously recognized pathways in Z. mays such as jasmonic acid, ethylene, and reactive oxygen species (ROS). For the pathogen A. flavus , a link between aflatoxin production and vesicular transport was identified within the network. There was significant interspecies correlation of expression between Z. mays and A. flavus for a subset of 104 Z. mays , and 1942 A. flavus genes. This resulted in an interspecies subnetwork enriched in multiple Z. mays genes involved in the production of ROS. In addition to the ROS from Z. mays , there was enrichment in the vesicular transport pathways and the aflatoxin pathway for A. flavus . Included in these genes, a key aflatoxin cluster regulator, AflS, was found to be co-regulated with multiple Z. mays ROS producing genes within the network, suggesting AflS may be monitoring host ROS levels. The entire GEN for both host and pathogen, and the subset of interspecies correlations, is presented as a tool for hypothesis generation and discovery for events in the early stages of fungal infection of Z. mays by A. flavus .

A Network Approach of Gene Co-expression in the Zea mays/Aspergillus flavus Pathosystem to Map Host/Pathogen Interaction Pathways

PubMed Central

Musungu, Bryan M.; Bhatnagar, Deepak; Brown, Robert L.; Payne, Gary A.; OBrian, Greg; Fakhoury, Ahmad M.; Geisler, Matt

2016-01-01

A gene co-expression network (GEN) was generated using a dual RNA-seq study with the fungal pathogen Aspergillus flavus and its plant host Zea mays during the initial 3 days of infection. The analysis deciphered novel pathways and mapped genes of interest in both organisms during the infection. This network revealed a high degree of connectivity in many of the previously recognized pathways in Z. mays such as jasmonic acid, ethylene, and reactive oxygen species (ROS). For the pathogen A. flavus, a link between aflatoxin production and vesicular transport was identified within the network. There was significant interspecies correlation of expression between Z. mays and A. flavus for a subset of 104 Z. mays, and 1942 A. flavus genes. This resulted in an interspecies subnetwork enriched in multiple Z. mays genes involved in the production of ROS. In addition to the ROS from Z. mays, there was enrichment in the vesicular transport pathways and the aflatoxin pathway for A. flavus. Included in these genes, a key aflatoxin cluster regulator, AflS, was found to be co-regulated with multiple Z. mays ROS producing genes within the network, suggesting AflS may be monitoring host ROS levels. The entire GEN for both host and pathogen, and the subset of interspecies correlations, is presented as a tool for hypothesis generation and discovery for events in the early stages of fungal infection of Z. mays by A. flavus. PMID:27917194

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.

Improved high-performance liquid chromatography (HPLC) method for qualitative and quantitative analysis of allantoin in Zea mays.

PubMed

Haghi, Ghasem; Arshi, Rohollah; Safaei, Alireza

2008-02-27

A high-performance liquid chromatography (HPLC) method for the qualitative and quantitative analysis of allantoin in silk and seed of Zea mays has been developed. Allantoin separation in crude extract was achieved using a C 18 column and phosphate buffer solution (pH 3.0) as a mobile phase at ambient temperature at a flow rate of 1.0 mL/min and detected at 210 nm. The results showed that the amount of allantoin in samples was between 14 and 271 mg/100 g of dry plant material. A comprehensive validation of the method including sensitivity, linearity, repeatability, and recovery was conducted. The calibration curve was linear over the range of 0.2-200 microg/mL with a correlation coefficient of r2>0.999. Limit of detection (LOD, S/N=3) and limit of quantification (LOQ) values of the allantoin were 0.05 and 0.2 microg/mL (1.0 and 4.0 ng) respectively. The relative standard deviation (RSD) value of the repeatability was reported within 1.2%. The average recovery of allantoin added to samples was 100.6% with RSD of 1.5%.

Agrobacterium-mediated transformation of maize (Zea mays) with Cre-lox site specific recombination cassettes in BIBAC vectors.

PubMed

Vega, Juan M; Yu, Weichang; Han, Fangpu; Kato, Akio; Peters, Eric M; Zhang, Zhanyuan J; Birchler, James A

2008-04-01

The Cre/loxP site-specific recombination system has been applied in various plant species including maize (Zea mays) for marker gene removal, gene targeting, and functional genomics. A BIBAC vector system was adapted for maize transformation with a large fragment of genetic material including a herbicide resistance marker gene, a 30 kb yeast genomic fragment as a marker for fluorescence in situ hybridization (FISH), and a 35S-lox-cre recombination cassette. Seventy-five transgenic lines were generated from Agrobacterium-mediated transformation of a maize Hi II line with multiple B chromosomes. Eighty-four inserts have been localized among all 10 A chromosome pairs by FISH using the yeast DNA probe together with a karyotyping cocktail. No inserts were found on the B chromosomes; thus a bias against the B chromosomes by the Agrobacterium-mediated transformation was revealed. The expression of a cre gene was confirmed in 68 of the 75 transgenic lines by a reporter construct for cre/lox mediated recombination. The placement of the cre/lox site-specific recombination system in many locations in the maize genome will be valuable materials for gene targeting and chromosome engineering.

[Embryos and embryo-like entities: problem of definition in the draft of the Swiss embryonic research law].

PubMed

Bürgin, M T; Bürkli, P

2002-11-01

At the end of May 2002, the draft of the Swiss "Federal Act on Research on Surplus Embryos and Embryonic Stem Cells" (EFG, Embryonic Research Act) reached the pre-legislative consultation stage. Under certain conditions, it would allow research on "surplus" embryos from in-vitro fertilization, and the derivation of embryonic stem cells from surplus embryos for research purposes. The EFG draft defines an embryo as "the developing organism from the point of nuclear fusion until the completion of organ development". New technological developments show that embryo-like entities can also be created without nuclear fusion having taken place. It remains unclear how to treat embryonic entities that don't fall under the draft's narrow definition of an embryo. Expanding this definition would be a welcome improvement.

Parallel altitudinal clines reveal trends in adaptive evolution of genome size in Zea mays

PubMed Central

Berg, Jeremy J.; Birchler, James A.; Grote, Mark N.; Lorant, Anne; Quezada, Juvenal

2018-01-01

While the vast majority of genome size variation in plants is due to differences in repetitive sequence, we know little about how selection acts on repeat content in natural populations. Here we investigate parallel changes in intraspecific genome size and repeat content of domesticated maize (Zea mays) landraces and their wild relative teosinte across altitudinal gradients in Mesoamerica and South America. We combine genotyping, low coverage whole-genome sequence data, and flow cytometry to test for evidence of selection on genome size and individual repeat abundance. We find that population structure alone cannot explain the observed variation, implying that clinal patterns of genome size are maintained by natural selection. Our modeling additionally provides evidence of selection on individual heterochromatic knob repeats, likely due to their large individual contribution to genome size. To better understand the phenotypes driving selection on genome size, we conducted a growth chamber experiment using a population of highland teosinte exhibiting extensive variation in genome size. We find weak support for a positive correlation between genome size and cell size, but stronger support for a negative correlation between genome size and the rate of cell production. Reanalyzing published data of cell counts in maize shoot apical meristems, we then identify a negative correlation between cell production rate and flowering time. Together, our data suggest a model in which variation in genome size is driven by natural selection on flowering time across altitudinal clines, connecting intraspecific variation in repetitive sequence to important differences in adaptive phenotypes. PMID:29746459

Value of Neonicotinoid Insecticide Seed Treatments in Mid-South Corn (Zea mays) Production Systems.

PubMed

North, J H; Gore, J; Catchot, A L; Stewart, S D; Lorenz, G M; Musser, F R; Cook, D R; Kerns, D L; Leonard, B R; Dodds, D M

2018-02-09

Neonicotinoid seed treatments are one of several effective control options used in corn, Zea mays L., production in the Mid-South for early season insect pests. An analysis was performed on 91 insecticide seed treatment trials from Arkansas, Louisiana, Mississippi, and Tennessee to determine the value of neonicotinoids in corn production systems. The analysis compared neonicotinoid insecticide treated seed plus a fungicide to seed only with the same fungicide. When analyzed by state, corn yields were significantly higher when neonicotinoid seed treatments were used compared to fungicide only treated seed in Louisiana and Mississippi. Corn seed treated with neonicotinoid seed treatments yielded 111, 1,093, 416, and 140 kg/ha, higher than fungicide only treatments for Arkansas, Louisiana, Mississippi, and Tennessee, respectively. Across all states, neonicotinoid seed treatments resulted in a 700 kg/ha advantage compared to fungicide only treated corn seed. Net returns for corn treated with neonicotinoid seed treatment were $1,446/ha compared with $1,390/ha for fungicide only treated corn seed across the Mid-South. Economic returns for neonicotinoid seed treated corn were significantly greater than fungicide-only-treated corn seed in 8 out of 14 yr. When analyzed by state, economic returns for neonicotinoid seed treatments were significantly greater than fungicide-only-treated seed in Louisiana. In some areas, dependent on year, neonicotinoid seed treatments provide significant yield and economic benefits in Mid-South corn. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Cloning and Functional Analysis of Phosphoethanolamine Methyltransferase Promoter from Maize (Zea mays L.)

PubMed Central

Niu, Gai-Li; Gou, Wei; Han, Xiang-Long; Qin, Cheng; Zhang, Li-Xin; Ashraf, Muhammad

2018-01-01

Betaine, a non-toxic osmoprotectant, is believed to accumulate considerably in plants under stress conditions to maintain the osmotic pressure and promote a variety of processes involved in growth and development. Phosphoethanolamine N-methyltransferase (PEAMT), a key enzyme for betaine synthesis, is reported to be regulated by its upstream promoter. In the present investigation, by using the transgenic approach, a 1048 bp long promoter region of ZmPEAMT gene from Zea mays was cloned and functionally characterized in tobacco. Computational analysis affirmed the existence of abiotic stress responsive cis-elements like ABRE, MYC, HST, LST etc., as well as pathogen, wound and phytohormone responsive motifs. For transformation in tobacco, four 5′-deletion constructs of 826 bp (P2), 642 bp (P3), 428 bp (P4) and 245 bp (P5) were constructed from the 1048 bp (P1) promoter fragment. The transgenic plants generated through a single event exhibited a promising expression of GUS reporter protein in the leaf tissues of treated with salt, drought, oxidative and cold stress as well as control plants. The GUS expression level progressively reduced from P1 to P5 in the leaf tissues, whereas a maximal expression was observed with the P3 construct in the leaves of control plants. The expression of GUS was noted to be higher in the leaves of osmotically- or salt-treated transgenic plants than that in the untreated (control) plants. An effective expression of GUS in the transgenic plants manifests that this promoter can be employed for both stress-inducible and constitutive expression of gene(s). Due to this characteristic, this potential promoter can be effectively used for genetic engineering of several crops. PMID:29316727

Cortical geometry may influence placement of interface between Par protein domains in early Caenorhabditis elegans embryos.

PubMed

Dawes, Adriana T; Iron, David

2013-09-21

During polarization, proteins and other polarity determinants segregate to the opposite ends of the cell (the poles) creating biochemically and dynamically distinct regions. Embryos of the nematode worm Caenorhabditis elegans (C. elegans) polarize shortly after fertilization, creating distinct regions of Par protein family members. These regions are maintained through to first cleavage when the embryo divides along the plane specified by the interface between regions, creating daughter cells with different protein content. In wild type single cell embryos the interface between these Par protein regions is reliably positioned at approximately 60% egg length, however, it is not known what mechanisms are responsible for specifying the position of the interface. In this investigation, we use two mathematical models to investigate the movement and positioning of the interface: a biologically based reaction-diffusion model of Par protein dynamics, and the analytically tractable perturbed Allen-Cahn equation. When we numerically simulate the models on a static 2D domain with constant thickness, both models exhibit a persistently moving interface that specifies the boundary between distinct regions. When we modify the simulation domain geometry, movement halts and the interface is stably positioned where the domain thickness increases. Using asymptotic analysis with the perturbed Allen-Cahn equation, we show that interface movement depends explicitly on domain geometry. Using a combination of analytic and numeric techniques, we demonstrate that domain geometry, a historically overlooked aspect of cellular simulations, may play a significant role in spatial protein patterning during polarization. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of citrate-coated silver nanoparticles on interactions between soil bacteria and the major crop plant Zea mays

NASA Astrophysics Data System (ADS)

Doody, Michael; Bais, Harsh; Jin, Yan

2014-05-01

The increasing use of silver nanoparticles (AgNPs) in commercial antimicrobial products presents an opportunity for increased environmental exposures. While the behavior of AgNPs in surface waters is becoming increasingly understood, little research has been conducted on the effects of these, or any nanoparticles, on soil-dwelling bacteria and major crop plants. Because of the importance of soil bacteria to the overall health of natural and agricultural soils, it is necessary to better understand how AgNPs interact with common bacterial species such as Bacillus subtilis and Escherichia coli. It is further necessary to quantify the effect of AgNPs on major crop plants, including Zea mays, a staple crop for much of the world. Finally, research is needed on how complex plant-microbe interactions that originate in the rhizosphere may be disrupted by AgNPs. Our preliminary data show highly statistically significant growth inhibition near 30% for both species of bacteria exposed to 1.0 mg L-1 citrate-coated AgNPs (c-AgNPs). Growth curves compiled from absorbance data show a similar dose-response for both species. Treatment with aqueous Ag as AgNO3 slightly inhibits E. coli (90 ± 5 %), but enhances growth of B. subtilis to 127 ± 23% of control. These results indicate that toxicity may be related to specific nano-scale properties of the c-AgNPs. On-going experiments measure potential growth inhibition, root development and morphology of Z. mays exposed to c-AgNPs, and resulting changes in plant-microbe interactions.

Variations in the accumulation, localization and rate of metabolization of selenium in mature Zea mays plants supplied with selenite or selenate.

PubMed

Longchamp, Mélanie; Castrec-Rouelle, Maryse; Biron, Philippe; Bariac, Thierry

2015-09-01

Quantification of selenium bioavailability from foods is a key challenge following the discovery of the antioxidant role of this micronutrient in human health. This study presents the uptake, accumulation and rate of metabolization in mature Zea mays plants grown in hydroponic solution supplemented with selenate or selenite. Selenium content was lower in plants supplemented with selenate and accumulated mainly in the leaves compared with selenite-treated plants where the selenium was retained in the roots. Selenite-treated grains accumulated more selenium. Selenate was metabolized less than selenite in whole plants, but in grains selenium was present exclusively as organic selenium compounds. For humans, the bioavailability of organic selenium was evaluated at 90% compared with only 50% for inorganic forms. Our results show that the potential for selenium bioavailability is increased with selenite treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Micromonospora zeae sp. nov., a novel endophytic actinomycete isolated from corn root (Zea mays L.).

PubMed

Shen, Yue; Zhang, Yuejing; Liu, Chongxi; Wang, Xiangjing; Zhao, Junwei; Jia, Feiyu; Yang, Lingyu; Yang, Deguang; Xiang, Wensheng

2014-11-01

A novel actinomycete, designated strain NEAU-gq9(T), was isolated from corn root (Zea mays L.) and characterized using a polyphasic approach. The organism was found to have morphological and chemotaxonomic characteristics typical of the genus Micromonospora. On the basis of 16S rRNA gene sequence similarity studies, strain NEAU-gq9(T) was most closely related to Micromonospora zamorensis CR38(T) (99.3%), Micromonospora jinlongensis NEAU-GRX11(T) (99.2%), Micromonospora saelicesensis Lupac 09(T) (99.2%), Micromonospora chokoriensis 2-19(6)(T) (98.9%), Micromonospora coxensis 2-30-b(28)(T) (98.6%) and Micromonospora lupini Lupac 14N(T) (98.5%). Phylogenetic analysis based on the 16S rRNA gene and gyrB gene demonstrated that strain NEAU-gq9(T) is a member of the genus Micromonospora and supported the closest phylogenetic relationship to M. zamorensis CR38(T), M. jinlongensis NEAU-GRX11(T), M. saelicesensis Lupac 09(T), M. chokoriensis 2-19(6)(T) and M. lupini Lupac 14N(T). A combination of DNA-DNA hybridization, morphological and physiological characteristics indicated that the novel strain could be readily distinguished from the closest phylogenetic relatives. Therefore, it is proposed that strain NEAU-gq9(T) represents a novel species of the genus Micromonospora, for which the name Micromonospora zeae sp. nov. is proposed. The type strain is NEAU-gq9(T) (=CGMCC 4.7092(T)=DSM 45882(T)).

Effect of biochar on reclaimed tidal land soil properties and maize (Zea mays L.) response.

PubMed

Kim, Hyuck-Soo; Kim, Kwon-Rae; Yang, Jae E; Ok, Yong Sik; Owens, Gary; Nehls, Thomas; Wessolek, Gerd; Kim, Kye-Hoon

2016-01-01

Reclaimed tidal land soil (RTLS) often contains high levels of soluble salts and exchangeable Na that can adversely affect plant growth. The current study examined the effect of biochar on the physicochemical properties of RTLS and subsequently the influence on plant growth performance. Rice hull derived biochar (BC) was applied to RTLS at three different rates (1%, 2%, and 5% (w/w)) and maize (Zea mays L.) subsequently cultivated for 6weeks. While maize was cultivated, 0.1% NaCl solution was supplied from the bottom of the pots to simulate the natural RTLS conditions. Biochar induced changes in soil properties were evaluated by the water stable aggregate (WSA) percentage, exchangeable sodium percentage (ESP), soil organic carbon contents, cation exchange capacity, and exchangeable cations. Plant response was measured by growth rate, nutrient contents, and antioxidant enzyme activity of ascorbate peroxidase (APX) and glutathione reductase (GR). Application of rice hull derived biochar increased the soil organic carbon content and the percentage of WSA by 36-69%, while decreasing the ESP. The highest dry weight maize yield was observed from soil which received 5% BC (w/w), which was attributed to increased stability of water-stable aggregates and elevated levels of phosphate in BC incorporated soils. Moreover, increased potassium, sourced from the BC, induced mitigation of Na uptake by maize and consequently, reduced the impact of salt stress as evidenced by overall declines in the antioxidant activities of APX and GR. Copyright © 2015 Elsevier Ltd. All rights reserved.

Growth, cadmium uptake and accumulation of maize (Zea mays L.) under the effects of arbuscular mycorrhizal fungi.

PubMed

Liu, Lingzhi; Gong, Zongqiang; Zhang, Yulong; Li, Peijun

2014-12-01

The effects of three arbuscular mycorrhizal fungi isolates on Cd uptake and accumulation by maize (Zea mays L.) were investigated in a planted pot experiment. Plants were inoculated with Glomus intraradices, Glomus constrictum and Glomus mosseae at three different Cd concentrations. The results showed that root colonization increased with Cd addition during a 6-week growth period, however, the fungal density on roots decreased after 9-week growth in the treatments with G. constrictum and G. mosseae isolates. The percentage of mycorrhizal colonization by the three arbuscular mycorrhizal fungi isolates ranged from 22.7 to 72.3%. Arbuscular mycorrhizal fungi inoculations decreased maize biomass especially during the first 6-week growth before Cd addition, and this inhibitory effect was less significant with Cd addition and growth time. Cd concentrations and uptake in maize plants increased with arbuscular mycorrhizal fungi colonization at low Cd concentration (0.02 mM): nonetheless, it decreased at high Cd concentration (0.20 mM) after 6-week growth period. Inoculation with G. constrictum isolates enhanced the root Cd concentrations and uptake, but G. mosseae isolates showed the opposite results at high Cd concentration level after 9 week growth period, as compared to non-mycorrhizal plants. In conclusion, maize plants inoculated with arbuscular mycorrhizal fungi were less sensitive to Cd stress than uninoculated plants. G. constrictum isolates enhanced Cd phytostabilization and G. mosseae isolates reduced Cd uptake in maize (Z. mays L.).

The influence of calcium and pH on growth in primary roots of Zea mays

NASA Technical Reports Server (NTRS)

Hasenstein, K. H.; Evans, M. L.

1988-01-01

We investigated the interaction of Ca2+ and pH on root elongation in Zea mays L. cv. B73 x Missouri 17 and cv. Merit. Seedlings were raised to contain high levels of Ca2+ (HC, imbibed and raised in 10 mM CaCl2) or low levels of Ca2+ (LC, imbibed and raised in distilled water). In HC roots, lowering the pH (5 mM MES/Tris) from 6.5 to 4.5 resulted in strong, long-lasting growth promotion. Surprisingly, increasing the pH from 6.5 to 8.5 also resulted in strong growth promotion. In LC roots acidification of the medium (pH 6.5 to 4.5) resulted in transient growth stimulation followed by a gradual decline in the growth rate toward zero. Exposure of LC roots to high pH (pH shift from 6.5 to 8.5) also promoted growth. Addition of EGTA resulted in strong growth promotion in both LC and HC roots. The ability of EGTA to stimulate growth appeared not to be related to H+ release from EGTA upon Ca2+ chelation since, 1) LC roots showed a strong and prolonged response to EGTA, but only a transient response to acid pH, and 2) promotion of growth by EGTA was observed in strongly buffered solutions. We also examined the pH dependence of the release of 45Ca2+ from roots of 3-day-old seedlings grown from grains imbibed in 45Ca2+. Release of 45Ca2+ from the root into agar blocks placed on the root surface was greater the more acidic the pH of the blocks. The results indicate that Ca2+ may be necessary for the acid growth response in roots.

Relationship between genetic parameters in maize (Zea mays) with seedling growth parameters under 40-100% soil moisture conditions.

PubMed

Muhammad, R W; Qayyum, A

2013-10-18

We estimated the association of genetic parameters with production characters in 64 maize (Zea mays) genotypes in a green house in soil with 40-100% moisture levels (percent of soil moisture capacity). To identify the major parameters that account for variation among the genotypes, we used single linkage cluster analysis and principle component analysis. Ten plant characters were measured. The first two, four, three, and again three components, with eigen values > 1 contributed 75.05, 80.11, 68.67, and 75.87% of the variability among the genotypes under the different moisture levels, i.e., 40, 60, 80, and 100%, respectively. Other principal components (3-10, 5-10, and 4-10) had eigen values less than 1. The highest estimates of heritability were found for root fresh weight, root volume (0.99), and shoot fresh weight (0.995) in 40% soil moisture. Values of genetic advance ranged from 23.4024 for SR at 40% soil moisture to 0.2538 for shoot dry weight in 60% soil moisture. The high magnitude of broad sense heritability provides evidence that these plant characters are under the control of additive genetic effects. This indicates that selection should lead to fast genetic improvement of the material. The superior agronomic types that we identified may be exploited for genetic potential to improve yield potential of the maize crop.

Potential of kenaf (Hibiscus cannabinus L.) and corn (Zea mays L.) for phytoremediation of dredging sludge contaminated by trace metals.

PubMed

Arbaoui, Sarra; Evlard, Aricia; Mhamdi, Mohamed El Wafi; Campanella, Bruno; Paul, Roger; Bettaieb, Taoufik

2013-07-01

The potential of kenaf (Hibiscus cannabinus L.) and corn (Zea mays L.) for accumulation of cadmium and zinc was investigated. Plants have been grown in lysimetres containing dredging sludge, a substratum naturally rich in trace metals. Biomass production was determined. Sludge and water percolating from lysimeters were analyzed by atomic absorption spectrometry. No visible symptoms of toxicity were observed during the three- month culture. Kenaf and corn tolerate trace metals content in sludge. Results showed that Zn and Cd were found in corn and kenaf shoots at different levels, 2.49 mg/kg of Cd and 82.5 mg/kg of Zn in kenaf shoots and 2.1 mg/kg of Cd and 10.19 mg/kg in corn shoots. Quantities of extracted trace metals showed that decontamination of Zn and Cd polluted substrates is possible by corn and kenaf crops. Tolerance and bioaccumulation factors indicated that both species could be used in phytoremediation.

Costs of jasmonic acid induced defense in aboveground and belowground parts of corn (Zea mays L.).

PubMed

Feng, Yuanjiao; Wang, Jianwu; Luo, Shiming; Fan, Huizhi; Jin, Qiong

2012-08-01

Costs of jasmonic acid (JA) induced plant defense have gained increasing attention. In this study, JA was applied continuously to the aboveground (AG) or belowground (BG) parts, or AG plus BG parts of corn (Zea mays L.) to investigate whether JA exposure in one part of the plant would affect defense responses in another part, and whether or not JA induced defense would incur allocation costs. The results indicated that continuous JA application to AG parts systemically affected the quantities of defense chemicals in the roots, and vice versa. Quantities of DIMBOA and total amounts of phenolic compounds in leaves or roots generally increased 2 or 4 wk after the JA treatment to different plant parts. In the first 2 wk after application, the increase of defense chemicals in leaves and roots was accompanied by a significant decrease of root length, root surface area, and root biomass. Four weeks after the JA application, however, no such costs for the increase of defense chemicals in leaves and roots were detected. Instead, shoot biomass and root biomass increased. The results suggest that JA as a defense signal can be transferred from AG parts to BG parts of corn, and vice versa. Costs for induced defense elicited by continuous JA application were found in the early 2 wk, while distinct benefits were observed later, i.e., 4 wk after JA treatment.

Spray particle drift mitigation using field corn (Zea mays L.) as a drift barrier.

PubMed

Vieira, Bruno C; Butts, Thomas R; Rodrigues, Andre O; Golus, Jeffrey A; Schroeder, Kasey; Kruger, Greg R

2018-04-24

Herbicide particle drift reduces application efficacy and can cause severe impacts on nearby vegetation depending on the herbicide mode-of-action, exposure level, and tolerance to the herbicide. A particle drift mitigation effort placing windbreaks or barriers on the field boundaries to reduce off-target movement of spray particles has been utilized in the past. The objective of this research was to evaluate the effectiveness of field corn (Zea mays L.) at different heights as a particle drift barrier. Applications with a non-air inclusion flat fan nozzle (ER11004) resulted in greater particle drift when compared to an air inclusion nozzle (TTI11004). Eight rows of corn were used as barriers (0.91, 1.22, and 1.98 m height) which reduced the particle drift for both nozzles, especially at shorter downwind distances. Applications with the ER11004 nozzle without corn barriers had 1% of the applied rate (D 99 ) predicted to deposit at 14.8 m downwind, whereas this distance was reduced (up to 7-fold) when applications were performed with corn barriers. The combination of corn drift barriers and nozzle selection (TTI11004) provided satisfactory particle drift reduction when the D 99 estimates were compared to applications with the ER11004 nozzle without corn barriers (up to 10-fold difference). The corn drift barriers were effective in reducing particle drift from applications with the ER11004 and the TTI11004 nozzles (Fine and Ultra Coarse spray classifications, respectively). The corn drift barrier had appropriate porosity and width as the airborne spray was captured within its canopy instead of deflecting up and over it. This article is protected by copyright. All rights reserved.

Influence of s-Triazines on Some Enzymes of Carbohydrates and Nitrogen Metabolism in Leaves of Pea (Pisum sativum L.) and Sweet Corn (Zea mays L.)

PubMed Central

Wu, M. T.; Singh, B.; Salunkhe, D. K.

1971-01-01

Foliar applications of 2 milligrams per liter of 2-chloro-4,6-bis (ethylamino)-s-triazine, 2-methylmercapto-4-ethylamino-6-isobutylamino-s-triazine, and 2-methoxy-4-isopropylamino-6-butylamino-s-triazine caused increases in the activities of starch phosphorylase, pyruvate kinase, cytochrome oxidase, and glutamate dehydrogenase 5, 10, and 15 days after treatment in the leaves of 3-week-old seedlings of pea (Pisum sativum L.) and sweet corn (Zea mays L.). The results indicate that sublethal concentrations of s-triazine compounds affect the physiological and biochemical events in plants which favor more utilization of carbohydrates for nitrate reduction and synthesis of amino acids and proteins. PMID:16657830

Defining the role of the MADS-box gene, Zea agamous like1, in maize domestication

USDA-ARS?s Scientific Manuscript database

Genomic scans for genes that show the signature of past selection have been widely applied to a number of species and have identified a large number of selection candidate genes. In cultivated maize (Zea mays ssp. mays) selection scans have identified several hundred candidate domestication genes...

Phosphorus-loaded biochar changes soil heavy metals availability and uptake potential of maize (Zea mays L.) plants.

PubMed

Ahmad, Munir; Usman, Adel R A; Al-Faraj, Abdullah S; Ahmad, Mahtab; Sallam, Abdelazeem; Al-Wabel, Mohammad I

2018-03-01

Biochar (BC) was produced by pyrolyzing the date palm leaf waste at 600 °C and then loaded with phosphorus (P) via sorption process. Greenhouse pot experiment was conducted to investigate the application effects of BC and P-loaded biochar (BCP) on growth and availability of P and heavy metals to maize (Zea mays L.) plants grown in contaminated mining soil. The treatments consisted of BC and BCP (at application rates of 5, 10, 20, and 30 g kg -1 of soil), recommended NK and NPK, and a control (no amendment). Sorption experiment showed that Langmuir predicted maximum P sorption capacity of BC was 13.71 mg g -1 . Applying BCP increased the soil available P, while BC and BCP significantly decreased the soil labile heavy metals compared to control. Likewise, heavy metals in exchangeable and reducible fractions were transformed to more stable fraction with BC and BCP applications. The highest application rate of BCP (3%) was most effective treatment in enhancing plant growth parameters (shoot and root lengths and dry matter) and uptake of P and heavy metals by 2-3 folds. However, based on metal uptake and phytoextraction indices, total heavy metals extraction by maize plants was very small for practical application. It could be concluded that using P-loaded biochar as a soil additive may be considered a promising tool to immobilize heavy metals in contaminated mining areas, while positive effects on the biomass growth of plants may assist the stabilization of contaminated areas affected by wind and water erosion. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of a new clinically applicable device for embryo evaluation which measures embryo oxygen consumption.

PubMed

Kurosawa, Hiroki; Utsunomiya, Hiroki; Shiga, Naomi; Takahashi, Aiko; Ihara, Motomasa; Ishibashi, Masumi; Nishimoto, Mitsuo; Watanabe, Zen; Abe, Hiroyuki; Kumagai, Jin; Terada, Yukihiro; Igarashi, Hideki; Takahashi, Toshifumi; Fukui, Atsushi; Suganuma, Ryota; Tachibana, Masahito; Yaegashi, Nobuo

2016-10-01

. Furthermore, the developed blastocysts were scored using the blastocyst quality score (BQS), and the correlation with oxygen consumption rate was also assessed. The device enabled the oxygen consumption rate of an embryo to be measured automatically within a minute. The oxygen concentration gradient profile showed excellent linearity in a distance-dependent change. A close correlation in the oxygen consumption rates of bovine embryos was observed between the SECM measuring system and CERMs, with a determination coefficient of 0.8203 (P = 0.0008). Oxygen consumption rates of human embryos that have reached the blastocyst stage were significantly higher than those of arrested embryos at 48, 72 and 96 h after thawing (P = 0.039, 0.004 and 0.049, respectively). Thus, in vitro development of frozen-thawed human embryos to the blastocyst stage would be predicted at 48 h after thawing (day 4) by measuring the oxygen consumption using CERMs. Although a positive linear relationship between BQS and the oxygen consumption rate was observed [the determination coefficient was R(2) = 0.6537 (P = 0.008)], two blastocysts exhibited low oxygen consumption rates considering their relatively high BQS. This suggests that morphology and metabolism in human embryos might not correlate consistently. Transfer of the embryo and pregnancy evaluation was not performed. Thus, a correlation between oxygen consumption and the in vivo viability of embryos remains unknown. Clinical trials, including embryo transfer, would be desirable to determine a threshold value to elect clinically relevant, quality embryos for transfer. We utilized frozen-thawed human embryos in this study. The effect of these manipulations on the respiratory activity of the embryo is also unknown. Selection of quality embryos, especially in a single embryo transfer cycle, by CERMs may have an impact on obtaining better clinical outcomes, albeit with clinical trials being required. Furthermore, the early determination of quality

Detection of the Entomopathogenic Fungus Beauveria bassiana in the Rhizosphere of Wound-Stressed Zea mays Plants

PubMed Central

McKinnon, Aimee C.; Glare, Travis R.; Ridgway, Hayley J.; Mendoza-Mendoza, Artemio; Holyoake, Andrew; Godsoe, William K.; Bufford, Jennifer L.

2018-01-01

Entomopathogenic fungi from the genus Beauveria (Vuillemin) play an important role in controlling insect populations and have been increasingly utilized for the biological control of insect pests. Various studies have reported that Beauveria bassiana (Bals.), Vuill. also has the ability to colonize a broad range of plant hosts as endophytes without causing disease but while still maintaining the capacity to infect insects. Beauveria is often applied as an inundative spore application, but little research has considered how plant colonization may alter the ability to persist in the environment. The aim of this study was to investigate potential interactions between B. bassiana and Zea mays L. (maize) in the rhizosphere following inoculation, in order to understand the factors that may affect environmental persistence of the fungi. The hypothesis was that different isolates of B. bassiana have the ability to colonize maize roots and/or rhizosphere soil, resulting in effects to the plant microbiome. To test this hypothesis, a two-step nested PCR protocol was developed to find and amplify Beauveria in planta or in soil; based on the translation elongation factor 1-alpha (ef1α) gene. The nested protocol was also designed to enable Beauveria species differentiation by sequence analysis. The impact of three selected B. bassiana isolates applied topically to roots on the rhizosphere soil community structure and function were consequently assessed using denaturing gradient gel electrophoresis (DGGE) and MicroRespTM techniques. The microbial community structure and function were not significantly affected by the presence of the isolates, however, retention of the inocula in the rhizosphere at 30 days after inoculation was enhanced when plants were subjected to intensive wounding of foliage to crudely simulate herbivory. The plant defense response likely changed under wound stress resulting in the apparent recruitment of Beauveria in the rhizosphere, which may be an indirect

Recovery of maize (Zea mays L.) inbreds and hybrids from chilling stress of various duration: photosynthesis and antioxidant enzymes.

PubMed

Holá, Dana; Kocová, Marie; Rothová, Olga; Wilhelmová, Nad'a; Benesová, Monika

2007-07-01

The differences between two maize (Zea mays L.) inbred lines and their F1 hybrids in their response to chilling periods of various duration (1, 2, 3 or 4 weeks) and subsequent return to optimum temperatures were analysed by the measurement of the photosystem (PS) 1 and 2 activity, the photosynthetic pigments' content and the activity of antioxidant enzymes. The PS2 activity and the chlorophyll content decreased in plants subjected to 3 or 4 weeks of chilling, but not in those subjected to 1 or 2 weeks of chilling. This decrease was more pronounced in inbreds compared to their hybrids. The activity of superoxide dismutase did not much change with the increasing length of chilling period in the inbreds but decreased in the hybrids, the glutathione reductase activity increased in both types of genotypes but more in the inbred lines, while for ascorbate peroxidase and catalase the changes in parents-hybrids relationship did not show any specific trend. The PS1 activity and the carotenoids' content was not much affected.

Leaching variations of heavy metals in chelator-assisted phytoextraction by Zea mays L. exposed to acid rainfall.

PubMed

Lu, Yayin; Luo, Dinggui; Liu, Lirong; Tan, Zicong; Lai, An; Liu, Guowei; Li, Junhui; Long, Jianyou; Huang, Xuexia; Chen, Yongheng

2017-11-01

Chelant-enhanced phytoextraction method has been put forward as an effective soil remediation method, whereas the heavy metal leaching could not be ignored. In this study, a cropping-leaching experiment, using soil columns, was applied to study the metal leaching variations during assisted phytoextraction of Cd- and Pb-polluted soils, using seedlings of Zea mays, applying three different chelators (EDTA, EDDS, and rhamnolipid), and artificial rainfall (acid rainfall or normal rainfall). It showed that artificial rainfall, especially artificial acid rain, after chelator application led to the increase of heavy metals in the leaching solution. EDTA increased both Cd and Pb concentrations in the leaching solution, obviously, whereas EDDS and rhamnolipid increased Cd concentration but not Pb. The amount of Cd and Pb decreased as the leaching solution increased, the patterns as well matched LRMs (linear regression models), with R-square (R 2 ) higher than 90 and 82% for Cd and Pb, respectively. The maximum cumulative Cd and Pb in the leaching solutions were 18.44 and 16.68%, respectively, which was amended by EDTA and acid rainwater (pH 4.5), and followed by EDDS (pH 4.5), EDDS (pH 6.5), rhamnolipid (0.5 g kg -1 soil, pH 4.5), and rhamnolipid (pH 6.5).

Potassium Management for Improving Growth and Grain Yield of Maize (Zea mays L.) under Moisture Stress Condition

PubMed Central

Amanullah; Iqbal, Asif; Irfanullah; Hidayat, Zeeshan

2016-01-01

Potassium (K) fertilizer management is beneficial for improving growth, yield and yield components of field crops under moisture stress condition in semiarid climates. Field experiments were conducted to study the response of maize (Zea mays L., cv. Azam) to foliar and soil applied K during summer 2013 and 2014. The experiments were carried out at the Agronomy Research Farm of The University of Agriculture Peshawar, Northwest Pakistan under limited irrigation (moisture stress) condition. It was concluded from the results that application of foliar K at the rate of 1–3% and foliar Zn at the rate of 0.1–0.2% was more beneficial in terms of better growth, higher yield and yield components of maize under moisture stress condition. Early spray (vegetative stage) resulted in better growth and higher yield than late spray (reproductive stage). Soil K treated plots (rest) plots performed better than control (K not applied) in terms of improved growth, higher yield and yield components of maize crop. The results further demonstrated that increasing the rate of soil applied K up to 90 kg P ha−1 in two equal splits (50% each at sowing and knee height) improve growth and maize productivity under semiarid climates. PMID:27694964

Potassium Management for Improving Growth and Grain Yield of Maize (Zea mays L.) under Moisture Stress Condition.

PubMed

Amanullah; Iqbal, Asif; Irfanullah; Hidayat, Zeeshan

2016-10-03

Potassium (K) fertilizer management is beneficial for improving growth, yield and yield components of field crops under moisture stress condition in semiarid climates. Field experiments were conducted to study the response of maize (Zea mays L., cv. Azam) to foliar and soil applied K during summer 2013 and 2014. The experiments were carried out at the Agronomy Research Farm of The University of Agriculture Peshawar, Northwest Pakistan under limited irrigation (moisture stress) condition. It was concluded from the results that application of foliar K at the rate of 1-3% and foliar Zn at the rate of 0.1-0.2% was more beneficial in terms of better growth, higher yield and yield components of maize under moisture stress condition. Early spray (vegetative stage) resulted in better growth and higher yield than late spray (reproductive stage). Soil K treated plots (rest) plots performed better than control (K not applied) in terms of improved growth, higher yield and yield components of maize crop. The results further demonstrated that increasing the rate of soil applied K up to 90 kg P ha -1 in two equal splits (50% each at sowing and knee height) improve growth and maize productivity under semiarid climates.

Comparative impact of genetically modified and non modified maize (Zea mays L.) on succeeding crop and associated weed.

PubMed

Ibrahim, Muhammad; Ahmed, Naseer; Ullah, Faizan; Shinwari, Zabta Khan; Bano, Asghari

2016-04-01

This research work documents the comparative impact of genetically modified (GM) (insect resistance) and non modified maize (Zea mays L.) on growth and germination of succeeding crop wheat (Triticum aestivum L.) and associated weed (Avena fatua L.). The aqueous extracts of both the GM and non-GM maize exhibited higher phenolic content than that of methanolic extracts. Germination percentage and germination index of wheat was significantly decreased by GM methanolic extract (10%) as well as that of non-GM maize at 3% aqueous extract. Similarly germination percentage of weed (Avena fatua L.) was significantly reduced by application of 3% and 5% methanolic GM extracts. All extracts of GM maize showed non-significant effect on the number of roots, root length and shoot length per plant but 5% and 10% methanolic extracts of non-GM maize significantly increased the number of roots per plant of wheat seedling. Similarly, 10% methanolic extract of GM maize significantly increased the number of roots per plant of weed seedling. Methanolic extracts of GM and non-GM maize (3% and 5%) significantly decreased the protease activity in wheat as compared to untreated control. © The Author(s) 2013.

Changes in the distribution of plastids and endoplasmic reticulum during cellular differentiation in root caps of Zea mays

NASA Technical Reports Server (NTRS)

Moore, R.; McClelen, C. E.

1985-01-01

In calyptrogen cells of Zea mays, proplastids are distributed randomly throughout the cell, and the endoplasmic reticulum (ER) is distributed parallel to the cell walls. The differentiation of calyptrogen cells into columella statocytes is characterized by the following sequential events: (1) formation of ER complexes at the distal and proximal ends of the cell, (2) differentiation of proplastids into amyloplasts, (3) sedimentation of amyloplasts onto the distal ER complex, (4) breakdown of the distal ER complex and sedimentation of amyloplasts to the bottom of the cell, and (5) formation of sheets of ER parallel to the longitudinal cell walls. Columella statocytes located in the centre of the cap each possess 4530 +/- 780 micrometers2 of ER surface area, an increase of 670 per cent over that of calyptrogen cells. The differentiation of peripheral cells correlates positively with (1) the ER becoming arranged in concentric sheets, (2) amyloplasts and ER becoming randomly distributed, and (3) a 280 per cent increase in ER surface area over that of columella statocytes. These results are discussed relative to graviperception and mucilage secretion, which are functions of columella and peripheral cells, respectively.

Embryo density and medium volume effects on early murine embryo development.

PubMed

Canseco, R S; Sparks, A E; Pearson, R E; Gwazdauskas, F C

1992-10-01

One-cell mouse embryos were used to determine the effects of drop size and number of embryos per drop for optimum development in vitro. Embryos were collected from immature C57BL6 female mice superovulated with pregnant mare serum gonadotropin and human chorionic gonadotropin and mated by CD1 males. Groups of 1, 5, 10, or 20 embryos were cultured in 5-, 10-, 20-, or 40-microliters drops of CZB under silicon oil at 37.5 degrees C in a humidified atmosphere of 5% CO2 and 95% air. Development score for embryos cultured in 10 microliters was higher than that of embryos cultured in 20 or 40 microliters. Embryos cultured in groups of 5, 10, or 20 had higher development scores than embryos cultured singly. The highest development score was obtained by the combination of 5 embryos per 10-microliters drop. The percentage of live embryos in 20 or 40 microliters was lower than that of embryos cultured in 10 microliters. Additionally, the percentage of live embryos cultured singly was lower than that of embryos cultured in groups. Our results suggest that a stimulatory interaction occurs among embryos possibly exerted through the secretion of growth factors. This effect can be diluted if the embryos are cultured in large drops or singly.

Effect of metal tolerant plant growth promoting bacteria on growth and metal accumulation in Zea mays plants grown in fly ash amended soil.

PubMed

Kumar, Kalpna V; Patra, D D

2013-01-01

The present study was undertaken to examine the effect of the application of fly ash (FA) into Garden soil (GS), with and without inoculation of plant growth promoting bacteria (PGPB), on the growth and metal uptake by Zea mays plants. Three FA tolerant PGPB strains, Pseudomonas sp. PS5, PS14, and Bacillus sp. BC29 were isolated from FA contaminated soils and assessed for their plant growth promoting features on the Z. mays plants. All three strains were also examined for their ability to solubilize phosphate and to produce Indole Acetic Acid (IAA), siderophores, and hydrogencynide acid (HCN) production. Although inoculation of all strains significantly enhanced the growth of plants at both the concentration of FA but maximum growth was observed in plants inoculated with BC29 and PS14 at low level (25%) of FA concentration. The experimental results explored the plant growth promoting features of selected strains which not only enhanced growth and biomass of plants but also protected them from toxicity of FA.

Growth and Deposition of Inorganic Nutrient Elements in Developing Leaves of Zea mays L. 1

PubMed Central

Meiri, Avraham; Silk, Wendy Kuhn; Läuchli, André

1992-01-01

Spatial distributions of growth and of the concentration of some inorganic nutrient elements were analyzed in developing leaves of maize (Zea mays L.). Growth was analyzed by pinprick experiments with numerical analysis to characterize fields of velocity and relative elemental elongation rate. Inductively coupled plasma and atomic emission spectroscopy were used to measure nutrients extracted from segments of leaf tissue collected by position. Leaves 7 and 8, both elongating 3 millimeters per hour had maximum relative elemental growth rates of 0.06 to 0.08 millimeters per hour with maximum rates 20 to 50 millimeters from the node and cessation of growth by 90 millimeters from the node. Spatial distribution of dry weight density revealed that the rate of biomass deposition was maximum in the most rapidly expanding region and continued beyond the elongation zone. The nutrient elements K, Cl, Ca, Mg, and P showed different distribution patterns of ion density (on a dry weight basis). K and Cl had minimal density in the leaf tips; K density was maximum in the growing region, whereas Cl density was maximum at the region of growth cessation. Ca, Mg, and P had relatively high densities at the base of the elongation zone near the node and also in the tip regions. Near the node, P and Mg densities were higher in the young, growing leaves, whereas Ca density near the node was higher in older leaves that had completed elongation. Deposition rates of all nutrients were greatest in the region of maximum elongation rate. PMID:16669027

Hydrogen sulfide enhances nitric oxide-induced tolerance of hypoxia in maize (Zea mays L.).

PubMed

Peng, Renyi; Bian, Zhiyuan; Zhou, Lina; Cheng, Wei; Hai, Na; Yang, Changquan; Yang, Tao; Wang, Xinyu; Wang, Chongying

2016-11-01

Our data present H 2 S in a new role, serving as a multi-faceted transducer to different response mechanisms during NO-induced acquisition of tolerance to flooding-induced hypoxia in maize seedling roots. Nitric oxide (NO), serving as a secondary messenger, modulates physiological processes in plants. Recently, hydrogen sulfide (H 2 S) has been demonstrated to have similar signaling functions. This study focused on the effects of treatment with H 2 S on NO-induced hypoxia tolerance in maize seedlings. The results showed that treatment with the NO donor sodium nitroprusside (SNP) enhanced survival rate of submerged maize roots through induced accumulation of endogenous H 2 S. The induced H 2 S then enhanced endogenous Ca 2+ levels as well as the Ca 2+ -dependent activity of alcohol dehydrogenase (ADH), improving the capacity for antioxidant defense and, ultimately, the hypoxia tolerance in maize seedlings. In addition, NO induced the activities of key enzymes in H 2 S biosynthesis, such as L-cysteine desulfhydrases (L-CDs), O-acetyl-L-serine (thiol)lyase (OAS-TL), and β-Cyanoalanine Synthase (CAS). SNP-induced hypoxia tolerance was enhanced by the application of NaHS, but was eliminated by the H 2 S-synthesis inhibitor hydroxylamine (HA) and the H 2 S-scavenger hypotaurine (HT). H 2 S concurrently enhanced the transcriptional levels of relative hypoxia-induced genes. Together, our findings indicated that H 2 S serves as a multi-faceted transducer that enhances the nitric oxide-induced hypoxia tolerance in maize (Zea mays L.).

Phytotoxic cyanamide affects maize (Zea mays) root growth and root tip function: from structure to gene expression.

PubMed

Soltys, Dorota; Rudzińska-Langwald, Anna; Kurek, Wojciech; Szajko, Katarzyna; Sliwinska, Elwira; Bogatek, Renata; Gniazdowska, Agnieszka

2014-05-01

Cyanamide (CA) is a phytotoxic compound produced by four Fabaceae species: hairy vetch, bird vetch, purple vetch and black locust. Its toxicity is due to complex activity that involves the modification of both cellular structures and physiological processes. To date, CA has been investigated mainly in dicot plants. The goal of this study was to investigate the effects of CA in the restriction of the root growth of maize (Zea mays), representing the monocot species. CA (3mM) reduced the number of border cells in the root tips of maize seedlings and degraded their protoplasts. However, CA did not induce any significant changes in the organelle structure of other root cells, apart from increased vacuolization. CA toxicity was also demonstrated by its effect on cell cycle activity, endoreduplication intensity, and modifications of cyclins CycA2, CycD2, and histone HisH3 gene expression. In contrast, the arrangement of microtubules was not altered by CA. Treatment of maize seedlings with CA did not completely arrest mitotic activity, although the frequency of dividing cells was reduced. Furthermore, prolonged CA treatment increased the proportion of endopolyploid cells in the root tip. Cytological malformations were accompanied by an induction of oxidative stress in root cells, which manifested as enhanced accumulation of H2O2. Exposure of maize seedlings to CA resulted in an increased concentration of auxin and stimulated ethylene emission. Taken together, these findings suggested that the inhibition of root growth by CA may be a consequence of stress-induced morphogenic responses. Copyright © 2014. Published by Elsevier GmbH.

Auxin as an inducer of asymmetrical division generating the subsidiary cells in stomatal complexes of Zea mays.

PubMed

Livanos, Pantelis; Giannoutsou, Eleni; Apostolakos, Panagiotis; Galatis, Basil

2015-01-01

The data presented in this work revealed that in Zea mays the exogenously added auxins indole-3-acetic acid (IAA) and 1-napthaleneacetic acid (NAA), promoted the establishment of subsidiary cell mother cell (SMC) polarity and the subsequent subsidiary cell formation, while treatment with auxin transport inhibitors 2,3,5-triiodobenzoic acid (TIBA) and 1-napthoxyacetic acid (NOA) specifically blocked SMC polarization and asymmetrical division. Furthermore, in young guard cell mother cells (GMCs) the PIN1 auxin efflux carriers were mainly localized in the transverse GMC faces, while in the advanced GMCs they appeared both in the transverse and the lateral ones adjacent to SMCs. Considering that phosphatidyl-inositol-3-kinase (PI3K) is an active component of auxin signal transduction and that phospholipid signaling contributes in the establishment of polarity, treatments with the specific inhibitor of the PI3K LY294002 were carried out. The presence of LY294002 suppressed polarization of SMCs and prevented their asymmetrical division, whereas combined treatment with exogenously added NAA and LY294002 restricted the promotional auxin influence on subsidiary cell formation. These findings support the view that auxin is involved in Z. mays subsidiary cell formation, probably functioning as inducer of the asymmetrical SMC division. Collectively, the results obtained from treatments with auxin transport inhibitors and the appearance of PIN1 proteins in the lateral GMC faces indicate a local transfer of auxin from GMCs to SMCs. Moreover, auxin signal transduction seems to be mediated by the catalytic function of PI3K.

Auxin as an inducer of asymmetrical division generating the subsidiary cells in stomatal complexes of Zea mays

PubMed Central

Livanos, Pantelis; Giannoutsou, Eleni; Apostolakos, Panagiotis; Galatis, Basil

2015-01-01

The data presented in this work revealed that in Zea mays the exogenously added auxins indole-3-acetic acid (IAA) and 1-napthaleneacetic acid (NAA), promoted the establishment of subsidiary cell mother cell (SMC) polarity and the subsequent subsidiary cell formation, while treatment with auxin transport inhibitors 2,3,5-triiodobenzoic acid (TIBA) and 1-napthoxyacetic acid (NOA) specifically blocked SMC polarization and asymmetrical division. Furthermore, in young guard cell mother cells (GMCs) the PIN1 auxin efflux carriers were mainly localized in the transverse GMC faces, while in the advanced GMCs they appeared both in the transverse and the lateral ones adjacent to SMCs. Considering that phosphatidyl-inositol-3-kinase (PI3K) is an active component of auxin signal transduction and that phospholipid signaling contributes in the establishment of polarity, treatments with the specific inhibitor of the PI3K LY294002 were carried out. The presence of LY294002 suppressed polarization of SMCs and prevented their asymmetrical division, whereas combined treatment with exogenously added NAA and LY294002 restricted the promotional auxin influence on subsidiary cell formation. These findings support the view that auxin is involved in Z. mays subsidiary cell formation, probably functioning as inducer of the asymmetrical SMC division. Collectively, the results obtained from treatments with auxin transport inhibitors and the appearance of PIN1 proteins in the lateral GMC faces indicate a local transfer of auxin from GMCs to SMCs. Moreover, auxin signal transduction seems to be mediated by the catalytic function of PI3K. PMID:25831267

"Zea"-Because It's There

NASA Astrophysics Data System (ADS)

Chamberlain, Eric

1983-03-01

The Subject is a long standing symbiotic relationship between Zea and the movies. As usual the impossible was required - to attain cinema release quality films with dramatic interpretation - at the same time using Hy-speed macro photographic techniques. The subject was not to be recognizable until the end of the film - some four minutes long. Zea is explosive, it reacts to heat and is extremely difficult to predict when it will explode, which left little time for the focus, stop down and shooting. Using a Hy-cam at 5,000 pictures per second - a 400 ft. roll of 7247 raw stock, left but a brief three seconds for synchronization. To add to the confusion, two co-directors, a cameraman, plus equipment, were jammed into a 2 x 2m space. To achieve reasonable resolution for theatrical showing, 400,000 foot/candles of light were needed. This was achieved. The film was edited and music from Vaughan Williams' "Fantasia" recorded at St. Martins-in-the-Fields, London was added. The result was sent to the Cannes Film Festival, where it was given the Jury Award.

Calcium ion dependency of ethylene production in segments of primary roots of Zea mays

NASA Technical Reports Server (NTRS)

Hasenstein, K. H.; Evans, M. L.

1986-01-01

We investigated the effect of Ca2+ on ethylene production in 2-cm long apical segments from primary roots of corn (Zea mays L., B73 x Missouri 17) seedlings. The seedlings were raised under different conditions of Ca2+ availability. Low-Ca and high-Ca seedlings were raised by soaking the grains and watering the seedlings with distilled water or 10 mM CaCl2, respectively. Segments from high-Ca roots produced more than twice as much ethylene as segments from low-Ca roots. Indoleacetic acid (IAA; 1 micromole) enhanced ethylene production in segments from both low-Ca and high-Ca roots but auxin-induced promotion of ethylene production was consistently higher in segments from high-Ca roots. Addition of 1-aminocyclopropane-1-carboxylic acid (ACC) to root segments from low-Ca seedlings doubled total ethylene production and the rate of production remained fairly constant during a 24 h period of monitoring. In segments from high-Ca seedlings ACC also increased total ethylene production but most of the ethylene was produced within the first 6 h. The data suggest that Ca2+ enhances the conversion of ACC to ethylene. The terminal 2 mm of the root tip were found to be especially important to ethylene biosynthesis by apical segments and, experiments using 45Ca2+ as tracer indicated that the apical 2 mm of the root is the region of strongest Ca2+ accumulation. Other cations such as Mn2+, Mg2+, and K+ could largely substitute for Ca2+. The significance of these findings is discussed with respect to recent evidence for gravity-induced Ca2+ redistribution and its relationship to the establishment of asymmetric growth during gravitropic curvature.

Zea mays iRS1563: A Comprehensive Genome-Scale Metabolic Reconstruction of Maize Metabolism

PubMed Central

Saha, Rajib; Suthers, Patrick F.; Maranas, Costas D.

2011-01-01

The scope and breadth of genome-scale metabolic reconstructions have continued to expand over the last decade. Herein, we introduce a genome-scale model for a plant with direct applications to food and bioenergy production (i.e., maize). Maize annotation is still underway, which introduces significant challenges in the association of metabolic functions to genes. The developed model is designed to meet rigorous standards on gene-protein-reaction (GPR) associations, elementally and charged balanced reactions and a biomass reaction abstracting the relative contribution of all biomass constituents. The metabolic network contains 1,563 genes and 1,825 metabolites involved in 1,985 reactions from primary and secondary maize metabolism. For approximately 42% of the reactions direct literature evidence for the participation of the reaction in maize was found. As many as 445 reactions and 369 metabolites are unique to the maize model compared to the AraGEM model for A. thaliana. 674 metabolites and 893 reactions are present in Zea mays iRS1563 that are not accounted for in maize C4GEM. All reactions are elementally and charged balanced and localized into six different compartments (i.e., cytoplasm, mitochondrion, plastid, peroxisome, vacuole and extracellular). GPR associations are also established based on the functional annotation information and homology prediction accounting for monofunctional, multifunctional and multimeric proteins, isozymes and protein complexes. We describe results from performing flux balance analysis under different physiological conditions, (i.e., photosynthesis, photorespiration and respiration) of a C4 plant and also explore model predictions against experimental observations for two naturally occurring mutants (i.e., bm1 and bm3). The developed model corresponds to the largest and more complete to-date effort at cataloguing metabolism for a plant species. PMID:21755001

Creating and selling embryos for "donation": ethical challenges.

PubMed

Klitzman, Robert; Sauer, Mark V

2015-02-01

The commercial creation and sale of embryos has begun, which poses a series of ethical questions that have received little scholarly attention. Some of the concerns that arise are similar to those posed by the sale of gametes, while other issues differ markedly. Questions emerge, first, regarding the rights of the unborn children and their ability to know their biological parents. Companies that create human embryos de novo may wish to keep gamete providers anonymous. Many of these offspring thus will never learn that their parents are not their biologic parents. Yet, such disclosures, regarding not only one but both of these biologic parents, may be important for these individuals; and a lack of this knowledge may impede their physical and psychological health. Second, questions surface regarding the fees that providers should charge for embryos and whether these amounts should vary based on the traits of 1 or both of the gamete donors. Some prospective parents may seek specific traits in a baby (eg, height or eye/hair coloring), which prompts the creation of embryos from 2 gamete donors who possess these characteristics. Third, ownership of embryos created without an advanced directive by patients poses dilemmas (eg, disposition of any remaining embryos). Fourth, guidelines do not yet exist to limit the number of embryos sold from each pair of gamete donors. Hence, unbeknownst to each other, full siblings could potentially meet, get married, and procreate. This discussion has several critical implications for future practice and professional education and policy. Patients with diseases associated with genetic tests may well ask obstetricians, gynecologists, and other physicians about these techniques and practices. Clinicians can refer such patients to assisted reproductive technology specialists; however, familiarity with the basic aspects of the issues and complexities involved could aid these providers and their patients Several of these issues can be

Trichostatin A (TSA) improves the development of rabbit-rabbit intraspecies cloned embryos, but not rabbit-human interspecies cloned embryos.

PubMed

Shi, Li-Hong; Miao, Yi-Liang; Ouyang, Ying-Chun; Huang, Jun-Cheng; Lei, Zi-Li; Yang, Ji-Wen; Han, Zhi-Ming; Song, Xiang-Fen; Sun, Qing-Yuan; Chen, Da-Yuan

2008-03-01

The interspecies somatic cell nuclear transfer (iSCNT) technique for therapeutic cloning gives great promise for treatment of many human diseases. However, the incomplete nuclear reprogramming and the low blastocyst rate of iSCNT are still big problems. Herein, we observed the effect of TSA on the development of rabbit-rabbit intraspecies and rabbit-human interspecies cloned embryos. After treatment with TSA for 6 hr during activation, we found that the blastocyst rate of rabbit-rabbit cloned embryos was more than two times higher than that of untreated embryos; however, the blastocyst rate of TSA-treated rabbit-human interspecies cloned embryos decreased. We also found evident time-dependent histone deacetylation-reacetylation changes in rabbit-rabbit cloned embryos, but not in rabbit-human cloned embryos from fusion to 6 hr after activation. Our results suggest that TSA-treatment does not improve blastocyst development of rabbit-human iSCNT embryos and that abnormal histone deacetylation-reacetylation changes in iSCNT embryos may account for their poor blastocyst development. (c) 2008 Wiley-Liss, Inc.

ZEA-TDMA: design and system level implementation of a TDMA protocol for anonymous wireless networks

NASA Astrophysics Data System (ADS)

Banerjee, Debasmit; Dong, Bo; Biswas, Subir

2013-05-01

Wireless sensor network used in military applications may be deployed in hostile environments, where privacy and security is of primary concern. This can lead to the formation of a trust-based sub-network among mutually-trusting nodes. However, designing a TDMA MAC protocol is very challenging in situations where such multiple sub-networks coexist, since TDMA protocols require node identity information for slot assignments. This paper introduces a novel distributed TDMA MAC protocol, ZEA-TDMA (Zero Exposure Anonymous TDMA), for anonymous wireless networks. ZEA-TDMA achieves slot allocation with strict anonymity constraints, i.e. without nodes having to exchange any identity revealing information. By using just the relative time of arrival of packets and a novel technique of wireless collision-detection and resolution for fixed packetsizes, ZEA-TDMA is able to achieve MAC slot-allocation which is described as follows. Initially, a newly joined node listens to its one-hop neighborhood channel usage and creates a slot allocation table based on its own relative time, and finally, selects a slot that is collision free within its one-hop neighborhood. The selected slot can however cause hidden collisions with a two-hop neighbor of the node. These collisions are resolved by a common neighbor of the colliding nodes, which first detects the collision, and then resolve them using an interrupt packet. ZEA-TDMA provides the following features: a) it is a TDMA protocol ideally suited for highly secure or strictly anonymous environments b) it can be used in heterogeneous environments where devices use different packet structures c) it does not require network time-synchronization, and d) it is insensitive to channel errors. We have implemented ZEA-TDMA on the MICA2 hardware platform running TinyOS and evaluated the protocol functionality and performance on a MICA2 test-bed.

Characterizing pathways by which gravitropic effectors could move from the root cap to the root of primary roots of Zea mays

NASA Technical Reports Server (NTRS)

Moore, R.; McClelen, C. E.

1989-01-01

Plasmodesmata linking the root cap and root in primary roots Zea mays are restricted to approx. 400 protodermal cells bordering approx. 110000 microns2 of the calyptrogen of the root cap. This area is less than 10% of the cross-sectional area of the root-tip at the cap junction. Therefore, gravitropic effectors moving from the root cap to the root can move symplastically only through a relatively small area in the centre of the root. Decapped roots are non-responsive to gravity. However, decapped roots whose caps are replaced immediately after decapping are strongly graviresponsive. Thus, gravicurvature occurs only when the root cap contacts the root, and symplastic continuity between the cap and root is not required for gravicurvature. Completely removing mucilage from the root tip renders the root non-responsive to gravity. Taken together, these data suggest that gravitropic effectors move apoplastically through mucilage from the cap to the root.

Salt stress differentially affects growth-mediating β-expansins in resistant and sensitive maize (Zea mays L.).

PubMed

Geilfus, Christoph-Martin; Zörb, Christian; Mühling, Karl H

2010-12-01

Salinity mainly reduces shoot growth by the inhibition of cell division and elongation. Expansins loosen plant cell walls. Moreover, the expression of some isoforms is clearly correlated with growth. Effects of salinity on β-expansin transcripts protein abundance were recently reported for different crop species. This study provides a broad analysis of the impact of an 8-day 100mM NaCl stress treatment on the mRNA expression of different maize (Zea mays L.) β-Expansin isoforms using real-time quantitative RT-PCR. The composite β-expansin protein expression was analyzed by western blotting using an anti-peptide antibody raised against a conserved 15-amino-acid region shared by vegetatively expressed β-expansin isoforms. For the first time, changes in β-expansin transcript and protein abundance have been analyzed together with the salinity-induced inhibition of shoot growth. A salt-resistant and a salt-sensitive cultivar were compared in order to elucidate physiological changes. Genotypic differences in the relative concentration of six β-expansin transcripts together with differences in the abundance β-expansin protein are shown in response NaCl stress. In salt-sensitive Lector, reduced β-expansin protein expression was found to correlate positively with reduced shoot growth under stress. A down-regulation of ZmExpB2, ZmExpB6, and ZmExpB8 transcripts possibly contribute to this decrease in protein abundance. In contrast, the maintenance of shoot growth in salt-resistant SR03 might be related to an unaffected abundance of growth-mediating β-expansin proteins in the shoot. Our data suggest that the up-regulation of ZmExpB2, ZmExpB6, and ZmExpB8 may sustain the stable expression of β-expansin protein under conditions of salt stress. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Elucidating the origin of chromosomal aberrations in IVF embryos by preimplantation genetic analysis.

PubMed

Frumkin, Tsvia; Malcov, Mira; Yaron, Yuval; Ben-Yosef, Dalit

2008-01-30

Preimplantation genetic screening (PGS) has been proposed as a method for improving success rates in patients with repeated IVF failures. This approach is based on the hypothesis that such failures are the result of aneuploid embryos. It has been suggested that FISH analysis of blastomeres removed from preimplantation embryos represent the chromosomal constitution of the entire embryo. However, it is not yet clear whether it also represents the chromosomal constitution of the implanted embryo. PGS reanalysis on day 5 of embryos designated as "aneuploid" on day 3 may demonstrate a high rate of mosaicism for chromosomal aberration. Some of these mosaic embryos are capable of developing into normal embryos by "self-correction". Others, however, may accumulate additional chromosomal anomalies. It is therefore concluded that the chromosomal constitution of a preimplantation embryo may evolve during early cleavages. Meiotic and post zygotic mitotic errors may account for these chromosomal aberrations. This review will focus on elucidating the origin of chromosomal changes during preimplantation embryo development by studying their chromosomal constitution at different stages.

Fumonisin B(1)-nonproducing strains of Fusarium verticillioides cause maize (Zea mays) ear infection and ear rot.

PubMed

Desjardins, A E; Plattner, R D

2000-11-01

Fumonisins are polyketide mycotoxins produced by Fusarium verticillioides (synonym F. moniliforme), a major pathogen of maize (Zea mays) worldwide. Most field strains produce high levels of fumonisin B(1) (FB(1)) and low levels of the less-oxygenated homologues FB(2) and FB(3), but fumonisin B(1)-nonproducing field strains have been obtained by natural variation. To test the role of various fumonisins in pathogenesis on maize under field conditions, one strain producing FB(1), FB(2), and FB(3), one strain producing only FB(2), one strain producing only FB(3), and one fumonisin-nonproducing strain were applied to ears via the silk channel and on seeds at planting. Disease severity on the harvested ears was evaluated by visible symptoms and by weight percent symptomatic kernels. Fumonisin levels in kernels were determined by high-performance liquid chromatography. The presence of the applied FB(1)-nonproducing strains in kernels was determined by analysis of recovered strains for fumonisin production and other traits. All three FB(1)-nonproducing strains were able to infect ears following either silk-channel application or seed application at planting and were as effective as the FB(1)-producing strain in causing ear rot following silk-channel application. These results indicate that production of FB(1), FB(2), or FB(3) is not required for F. verticillioides to cause maize ear infection and ear rot.

An economic assessment of embryo diagnostics (Dx) - the costs of introducing non-invasive embryo diagnostics into IVF standard treatment practices.

PubMed

Fugel, Hans-Joerg; Connolly, Mark; Nuijten, Mark

2014-10-09

New techniques in assessing oocytes and embryo quality are currently explored to improve pregnancy and delivery rates per embryo transfer. While a better understanding of embryo quality could help optimize the existing "in vitro fertilization" (IVF) therapy schemes, it is essential to address the economic viability of such technologies in the healthcare setting. An Embryo-Dx economic model was constructed to assess the cost-effectiveness of 3 different IVF strategies from a payer's perspective; it compares Embryo-Dx with single embryo transfer (SET) to elective single embryo transfer (eSET) and to double embryo transfer (DET) treatment practices. The introduction of a new non-invasive embryo technology (Embryo-Dx) associated with a cost up to €460 is cost-effective compared to eSET and DET based on the cost per live birth. The model assumed that Embryo-Dx will improve ongoing pregnancy rate/realize an absolute improvement in live births of 9% in this case. This study shows that improved embryo diagnosis combined with SET may have the potential to reduce the cost per live birth per couple treated in IVF treatment practices. The results of this study are likely more sensitive to changes in the ongoing pregnancy rate and consequently the live birth rate than the diagnosis costs. The introduction of a validated Embryo-Dx technology will further support a move towards increased eSET procedures in IVF clinical practice and vice versa.

Enzymic synthesis of indole-3-acetyl-1-O-beta-d-glucose. I. Partial purification and characterization of the enzyme from Zea mays

NASA Technical Reports Server (NTRS)

Leznicki, A. J.; Bandurski, R. S.

1988-01-01

The first enzyme-catalyzed reaction leading from indole-3-acetic acid (IAA) to the myo-inositol esters of IAA is the synthesis of indole-3-acetyl-1-O-beta-D-glucose from uridine-5'-diphosphoglucose (UDPG) and IAA. The reaction is catalyzed by the enzyme, UDPG-indol-3-ylacetyl glucosyl transferase (IAA-glucose-synthase). This work reports methods for the assay of the enzyme and for the extraction and partial purification of the enzyme from kernels of Zea mays sweet corn. The enzyme has an apparent molecular weight of 46,500 an isoelectric point of 5.5, and its pH optimum lies between 7.3 and 7.6. The enzyme is stable to storage at zero degrees but loses activity during column chromatographic procedures which can be restored only fractionally by addition of column eluates. The data suggest either multiple unknown cofactors or conformational changes leading to activity loss.

Timing embryo biopsy for PGD - before or after cryopreservation?

PubMed

Shinar, S; Kornecki, N; Schwartz, T; Mey-Raz, N; Amir, H; Almog, B; Shavit, T; Hasson, J

2016-09-01

Pre-implantation genetic diagnosis (PGD) is required in order to screen and diagnose embryos of patients at risk of having a genetically affected offspring. A biopsy to diagnose the genetic profile of the embryo may be performed either before or after cryopreservation. The aim of this study was to determine which biopsy timing yields higher embryo survival rates. Retrospective cohort study of all PGD patients in a public IVF unit between 2010 and 2013. Inclusion criteria were patients with good-quality embryos available for cryopreservation by the slow freezing method. Embryos were divided into two groups: biopsy before and biopsy after cryopreservation. The primary outcome was embryo survival rates post thawing. Sixty-five patients met inclusion criteria. 145 embryos were biopsied before cryopreservation and 228 embryos were cryopreserved and biopsied after thawing. Embryo survival was significantly greater in the latter group (77% vs. 68%, p < 0.0001). Cryopreservation preceding biopsy results in better embryo survival compared to biopsy before cryopreservation.

Occultifur kilbournensis f.a. sp. nov., a new member of the Cystobasidiales associated with maize (Zea mays) cultivation.

PubMed

Kurtzman, Cletus P; Robnett, Christie J

2015-05-01

During a study of microorganisms associated with maize (Zea mays) cultivation, yeasts were isolated from overwintered stalks, cobs and surrounding soil, which were collected from an agricultural field in south-central Illinois, USA. Predominant among isolates were two species of Cryptococcus (Cr. flavescens, Cr. magnus) and a red yeast that D1/D2 LSU rRNA gene sequences revealed to be a new species of the basidiomycete yeast genus Occultifur. The species, which was not detected in the same field during the growing season, is described here as Occultifur kilbournensis (MycoBank number MB 811259; type strain NRRL Y-63695, CBS 13982, GenBank numbers, D1/D2 LSU rRNA gene, KP413160, ITS, KP413162; allotype strain NRRL Y-63699, CBS 13983). Mixture of the type and allotype strains resulted in formation of hyphae with clamp connections and a small number of apparent basidia following incubation on 5% malt extract agar at 15 °C for 2 months. In view of the uncertainty of the life cycle, the new species is being designated as forma asexualis. From analysis of D1/D2 and ITS nucleotide sequences, the new species is most closely related to Occultifur externus.

Phosphorus and Compost Management Influence Maize (Zea mays) Productivity Under Semiarid Condition with and without Phosphate Solubilizing Bacteria.

PubMed

Amanullah; Khan, Adil

2015-01-01

Phosphorus (P) unavailability and lack of organic matter in the soils under semiarid climates are the two major constraints for low crop productivity. Field trial was conducted to study the effects of P levels, compost application times and seed inoculation with phosphate solubilizing bacteria (PSB) on the yield and yield components of maize (Zea mays L., cv. Azam). The experiment was conducted at the Agronomy Research Farm of The University of Agriculture Peshawar-Pakistan during summer 2014. The experiment was laid out in randomized complete block design with split plot arrangement using three replications. The two PSB levels [(1) inoculated seed with PSB (+) and (2) seed not inoculated with PSB (- or control)] and three compost application times (30, 15, and 0 days before sowing) combination (six treatments) were used as main plot factor, while four P levels (25, 50, 75, and 100 kg P ha(-1)) used as subplot factor. The results confirmed that compost applied at sowing time and P applied at the two higher rates (75 and 100 kg P ha(-1)) had significantly increased yield and yield components of maize under semiarid condition. Maize seed inoculated with PSB (+) had tremendously increased yield and yield components of maize over PSB-control plots (-) under semiarid condition.

Phosphorus and Compost Management Influence Maize (Zea mays) Productivity Under Semiarid Condition with and without Phosphate Solubilizing Bacteria

PubMed Central

Amanullah

2015-01-01

Phosphorus (P) unavailability and lack of organic matter in the soils under semiarid climates are the two major constraints for low crop productivity. Field trial was conducted to study the effects of P levels, compost application times and seed inoculation with phosphate solubilizing bacteria (PSB) on the yield and yield components of maize (Zea mays L., cv. Azam). The experiment was conducted at the Agronomy Research Farm of The University of Agriculture Peshawar-Pakistan during summer 2014. The experiment was laid out in randomized complete block design with split plot arrangement using three replications. The two PSB levels [(1) inoculated seed with PSB (+) and (2) seed not inoculated with PSB (- or control)] and three compost application times (30, 15, and 0 days before sowing) combination (six treatments) were used as main plot factor, while four P levels (25, 50, 75, and 100 kg P ha-1) used as subplot factor. The results confirmed that compost applied at sowing time and P applied at the two higher rates (75 and 100 kg P ha-1) had significantly increased yield and yield components of maize under semiarid condition. Maize seed inoculated with PSB (+) had tremendously increased yield and yield components of maize over PSB-control plots (-) under semiarid condition. PMID:26697038

Using in situ pore water concentrations to estimate the phytotoxicity of nicosulfuron in soils to corn (Zea mays L.).

PubMed

Liu, Kailin; Cao, Zhengya; Pan, Xiong; Yu, Yunlong

2012-08-01

The phytotoxicity of an herbicide in soil is typically dependent on the soil characteristics. To obtain a comparable value of the concentration that inhibits growth by 50% (IC50), 0.01 M CaCl(2) , excess pore water (EPW) and in situ pore water (IPW) were used to extract the bioavailable fraction of nicosulfuron from five different soils to estimate the nicosulfuron phytotoxicity to corn (Zea mays L.). The results indicated that the phytotoxicity of nicosulfuron in soils to corn depended on the soil type, and the IC50 values calculated based on the amended concentration of nicosulfuron ranged from 0.77 to 9.77 mg/kg among the five tested soils. The range of variation in IC50 values for nicosulfuron was smaller when the concentrations of nicosulfuron extracted with 0.01 M CaCl(2) and EPW were used instead of the amended concentration. No significant difference was observed among the IC50 values calculated from the IPW concentrations of nicosulfuron in the five tested soils, suggesting that the concentration of nicosulfuron in IPW could be used to estimate the phytotoxicity of residual nicosulfuron in soils. Copyright © 2012 SETAC.

Effect of Microbial inoculation in combating the aluminium toxicity effect on growth of Zea mays.

PubMed

Arora, P; Singh, G; Tiwari, A

2017-07-31

The present study is aimed at improving the aluminium tolerance in maize crop employing the potential of microbial inoculants in conferring resistance to these toxicities via production of certain chelating compounds like siderophores, exopolysachharides and organic acids. Acid soils have now-a-days become one of the key factors for limiting growth of many agriculturally important crops. Aluminium  is one of the major elements present in acid soils and is mainly responsible for toxicity in the soil. This aluminium is rapidly soluble in soil water and hence absorbed by plant roots under conditions where soil pH is below 5. This toxicity leads to severe root growth inhibition, thereby limiting the production of maize crops. It was observed that use of microbial inoculums can be helpful in elimination of these toxic compounds and prevent the inhibition of root growth . It was found that the soils contaminated with aluminium toxicity decreased the root length of maize plant significantly by 65% but Bacillus and Burkholderia inoculation increased this root length significantly by 1.4- folds and 2- folds respectively thereby combating the effect of aluminium toxicity. Aluminium concentration was found maximum in roots of plants which were grown under aluminium stress condition. But this aluminium accumulation decreased ̴ 2-folds when Burkholderia was used as seed inoculants under aluminium stress conditions. Also, at 60mM aluminium accumulation, phosphorus solubilisation in roots was found to be increased upto 30% on Burkholderia inoculation. However, Bacillus inoculation didn't show any significant difference in either of the case. Thus, the inoculation of seeds with Burkholderia isolates could prove to be a boon in sequestering aluminium toxicity in Zea mays.

In vitro culture of individual mouse preimplantation embryos: the role of embryo density, microwells, oxygen, timing and conditioned media.

PubMed

Kelley, Rebecca L; Gardner, David K

2017-05-01

Single embryo culture is suboptimal compared with group culture, but necessary for embryo monitoring, and culture systems should be improved for single embryos. Pronucleate mouse embryos were used to assess the effect of culture conditions on single embryo development. Single culture either before or after compaction reduced cell numbers (112.2 ± 3.1; 110.2 ± 3.5) compared with group culture throughout (127.0 ± 3.4; P < 0.05). Reduction of media volume from 20 µl to 2 µl increased blastocyst cell numbers in single embryos cultured in 5% oxygen (84.4 ± 3.2 versus 97.8 ± 2.8; P < 0.05), but not in 20% oxygen (55.2 ± 2.9 versus 57.1 ± 2.8). Culture in microwell plates for the EmbryoScope and Primo Vision time-lapse systems changed cleavage timings and increased inner cell mass cell number (24.1 ± 1.0; 23.4 ± 1.2) compared with a 2 µl microdrop (18.4 ± 1.0; P < 0.05). Addition of embryo-conditioned media to single embryos increased hatching rate and blastocyst cell number (91.5 ± 4.7 versus 113.1 ± 4.4; P < 0.01). Single culture before or after compaction is therefore detrimental; oxygen, media volume and microwells influence single embryo development; and embryo-conditioned media may substitute for group culture. Copyright © 2017 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

A Technique for Facile and Precise Transfer of Mouse Embryos

PubMed Central

Sarvari, Ali; Naderi, Mohammad Mehdi; Sadeghi, Mohammad Reza; Akhondi, Mohammad Mehdi

2013-01-01

Background Successful Embryo Transfer (ET) technique is a fateful step of all efforts to achieve live births from in vitro produced embryos in assisted reproductive techniques or in knockout, transgenic or cloned animal projects. Small reproductive tract of mice and limitation of current techniques may not well satisfy the requirements for mass production of genetically modified mice. Genetic abnormalities of embryos, receptivity and uterine contractions, expulsion of embryos, blood, mucus or bacterial contamination on the transfer pipette tip, technical problems and even animal strain may affect embryo transfer outcome. Methods In this study, two techniques of embryo transfer in mice were compared. In conventional technique the oviduct wall was punctured with a 30-gauge needle and the loaded Pasteur pipette with embryos and medium was inserted into the hole. In new technique, embryos that were loaded in modified micropipette with minimal medium were transferred directly to the oviduct by manual piston micro-pump easily. Embryo viability was evaluated considering the percentage of live healthy newborns. Results Results of the two techniques were compared by t-test within the NPAR1WAY procedure of SAS software (ver. 9.2). The average live birth rates in the novel methods was significantly higher (42.4%) than the conventional method (21.7%, p<0.05). Conclusion In conclusion, using new embryo transfer technique improved birth rate by preventing embryos expulsion from the oviduct, saving time and easy transfer of embryos with minimum volume of medium. PMID:23626878

Heterosis-associated proteome analyses of maize (Zea mays L.) seminal roots by quantitative label-free LC-MS.

PubMed

Marcon, Caroline; Lamkemeyer, Tobias; Malik, Waqas Ahmed; Ungrue, Denise; Piepho, Hans-Peter; Hochholdinger, Frank

2013-11-20

Heterosis is the superior performance of heterozygous F1-hybrid plants compared to their homozygous genetically distinct parents. Seminal roots are embryonic roots that play an important role during early maize (Zea mays L.) seedling development. In the present study the most abundant soluble proteins of 2-4cm seminal roots of the reciprocal maize F1-hybrids B73×Mo17 and Mo17×B73 and their parental inbred lines B73 and Mo17 were quantified by label-free LC-MS/MS. In total, 1918 proteins were detected by this shot-gun approach. Among those, 970 were represented by at least two peptides and were further analyzed. Eighty-five proteins displayed non-additive accumulation in at least one hybrid. The functional category protein metabolism was the most abundant class of non-additive proteins represented by 27 proteins. Within this category 16 of 17 non-additively accumulated ribosomal proteins showed high or above high parent expression in seminal roots. These results imply that an increased protein synthesis rate in hybrids might be related to the early manifestation of hybrid vigor in seminal roots. In the present study a shot-gun proteomics approach allowed for the identification of 1917 proteins and analysis of 970 seminal root proteins of maize that were represented by at least 2 peptides. The comparison of proteome complexity of reciprocal hybrids and their parental inbred lines indicates an increased protein synthesis rate in hybrids that may contribute to the early manifestation of heterosis in seminal roots. This article is part of a Special Issue entitled: Translational Plant Proteomics. Copyright © 2013 Elsevier B.V. All rights reserved.

Impacts of industrial waste resources on maize (Zea mays L.) growth, yield, nutrients uptake and soil properties.

PubMed

Singh, Satnam; Young, Li-Sen; Shen, Fo-Ting; Young, Chiu-Chung

2014-10-01

Discharging untreated highly acidic (pH<4.0), organic and nutrients rich monosodium glutamate wastewater (MW), and highly alkaline (pH>10.0) paper-mill wastewater (PW) causes environmental pollution. When acidity of MW neutralized (pH 6.5±0.1) with PW and lime (treatments represented as MW+PW and MW+Lime), then MW may be utilized as a potential source of nutrients and organic carbon for sustainable food production. Objectives of this study were to compare the effects of PW and lime neutralized MW and chemical fertilizers on maize (Zea mays L. cv. Snow Jean) plant growth, yield, nutrients uptake, soil organic matter and humic substances. The field experiment was carried out on maize using MW at 6000 L ha(-1). Impacts of the MW application on maize crop and soil properties were evaluated at different stages. At harvest, plant height, and plant N and K uptake were higher in MW treatment. Leaf area index at 60 days after sowing, plant dry matter accumulation at harvest, and kernels ear(-1) and 100-kernel weight were higher in MW+Lime treatment. Kernel N, P, K, Mn, Fe and Zn, and plant Zn uptake were highest in MW+Lime. Plant Fe uptake, and soil organic matter and humic substances were highest in MW+PW. The MW+PW and MW+Lime treatments exhibited comparable results with chemically fertilized treatment. The MW acidity neutralized with lime showed positive impacts on growth, yield and nutrients uptake; nevertheless, when MW pH neutralized with PW has an additional benefit on increase in soil organic matter and humic substances. Copyright © 2014. Published by Elsevier Ltd.

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.

Heterogeneous nuclear ribonucleoprotein C1 may control miR-30d levels in endometrial exosomes affecting early embryo implantation.

PubMed

Balaguer, N; Moreno, I; Herrero, M; González, M; Simón, C; Vilella, F

2018-05-29

as a model of hEECs in silencing experiments due to the low survival rates of primary hEECs after transfection. The data show that hnRNPC1 may be involved in the internalization of miR-30d inside Exosomes. The decreased rates of embryo adhesion in endometrial epithelial-like cells transiently silenced with sihnRNPC1evidence that hnRNPC1 could be an important player in the maternal-embryo communication established in the early stages of implantation. This work was supported by the Miguel Servet Program Type I of Instituto de Salud Carlos III [CP13/00038]; FIS project [PI14/00545] to FV; the 'Atracció de Talent' Program from VLC-CAMPUS [UV-INV-PREDOC14-178329 to NB]; a Torres-Quevedo grant (PTQ-13-06133) by the Spanish Ministry of Economy and Competitiveness to IM; and MINECO/FEDER Grant [SAF2015-67154-R] to CS. The authors declare there is no conflict of interest.

Long-Term Empirical and Observational Evidence of Practical Helicoverpa zea Resistance to Cotton With Pyramided Bt Toxins.

PubMed

Reisig, Dominic D; Huseth, Anders S; Bacheler, Jack S; Aghaee, Mohammad-Amir; Braswell, Lewis; Burrack, Hannah J; Flanders, Kathy; Greene, Jeremy K; Herbert, D Ames; Jacobson, Alana; Paula-Moraes, Silvana V; Roberts, Phillip; Taylor, Sally V

2018-04-16

Evidence of practical resistance of Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) to Bt cotton in the United States is debatable, supported with occasional reports of boll damage in the field. Our objective was to provide both empirical and long-term observational evidence of practical resistance by linking both in-season and end-of-season measurements of H. zea damage to pyramided Bt cotton bolls and to provide Cry1Ac diet-based bioassay data in support of these damage estimates. In-season boll damage from H. zea was highly correlated to end-of-season damaged bolls. Across North Carolina, Bt cotton fields with end-of-season bolls damaged by H. zea increased during 2016 compared to previous years. Elevated damage was coupled with an increase in field sprays targeting H. zea during 2016, but not related to an increase in H. zea abundance. Bioassay data indicated that there was a range of Cry1Ac susceptibility across the southeastern United States. Given the range of susceptibility to Cry1Ac across the southeastern United States, it is probable that resistant populations are common. Since H. zea is resistant to cotton expressing pyramided Cry toxins, the adoption of new cotton varieties expressing Vip3Aa will be rapid. Efforts should be made to delay resistance of H. zea to the Vip3Aa toxin to avoid foliar insecticide use.

The solute specificity profiles of nucleobase cation symporter 1 (NCS1) from Zea mays and Setaria viridis illustrate functional flexibility.

PubMed

Rapp, Micah; Schein, Jessica; Hunt, Kevin A; Nalam, Vamsi; Mourad, George S; Schultes, Neil P

2016-03-01

The solute specificity profiles (transport and binding) for the nucleobase cation symporter 1 (NCS1) proteins, from the closely related C4 grasses Zea mays and Setaria viridis, differ from that of Arabidopsis thaliana and Chlamydomonas reinhardtii NCS1. Solute specificity profiles for NCS1 from Z. mays (ZmNCS1) and S. viridis (SvNCS1) were determined through heterologous complementation studies in NCS1-deficient Saccharomyces cerevisiae strains. The four Viridiplantae NCS1 proteins transport the purines adenine and guanine, but unlike the dicot and algal NCS1, grass NCS1 proteins fail to transport the pyrimidine uracil. Despite the high level of amino acid sequence similarity, ZmNCS1 and SvNCS1 display distinct solute transport and recognition profiles. SvNCS1 transports adenine, guanine, hypoxanthine, cytosine, and allantoin and competitively binds xanthine and uric acid. ZmNCS1 transports adenine, guanine, and cytosine and competitively binds, 5-fluorocytosine, hypoxanthine, xanthine, and uric acid. The differences in grass NCS1 profiles are due to a limited number of amino acid alterations. These amino acid residues do not correspond to amino acids essential for overall solute and cation binding or solute transport, as previously identified in bacterial and fungal NCS1, but rather may represent residues involved in subtle solute discrimination. The data presented here reveal that within Viridiplantae, NCS1 proteins transport a broad range of nucleobase compounds and that the solute specificity profile varies with species.

Production and Characterization of Bacillus thuringiensis Cry1Ac-Resistant Cotton Bollworm Helicoverpa zea (Boddie)▿

PubMed Central

Anilkumar, Konasale J.; Rodrigo-Simón, Ana; Ferré, Juan; Pusztai-Carey, Marianne; Sivasupramaniam, Sakuntala; Moar, William J.

2008-01-01

Laboratory-selected Bacillus thuringiensis-resistant colonies are important tools for elucidating B. thuringiensis resistance mechanisms. However, cotton bollworm, Helicoverpa zea, a target pest of transgenic corn and cotton expressing B. thuringiensis Cry1Ac (Bt corn and cotton), has proven difficult to select for stable resistance. Two populations of H. zea (AR and MR), resistant to the B. thuringiensis protein found in all commercial Bt cotton varieties (Cry1Ac), were established by selection with Cry1Ac activated toxin (AR) or MVP II (MR). Cry1Ac toxin reflects the form ingested by H. zea when feeding on Bt cotton, whereas MVP II is a Cry1Ac formulation used for resistance selection and monitoring. The resistance ratio (RR) for AR exceeded 100-fold after 11 generations and has been maintained at this level for nine generations. This is the first report of stable Cry1Ac resistance in H. zea. MR crashed after 11 generations, reaching only an RR of 12. AR was only partially cross-resistant to MVP II, suggesting that MVP II does not have the same Cry1Ac selection pressure as Cry1Ac toxin against H. zea and that proteases may be involved with resistance. AR was highly cross-resistant to Cry1Ab toxin but only slightly cross-resistant to Cry1Ab expressing corn leaf powder. AR was not cross-resistant to Cry2Aa2, Cry2Ab2-expressing corn leaf powder, Vip3A, and cypermethrin. Toxin-binding assays showed no significant differences, indicating that resistance was not linked to a reduction in binding. These results aid in understanding why this pest has not evolved B. thuringiensis resistance, and highlight the need to choose carefully the form of B. thuringiensis protein used in experiments. PMID:18024681

Expression of Foreign Genes Demonstrates the Effectiveness of Pollen-Mediated Transformation in Zea mays.

PubMed

Yang, Liyan; Cui, Guimei; Wang, Yixue; Hao, Yaoshan; Du, Jianzhong; Zhang, Hongmei; Wang, Changbiao; Zhang, Huanhuan; Wu, Shu-Biao; Sun, Yi

2017-01-01

Plant genetic transformation has arguably been the core of plant improvement in recent decades. Efforts have been made to develop in planta transformation systems due to the limitations present in the tissue-culture-based methods. Herein, we report an improved in planta transformation system, and provide the evidence of reporter gene expression in pollen tube, embryos and stable transgenicity of the plants following pollen-mediated plant transformation with optimized sonication treatment of pollen. The results showed that the aeration at 4°C treatment of pollen grains in sucrose prior to sonication significantly improved the pollen viability leading to improved kernel set and transformation efficiency. Scanning electron microscopy observation revealed that the removal of operculum covering pollen pore by ultrasonication might be one of the reasons for the pollen grains to become competent for transformation. Evidences have shown that the eGfp gene was expressed in the pollen tube and embryos, and the Cry1Ac gene was detected in the subsequent T 1 and T 2 progenies, suggesting the successful transfer of the foreign genes to the recipient plants. The Southern blot analysis of Cry1Ac gene in T 2 progenies and PCR-identified Apr gene segregation in T 2 seedlings confirmed the stable inheritance of the transgene. The outcome illustrated that the pollen-mediated genetic transformation system can be widely applied in the plant improvement programs with apparent advantages over tissue-culture-based transformation methods.

Genome-wide identification, splicing, and expression analysis of the myosin gene family in maize (Zea mays)

PubMed Central

Wang, Guifeng; Zhong, Mingyu; Wang, Gang; Song, Rentao

2014-01-01

The actin-based myosin system is essential for the organization and dynamics of the endomembrane system and transport network in plant cells. Plants harbour two unique myosin groups, class VIII and class XI, and the latter is structurally and functionally analogous to the animal and fungal class V myosin. Little is known about myosins in grass, even though grass includes several agronomically important cereal crops. Here, we identified 14 myosin genes from the genome of maize (Zea mays). The relatively larger sizes of maize myosin genes are due to their much longer introns, which are abundant in transposable elements. Phylogenetic analysis indicated that maize myosin genes could be classified into class VIII and class XI, with three and 11 members, respectively. Apart from subgroup XI-F, the remaining subgroups were duplicated at least in one analysed lineage, and the duplication events occurred more extensively in Arabidopsis than in maize. Only two pairs of maize myosins were generated from segmental duplication. Expression analysis revealed that most maize myosin genes were expressed universally, whereas a few members (XI-1, -6, and -11) showed an anther-specific pattern, and many underwent extensive alternative splicing. We also found a short transcript at the O1 locus, which conceptually encoded a headless myosin that most likely functions at the transcriptional level rather than via a dominant-negative mechanism at the translational level. Together, these data provide significant insights into the evolutionary and functional characterization of maize myosin genes that could transfer to the identification and application of homologous myosins of other grasses. PMID:24363426

Disruption of actin filaments in Zea mays by bisphenol A depends on their crosstalk with microtubules.

PubMed

Stavropoulou, Konstantina; Adamakis, Ioannis-Dimosthenis S; Panteris, Emmanuel; Arseni, Ermioni-Makedonia; Eleftheriou, Eleftherios P

2018-03-01

Bisphenol A (BPA) is a widespread environmental pollutant, reportedly harmful to living organisms. In plant cells, BPA was shown to disrupt microtubule (MT) arrays and perturb mitosis, but its effects on filamentous actin (F-actin) have not been explored. Here we studied the effects of BPA on actin filaments (AFs) in meristematic root tip and leaf cells of Zea mays, by fluorescent labeling and confocal microscopy. Considering the typical dynamic interaction between MTs and AFs, the effects on these two essential components of the plant cytoskeleton were correlated. It was found that BPA disorganized rapidly AFs in a concentration- and time-dependent manner. The fine filaments were first to be affected, followed by the subcortical bundles, resulting in rod- and ring-like conformations. The observed differences in sensitivity between protodermal and cortex cells were attributed to the deeper location of the latter. Depolymerization or stabilization of MTs by relevant drugs (oryzalin, taxol) revealed that AF susceptibility to BPA depends on MT integrity. Developing leaves required harder and longer treatment to be affected by BPA. Ontogenesis of stomatal complexes was highly disturbed, arrangement of AFs and MT arrays was disordered and accuracy of cell division sequence was deranged or completely arrested. The effect of BPA confirmed that subsidiary cell mother cell polarization is not mediated by F-actin patch neither of preprophase band organization. On the overall, it is concluded that AFs in plant cells constitute a subcellular target of BPA and their disruption depends on their crosstalk with MTs. Copyright © 2017 Elsevier Ltd. All rights reserved.

In vivo dynamic analysis of water refilling in embolized xylem vessels of intact Zea mays leaves

PubMed Central

Ryu, Jeongeun; Hwang, Bae Geun; Lee, Sang Joon

2016-01-01

Background and Aims The refilling of embolized xylem vessels under tension is a major issue in water transport among vascular plants. However, xylem embolism and refilling remain poorly understood because of technical limitations. Direct observation of embolism repair in intact plants is essential to understand the biophysical aspects of water refilling in embolized xylem vessels. This paper reports on details of the water refilling process in leaves of the intact herbaceous monocot plant Zea mays and its refilling kinetics obtained by a direct visualization technique. Methods A synchrotron X-ray micro-imaging technique was used to monitor water refilling in embolized xylem vessels of intact maize leaves. Xylem embolism was artificially induced by using a glass capillary; real-time images of water refilling dynamics were consecutively captured at a frame rate of 50 f.p.s. Key Results Water supply in the radial direction initiates droplet formation on the wall of embolized xylem vessels. Each droplet grows into a water column; this phenomenon shows translation motion or continuous increase in water column volume. In some instances, water columns merge and form one large water column. Water refilling in the radial direction causes rapid recovery from embolism in several minutes. The average water refilling velocity is approx. 1 μm s−1. Conclusions Non-destructive visualization of embolized xylem vessels demonstrates rapid water refilling and gas bubble removal as key elements of embolism repair in a herbaceous monocot species. The refilling kinetics provides new insights into the dynamic mechanism of water refilling phenomena. PMID:27539601

Successful pregnancies from vitrified embryos in the dromedary camel: Avoidance of a possible toxic effect of sucrose on embryos.

PubMed

Herrid, M; Billah, M; Skidmore, J A

2017-12-01

Successful embryo cryopreservation facilitates the wider application of assisted reproduction technologies and also provides a useful method for gene banking of valuable genetics. Unfortunately attempts to establish an effective cryopreservation protocol for camelid embryos have been unsuccessful. In the current study, a modified vitrification protocol with three steps was investigated, whereby embryos were exposed to solutions containing increasing amounts of glycerol and ethylene glycol for fixed time periods. Embryos were then loaded into an Open Pull Straw (OPS) and plunged directly into liquid nitrogen for storage. Three experiments were designed to investigate the effect of 1) artificial shrinkage (AS) of embryos, 2) the addition of sucrose to the vitrification solutions, and 3) the replacement of sucrose by galactose in the warming solution, on the outcome of vitrification. The results showed that neither AS of hatched embryos prior to vitrification, nor the addition of sucrose into vitrification solutions improves the outcome of vitrification, while replacement of sucrose with galactose in warming solution increases the survival and developmental rates of vitrified embryos in culture. Transfer of vitrified embryos that were warmed in galactose resulted in a pregnancy rate of 42.8% per embryo or 46.1% per recipient. Collectively, these results suggest a possible species-specific toxic effect of sucrose on camel embryos, and that avoiding its use either in vitrification or warming solution is critical for establishing an effective protocol. This study may also be applicable to the vitrification of embryos of other camelid species including alpaca and llamas. Copyright © 2017 Elsevier B.V. All rights reserved.

Creating and Selling Embryos for “Donation”: Ethical Challenges

PubMed Central

Klitzman, Robert; Sauer, Mark V.

2015-01-01

The commercial creation and sale of embryos has begun, posing a series of ethical questions that have received little scholarly attention. Some of the concerns that arise are similar to those posed by the sale of gametes, while other issues differ markedly. Questions emerge, firstly, regarding the rights of the unborn children – their ability to know their biological parents. Companies that create human embryos de novo may wish to keep gamete providers anonymous. Many of these offspring will thus never learn that their parents are not their biological parents. Yet, such disclosures – regarding not only one, but both of these biological parents – may be important for these individuals; and lack of this knowledge may impede their physical and psychological health. Secondly, questions surface regarding the fees that providers should charge for embryos, and whether these amounts should vary based on the traits of one or both of the gamete donors. Some prospective parents may seek specific traits in a baby (e.g., height or eye/hair coloring), prompting creation of embryos from two gamete donors who possess these characteristics. Thirdly, ownership of embryos created without an advanced directive by patients poses dilemmas – e.g., disposition of any remaining embryos. Fourthly, guidelines do not yet exist to limit the number of embryos sold from each pair of gamete donors. Hence, unbeknownst to each other, full siblings could potentially meet, get married and procreate. This discussion has several critical implications for future practice, and professional education and policy. Patients with diseases associated with genetic tests may well ask obstetricians, gynecologists and other physicians about these techniques and practices. Clinicians can refer such patients to Assisted Reproductive Technology specialists, but familiarity with the basic aspects of the issues and complexities involved could aid themselves and their patients Several of these issues can be

Inhibition of Helicoverpa zea (Lepidoptera: Noctuidae) Growth by Transgenic Corn Expressing Bt Toxins and Development of Resistance to Cry1Ab.

PubMed

Reisig, Dominic D; Reay-Jones, Francis P F

2015-08-01

Transgenic corn, Zea mays L., that expresses the Bacillus thuringiensis (Bt) toxin Cry1Ab is only moderately toxic to Helicoverpa zea (Boddie) and has been planted commercially since 1996. Growth and development of H. zea was monitored to determine potential changes in susceptibility to this toxin over time. Small plots of corn hybrids expressing Cry1F, Cry1F × Cry1Ab, Cry1Ab × Cry3Bb1, Cry1A.105 × Cry2Ab2 × Cry3Bb1, Cry1A.105 × Cry2Ab2, and Vip3Aa20 × Cry1Ab × mCry3A were planted in both 2012 and 2013 inNorth and South Carolina with paired non-Bt hybrids from the same genetic background. H. zea larvae were sampled on three time periods from ears and the following factors were measured: kernel area injured (cm(2)) by H. zea larvae, larval number per ear, larval weight, larval length, and larval head width. Pupae were sampled on a single time period and the following factors recorded: number per ear, weight, time to eclosion, and the number that eclosed. There was no reduction in larval weight, number of insect entering the pupal stadium, pupal weight, time to eclosion, and number of pupae able to successfully eclose to adulthood in the hybrid expressing Cry1Ab compared with a non-Bt paired hybrid. As Cry1Ab affected these in 1996, H. zea may be developing resistance to Cry1Ab in corn, although these results are not comprehensive, given the limited sampling period, size, and geography. We also found that the negative impacts on larval growth and development were greater in corn hybrids with pyramided traits compared with single traits. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Zea mays Taxilin Protein Negatively Regulates Opaque-2 Transcriptional Activity by Causing a Change in Its Sub-Cellular Distribution

PubMed Central

Zhang, Nan; Qiao, Zhenyi; Liang, Zheng; Mei, Bing; Xu, Zhengkai; Song, Rentao

2012-01-01

Zea mays (maize) Opaque-2 (ZmO2) protein is an important bZIP transcription factor that regulates the expression of major storage proteins (22-kD zeins) and other important genes during maize seed development. ZmO2 is subject to functional regulation through protein-protein interactions. To unveil the potential regulatory network associated with ZmO2, a protein-protein interaction study was carried out using the truncated version of ZmO2 (O2-2) as bait in a yeast two-hybrid screen with a maize seed cDNA library. A protein with homology to Taxilin was found to have stable interaction with ZmO2 in yeast and was designated as ZmTaxilin. Sequence analysis indicated that ZmTaxilin has a long coiled-coil domain containing three conserved zipper motifs. Each of the three zipper motifs is individually able to interact with ZmO2 in yeast. A GST pull-down assay demonstrated the interaction between GST-fused ZmTaxilin and ZmO2 extracted from developing maize seeds. Using onion epidermal cells as in vivo assay system, we found that ZmTaxilin could change the sub-cellular distribution of ZmO2. We also demonstrated that this change significantly repressed the transcriptional activity of ZmO2 on the 22-kD zein promoter. Our study suggests that a Taxilin-mediated change in sub-cellular distribution of ZmO2 may have important functional consequences for ZmO2 activity. PMID:22937104

Mesophyll conductance in Zea mays responds transiently to CO2 availability: implications for transpiration efficiency in C4 crops.

PubMed

Kolbe, Allison R; Cousins, Asaph B

2018-03-01

Mesophyll conductance (g m ) describes the movement of CO 2 from the intercellular air spaces below the stomata to the site of initial carboxylation in the mesophyll. In contrast with C 3 -g m , little is currently known about the intraspecific variation in C 4 -g m or its responsiveness to environmental stimuli. To address these questions, g m was measured on five maize (Zea mays) lines in response to CO 2 , employing three different estimates of g m . Each of the methods indicated a significant response of g m to CO 2 . Estimates of g m were similar between methods at ambient and higher CO 2 , but diverged significantly at low partial pressures of CO 2 . These differences are probably driven by incomplete chemical and isotopic equilibrium between CO 2 and bicarbonate under these conditions. Carbonic anhydrase and phosphoenolpyruvate carboxylase in vitro activity varied significantly despite similar values of g m and leaf anatomical traits. These results provide strong support for a CO 2 response of g m in Z. mays, and indicate that g m in maize is probably driven by anatomical constraints rather than by biochemical limitations. The CO 2 response of g m indicates a potential role for facilitated diffusion in C 4 -g m . These results also suggest that water-use efficiency could be enhanced in C 4 species by targeting g m . © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Vitrification-based cryopreservation of Drosophila embryos

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

Schreuders, P.D.; Mazur, P.

1994-12-31

Currently, over 30,000 strains of Drosophila melanogaster are maintained by geneticists through regular transfer of breeding stocks. A more cost effective solution is to cryopreserve their embryos. Cooling and warming rates >10,000{degrees}C/min. are required to prevent chilling injury. To avoid the lethal intracellular ice normally produced at such high cooling rates, it is necessary to use {ge}50% (w/w) concentrations of glass-inducing solutes to vitrify the embryos. Differential scanning calorimetry (DSC) is used to develop and evaluate ethylene glycol and polyvinyl pyrrolidone based vitrification solutions. The resulting solution consists of 8.5M ethylene glycol + 10% polyvinylpyrrolidone in D-20 Drosophila culture medium.more » A two stage method is used for the introduction and concentration of these solutes within the embryo. The method reduces the exposure time to the solution and, consequently, reduces toxicity. Both DSC and freezing experiments suggest that, while twelve-hour embryos will vitrify using cooling rates >200{degrees}C/min., they will devitrify and be killed with even moderately rapid warming rates of {approximately}1,900{degrees}C/min. Very rapid warming ({approximately}100,000{degrees}C/min.) results in variable numbers of successfully cryopreserved embryos. This sensitivity to warming rite is typical of devitrification. The variability in survival is reduced using embryos of a precisely determined embryonic stage. The vitrification of the older, fifteen-hour, embryos yields an optimized hatching rate of 68%, with 35 - 40% of the resulting larvae developing to normal adults. This Success rite in embryos of this age may reflect a reduced sensitivity to limited devitrification or a more even distribution of the ethylene glycol within the embryo.« less

Natural Selection of Human Embryos: Decidualizing Endometrial Stromal Cells Serve as Sensors of Embryo Quality upon Implantation

PubMed Central

Teklenburg, Gijs; Salker, Madhuri; Molokhia, Mariam; Lavery, Stuart; Trew, Geoffrey; Aojanepong, Tepchongchit; Mardon, Helen J.; Lokugamage, Amali U.; Rai, Raj; Landles, Christian; Roelen, Bernard A. J.; Quenby, Siobhan; Kuijk, Ewart W.; Kavelaars, Annemieke; Heijnen, Cobi J.; Regan, Lesley; Brosens, Jan J.; Macklon, Nick S.

2010-01-01

Background Pregnancy is widely viewed as dependent upon an intimate dialogue, mediated by locally secreted factors between a developmentally competent embryo and a receptive endometrium. Reproductive success in humans is however limited, largely because of the high prevalence of chromosomally abnormal preimplantation embryos. Moreover, the transient period of endometrial receptivity in humans uniquely coincides with differentiation of endometrial stromal cells (ESCs) into highly specialized decidual cells, which in the absence of pregnancy invariably triggers menstruation. The role of cyclic decidualization of the endometrium in the implantation process and the nature of the decidual cytokines and growth factors that mediate the crosstalk with the embryo are unknown. Methodology/Principal Findings We employed a human co-culture model, consisting of decidualizing ESCs and single hatched blastocysts, to identify the soluble factors involved in implantation. Over the 3-day co-culture period, approximately 75% of embryos arrested whereas the remainder showed normal development. The levels of 14 implantation factors secreted by the stromal cells were determined by multiplex immunoassay. Surprisingly, the presence of a developing embryo had no significant effect on decidual secretions, apart from a modest reduction in IL-5 levels. In contrast, arresting embryos triggered a strong response, characterized by selective inhibition of IL-1β, -6, -10, -17, -18, eotaxin, and HB-EGF secretion. Co-cultures were repeated with undifferentiated ESCs but none of the secreted cytokines were affected by the presence of a developing or arresting embryo. Conclusions Human ESCs become biosensors of embryo quality upon differentiation into decidual cells. In view of the high incidence of gross chromosomal errors in human preimplantation embryos, cyclic decidualization followed by menstrual shedding may represent a mechanism of natural embryo selection that limits maternal investment in

Long distance migration in Helicoverpa zea: What we know and need to know

USDA-ARS?s Scientific Manuscript database

This paper identifies knowledge and knowledge gaps in the areas of biology and ecology, and migratory flight of corn earworm, Helicoverpa zea (Boddie). The paper focuses on results from studies of H. zea population dynamics and migration in Texas during a period of substantial irrigated corn produc...

Novel embryo selection techniques to increase embryo implantation in IVF attempts.

PubMed

Sigalos, George Α; Triantafyllidou, Olga; Vlahos, Nikos F

2016-11-01

The final success of an IVF attempt depends on several steps and decisions taken during the ovarian stimulation, the oocyte retrieval, the embryo culture and the embryo transfer. The final selection of the embryos most likely to implant is the final step in this process and the responsibility of the lab. Apart from strict morphologic criteria that historically have been used in embryo selection, additional information on genetic, metabolomic and morphokinetic characteristics of the embryo is recently combined to morphology to select the embryo most likely to produce a pregnancy. In this manuscript, we review the most recent information on the current methods used for embryo selection presenting the predictive capability of each one. A literature search was performed on Pubmed, Medline and Cochrane Database of Systematic Reviews for published studies using appropriate key words and phrases with no limits placed on time. It seems that the combination of morphologic criteria in conjunction to embryo kinetics as documented by time-lapse technology provides the most reliable information on embryo quality. Blastocyst biopsy with subsequent comprehensive chromosome analysis allows the selection of the euploid embryos with the higher implantation potential. Embryo time-lapse imaging and blastocyst biopsy combined to comprehensive chromosome analysis are the most promising technologies to increase pregnancy rates and reduce the possibility of multiple pregnancies. However, further studies will demonstrate the capability of routinely using these technologies to significantly improve IVF outcomes.

Morphological embryo selection: an elective single embryo transfer proposal.

PubMed

Déniz, Francisco Parera; Encinas, Carlos; Fuente, Jorge La

2018-03-01

To describe a patient selection method for elective single embryo transfer (eSET), emphasizing inclusion criteria and results. This retrospective study included all cases seen in a private clinic between June 2011 and December 2016, in La Paz, Bolivia (3600 meters above sea level). Elective single embryo transfer was the method of choice in 34 IVF/ICSI cycles, all in the blastocyst stage. Gardner's blastocyst classification criteria were used. Between the two stages of the study (July 2015), each embryo grade implantation rate was recalculated, which led to the expansion of the inclusion criteria. The clinical pregnancy rate of the 34 cases in the first transfer group was 55.9% (19/34). Twin or multiple pregnancies did not occur. The cumulative pregnancy rate to date is 64% [(19+3)/34]. The first stage comprised 2.56% (12/468) of the patients offered elective single embryo transfers; the implantation rate was 58.3% (7/12). In the second stage, 14.29% (22/154) of the patients were eligible, and the implantation rate was 54.55% (12/22). The implementation of an eSET program based on in-depth morphological embryo assessment combined with the calculation of the implantation potential of each embryo grade led to acceptable clinical outcomes and fewer multiple pregnancies in patients transferred two embryos. Each clinic should be aware of the implantation rates of each embryo grade in its own setting.

Morphological embryo selection: an elective single embryo transfer proposal

PubMed Central

Déniz, Francisco Parera; Encinas, Carlos; Fuente, Jorge La

2018-01-01

Objective To describe a patient selection method for elective single embryo transfer (eSET), emphasizing inclusion criteria and results. Methods This retrospective study included all cases seen in a private clinic between June 2011 and December 2016, in La Paz, Bolivia (3600 meters above sea level). Elective single embryo transfer was the method of choice in 34 IVF/ICSI cycles, all in the blastocyst stage. Gardner's blastocyst classification criteria were used. Between the two stages of the study (July 2015), each embryo grade implantation rate was recalculated, which led to the expansion of the inclusion criteria. Results The clinical pregnancy rate of the 34 cases in the first transfer group was 55.9% (19/34). Twin or multiple pregnancies did not occur. The cumulative pregnancy rate to date is 64% [(19+3)/34]. The first stage comprised 2.56% (12/468) of the patients offered elective single embryo transfers; the implantation rate was 58.3% (7/12). In the second stage, 14.29% (22/154) of the patients were eligible, and the implantation rate was 54.55% (12/22). Conclusion The implementation of an eSET program based on in-depth morphological embryo assessment combined with the calculation of the implantation potential of each embryo grade led to acceptable clinical outcomes and fewer multiple pregnancies in patients transferred two embryos. Each clinic should be aware of the implantation rates of each embryo grade in its own setting. PMID:29338137

Genome-Wide Identification and Characterization of microRNAs in Developing Grains of Zea mays L.

PubMed

Li, Dandan; Liu, Zongcai; Gao, Lei; Wang, Lifang; Gao, Meijuan; Jiao, Zhujin; Qiao, Huili; Yang, Jianwei; Chen, Min; Yao, Lunguang; Liu, Renyi; Kan, Yunchao

2016-01-01

The development and maturation of maize kernel involves meticulous and fine gene regulation at transcriptional and post-transcriptional levels, and miRNAs play important roles during this process. Although a number of miRNAs have been identified in maize seed, the ones involved in the early development of grains and in different lines of maize have not been well studied. Here, we profiled four small RNA libraries, each constructed from groups of immature grains of Zea mays inbred line Chang 7-2 collected 4-6, 7-9, 12-14, and 18-23 days after pollination (DAP). A total of 40 known (containing 111 unique miRNAs) and 162 novel (containing 196 unique miRNA candidates) miRNA families were identified. For conserved and novel miRNAs with over 100 total reads, 44% had higher accumulation before the 9th DAP, especially miR166 family members. 42% of miRNAs had highest accumulation during 12-14 DAP (which is the transition stage from embryogenesis to nutrient storage). Only 14% of miRNAs had higher expression 18-23 DAP. Prediction of potential targets of all miRNAs showed that 165 miRNA families had 377 target genes. For miR164 and miR166, we showed that the transcriptional levels of their target genes were significantly decreased when co-expressed with their cognate miRNA precursors in vivo. Further analysis shows miR159, miR164, miR166, miR171, miR390, miR399, and miR529 families have putative roles in the embryogenesis of maize grain development by participating in transcriptional regulation and morphogenesis, while miR167 and miR528 families participate in metabolism process and stress response during nutrient storage. Our study is the first to present an integrated dynamic expression pattern of miRNAs during maize kernel formation and maturation.

An approach to successful freezing of demi-embryos derived from day-7 bovine embryos.

PubMed

Niemann, H; Brem, G; Sacher, B; Smidt, D; Kräusslich, H

1986-04-01

The developmental capacity of frozen/thawed bisected embryos (n = 33) derived from day-7 bovine embryos was investigated and compared to ordinary embryos after freezing and thawing (n = 28) and to freshly bisected embryos (n = 19). The freezing and thawing protocol was identical for ordinary and demi-embryos. The percentage of intact embryos classified as excellent, good, or poor after thawing was 92.9 and 96.3% for ordinary and demi-embryos, respectively. Pregnancy rates of 53.8 (8 15 ), 46.2 (6 13 ), and 47.5% (9 19 ) were obtained when frozen/thawed ordinary embryos and frozen/thawed demi-embryos classified as excellent or good and sealed with an additional zona pellucida from hatched pig blastocysts or freshly bisected embryos were transferred. One pair of identical twins resulted from the transfer of frozen/thawed demi-embryos sealed with an additional zona pellucida. Transfer of four frozen/thawed demi-embryos without an additional zona pellucida led to one pregnancy. In contrast, demi-embryos derived from frozen/thawed ordinary embryos (n = 8) as well as frozen/thawed demi-embryos classified as poor (n = 6) did not result in any pregnancies although two halves were transferred per recipient. It is concluded that sealing the punctured zona pellucida improves the developmental capacity of frozen/thawed demi-embryos derived from day-7 bovine embryos, and freezing demi-embryos is more efficient compared to the splitting of frozen/thawed ordinary embryos.

Function of isoamylase-type starch debranching enzymes ISA1 and ISA2 in the Zea mays leaf.

PubMed

Lin, Qiaohui; Facon, Maud; Putaux, Jean-Luc; Dinges, Jason R; Wattebled, Fabrice; D'Hulst, Christophe; Hennen-Bierwagen, Tracie A; Myers, Alan M

2013-12-01

Conserved isoamylase-type starch debranching enzymes (ISAs), including the catalytic ISA1 and noncatalytic ISA2, are major starch biosynthesis determinants. Arabidopsis thaliana leaves require ISA1 and ISA2 for physiological function, whereas endosperm starch is near normal with only ISA1. ISA functions were characterized in maize (Zea mays) leaves to determine whether species-specific distinctions in ISA1 primary structure, or metabolic differences in tissues, are responsible for the differing ISA2 requirement. Genetic methods provided lines lacking ISA1 or ISA2. Biochemical analyses characterized ISA activities in mutant tissues. Starch content, granule morphology, and amylopectin fine structure were determined. Three ISA activity forms were observed in leaves, two ISA1/ISA2 heteromultimers and one ISA1 homomultimer. ISA1 homomultimer activity existed in mutants lacking ISA2. Mutants without ISA2 differed in leaf starch content, granule morphology, and amylopectin structure compared with nonmutants or lines lacking both ISA1 and ISA2. The data imply that both the ISA1 homomultimer and ISA1/ISA2 heteromultimer function in the maize leaf. The ISA1 homomultimer is present and functions in the maize leaf. Evolutionary divergence between monocots and dicots probably explains the ability of ISA1 to function as a homomultimer in maize leaves, in contrast to other species where the ISA1/ISA2 heteromultimer is the only active form. No claim to original US goverment works. New Phytologist © 2013 New Phytologist Trust.

Fresh embryo transfer versus frozen embryo transfer in in vitro fertilization cycles: a systematic review and meta-analysis.

PubMed

Roque, Matheus; Lattes, Karinna; Serra, Sandra; Solà, Ivan; Geber, Selmo; Carreras, Ramón; Checa, Miguel Angel

2013-01-01

To examine the available evidence to assess if cryopreservation of all embryos and subsequent frozen embryo transfer (FET) results in better outcomes compared with fresh transfer. Systematic review and meta-analysis. Centers for reproductive care. Infertility patient(s). An exhaustive electronic literature search in MEDLINE, EMBASE, and the Cochrane Library was performed through December 2011. We included randomized clinical trials comparing outcomes of IVF cycles between fresh and frozen embryo transfers. The outcomes of interest were ongoing pregnancy rate, clinical pregnancy rate, and miscarriage. We included three trials accounting for 633 cycles in women aged 27-33 years. Data analysis showed that FET resulted in significantly higher ongoing pregnancy rates and clinical pregnancy rates. Our results suggest that there is evidence that IVF outcomes may be improved by performing FET compared with fresh embryo transfer. This could be explained by a better embryo-endometrium synchrony achieved with endometrium preparation cycles. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

The locations and amounts of endogenous ions and elements in the cap and elongating zone of horizontally oriented roots of Zea mays L.: an electron-probe EDS study

NASA Technical Reports Server (NTRS)

Moore, R.; Cameron, I. L.; Hunter, K. E.; Olmos, D.; Smith, N. K.

1987-01-01

We used quantitative electron-probe energy-dispersive x-ray microanalysis to localize endogenous Na, Cl, K, P, S, Mg and Ca in cryofixed and freeze-dried cryosections of the cap (i.e. the putative site of graviperception) and elongating zone (i.e. site of gravicurvature) of horizontally oriented roots of Zea mays. Ca, Na, Cl, K and Mg accumulate along the lower side of caps of horizontally oriented roots. The most dramatic asymmetries of these ions occur in the apoplast, especially the mucilage. We could not detect any significant differences in the concentrations of these ions in the central cytoplasm of columella cells along the upper and lower sides of caps of horizontally-oriented roots. However, the increased amounts of Na, Cl, K and Mg in the longitudinal walls of columella cells along the lower side of the cap suggest that these ions may move down through the columella tissue of horizontally-oriented roots. Ca also accumulates (largely in the mucilage) along the lower side of the elongating zone of horizontally-oriented roots, while Na, P, Cl and K tend to accumulate along the upper side of the elongating zone. Of these ions, only K increases in concentration in the cytoplasm and longitudinal walls of cortical cells in the upper vs lower sides of the elongating zone. These results indicate that (1) gravity-induced asymmetries of ions differ significantly in the cap and elongating zone of graviresponding roots, (2) Ca accumulates along the lower side of the cap and elongating zone of graviresponding roots, (3) increased growth of the upper side of the elongating zone of horizontally-oriented roots correlates positively with increased amounts of K in the cytoplasm and longitudinal walls of cortical cells, and (4) the apoplast (especially the mucilage) may be an important component of the pathway via which ions move in graviresponding rots of Zea mays. These results are discussed relative to mechanisms for graviperception and gravicurvature of roots.

Oxidation of indole-3-acetic acid and oxindole-3-acetic acid to 2,3-dihydro-7-hydroxy-2-oxo-1H indole-3-acetic acid-7'-O-beta-D-glucopyranoside in Zea mays seedlings

NASA Technical Reports Server (NTRS)

Nonhebel, H. M.; Bandurski, R. S.

1984-01-01

Radiolabeled oxindole-3-acetic acid was metabolized by roots, shoots, and caryopses of dark grown Zea mays seedlings to 2,3-dihydro-7-hydroxy-2-oxo-1H indole-3-acetic acid-7'-O-beta-D-glycopyranoside with the simpler name of 7-hydroxyoxindole-3-acetic acid-glucoside. This compound was also formed from labeled indole-3-acetic acid supplied to intact seedlings and root segments. The glucoside of 7-hydroxyoxindole-3-acetic acid was also isolated as an endogenous compound in the caryopses and shoots of 4-day-old seedlings. It accumulates to a level of 4.8 nanomoles per plant in the kernel, more than 10 times the amount of oxindole-3-acetic acid. In the shoot it is present at levels comparable to that of oxindole-3-acetic acid and indole-3-acetic acid (62 picomoles per shoot). We conclude that 7-hydroxyoxindole-3-acetic acid-glucoside is a natural metabolite of indole-3-acetic acid in Z. mays seedlings. From the data presented in this paper and in previous work, we propose the following route as the principal catabolic pathway for indole-3-acetic acid in Zea seedlings: Indole-3-acetic acid --> Oxindole-3-acetic acid --> 7-Hydroxyoxindole-3-acetic acid --> 7-Hydroxyoxindole-3-acetic acid-glucoside.

Proliferation of maize (Zea mays L.) roots in response to localized supply of nitrate

NASA Technical Reports Server (NTRS)

Granato, T. C.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

1989-01-01

Maize (Zea mays L.) plants with two primary nodal root axes were grown for 8 d in flowing nutrient culture with each axis independently supplied with NO3-. Dry matter accumulation by roots was similar whether 1.0 mol m-3 NO3- was supplied to one or both axes. When NO3- was supplied to only one axis, however, accumulation of dry matter within the root system was significantly greater in the axis supplied with NO3-. The increased dry matter accumulation by the +N-treated axis was attributable entirely to increased density and growth of lateral branches and not to a difference in growth of the primary axis. Proliferation of lateral branches for the +N axis was associated with the capacity for in situ reduction and utilization of a portion of the absorbed NO3-, especially in the apical region where lateral primordia are initiated. Although reduced nitrogen was translocated to the -N axis, concentrations in the -N axis remained significantly lower than in the +N axis. The concentration of reduced nitrogen, as well as in vitro NO3- reductase activity, was greater in apical than in more basal regions of the +N axis. The enhanced proliferation of lateral branches in the +N axis was accompanied by an increase in total respiration rate of the axis. Part of the increased respiration was attributable to increased mass of roots. The specific respiration rate (micromoles CO2 evolved per hour per gram root dry weight) was also greater for the +N than for the -N axis. If respiration rate is taken as representative of sink demand, stimulation of initiation and growth of laterals by in situ utilization of a localized exogenous supply of NO3- establishes an increased sink demand through enhanced metabolic activity and the increased partitioning of assimilates to the +N axis responds to the difference in sink demand between +N and -N axes.

Increase in Dry Weight and Total Nitrogen Content in Zea mays and Setaria italica Associated with Nitrogen-fixing Azospirillum spp. 1

PubMed Central

Cohen, Efraim; Okon, Yaacov; Kigel, Jaime; Nur, Israel; Henis, Yigal

1980-01-01

The association between nitrogen-fixing bacteria from the genus Azospirillum and the grasses Zea mays and Setaria italica was investigated in sterilized Leonard-jar assemblies. Nitrogen-fixing bacteria isolated from Cynodon dactylon roots in Israel and Azospirillum brasilense (Sp-7, Sp-80, and Cd) were examined. C2H2 reduction activity was detected in systems containing 0.0 to 0.08 but not in those containing 0.16 gram per liter NH4NO3. The organisms tested significantly increased plant dry weight (50-100%), total N content of leaves (50-100%) and C2H4 production (300-1000 nanomoles C2H4 per plant per hour). Highest C2H2 reduction activities were obtained above 30 C and with high light intensities. Significant increases in S. italica dry weight (DW) and nitrogen (N) content were observed in sand (DW = 80%, N = 150%), sandy loam soil (DW = 80%, N = 75%) and loess (DW = 37%, N = 25%). The results obtained in this work clearly demonstrate the potential benefit of inoculating grasses with Azospirillum. PMID:16661514

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.

Reproduction of the whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) B biotype in maize fields (Zea mays L.) in Brazil.

PubMed

Quintela, Eliane D; Abreu, Aluana G; Lima, Julyana F Dos S; Mascarin, Gabriel M; Santos, Jardel B Dos; Brown, Judith K

2016-11-01

Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae) was observed to have completed its reproductive cycle from the egg to the adult on maize (Zea mays L.). Field and screenhouse studies were carried out to investigate the durability of this putative and unprecedented adaptation to a grass host. Analysis of the mitochondrial COI gene sequence identified the maize-associated B. tabaci as the exotic B biotype (major clade North Africa-Mediterranean-Middle East). Results showed that whiteflies migrated from soybean crops and successfully established in maize plants. Females exhibited a preference for oviposition primarily on the first and second leaves of maize, but were also able to colonise developing leaves. A high, natural infestation on maize (193.3 individuals, all developmental stages) was observed within a 7.1 cm 2 designated 'observation area'. Whiteflies collected from naturally infested maize leaves and allowed to oviposit on maize seedlings grown in a screenhouse developed from egg to adulthood in 28.6 ± 0.2 days. This is the first report of the B biotype completing its development on maize plants. This surprising anomaly indicates that the B biotype is capable of adapting to monocotyledonous host plants, and importantly, broadens the host range to include at least one species in the Poaceae. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Responses of seed germination, seedling growth, and seed yield traits to seed pretreatment in maize (Zea mays L.).

PubMed

Tian, Yu; Guan, Bo; Zhou, Daowei; Yu, Junbao; Li, Guangdi; Lou, Yujie

2014-01-01

A series of seed priming experiments were conducted to test the effects of different pretreatment methods to seed germination, seedling growth, and seed yield traits in maize (Zea mays L.). Results indicated that the seeds primed by gibberellins (GA), NaCl, and polyethylene glycol (PEG) reagents showed a higher imbibitions rate compared to those primed with water. The final germination percentage and germination rate varied with different reagents significantly (P < 0.05). The recommended prime reagents were GA at 10 mg/L, NaCl at 50 mM, and PEG at 15% on account of germination experiment. 15% PEG priming reagent increased shoot and root biomass of maize seedling. The shoot biomass of seedlings after presoaking the seeds with NaCl reagent was significantly higher than the seedlings without priming treatment. No significant differences of plant height, leaf number, and hundred-grain weight were observed between control group and priming treatments. Presoaking with water, NaCl (50 mM), or PEG (15%) significantly increased the hundred-grain weight of maize. Therefore, seed pretreatment is proved to be an effective technique to improve the germination performance, seedling growth, and seed yield of maize. However, when compared with the two methods, if immediate sowing is possible, presoaking is recommended to harvest better benefits compared to priming method.

Studies on the growth and indole-3-acetic acid and abscisic acid content of Zea mays seedlings grown in microgravity

NASA Technical Reports Server (NTRS)

Schulze, A.; Jensen, P. J.; Desrosiers, M.; Buta, J. G.; Bandurski, R. S.

1992-01-01

Measurements were made of the fresh weight, dry weight, dry weight-fresh weight ratio, free and conjugated indole-3-acetic acid, and free and conjugated abscisic acid in seedlings of Zea mays grown in darkness in microgravity and on earth. Imbibition of the dry kernels was 17 h prior to launch. Growth was for 5 d at ambient orbiter temperature and at a chronic accelerational force of the order of 3 x 10(-5) times earth gravity. Weights and hormone content of the microgravity seedlings were, with minor exceptions, not statistically different from seedlings grown in normal gravity. The tissues of the shuttle-grown plants appeared normal and the seedlings differed only in the lack of orientation of roots and shoots. These findings, based upon 5 d of growth in microgravity, cannot be extrapolated to growth in microgravity for weeks, months, and years, as might occur on a space station. Nonetheless, it is encouraging, for prospects of bioregeneration of the atmosphere and food production in a space station, that no pronounced differences in the parameters measured were apparent during the 5 d of plant seedling growth in microgravity.

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.

Analysis of growth patterns during gravitropic curvature in roots of Zea mays by use of a computer-based video digitizer

NASA Technical Reports Server (NTRS)

Nelson, A. J.; Evans, M. L.

1986-01-01

A computer-based video digitizer system is described which allows automated tracking of markers placed on a plant surface. The system uses customized software to calculate relative growth rates at selected positions along the plant surface and to determine rates of gravitropic curvature based on the changing pattern of distribution of the surface markers. The system was used to study the time course of gravitropic curvature and changes in relative growth rate along the upper and lower surface of horizontally-oriented roots of maize (Zea mays L.). The growing region of the root was found to extend from about 1 mm behind the tip to approximately 6 mm behind the tip. In vertically-oriented roots the relative growth rate was maximal at about 2.5 mm behind the tip and declined smoothly on either side of the maximum. Curvature was initiated approximately 30 min after horizontal orientation with maximal (50 degrees) curvature being attained in 3 h. Analysis of surface extension patterns during the response indicated that curvature results from a reduction in growth rate along both the upper and lower surfaces with stronger reduction along the lower surface.

Characterization of ApB73, a virulence factor important for colonization of Zea mays by the smut Ustilago maydis

PubMed Central

Stirnberg, Alexandra

2016-01-01

Summary The biotrophic fungus Ustilago maydis, the causal agent of corn smut disease, uses numerous small secreted effector proteins to suppress plant defence responses and reshape the host metabolism. However, the role of specific effectors remains poorly understood. Here, we describe the identification of ApB73 (Apathogenic in B73), an as yet uncharacterized protein essential for the successful colonization of maize by U. maydis. We show that apB73 is transcriptionally induced during the biotrophic stages of the fungal life cycle. The deletion of the apB73 gene results in cultivar‐specific loss of gall formation in the host. The ApB73 protein is conserved among closely related smut fungi. However, using virulence assays, we show that only the orthologue of the maize‐infecting head smut Sporisorium reilianum can complement the mutant phenotype of U. maydis. Although microscopy shows that ApB73 is secreted into the biotrophic interface, it seems to remain associated with fungal cell wall components or the fungal plasma membrane. Taken together, the results show that ApB73 is a conserved and important virulence factor of U. maydis that localizes to the interface between the pathogen and its host Zea mays. PMID:27279632

Pre-persons, commodities or cyborgs: the legal construction and representation of the embryo.

PubMed

Fox, M

2000-01-01

This paper explores how embryos have been represented in law. It argues that two main models have underpinned legal discourse concerning the embryo. One discourse, which has become increasingly prevalent, views embryos as legal subjects or persons. Such representations are facilitated by technological developments such as ultrasound imaging. In addition to influencing Parliamentary debate prior to the passage of the Human Fertilisation and Embryology Act 1990, images of embryos as persons feature prominently in popular culture, including advertising and films, and this discourse came to the fore in the 'orphaned embryo' debate in 1996. The main opposing discourse dismisses embryos as commodifiable objects, which fits with a trend towards legal recognition that reproductive materials such as sperm may be classified as property which may be donated or sold. In the case of cryopreserved embryos these competing perspectives have resulted in litigation over the status of frozen embryos. In this paper I argue that it might be productive to shift the debate from this polarised dispute over whether embryos matter or not, whether they are pre-persons or commodities. Instead, I suggest that we should attempt to locate them in a biotechnological milieu, where cyborg metaphors may be utilised, and questions of how we should treat embryos would be contextualized alongside our response to other cyborgs.

Effects of laser polar-body biopsy on embryo quality.

PubMed

Levin, Ishai; Almog, Benny; Shwartz, Tamar; Gold, Veronica; Ben-Yosef, Dalit; Shaubi, Michal; Amit, Ami; Malcov, Mira

2012-05-01

To evaluate the effect of laser polar-body biopsy (PBB) for preimplantation genetic diagnosis on embryo quality. Retrospective case-control analysis. The quality of 145 embryos after PBB was compared to 276 embryos of the same group of women without biopsy. University-based tertiary-care medical center. Women with inherited genetics disease. Laser PBB of IVF embryos for genetic diagnosis. The study and control embryos were compared for fertilization rate, pronuclear grading, and cleavage-stage parameters on days 1, 2, and 3 after oocyte retrieval. The study embryos demonstrated higher rates of cleavage arrest (3.6% vs. 0.7%), higher rate of significant fragmentation on day 2 (9.5% vs. 3.0%), and lower rate of good cleavage embryos on day 2 (69.1% vs. 78.4%) compared with control embryos. On day 3, the study embryos had lower cleavage rates (six or more blastomeres; 56.5% vs. 74.5%), higher fragmentation (11.7% vs. 3.9%), higher rate of embryos presenting inferior cleavage pattern (57.2% vs. 38.5%), and lower mean blastomere number (5.8 ± 2.1 vs. 6.6 ± 1.9) compared with control embryos. Polar-body biopsy may have a negative effect on embryo quality. Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Effect of Embryo Density on In Vitro Development and Gene Expression in Bovine In Vitro-fertilized Embryos Cultured in a Microwell System

PubMed Central

SUGIMURA, Satoshi; AKAI, Tomonori; HASHIYADA, Yutaka; AIKAWA, Yoshio; OHTAKE, Masaki; MATSUDA, Hideo; KOBAYASHI, Shuji; KOBAYASHI, Eiji; KONISHI, Kazuyuki; IMAI, Kei

2012-01-01

Abstract To identify embryos individually during in vitro development, we previously developed the well-of-the-well (WOW) dish, which contains 25 microwells. Here we investigated the effect of embryo density (the number of embryos per volume of medium) on in vitro development and gene expression of bovine in vitro-fertilized embryos cultured in WOW dishes. Using both conventional droplet and WOW culture formats, 5, 15, and 25 bovine embryos were cultured in 125 µl medium for 168 h. The blastocysts at Day 7 were analyzed for number of cells and expression of ten genes (CDX2, IFN-tau, PLAC8, NANOG, OCT4, SOX2, AKR1B1, ATP5A1, GLUT1 and IGF2R). In droplet culture, the rates of formation of >4-cell cleavage embryos and blastocysts were significantly lower in embryos cultured at 5 embryos per droplet than in those cultured at 15 or 25 embryos per droplet, but not in WOW culture. In both droplet and WOW culture, developmental kinetics and blastocyst cell numbers did not differ among any groups. IFN-tau expression in embryos cultured at 25 embryos per droplet was significantly higher than in those cultured at 15 embryos per droplet and in artificial insemination (AI)-derived blastocysts. Moreover, IGF2R expression was significantly lower in the 25-embryo group than in the 5-embryo group and in AI-derived blastocysts. In WOW culture, these expressions were not affected by embryo density and were similar to those in AI-derived blastocysts. These results suggest that, as compared with conventional droplet culture, in vitro development and expression of IFN-tau and IGF2R in the microwell system may be insensitive to embryo density. PMID:23154384

EMF radiations (1800 MHz)-inhibited early seedling growth of maize (Zea mays) involves alterations in starch and sucrose metabolism.

PubMed

Kumar, Arvind; Singh, Harminder Pal; Batish, Daizy R; Kaur, Shalinder; Kohli, Ravinder Kumar

2016-07-01

The present study investigated the impact of 1800-MHz electromagnetic field radiations (EMF-r), widely used in mobile communication, on the growth and activity of starch-, sucrose-, and phosphate-hydrolyzing enzymes in Zea mays seedlings. We exposed Z. mays to modulated continuous wave homogenous EMF-r at specific absorption rate (SAR) of 1.69±0.0 × 10(-1) W kg(-1) for ½, 1, 2, and 4 h. The analysis of seedlings after 7 days revealed that short-term exposure did not induce any significant change, while longer exposure of 4 h caused significant growth and biochemical alterations. There was a reduction in the root and coleoptile length with more pronounced effect on coleoptile growth (23 % reduction on 4-h exposure). The contents of photosynthetic pigments and total carbohydrates declined by 13 and 18 %, respectively, in 4-h exposure treatments compared to unexposed control. The activity of starch-hydrolyzing enzymes-α- and β-amylases-increased by ∼92 and 94 %, respectively, at an exposure duration of 4 h, over that in the control. In response to 4-h exposure treatment, the activity of sucrolytic enzymes-acid invertases and alkaline invertases-was increased by 88 and 266 %, whereas the specific activities of phosphohydrolytic enzymes (acid phosphatases and alkaline phosphatases) showed initial increase up to ≤2 h duration and then declined at >2 h exposure duration. The study concludes that EMF-r-inhibited seedling growth of Z. mays involves interference with starch and sucrose metabolism.

The Effects of Temperature and Precipitation on the Yield of Zea Mays L. I the Southeastern United States

NASA Astrophysics Data System (ADS)

Stooksbury, David Emory

Three families of straightforward maize (Zea mays L.) yield/climate models using monthly temperature and precipitation terms are produced. One family of models uses USDA's Crop Reporting Districts (CRD) as its scale of aggregation. The other two families of models use three different district aggregates based on climate or yield patterns. The climate and yield districts are determined by using a two-stage cluster analysis. The CRD-based family of models perform as well as the climate and yield based models. All models explain between 80% and 90% of the variance in maize yield. The most important climate term affecting maize yield in the South is the daily maximum temperature at pollination time. The higher the maximum temperature, the lower the yield. Above normal minimum temperature during pollination increases yield in the Middle South. Weather that favors early planting and rapid vegetative growth increases yield. Ideal maize yield weather includes a dry period during planting followed by a warm period during vegetative growth. Moisture variables are important only during the planting and harvest periods when above normal precipitation delays field work and thereby reduces yield. The model results indicate that the dire predictions about the fate of Southern agriculture in a trace gas warmed world may not be true. This is due to the overwhelming influence of the daily maximum temperature on yield. An optimum aggregate for climate impact studies was not found. I postulate that this is due to the dynamic nature of the American maize production system. For most climate impact studies on a dynamic agricultural system, there does not need to be a concern about the model aggregation.

Uptake and effects of a mixture of widely used therapeutic drugs in Eruca sativa L. and Zea mays L. plants.

PubMed

Marsoni, Milena; De Mattia, Fabrizio; Labra, Massimo; Bruno, Antonia; Bracale, Marcella; Vannini, Candida

2014-10-01

Pharmaceutically active compounds (PACs) are continuously dispersed into the environment due to human and veterinary use, giving rise to their potential accumulation in edible plants. In this study, Eruca sativa L. and Zea mays L. were selected to determine the potential uptake and accumulation of eight different PACs (Salbutamol, Atenolol, Lincomycin, Cyclophosphamide, Carbamazepine, Bezafibrate, Ofloxacin and Ranitidine) designed for human use. To mimic environmental conditions, the plants were grown in pots and irrigated with water spiked with a mixture of PACs at concentrations found in Italian wastewaters and rivers. Moreover, 10× and 100× concentrations of these pharmaceuticals were also tested. The presence of the pharmaceuticals was tested in the edible parts of the plants, namely leaves for E. sativa and grains for Z. mays. Quantification was performed by liquid chromatography mass spectroscopy (LC/MS/MS). In the grains of 100× treated Z. mays, only atenolol, lincomycin and carbamazepine were above the limit of detection (LOD). At the same concentration in E. sativa plants the uptake of all PACs was >LOD. Lincomycin and oflaxacin were above the limit of quantitation in all conditions tested in E. sativa. The results suggest that uptake of some pharmaceuticals from the soil may indeed be a potential transport route to plants and that these environmental pollutants can reach different edible parts of the selected crops. Measurements of the concentrations of these pharmaceuticals in plant materials were used to model potential adult human exposure to these compounds. The results indicate that under the current experimental conditions, crops exposed to the selected pharmaceutical mixture would not have any negative effects on human health. Moreover, no significant differences in the growth of E. sativa or Z. mays plants irrigated with PAC-spiked vs. non-spiked water were observed. Copyright © 2014 Elsevier Inc. All rights reserved.

Clinical evaluation of frozen/thawed embryo transfer following transport of oocytes and embryos

PubMed Central

2004-01-01

Background and Aims:  We evaluated the efficacy of the transport oocyte/embryo frozen/thawed embryo transfer method, in which oocytes or embryos were transported from satellite clinics to the main assisted reproductive technology (ART) center, and surplus embryos were placed in cryopreservation. Methods:  We evaluated 41 cycles in 34 patients in the transport oocyte group (TO group). In the TO group the oocytes were collected at the satellite clinics, transported to the main ART center and underwent in vitro fertilization or intracytoplasmic sperm injection. Surplus embryos were used for frozen/thawed embryo transfer. We also evaluated 17 cycles in 10 patients in the transport embryo group (TE group), where surplus embryos were transported to the main ART center and used for frozen/thawed embryo transfer; and 189 cycles in 134 patients in the center group (C group), where surplus embryos collected at the same time at the main ART center were used for frozen/thawed embryo transfer. Oocytes were transported from satellite clinics in HEPES buffered human tubal fluid (HTF) culture medium, and embryos in 30% synthetic serum substitute + HEPES buffered HTF, using a portable incubator we devised. Results:  The proportions of undamaged embryos after freeze/thawing were 47% for the C group, 46% for the TO group, and 46% for the TE group. The numbers of embryos transferred were 2.0 ± 0.7 for the C group, 2.0 ± 0.6 for the TO group, and 2.2 ± 0.4 for the TE group. The rate of embryo transfer was 63% for the C group, 68% for the TO group, and 76% for the TE group. Pregnancy rates per patient were 16% for the C group, 24% for the TO group, and 40% for the TE group. The embryo survival rates (number of embryos with ≥50% viable blastomeres/total number of embryos) were 55% for the C group, 60% for the TO group, and 54% for the TE group. No significant differences were seen between the C group and either the TO or TE groups in any of these parameters

Identification and suppression of the p-coumaroyl CoA:hydroxycinnamyl alcohol transferase in Zea mays L.

PubMed Central

Marita, Jane M; Hatfield, Ronald D; Rancour, David M; Frost, Kenneth E

2014-01-01

Grasses, such as Zea mays L. (maize), contain relatively high levels of p-coumarates (pCA) within their cell walls. Incorporation of pCA into cell walls is believed to be due to a hydroxycinnamyl transferase that couples pCA to monolignols. To understand the role of pCA in maize development, the p-coumaroyl CoA:hydroxycinnamyl alcohol transferase (pCAT) was isolated and purified from maize stems. Purified pCAT was subjected to partial trypsin digestion, and peptides were sequenced by tandem mass spectrometry. TBLASTN analysis of the acquired peptide sequences identified a single full-length maize cDNA clone encoding all the peptide sequences obtained from the purified enzyme. The cDNA clone was obtained and used to generate an RNAi construct for suppressing pCAT expression in maize. Here we describe the effects of suppression of pCAT in maize. Primary screening of transgenic maize seedling leaves using a new rapid analytical platform was used to identify plants with decreased amounts of pCA. Using this screening method, mature leaves from fully developed plants were analyzed, confirming reduced pCA levels throughout plant development. Complete analysis of isolated cell walls from mature transgenic stems and leaves revealed that lignin levels did not change, but pCA levels decreased and the lignin composition was altered. Transgenic plants with the lowest levels of pCA had decreased levels of syringyl units in the lignin. Thus, altering the levels of pCAT expression in maize leads to altered lignin composition, but does not appear to alter the total amount of lignin present in the cell walls. PMID:24654730

How does embryo manipulation fit into present and future pig reproduction?

PubMed

Polge, C

1985-01-01

Available techniques for the collection and direct transplantation of pig embryos are simple and efficient and could be used for the expansion of new lines, for increasing selection pressure in nucleus herds and for extracting healthy stock from a diseased source. However, the reduced viability of pig embryos during culture in vitro and the inability as yet to preserve them by deep-freezing impose limits to the use of embryo transplantation for the export or import of potential breeding stock. The efficiency of breeding schemes could be improved by the sexing of embryos and the possibility of producing genetically identical twins or quadruplets by micromanipulation of embryos should improve the efficiency of animal experimentation. Chimaerism may be used to rescue embryos of a non-viable genotype such as parthenotes or those derived by hybridization, but the greatest revolution in pig breeding may be brought about by the introduction of foreign cloned genes into eggs and the production of transgenic animals. Eggs at an appropriate stage for microinjection may be provided in the future by techniques for the maturation and fertilization of oocytes in vitro. Animal breeders should be aware of the potential impact of techniques for the manipulation of eggs and embryos on future developments in animal production.

The avian embryo responding to microgravity of space flight

NASA Technical Reports Server (NTRS)

Hullinger, Ronald L.

1993-01-01

Of all the many potential and real microenvironmental influences, only gravity would appear to have remained relatively constant and ubiquitous for developing organisms. Histo- and organogenesis as well as differential growth of the embryo and fetus may have evolved with a constant environmental factor of gravity. Chick embryos of 2-day and 9-day stages of incubation were flown in an incubator on the Space Shuttle during a 9-day mission. Significant differences in embryo response to this microgravity environment were observed. This paper offers an analysis and suggests mechanisms which may contribute to these results.

Dissection of the genetic architecture underlying the plant density response by mapping plant height-related traits in maize (Zea mays L.).

PubMed

Ku, Lixia; Zhang, Liangkun; Tian, Zhiqiang; Guo, Shulei; Su, Huihui; Ren, Zhenzhen; Wang, Zhiyong; Li, Guohui; Wang, Xiaobo; Zhu, Yuguang; Zhou, Jinlong; Chen, Yanhui

2015-08-01

Plant height is one of the most heritable traits in maize (Zea mays L.). Understanding the genetic control of plant height is important for elucidating the molecular mechanisms that regulate maize development. To investigate the genetic basis of the plant height response to density in maize, we evaluated the effects of two different plant densities (60,000 and 120,000 plant/hm(2)) on three plant height-related traits (plant height, ear height, and ear height-to-plant height ratio) using four sets of recombinant inbred line populations. The phenotypes observed under the two-plant density treatments indicated that high plant density increased the phenotypic performance values of the three measured traits. Twenty-three quantitative trait loci (QTLs) were detected under the two-plant density treatments, and five QTL clusters were located. Nine QTLs were detected under the low plant density treatment, and seven QTLs were detected under the high plant density treatment. Our results suggested that plant height may be controlled mainly by a common set of genes that could be influenced by additional genetic mechanisms when the plants were grown under high plant density. Fine mapping for genetic regions of the stable QTLs across different plant density environments may provide additional information about their different responses to density. The results presented here provide useful information for further research and will help to reveal the molecular mechanisms related to plant height in response to density.

Cell-wall properties contributing to improved deconstruction by alkaline pre-treatment and enzymatic hydrolysis in diverse maize (Zea mays L.) lines

PubMed Central

Li, Muyang; Heckwolf, Marlies; Crowe, Jacob D.; Williams, Daniel L.; Magee, Timothy D.; Kaeppler, Shawn M.; de Leon, Natalia; Hodge, David B.

2015-01-01

A maize (Zea mays L. subsp. mays) diversity panel consisting of 26 maize lines exhibiting a wide range of cell-wall properties and responses to hydrolysis by cellulolytic enzymes was employed to investigate the relationship between cell-wall properties, cell-wall responses to mild NaOH pre-treatment, and enzymatic hydrolysis yields. Enzymatic hydrolysis of the cellulose in the untreated maize was found to be positively correlated with the water retention value, which is a measure of cell-wall susceptibility to swelling. It was also positively correlated with the lignin syringyl/guaiacyl ratio and negatively correlated with the initial cell-wall lignin, xylan, acetate, and p-coumaric acid (pCA) content, as well as pCA released from the cell wall by pre-treatment. The hydrolysis yield following pre-treatment exhibited statistically significant negative correlations to the lignin content after pre-treatment and positive correlations to the solubilized ferulic acid and pCA. Several unanticipated results were observed, including a positive correlation between initial lignin and acetate content, lack of correlation between acetate content and initial xylan content, and negative correlation between each of these three variables to the hydrolysis yields for untreated maize. Another surprising result was that pCA release was negatively correlated with hydrolysis yields for untreated maize and, along with ferulic acid release, was positively correlated with the pre-treated maize hydrolysis yields. This indicates that these properties that may negatively contribute to the recalcitrance in untreated cell walls may positively contribute to their deconstruction by alkaline pre-treatment. PMID:25871649

Cell-wall properties contributing to improved deconstruction by alkaline pre-treatment and enzymatic hydrolysis in diverse maize ( Zea mays L.) lines

DOE PAGES

Li, Muyang; Heckwolf, Marlies; Crowe, Jacob D.; ...

2015-02-20

A maize (Zea mays L. subsp. mays) diversity panel consisting of 26 maize lines exhibiting a wide range of cell-wall properties and responses to hydrolysis by cellulolytic enzymes was employed to investigate the relationship between cell-wall properties, cell-wall responses to mild NaOH pre-treatment, and enzymatic hydrolysis yields. Enzymatic hydrolysis of the cellulose in the untreated maize was found to be positively correlated with the water retention value, which is a measure of cell-wall susceptibility to swelling. It was also positively correlated with the lignin syringyl/guaiacyl ratio and negatively correlated with the initial cell-wall lignin, xylan, acetate, and p-coumaric acid (pCA)more » content, as well as pCA released from the cell wall by pre-treatment. The hydrolysis yield following pre-treatment exhibited statistically significant negative correlations to the lignin content after pre-treatment and positive correlations to the solubilized ferulic acid and pCA. Several unanticipated results were observed, including a positive correlation between initial lignin and acetate content, lack of correlation between acetate content and initial xylan content, and negative correlation between each of these three variables to the hydrolysis yields for untreated maize. Also, another surprising result was that pCA release was negatively correlated with hydrolysis yields for untreated maize and, along with ferulic acid release, was positively correlated with the pre-treated maize hydrolysis yields. In conclusion, this indicates that these properties that may negatively contribute to the recalcitrance in untreated cell walls may positively contribute to their deconstruction by alkaline pre-treatment« less

Cell-wall properties contributing to improved deconstruction by alkaline pre-treatment and enzymatic hydrolysis in diverse maize ( Zea mays L.) lines

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

Li, Muyang; Heckwolf, Marlies; Crowe, Jacob D.

A maize (Zea mays L. subsp. mays) diversity panel consisting of 26 maize lines exhibiting a wide range of cell-wall properties and responses to hydrolysis by cellulolytic enzymes was employed to investigate the relationship between cell-wall properties, cell-wall responses to mild NaOH pre-treatment, and enzymatic hydrolysis yields. Enzymatic hydrolysis of the cellulose in the untreated maize was found to be positively correlated with the water retention value, which is a measure of cell-wall susceptibility to swelling. It was also positively correlated with the lignin syringyl/guaiacyl ratio and negatively correlated with the initial cell-wall lignin, xylan, acetate, and p-coumaric acid (pCA)more » content, as well as pCA released from the cell wall by pre-treatment. The hydrolysis yield following pre-treatment exhibited statistically significant negative correlations to the lignin content after pre-treatment and positive correlations to the solubilized ferulic acid and pCA. Several unanticipated results were observed, including a positive correlation between initial lignin and acetate content, lack of correlation between acetate content and initial xylan content, and negative correlation between each of these three variables to the hydrolysis yields for untreated maize. Also, another surprising result was that pCA release was negatively correlated with hydrolysis yields for untreated maize and, along with ferulic acid release, was positively correlated with the pre-treated maize hydrolysis yields. In conclusion, this indicates that these properties that may negatively contribute to the recalcitrance in untreated cell walls may positively contribute to their deconstruction by alkaline pre-treatment« less

We wanted to choose us: how embryo donors choose recipients for their surplus embryos.

PubMed

Goedeke, S; Daniels, K

2018-04-01

This study aimed to explore factors affecting donors' choice of recipients for their surplus embryos in the New Zealand context of conditional, known donations. Internationally, embryo donation has a low uptake in spite of large numbers of cryopreserved embryos. Possible reasons include a lack of knowledge about and concern for the future welfare of the resultant offspring. In New Zealand, donors and recipients meet prior to donation and legislation supports disclosure and access to genetic knowledge. Twenty-two embryo donors (10 couples, two individuals) were interviewed between March 2012 and February 2013 about their experiences of donation and factors affecting their donation. Interview data were analysed thematically. In the interests of the welfare of the child resulting from donation, donors were invested in choosing recipients who would make suitable parents. They attempted to choose recipients similar to themselves, as well as those that they trusted to disclose the manner of conception and facilitate agreed-upon information exchange and contact. The interest of donors in ensuring offspring well-being may lend support to conditional forms of open donation, allowing for assessment of recipients' suitability to parent, and for negotiation around information exchange and contact.

Phytotoxical effect of Lepidium draba L. extracts on the germination and growth of monocot (Zea mays L.) and dicot (Amaranthus retroflexus L.) seeds.

PubMed

Kaya, Yusuf; Aksakal, Ozkan; Sunar, Serap; Erturk, Filiz Aygun; Bozari, Sedat; Agar, Guleray; Erez, Mehmet Emre; Battal, Peyami

2015-03-01

Laboratory experiments were performed to determine phytotoxic potentials of white top (Lepidium draba) methanol extracts (root, stem and leaf) on germination and early growth of corn (Zea mays) and redroot pigweed (Amaranthus retroflexus). Furthermore, the effects of different methanol extracts of L. draba on the phytohormone (indole-3-acetic acid (IAA), gibberellic acid (GA), abscisic acid (ABA) and zeatin) levels of corn and redroot pigweed were investigated. It was observed that all concentrations of methanol extracts of root, stem and leaf of L. draba inhibited germination, radicle and plumule elongation when compared with the respective controls. Besides this, the degree of inhibition was increased in concert with increasing concentrations of extracts used. On the other hand, phytohormone levels changed with the application of different extract concentrations. Comparing with the control, the GA levels significantly decreased while the ABA levels increased in all the application groups. Zeatin and IAA levels showed changes depending upon the applied extracts and concentrations. © The Author(s) 2012.

[Relationship between mitochondrial DNA copy number, membrane potential of human embryo and embryo morphology].

PubMed

Zhao, H; Teng, X M; Li, Y F

2017-11-25

Objective: To explore the relationship between the embryo with the different morphological types in the third day and its mitochondrial copy number, the membrane potential. Methods: Totally 117 embryos with poor development after normal fertilization and were not suitable transferred in the fresh cycle and 106 frozen embryos that were discarded voluntarily by infertility patients with in vitro fertilization-embryo transfer after successful pregnancy were selected. According to evaluation of international standard in embryos, all cleavage stage embryos were divided into class Ⅰ frozen embryo group ( n= 64), class Ⅱ frozen embryo group ( n= 42) and class Ⅲ fresh embryonic group (not transplanted embryos; n= 117). Real-time PCR and confocal microscopy methods were used to detect mitochondrial DNA (mtDNA) copy number and the mitochondrial membrane potential of a single embryo. The differences between embryo quality and mtDNA copy number and membrane potential of each group were compared. Results: The copy number of mtDNA and the mitochondrial membrane potential in class Ⅲ fresh embryonic group [(1.7±1.0)×10(5) copy/μl, 1.56±0.32] were significantly lower than those in class Ⅰ frozen embryo group [(3.4±1.7)×10(5) copy/μl, 2.66±0.21] and class Ⅱ frozen embryo group [(2.6±1.2)×10(5) copy/μl, 1.80±0.32; all P< 0.05]. The copy number of mtDNA and the mitochondrial membrane potential in classⅠ frozen embryo group were significantly higher than those in classⅡ frozen embryo group (both P< 0.05). Conclusion: The mtDNA copy number and the mitochondrial membrane potential of embryos of the better quality embryo are higher.

Purification and Properties of Mesophyll and Bundle Sheath Cell α-Glucan Phosphorylases from Zea mays L. 1

PubMed Central

Mateyka, Christian; Schnarrenberger, Claus

1988-01-01

Two major α-glucan phosphorylases (I and II) from leaves of the C4 plant corn (Zea mays L.) were previously shown to be compartmented in mesophyll and bundle sheath cells, respectively (C Mateyka, C Schnarrenberger 1984 Plant Sci Lett 36: 119-123). The two enzymes were separated by chromatography on DEAE-cellulose and purified to homogeneity by affinity chromatography on immobilized starch, according to published procedures, as developed for the cytosol and chloroplast phosphorylase from the C3 plant spinach. The two α-glucan phosphorylases have their pH optimum at pH 7. The specificity for polyglucans was similar for soluble starch and amylopectin, however, differed for glycogen (Km = 16 micrograms per milliliter for the mesophyll cell and 250 micrograms per milliliter for the bundle sheath cell phosphorylase). Maltose, maltotriose, and maltotetraose were not cleaved by either phosphorylase. If maltopentaose was used as substrate, the rate was about twice as high with the bundle sheath cell phosphorylase, than with the mesophyll cell phosphorylase. The phosphorylase I showed a molecular mass of 174 kilodaltons and the phosphorylase II of 195 kilodaltons for the native enzyme and of 87 and of 53 kilodaltons for the SDS-treated proteins, respectively. Specific antisera raised against mesophyll cell phosphorylase from corn leaves and against chloroplast phosphorylase from spinach leaves implied high similarity for the cytosol phosphorylase of the C3 plant spinach with mesophyll cell phosphorylase of the C4 plant corn and of chloroplast phosphorylase of spinach with the bundle sheath cell phosphorylase of corn. Images Fig. 2 Fig. 7 PMID:16665923

Effects of ethylene on the kinetics of curvature and auxin redistribution in gravistimulated roots of Zea mays

NASA Technical Reports Server (NTRS)

Lee, J. S.; Evans, M. L.

1990-01-01

We tested the involvement of ethylene in maize (Zea mays L.) root gravitropism by measuring the kinetics of curvature and lateral auxin movement in roots treated with ethylene, inhibitors of ethylene synthesis, or inhibitors of ethylene action. In the presence of ethylene the latent period of gravitropic curvature appeared to be increased somewhat. However, ethylene-treated roots continued to curve after control roots had reached their final angle of curvature. Consequently, maximum curvature in the presence of ethylene was much greater in ethylene-treated roots than in controls. Inhibitors of ethylene biosynthesis or action had effects on the kinetics of curvature opposite to that of ethylene, i.e. the latent period appeared to be shortened somewhat while total curvature was reduced relative to that of controls. Label from applied 3H-indole-3-acetic acid was preferentially transported toward the lower side of stimulated roots. In parallel with effects on curvature, ethylene treatment delayed the development of gravity-induced asymmetric auxin movement across the root but extended its duration once initiated. The auxin transport inhibitor, 1-N-naphthylphthalamic acid reduced both gravitropic curvature and the effect of ethylene on curvature. Since neither ethylene nor inhibitors of ethylene biosynthesis or action prevented curvature, we conclude that ethylene does not mediate the primary differential growth response causing curvature. Because ethylene affects curvature and auxin transport in parallel, we suggest that ethylene modifies curvature by affecting gravity-induced lateral transport of auxin, perhaps by interfering with adaptation of the auxin transport system to the gravistimulus.

Lessons from Embryos: Haeckel's Embryo Drawings, Evolution, and Secondary Biology Textbooks

ERIC Educational Resources Information Center

Wellner, Karen L.

2014-01-01

In 1997, developmental biologist Michael Richardson compared his research team's embryo photographs to Ernst Haeckel's 1874 embryo drawings and called Haeckel's work "noncredible". "Science" soon published "Haeckel's Embryos: Fraud Rediscovered," and Richardson's comments further reinvigorated criticism of Haeckel by…

Automation and Optimization of Multipulse Laser Zona Drilling of Mouse Embryos During Embryo Biopsy.

PubMed

Wong, Christopher Yee; Mills, James K

2017-03-01

Laser zona drilling (LZD) is a required step in many embryonic surgical procedures, for example, assisted hatching and preimplantation genetic diagnosis. LZD involves the ablation of the zona pellucida (ZP) using a laser while minimizing potentially harmful thermal effects on critical internal cell structures. Develop a method for the automation and optimization of multipulse LZD, applied to cleavage-stage embryos. A two-stage optimization is used. The first stage uses computer vision algorithms to identify embryonic structures and determines the optimal ablation zone farthest away from critical structures such as blastomeres. The second stage combines a genetic algorithm with a previously reported thermal analysis of LZD to optimize the combination of laser pulse locations and pulse durations. The goal is to minimize the peak temperature experienced by the blastomeres while creating the desired opening in the ZP. A proof of concept of the proposed LZD automation and optimization method is demonstrated through experiments on mouse embryos with positive results, as adequately sized openings are created. Automation of LZD is feasible and is a viable step toward the automation of embryo biopsy procedures. LZD is a common but delicate procedure performed by human operators using subjective methods to gauge proper LZD procedure. Automation of LZD removes human error to increase the success rate of LZD. Although the proposed methods are developed for cleavage-stage embryos, the same methods may be applied to most types LZD procedures, embryos at different developmental stages, or nonembryonic cells.

Interchromosomal recombination in Zea mays.

PubMed Central

Hu, W; Timmermans, M C; Messing, J

1998-01-01

A new allele of the 27-kD zein locus in maize has been generated by interchromosomal recombination between chromosomes of two different inbred lines. A continuous patch of at least 11,817 bp of inbred W64A, containing the previously characterized Ra allele of the 27-kD zein gene, has been inserted into the genome of A188 by a single crossover. While both junction sequences are conserved, sequences of the two homologs between these junctions differ considerably. W64A contains the 7313-bp-long retrotransposon, Zeon-1. A188 contains a second copy of the 27-kD zein gene and a 2-kb repetitive element. Therefore, recombination results in a 7.3-kb insertion and a 14-kb deletion compared to the original S+A188 allele. If nonpairing sequences are looped out, 206 single base changes, frequently clustered, are present. The structure of this allele may explain how a recently discovered example of somatic recombination occurred in an A188/W64A hybrid. This would indicate that despite these sequence differences, pairing between these alleles could occur early during plant development. Therefore, such a somatically derived chimeric chromosome can also be heritable and give rise to new alleles. PMID:9799274

Lipid Extracted Microalgal Biomass Residue as a Fertilizer Substitute for Zea mays L.

PubMed Central

Maurya, Rahulkumar; Chokshi, Kaumeel; Ghosh, Tonmoy; Trivedi, Khanjan; Pancha, Imran; Kubavat, Denish; Mishra, Sandhya; Ghosh, Arup

2016-01-01

High volumes of lipid extracted microalgal biomass residues (LMBRs) are expected to be produced upon commencement of biodiesel production on a large scale, thus necessitating its value addition for sustainable development. LMBRs of Chlorella variabilis and Lyngbya majuscula were employed to substitute the nitrogen content of recommended rate of fertilizer (RRF) for Zea mays L. The pot experiment comprised of 10 treatments, i.e., T1 (No fertilizer); T2 (RRF-120 N: 60 P2O5: 40 K2O kg ha−1); T3 to T6—100, 75, 50, and 25% N through LMBR of the Chlorella sp., respectively; T7 to T10—100, 75, 50, and 25% N through LMBR of Lyngbya sp., respectively. It was found that all LMBR substitution treatments were at par to RRF with respect to grain yield production. T10 gave the highest grain yield (65.16 g plant−1), which was closely followed by that (63.48 g plant−1) under T5. T10 also recorded the highest phosphorus and potassium contents in grains. T4 was markedly superior over control in terms of dry matter accumulation (DMA) as well as carbohydrate content, which was ascribed to higher pigment content and photosynthetic activity in leaves. Even though considerably lower DMA was obtained in Lyngbya treatments, which might have been due to the presence of some toxic factors, no reduction in grain yield was apparent. The length of the tassel was significantly higher in either of the LMBRs at any substitution rates over RRF, except T6 and T7. The ascorbate peroxidase activity decreased with decreasing dose of Chlorella LMBR, while all the Lyngbya LMBR treatments recorded lower activity, which were at par with each other. Among the Chlorella treatments, only T5 recorded significantly higher values of glutathione reductase activity over RRF, while the rest were at par. There were significant increases in carbohydrate and crude fat, respectively, only in T4 and T3 over RRF, while no change was observed in crude protein due to LMBR treatments. Apparently, there was no

Lipid Extracted Microalgal Biomass Residue as a Fertilizer Substitute for Zea mays L.

PubMed

Maurya, Rahulkumar; Chokshi, Kaumeel; Ghosh, Tonmoy; Trivedi, Khanjan; Pancha, Imran; Kubavat, Denish; Mishra, Sandhya; Ghosh, Arup

2015-01-01

High volumes of lipid extracted microalgal biomass residues (LMBRs) are expected to be produced upon commencement of biodiesel production on a large scale, thus necessitating its value addition for sustainable development. LMBRs of Chlorella variabilis and Lyngbya majuscula were employed to substitute the nitrogen content of recommended rate of fertilizer (RRF) for Zea mays L. The pot experiment comprised of 10 treatments, i.e., T1 (No fertilizer); T2 (RRF-120 N: 60 P2O5: 40 K2O kg ha(-1)); T3 to T6-100, 75, 50, and 25% N through LMBR of the Chlorella sp., respectively; T7 to T10-100, 75, 50, and 25% N through LMBR of Lyngbya sp., respectively. It was found that all LMBR substitution treatments were at par to RRF with respect to grain yield production. T10 gave the highest grain yield (65.16 g plant(-1)), which was closely followed by that (63.48 g plant(-1)) under T5. T10 also recorded the highest phosphorus and potassium contents in grains. T4 was markedly superior over control in terms of dry matter accumulation (DMA) as well as carbohydrate content, which was ascribed to higher pigment content and photosynthetic activity in leaves. Even though considerably lower DMA was obtained in Lyngbya treatments, which might have been due to the presence of some toxic factors, no reduction in grain yield was apparent. The length of the tassel was significantly higher in either of the LMBRs at any substitution rates over RRF, except T6 and T7. The ascorbate peroxidase activity decreased with decreasing dose of Chlorella LMBR, while all the Lyngbya LMBR treatments recorded lower activity, which were at par with each other. Among the Chlorella treatments, only T5 recorded significantly higher values of glutathione reductase activity over RRF, while the rest were at par. There were significant increases in carbohydrate and crude fat, respectively, only in T4 and T3 over RRF, while no change was observed in crude protein due to LMBR treatments. Apparently, there was no

Miniaturized Embryo Array for Automated Trapping, Immobilization and Microperfusion of Zebrafish Embryos

PubMed Central

Akagi, Jin; Khoshmanesh, Khashayar; Evans, Barbara; Hall, Chris J.; Crosier, Kathryn E.; Cooper, Jonathan M.; Crosier, Philip S.; Wlodkowic, Donald

2012-01-01

Zebrafish (Danio rerio) has recently emerged as a powerful experimental model in drug discovery and environmental toxicology. Drug discovery screens performed on zebrafish embryos mirror with a high level of accuracy the tests usually performed on mammalian animal models, and fish embryo toxicity assay (FET) is one of the most promising alternative approaches to acute ecotoxicity testing with adult fish. Notwithstanding this, automated in-situ analysis of zebrafish embryos is still deeply in its infancy. This is mostly due to the inherent limitations of conventional techniques and the fact that metazoan organisms are not easily susceptible to laboratory automation. In this work, we describe the development of an innovative miniaturized chip-based device for the in-situ analysis of zebrafish embryos. We present evidence that automatic, hydrodynamic positioning, trapping and long-term immobilization of single embryos inside the microfluidic chips can be combined with time-lapse imaging to provide real-time developmental analysis. Our platform, fabricated using biocompatible polymer molding technology, enables rapid trapping of embryos in low shear stress zones, uniform drug microperfusion and high-resolution imaging without the need of manual embryo handling at various developmental stages. The device provides a highly controllable fluidic microenvironment and post-analysis eleuthero-embryo stage recovery. Throughout the incubation, the position of individual embryos is registered. Importantly, we also for first time show that microfluidic embryo array technology can be effectively used for the analysis of anti-angiogenic compounds using transgenic zebrafish line (fli1a:EGFP). The work provides a new rationale for rapid and automated manipulation and analysis of developing zebrafish embryos at a large scale. PMID:22606275

A novel beta-glucosidase from the cell wall of maize (Zea mays L.): rapid purification and partial characterization

NASA Technical Reports Server (NTRS)

Nematollahi, W. P.; Roux, S. J.

1999-01-01

Plants have a variety of glycosidic conjugates of hormones, defense compounds, and other molecules that are hydrolyzed by beta-glucosidases (beta-D-glucoside glucohydrolases, E.C. 3.2.1.21). Workers have reported several beta-glucosidases from maize (Zea mays L.; Poaceae), but have localized them mostly by indirect means. We have purified and partly characterized a 58-Ku beta-glucosidase from maize, which we conclude from a partial sequence analysis, from kinetic data, and from its localization is not identical to any of those already reported. A monoclonal antibody, mWP 19, binds this enzyme, and localizes it in the cell walls of maize coleoptiles. An earlier report showed that mWP19 inhibits peroxidase activity in crude cell wall extracts and can immunoprecipitate peroxidase activity from these extracts, yet purified preparations of the 58 Ku protein had little or no peroxidase activity. The level of sequence similarity between beta-glucosidases and peroxidases makes it unlikely that these enzymes share epitopes in common. Contrary to a previous conclusion, these results suggest that the enzyme recognized by mWP19 is not a peroxidase, but there is a wall peroxidase closely associated with the 58 Ku beta-glucosidase in crude preparations. Other workers also have co-purified distinct proteins with beta-glucosidases. We found no significant charge in the level of immunodetectable beta-glucosidase in mesocotyls or coleoptiles that precedes the red light-induced changes in the growth rate of these tissues.

Deciphering the role of NADPH oxidase in complex interactions between maize (Zea mays L.) genotypes and cereal aphids.

PubMed

Sytykiewicz, Hubert

2016-07-22

Plant NADPH oxidases (NOXs) encompass a group of membrane-bound enzymes participating in formation of reactive oxygen species (ROS) under physiological conditions as well as in response to environmental stressors. The purpose of the survey was to unveil the role of NADPH oxidase in pro-oxidative responses of maize (Zea mays L.) seedling leaves exposed to cereal aphids' infestation. The impact of apteral females of bird cherry-oat aphid (Rhopalosiphum padi L.) and grain aphid (Sitobion avenae F.) feeding on expression levels of all four NADPH oxidase genes (rbohA, rbohB, rbohC, rbohD) and total activity of NOX enzyme in maize plants were investigated. In addition, inhibitory effect of diphenylene iodonium (DPI) pre-treatment on NOX activity and hydrogen peroxide content in aphid-stressed maize seedlings was studied. Leaf infestation biotests were accomplished on 14-day-old seedlings representing two aphid-resistant varieties (Ambrozja and Waza) and two aphid-susceptible ones (Tasty Sweet and Złota Karłowa). Insects' attack led to profound upregulation of rbohA and rbohD genes in tested host plants, lower elevations were noted in level of rbohB mRNA, whereas abundance of rbohC transcript was not significantly altered. It was uncovered aphid-induced enhancement of NOX activity in examined plants. Higher increases in expression of all investigated rboh genes and activity of NADPH oxidase occurred in tissues of more resistant maize cultivars than in susceptible ones. Furthermore, DPI treatment resulted in strong reduction of NOX activity and H2O2 accumulation in aphid-infested Z. mays plants, thus evidencing circumstantial role of the enzyme in insect-elicited ROS generation. Copyright © 2016 Elsevier Inc. All rights reserved.

Embryo deaths in reproduction and embryo research: a reply to Murphy's double effect argument.

PubMed

Devolder, Katrien

2013-08-01

The majority of embryos created in natural reproduction die spontaneously within a few weeks of conception. Some have argued that, therefore, if one believes the embryo is a person (in the normative sense) one should find 'natural' reproduction morally problematic. An extension of this argument holds that, if one accepts embryo deaths in natural reproduction, consistency requires that one also accepts embryo deaths that occur in (i) assisted reproduction via in vitro fertilisation (IVF) and (ii) embryo research. In a recent paper in this journal, Timothy Murphy criticises both the initial argument and its extension. Murphy argues that double-effect reasoning can justify embryo deaths both in natural reproduction and IVF, but not in embryo research. Thus, according to Murphy, one can, without being inconsistent, (1) believe the embryo is a person and accept natural reproduction and IVF, and (2) accept natural reproduction and IVF, while rejecting embryo research on the ground that it involves embryo deaths. I show that Murphy's argument is problematic because double effect cannot justify embryo deaths in standard IVF practices. The problem is that the proportionality criterion of double effect is not met by such practices. Thus, Murphy's argument fails to support (1) and (2). An implication of his argument failing to support (2) is that it does not defeat the position I have defended in the past-that if one accepts standard IVF practices one should also accept embryo research, including research with embryos created solely for that purpose.

Identification and suppression of the p-coumaroyl CoA:hydroxycinnamyl alcohol transferase in Zea mays L.

PubMed

Marita, Jane M; Hatfield, Ronald D; Rancour, David M; Frost, Kenneth E

2014-06-01

Grasses, such as Zea mays L. (maize), contain relatively high levels of p-coumarates (pCA) within their cell walls. Incorporation of pCA into cell walls is believed to be due to a hydroxycinnamyl transferase that couples pCA to monolignols. To understand the role of pCA in maize development, the p-coumaroyl CoA:hydroxycinnamyl alcohol transferase (pCAT) was isolated and purified from maize stems. Purified pCAT was subjected to partial trypsin digestion, and peptides were sequenced by tandem mass spectrometry. TBLASTN analysis of the acquired peptide sequences identified a single full-length maize cDNA clone encoding all the peptide sequences obtained from the purified enzyme. The cDNA clone was obtained and used to generate an RNAi construct for suppressing pCAT expression in maize. Here we describe the effects of suppression of pCAT in maize. Primary screening of transgenic maize seedling leaves using a new rapid analytical platform was used to identify plants with decreased amounts of pCA. Using this screening method, mature leaves from fully developed plants were analyzed, confirming reduced pCA levels throughout plant development. Complete analysis of isolated cell walls from mature transgenic stems and leaves revealed that lignin levels did not change, but pCA levels decreased and the lignin composition was altered. Transgenic plants with the lowest levels of pCA had decreased levels of syringyl units in the lignin. Thus, altering the levels of pCAT expression in maize leads to altered lignin composition, but does not appear to alter the total amount of lignin present in the cell walls. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

Genomic Analysis of the DNA Replication Timing Program during Mitotic S Phase in Maize (Zea mays) Root Tips[OPEN

PubMed Central

LeBlanc, Chantal; Lee, Tae-Jin; Mulvaney, Patrick; Allen, George C.; Martienssen, Robert A.; Thompson, William F.

2017-01-01

All plants and animals must replicate their DNA, using a regulated process to ensure that their genomes are completely and accurately replicated. DNA replication timing programs have been extensively studied in yeast and animal systems, but much less is known about the replication programs of plants. We report a novel adaptation of the “Repli-seq” assay for use in intact root tips of maize (Zea mays) that includes several different cell lineages and present whole-genome replication timing profiles from cells in early, mid, and late S phase of the mitotic cell cycle. Maize root tips have a complex replication timing program, including regions of distinct early, mid, and late S replication that each constitute between 20 and 24% of the genome, as well as other loci corresponding to ∼32% of the genome that exhibit replication activity in two different time windows. Analyses of genomic, transcriptional, and chromatin features of the euchromatic portion of the maize genome provide evidence for a gradient of early replicating, open chromatin that transitions gradually to less open and less transcriptionally active chromatin replicating in mid S phase. Our genomic level analysis also demonstrated that the centromere core replicates in mid S, before heavily compacted classical heterochromatin, including pericentromeres and knobs, which replicate during late S phase. PMID:28842533

Characterization of ApB73, a virulence factor important for colonization of Zea mays by the smut Ustilago maydis.

PubMed

Stirnberg, Alexandra; Djamei, Armin

2016-12-01

The biotrophic fungus Ustilago maydis, the causal agent of corn smut disease, uses numerous small secreted effector proteins to suppress plant defence responses and reshape the host metabolism. However, the role of specific effectors remains poorly understood. Here, we describe the identification of ApB73 (Apathogenic in B73), an as yet uncharacterized protein essential for the successful colonization of maize by U. maydis. We show that apB73 is transcriptionally induced during the biotrophic stages of the fungal life cycle. The deletion of the apB73 gene results in cultivar-specific loss of gall formation in the host. The ApB73 protein is conserved among closely related smut fungi. However, using virulence assays, we show that only the orthologue of the maize-infecting head smut Sporisorium reilianum can complement the mutant phenotype of U. maydis. Although microscopy shows that ApB73 is secreted into the biotrophic interface, it seems to remain associated with fungal cell wall components or the fungal plasma membrane. Taken together, the results show that ApB73 is a conserved and important virulence factor of U. maydis that localizes to the interface between the pathogen and its host Zea mays. © 2016 THE AUTHORS. MOLECULAR PLANT PATHOLOGY PUBLISHED BY BRITISH SOCIETY FOR PLANT PATHOLOGY AND JOHN WILEY & SONS LTD.

Comparative study on the nutritional and antioxidant properties of two Mexican corn (Zea mays) based meals versus processed cereals.

PubMed

Sánchez-Herrera, Marissa; Martínez-Cano, Evelia; Maldonado-Santoyo, María; Aparicio-Fernández, Xochitl

2014-06-01

The present study was conducted to analyze the chemical composition, total phenolics content and antioxidant capacity of two whole corn (Zea mays) based meals traditional from Mexico: "traditional pinole" and "seven grain pinole"; and compare it with information available from ready to eat cereal products based on refined corn and whole grain cereals. Proximate analyses (moisture, ash, fat, protein and fiber) were carried out according to the procedures of AOAC, sugars content was determined by HPLC method; calcium and iron were quantified using atomic absorption spectroscopy. Total phenolic compounds were determined by Folin-Ciocalteu spectrophotometric method; the antiradical capacity was determined by DPPH colorimetric method and total antioxidant capacity was determined by FRAP method. Traditional and seven grain pinole presented higher energy content and nutrient density (protein and fat) than processed cereals. Calcium content was higher in processed cereals than pinole; seven grain pinole presented the highest conentration of iron. Polyphenolic concentration was higher in both kinds of pinole compared to processed cereals; traditional pinole presented the highest antioxidant activity measured by DPPH and FRAP methods. The results provide evidence about the important nutrient and antioxidant content of traditional and seven grain pinole compared to processed cereals based on corn and other grains. It is recommended their incorporation in to regular diet as a healthy food, with a good protein level, low sugar content and good antioxidant capacity.

Unraveling the role of dark septate endophyte (DSE) colonizing maize (Zea mays) under cadmium stress: physiological, cytological and genic aspects.

PubMed

Wang, Jun-ling; Li, Tao; Liu, Gao-yuan; Smith, Joshua M; Zhao, Zhi-wei

2016-02-25

A growing body of evidence suggests that plant root-associated fungi such as dark septate endophytes (DSE) can help plants overcome many biotic and abiotic stresses, of great interest is DSE-plant metal tolerance and alleviation capabilities on contaminated soils. However, the tolerance and alleviation mechanisms involved have not yet been elucidated. In the current study, the regulation and physiological response of Zea mays to its root-associated DSE, Exophiala pisciphila was analyzed under increased soil Cd stress (0, 10, 50, 100 mg kg(-1)). Under Cd stress, DSE inoculation significantly enhanced the activities of antioxidant enzymes and low-molecular weight antioxidants, while also inducing increased Cd accumulation in the cell wall and conversion of Cd into inactive forms by shoot and root specific regulation of genes related to metal uptake, translocation and chelation. Our results showed that DSE colonization resulted in a marked tolerance to Cd, with a significant decrease in cadmium phytotoxicity and a significant increase in maize growth by triggering antioxidant systems, altering metal chemical forms into inactive Cd, and repartitioning subcellular Cd into the cell wall. These results provide comprehensive evidence for the mechanisms by which DSE colonization bioaugments Cd tolerance in maize at physiological, cytological and molecular levels.

Unraveling the role of dark septate endophyte (DSE) colonizing maize (Zea mays) under cadmium stress: physiological, cytological and genic aspects

NASA Astrophysics Data System (ADS)

Wang, Jun-Ling; Li, Tao; Liu, Gao-Yuan; Smith, Joshua M.; Zhao, Zhi-Wei

2016-02-01

A growing body of evidence suggests that plant root-associated fungi such as dark septate endophytes (DSE) can help plants overcome many biotic and abiotic stresses, of great interest is DSE-plant metal tolerance and alleviation capabilities on contaminated soils. However, the tolerance and alleviation mechanisms involved have not yet been elucidated. In the current study, the regulation and physiological response of Zea mays to its root-associated DSE, Exophiala pisciphila was analyzed under increased soil Cd stress (0, 10, 50, 100 mg kg-1). Under Cd stress, DSE inoculation significantly enhanced the activities of antioxidant enzymes and low-molecular weight antioxidants, while also inducing increased Cd accumulation in the cell wall and conversion of Cd into inactive forms by shoot and root specific regulation of genes related to metal uptake, translocation and chelation. Our results showed that DSE colonization resulted in a marked tolerance to Cd, with a significant decrease in cadmium phytotoxicity and a significant increase in maize growth by triggering antioxidant systems, altering metal chemical forms into inactive Cd, and repartitioning subcellular Cd into the cell wall. These results provide comprehensive evidence for the mechanisms by which DSE colonization bioaugments Cd tolerance in maize at physiological, cytological and molecular levels.

Embryo transcriptome response to environmental factors: implication for its survival under suboptimal conditions.

PubMed

Salilew-Wondim, Dessie; Tesfaye, Dawit; Hoelker, Michael; Schellander, Karl

2014-09-01

After its formation, the mammalian zygote undergoes a series of morphological, physiological and biochemical alterations prior to undergoing cell differentiation. The zygote is then transformed into a complex multicellular organism in a defined time window which may differ between species. These orderly embryonic developmental events are tightly regulated by temporal and spatial activation and/or deactivation of genes and gene products. This phenomenon may in turn be dependent on the intrinsic characteristics of the embryo itself, the physiological and biochemical composition of the maternal environment or by in vitro culture condition. In fact, when embryos are subjected to suboptimal culture condition, some of the embryos may escape the environmental stress by activating certain transcripts and some others which are unable to activate anti-stress agents may die or exhibit abnormal development. This phenomenon may partly depend on transcripts and proteins stored during oogenesis. Indeed after embryonic genome activation, the embryo destiny is governed by its own transcripts and protein synthesized over time. Therefore, this review begins by highlighting the type and quality of transcripts accumulated or degraded during oogenesis and its impact on the embryo survival. Thereafter, emphasis is given to the transcriptome response of preimplantation embryos to suboptimal culture conditions. In addition, the long term effect of preimplantation culture environment on the transcriptome response embryos/fetus during peri and post implantation has been addressed. Finally, a brief summary of the epigenetic control of culture induced genetic variation of the embryos has been highlighted. Copyright © 2014 Elsevier B.V. All rights reserved.

Emergence and patterning of the five cell types of the Zea mays anther locule

PubMed Central

Kelliher, Timothy; Walbot, Virginia

2011-01-01

One fundamental difference between plants and animals is the existence of a germ-line in animals and its absence in plants. In flowering plants the sexual organs (stamens and carpels) are composed almost entirely of somatic cells, a small subset of which switch to meiosis, however, the mechanism of meiotic cell fate acquisition is a long-standing botanical mystery. In the maize (Zea mays) anther microsporangium the somatic tissues consist of four concentric cell layers which surround and support reproductive cells as they progress through meiosis and pollen maturation. Male sterility, defined as the absence of viable pollen, is a common phenotype in flowering plants, and many male sterile mutants have defects in somatic and reproductive cell fate acquisition. However, without a robust model of anther cell fate acquisition based on careful observation of wild type anther ontogeny, interpretation of cell fate mutants is limited. To address this, the pattern of cell proliferation, expansion, and differentiation was tracked in three dimensions over thirty days of wild type (W23) anther development, using anthers stained with propidium iodide (PI) and/or 5-ethynyl-2′-deoxyuridine (EdU) (S-phase label) and imaged by confocal microscopy. The pervading lineage model of anther development claims that new cell layers are generated by coordinated, oriented cell divisions in transient precursor cell types. In reconstructing anther cell division patterns, however, we can only confirm this for the origin of the middle layer (ml) and tapetum, while young anther development appears more complex. We find that each anther cell type undergoes a burst of cell division after specification with a characteristic pattern of both cell expansion and division. Comparisons between two inbreds lines and between ab- and adaxial anther florets indicated near identity: anther development is highly canalized and synchronized. Three classical models of plant organ development are tested and ruled

Cell-wall properties contributing to improved deconstruction by alkaline pre-treatment and enzymatic hydrolysis in diverse maize (Zea mays L.) lines.

PubMed

Li, Muyang; Heckwolf, Marlies; Crowe, Jacob D; Williams, Daniel L; Magee, Timothy D; Kaeppler, Shawn M; de Leon, Natalia; Hodge, David B

2015-07-01

A maize (Zea mays L. subsp. mays) diversity panel consisting of 26 maize lines exhibiting a wide range of cell-wall properties and responses to hydrolysis by cellulolytic enzymes was employed to investigate the relationship between cell-wall properties, cell-wall responses to mild NaOH pre-treatment, and enzymatic hydrolysis yields. Enzymatic hydrolysis of the cellulose in the untreated maize was found to be positively correlated with the water retention value, which is a measure of cell-wall susceptibility to swelling. It was also positively correlated with the lignin syringyl/guaiacyl ratio and negatively correlated with the initial cell-wall lignin, xylan, acetate, and p-coumaric acid (pCA) content, as well as pCA released from the cell wall by pre-treatment. The hydrolysis yield following pre-treatment exhibited statistically significant negative correlations to the lignin content after pre-treatment and positive correlations to the solubilized ferulic acid and pCA. Several unanticipated results were observed, including a positive correlation between initial lignin and acetate content, lack of correlation between acetate content and initial xylan content, and negative correlation between each of these three variables to the hydrolysis yields for untreated maize. Another surprising result was that pCA release was negatively correlated with hydrolysis yields for untreated maize and, along with ferulic acid release, was positively correlated with the pre-treated maize hydrolysis yields. This indicates that these properties that may negatively contribute to the recalcitrance in untreated cell walls may positively contribute to their deconstruction by alkaline pre-treatment. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

A dysmorphology score system for assessing embryo abnormalities in rat whole embryo culture.

PubMed

Zhang, Cindy X; Danberry, Tracy; Jacobs, Mary Ann; Augustine-Rauch, Karen

2010-12-01

The rodent whole embryo culture (WEC) system is a well-established model for characterizing developmental toxicity of test compounds and conducting mechanistic studies. Laboratories have taken various approaches in describing type and severity of developmental findings of organogenesis-stage rodent embryos, but the Brown and Fabro morphological score system is commonly used as a quantitative approach. The associated score criteria is based upon developmental stage and growth parameters, where a series of embryonic structures are assessed and assigned respective scores relative to their gestational stage, with a Total Morphological Score (TMS) assigned to the embryo. This score system is beneficial because it assesses a series of stage-specific anatomical landmarks, facilitating harmonized evaluation across laboratories. Although the TMS provides a quantitative approach to assess growth and determine developmental delay, it is limited to its ability to identify and/or delineate subtle or structure-specific abnormalities. Because of this, the TMS may not be sufficiently sensitive for identifying compounds that induce structure or organ-selective effects. This study describes a distinct morphological score system called the "Dysmorphology Score System (DMS system)" that has been developed for assessing gestation day 11 (approximately 20-26 somite stage) rat embryos using numerical scores to differentiate normal from abnormal morphology and define the respective severity of dysmorphology of specific embryonic structures and organ systems. This method can also be used in scoring mouse embryos of the equivalent developmental stage. The DMS system enhances capabilities to rank-order compounds based upon teratogenic potency, conduct structure- relationships of chemicals, and develop statistical prediction models to support abbreviated developmental toxicity screens. © 2010 Wiley-Liss, Inc.

Genome-Wide Identification and Characterization of microRNAs in Developing Grains of Zea mays L.

PubMed Central

Gao, Lei; Wang, Lifang; Gao, Meijuan; Jiao, Zhujin; Qiao, Huili; Yang, Jianwei; Chen, Min; Yao, Lunguang; Liu, Renyi; Kan, Yunchao

2016-01-01

The development and maturation of maize kernel involves meticulous and fine gene regulation at transcriptional and post-transcriptional levels, and miRNAs play important roles during this process. Although a number of miRNAs have been identified in maize seed, the ones involved in the early development of grains and in different lines of maize have not been well studied. Here, we profiled four small RNA libraries, each constructed from groups of immature grains of Zea mays inbred line Chang 7–2 collected 4–6, 7–9, 12–14, and 18–23 days after pollination (DAP). A total of 40 known (containing 111 unique miRNAs) and 162 novel (containing 196 unique miRNA candidates) miRNA families were identified. For conserved and novel miRNAs with over 100 total reads, 44% had higher accumulation before the 9th DAP, especially miR166 family members. 42% of miRNAs had highest accumulation during 12–14 DAP (which is the transition stage from embryogenesis to nutrient storage). Only 14% of miRNAs had higher expression 18–23 DAP. Prediction of potential targets of all miRNAs showed that 165 miRNA families had 377 target genes. For miR164 and miR166, we showed that the transcriptional levels of their target genes were significantly decreased when co-expressed with their cognate miRNA precursors in vivo. Further analysis shows miR159, miR164, miR166, miR171, miR390, miR399, and miR529 families have putative roles in the embryogenesis of maize grain development by participating in transcriptional regulation and morphogenesis, while miR167 and miR528 families participate in metabolism process and stress response during nutrient storage. Our study is the first to present an integrated dynamic expression pattern of miRNAs during maize kernel formation and maturation. PMID:27082634

Comprehensive embryo testing. Experts' opinions regarding future directions: an expert panel study on comprehensive embryo testing.

PubMed

Hens, Kristien; Dondorp, Wybo J; Geraedts, Joep P M; de Wert, Guido M

2013-05-01

four Western Europe countries. As willingness to participate in this study may be connected with expectations regarding the pace and direction of future developments, selection bias cannot be excluded. The introduction of comprehensive screening techniques in embryo testing calls for further ethical reflection that is grounded in empirical work. Specifically, there is a need for studies querying the opinions of infertile couples undergoing IVF/PGS regarding the desirability of embryo screening beyond aneuploidy. This research was supported by the CSG, Centre for Society and Life Sciences (project number: 70.1.074). The authors declare no conflict of interest. N/A.

Secretion of interferon-tau by bovine embryos in long-term culture: comparison of in vivo derived, in vitro produced, nuclear transfer and demi-embryos.

PubMed

Stojkovic, M; Büttner, M; Zakhartchenko, V; Riedl, J; Reichenbach, H D; Wenigerkind, H; Brem, G; Wolf, E

1999-04-30

Interferon-tau (IFNtau) is the pregnancy recognition signal of bovine embryos, inhibiting luteolysis. We studied trophoblastic growth and IFNtau secretion of embryos with different developmental potential, i.e., in vivo derived and in vitro produced embryos, cloned embryos and demi-embryos, to evaluate if the ability of secreting IFNtau might be responsible for differences in pregnancy rates after transfer of these categories of embryos to recipients. Day 8 embryos of excellent quality were individually placed in microdrops of buffalo rat liver cell-conditioned medium and maintained for up to 23 days. Embryos were observed on Days 11, 15, 19 and 23, the mean diameter (2r) of attached and spherical embryos was measured, and their trophoblastic area was calculated as r2pi or 4r2pi, respectively. Simultaneously, medium was changed and the IFNtau levels of conditioned media were determined using a bioassay of antiviral activity. Trophoblastic area was smaller (P < 0.05) in demi-embryos than in all other groups, which exhibited similar trophoblastic growth until Day 19. However, on Day 23 trophoblastic area of in vivo derived embryos was more than twice (P < 0.05) as large as those of in vitro produced and nuclear transfer (NT) embryos. IFNtau levels increased only slowly with time in culture of demi-embryos. By contrast, the level of IFNtau doubled from Day 11 to Day 15 in conditioned media from all other groups of embryos. The linear increase in IFNtau production of vivo and in vitro derived embryos continued until the end of the culture period, whereas conditioned media from NT embryos contained significantly (P < 0.05) less IFNtau activity on Days 19 and 23 than those of the former two groups. Our results demonstrate different capabilities of secreting IFNtau for in vivo derived and in vitro produced embryos vs. NT and demi-embryos, which may--at least part--be responsible for the differences in pregnancy rates after transfer to recipients.

Characterization of somatic embryo attached structures in Feijoa sellowiana Berg. (Myrtaceae).

PubMed

Correia, Sandra M; Canhoto, Jorge M

2010-06-01

The presence of an attached organ to somatic embryos of angiosperms connecting the embryo to the supporting tissue has been a subject of controversy. This study shows that 67% of the morphologically normal somatic embryos of Feijoa sellowiana possess this type of organ and that its formation was not affected by culture media composition. Histological and ultrastructural analysis indicated that the attached structures of somatic embryos displayed a great morphological diversity ranging from a few cells to massive and columnar structures. This contrast with the simple suspensors observed in zygotic embryos which were only formed by five cells. As well as the suspensor of zygotic embryos, somatic embryo attached structures undergo a process of degeneration in later stages of embryo development. Other characteristic shared by zygotic suspensors and somatic embryo attached structures was the presence of thick cell walls surrounding the cells. Elongated thin filaments were often associated with the structures attached to somatic embryos, whereas in other cases, tubular cells containing starch grains connected the embryo to the supporting tissue. These characteristics associated with the presence of plasmodesmata in the cells of the attached structures seem to indicate a role on embryo nutrition. However, cell proliferation in the attached structures resulting into new somatic embryos may also suggest a more complex relationship between the embryo and the structures connecting it to the supporting tissue.

Chilling-induced physiological, anatomical and biochemical responses in the leaves of Miscanthus × giganteus and maize (Zea mays L.).

PubMed

Bilska-Kos, Anna; Panek, Piotr; Szulc-Głaz, Anna; Ochodzki, Piotr; Cisło, Aneta; Zebrowski, Jacek

2018-06-08

Miscanthus × giganteus and Zea mays, closely-related C 4 grasses, originated from warm climates react differently to low temperature. To investigate the response to cold (12-14 °C) in these species, the photosynthetic and anatomical parameters as well as biochemical properties of the cell wall were studied. The research was performed using M. giganteus (MG) and two Z. mays lines differentiated for chilling-sensitivity: chilling-tolerant (Zm-T) and chilling-sensitive (Zm-S). The chilled plants of Zm-S line demonstrated strong inhibition of net CO 2 assimilation and a clear decrease in F' v /F' m , F v /F m and ɸ PSII, while in MG and Zm-T plants these parameters were almost unchanged. The anatomical studies revealed that MG plants had thinner leaves, epidermis and mesophyll cell layer as well as thicker cell walls in the comparison to both maize lines. Cold led to an increase in leaf thickness and mesophyll cell layer thickness in the Zm-T maize line, while the opposite response was observed in Zm-S. In turn, in chilled plants of MG and Zm-T lines, some anatomical parameters associated with bundle sheath cells were higher. In addition, Zm-S line showed the strong increase in the cell wall thickness at cold for mesophyll and bundle sheath cells. Chilling-treatment induced the changes in the cell wall biochemistry of tested species, mainly in the content of glucuronoarabinoxylan, uronic acid, β-glucan and phenolic compounds. This work presents a new approach in searching of mechanism(s) of tolerance/sensitivity to low temperature in two thermophilic plants: Miscanthus and maize. Copyright © 2018 Elsevier GmbH. All rights reserved.

Deliberate ROS production and auxin synergistically trigger the asymmetrical division generating the subsidiary cells in Zea mays stomatal complexes.

PubMed

Livanos, Pantelis; Galatis, Basil; Apostolakos, Panagiotis

2016-07-01

Subsidiary cell generation in Poaceae is an outstanding example of local intercellular stimulation. An inductive stimulus emanates from the guard cell mother cells (GMCs) towards their laterally adjacent subsidiary cell mother cells (SMCs) and triggers the asymmetrical division of the latter. Indole-3-acetic acid (IAA) immunolocalization in Zea mays protoderm confirmed that the GMCs function as local sources of auxin and revealed that auxin is polarly accumulated between GMCs and SMCs in a timely-dependent manner. Besides, staining techniques showed that reactive oxygen species (ROS) exhibit a closely similar, also time-dependent, pattern of appearance suggesting ROS implication in subsidiary cell formation. This phenomenon was further investigated by using the specific NADPH-oxidase inhibitor diphenylene iodonium, the ROS scavenger N-acetyl-cysteine, menadione which leads to ROS overproduction, and H2O2. Treatments with diphenylene iodonium, N-acetyl-cysteine, and menadione specifically blocked SMC polarization and asymmetrical division. In contrast, H2O2 promoted the establishment of SMC polarity and subsequently subsidiary cell formation in "younger" protodermal areas. Surprisingly, H2O2 favored the asymmetrical division of the intervening cells of the stomatal rows leading to the creation of extra apical subsidiary cells. Moreover, H2O2 altered IAA localization, whereas synthetic auxin analogue 1-napthaleneacetic acid enhanced ROS accumulation. Combined treatments with ROS modulators along with 1-napthaleneacetic acid or 2,3,5-triiodobenzoic acid, an auxin efflux inhibitor, confirmed the crosstalk between ROS and auxin functioning during subsidiary cell generation. Collectively, our results demonstrate that ROS are critical partners of auxin during development of Z. mays stomatal complexes. The interplay between auxin and ROS seems to be spatially and temporarily regulated.

Effect of embryo source and recipient progesterone environment on embryo development in cattle.

PubMed

Lonergan, P; Woods, A; Fair, T; Carter, F; Rizos, D; Ward, F; Quinn, K; Evans, A

2007-01-01

The aim of the present study was to examine the effect of embryo source (in vivo v. in vitro) and the progesterone environment into which it was transferred on Day 7 on embryo survival and size on Day 13. Day 7 blastocysts were produced either in vivo using superovulation, artificial insemination and non-surgical embryo recovery or in vitro using in vitro maturation, fertilisation and culture. In order to produce animals with divergent progesterone concentrations, following synchronisation recipients were either superovulated (High progesterone; n = 10) or not (Control progesterone; n = 10). Ten blastocysts, produced either in vivo or in vitro, were transferred to each recipient on Day 7. Both groups were killed on Day 13. The mean progesterone concentration from Day 7 to Day 13 (the period when the embryos were in the uterus) in the High and Control progesterone recipients was 36.32 +/- 1.28 and 10.30 +/- 0.51 ng mL(-1), respectively. Of the in vivo embryos transferred, the overall recovery rate at Day 13 was 64%, which was higher (P < 0.001) than that of 20% for the in vitro embryos transferred. The mean area of embryos recovered from High progesterone recipients was 3.86 +/- 0.45 mm(2) (n = 28) compared with 1.66 +/- 0.38 mm(2) (n = 24) for embryos recovered from Control progesterone recipients (P < 0.001). Similarly, the origin of the embryo used for transfer affected embryo size on Day 13. In summary, the recovery rate of blastocysts was higher for in vivo- than in vitro-derived embryos. Blastocyst size was approximately 2.3-fold greater in recipients with high compared with normal progesterone. The present study lends strong support to the hypothesis that an earlier rise in progesterone after conception stimulates blastocyst growth and the development of competent embryos.

[Association of human chorionic gonadotropin level in embryo culture media with early embryo development].

PubMed

Wang, Haiying; Zhang, Renli; Han, Dong; Liu, Caixia; Cai, Jiajie; Bi, Yanling; Wen, Anmin; Quan, Song

2014-06-01

To investigate the association of human chorionic gonadotropin (HCG) level on day 3 of embryo culture with embryo development. Spent culture media were collected from individually cultured embryos on day 3 of in vitro fertilization and embryo transfer (IVF-ET) cycles. HCG concentration in the culture media was measured using an ELISA kit and its association with embryo development was assessed. In the 163 samples of embryo culture media from 60 patients, HCG was positive in 153 sample (93.8%) with a mean level of 0.85 ± 0.43 mIU/ml. The concentration of hCG in the culture media increased gradually as the number of blastomeres increased (F=2.273, P=0.03), and decreased as the morphological grade of the embryo was lowered (F=3.900, P=0.02). ELISA is capable of detecting HCG levels in spent culture media of embryos on day 3 of in vitro culture. The concentration of HCG in spent culture media is positively correlated with the status of early embryo development and implantation rate and thus serves as a useful marker for embryo selection in IVF-ET procedure.

Potential of human twin embryos generated by embryo splitting in assisted reproduction and research.

PubMed

Noli, Laila; Ogilvie, Caroline; Khalaf, Yacoub; Ilic, Dusko

2017-03-01

Embryo splitting or twinning has been widely used in veterinary medicine over 20 years to generate monozygotic twins with desirable genetic characteristics. The first human embryo splitting, reported in 1993, triggered fierce ethical debate on human embryo cloning. Since Dolly the sheep was born in 1997, the international community has acknowledged the complexity of the moral arguments related to this research and has expressed concerns about the potential for reproductive cloning in humans. A number of countries have formulated bans either through laws, decrees or official statements. However, in general, these laws specifically define cloning as an embryo that is generated via nuclear transfer (NT) and do not mention embryo splitting. Only the UK includes under cloning both embryo splitting and NT in the same legislation. On the contrary, the Ethics Committee of the American Society for Reproductive Medicine does not have a major ethical objection to transferring two or more artificially created embryos with the same genome with the aim of producing a single pregnancy, stating that 'since embryo splitting has the potential to improve the efficacy of IVF treatments for infertility, research to investigate the technique is ethically acceptable'. Embryo splitting has been introduced successfully to the veterinary medicine several decades ago and today is a part of standard practice. We present here an overview of embryo splitting experiments in humans and non-human primates and discuss the potential of this technology in assisted reproduction and research. A comprehensive literature search was carried out using PUBMED and Google Scholar databases to identify studies on embryo splitting in humans and non-human primates. 'Embryo splitting' and 'embryo twinning' were used as the keywords, alone or in combination with other search phrases relevant to the topics of biology of preimplantation embryos. A very limited number of studies have been conducted in humans and non

Comparison of effects of albendazole sulfoxide on in vitro produced bovine embryos and rat embryos.

PubMed

Piscopo, S E; Smoak, I W

1997-09-01

To evaluate and compare effects of albendazole sulfoxide (ABZSO) on rat embryos and bovine embryos produced in vitro. In vitro produced bovine embryos. Rat embryos recovered from naturally bred Sprague-Dawley rats. 4- and 8-cell bovine embryos were randomly allocated to ABZSO or vehicle control groups. After 48 hours, embryos were evaluated for cell number and blastomere morphology. Rat embryos of similar stages, flushed from the uterine tube on gestational day 2-5, were randomly allocated to treatment or control groups. After 24 hours, embryos were evaluated as described previously. 44% of control bovine embryos divided in culture (> or = 16-cell stage). Fifteen percent of the controls had morphologic abnormalities, including disparity in blastomere size and cytoplasmic vacuoles and stippling. Treated (> or = 1 microgram of ABZSO/ml) bovine embryos differed (P < 0.0001) from controls, with 4% development and 93% abnormal morphology. Forty-five percent of control rat embryos divided in culture. Treated (> or = 500 ng of ABZSO/ml) rat embryos differed (P < 0.0003) from controls with regard to ability to divide. There were no consistent morphologic abnormalities in rat embryos. In vitro produced bovine embryos were susceptible to ABZSO at a concentration > or = 1 microgram/ ml, resulting in decreased ability to divide and presence of gross morphologic abnormalities. Rat embryos produced in vivo and exposed in vitro to ABZSO at a concentration > or = 500 ng/ml had decreased ability to divide in culture. Despite severe effects of ABZSO (> or = 1 microgram/ml) on bovine embryo development in vitro, it is beyond the scope of this study to speculate whether a therapeutic dosage of albendazole (10 mg/kg of body weight) would result in necessary concentrations of ABZSO in vivo to disrupt embryogenesis.

Developmental consequences of cryopreservation of mammalian oocytes and embryos.

PubMed

Smith, Gary D; Silva E Silva, Cristine Ane

2004-08-01

During the last three decades, significant advances have been made in successful cryopreservation of mammalian preimplantation embryos, and more recently oocytes. The ability to cryopreserve, thaw, and establish pregnancies with supernumerary preimplantation embryos has become an important tool in fertility treatment. Human oocyte cryopreservation has practical application in preserving fertility for individuals at risk of compromised egg quality due to cancer treatments or advanced maternal age. While oocyte/embryo cryopreservation success has increased over time, there is still room for improvement. Oocytes and embryos are susceptible to cryo-damage, which collectively entails cellular damage caused by mechanical, chemical, or thermal forces during the freeze-thaw process. Basic studies focused on understanding cellular structures, their composition, and more importantly their functions, in normal cell developments will continue to be critical in assessing, understanding, and correcting oocyte/embryo cryo-damage. This review will delineate many of the oocyte/embryo intracellular and extracellular structures that are or may be compromised during cryopreservation. A global theme presented throughout this review is that many structural components of the oocyte/embryo also have essential functional roles in development. Compromising these cellular structures, and thus their cellular homeostatic functions, can deleteriously influence initial cryo-survival or compromise subsequent normal development through effects on the oocyte and/or early embryo.

Nuclear and mitochondrial DNA in blastocoele fluid and embryo culture medium: evidence and potential clinical use.

PubMed

Hammond, Elizabeth R; Shelling, Andrew N; Cree, Lynsey M

2016-08-01

The ability to screen embryos for aneuploidy or inherited disorders in a minimally invasive manner may represent a major advancement for the future of embryo viability assessment. Recent studies have demonstrated that both blastocoele fluid and embryo culture medium contain genetic material, which can be isolated and subjected to downstream genetic analysis. The blastocoele fluid may represent an alternative source of nuclear DNA for aneuploidy testing, although the degree to which the isolated genetic material is solely representative of the developing embryo is currently unclear. In addition to nuclear DNA, mitochondrial DNA (mtDNA) can be detected in the embryo culture medium. Currently, the origin of this nuclear and mtDNA has not been fully evaluated and there are several potential sources of contamination that may contribute to the genetic material detected in the culture medium. There is however evidence that the mtDNA content of the culture medium is related to embryo fragmentation levels and its presence is predictive of blastulation, indicating that embryo development may influence the levels of genetic material detected. If the levels of genetic material are strongly related to aspects of embryo quality, then this may be a novel biomarker of embryo viability. If the genetic material does have an embryo origin, the mechanisms by which DNA may be released into the blastocoele fluid and embryo culture medium are unknown, although apoptosis may play a role. While the presence of this genetic material is an exciting discovery, the DNA in the blastocoele fluid and embryo culture medium appears to be of low yield and integrity, which makes it challenging to study. Further research aimed at assessing the methodologies used for both isolating and analysing this genetic material, as well as tracing its origin, are needed in order to evaluate its potential for clinical use. Should such methodologies prove to be routinely successful and the DNA recovered

Transition of cell numbers in bovine preimplantation embryos: in vivo collected and in vitro produced embryos.

PubMed

Ushijima, Hitoshi; Akiyama, Kiyoshi; Tajima, Toshio

2008-08-01

The total cell numbers (TCNs) of bovine embryos collected from superovulated donors (VIVO embryos) were counted 0-9 d after ovulation to quantify the developmental process. Using numerical analysis of embryo development, we also compared the developmental process of VIVO embryos, in vitro-fertilized (IVF) embryos and nuclear transfer (NT) embryos obtained from enucleated oocytes and blastomere nuclei. The TCNs of embryos were measured using the air-dry method. Cleavage divisions (CD) of the embryos were obtained using logarithmic transformation of the TCN. The TCN of the VIVO embryos increased significantly (P<0.001) with time. The relationship between the CD of the VIVO embryos at 0-9 d after ovulation and age in days was described by a linear equation with a high correlation (y=1.03x+0.16, r=0.99), showing that CD occurs about once each day for all blastomeres. However, compared to the VIVO embryos, the TCN of the IVF embryos did not increase from 3-4 d nor after 7 d; the TCN of the NT embryos did not increase after 7 d (P>0.05). The results suggest a delay in development at these developmental stages. The slopes of regression lines of the IVF and NT embryos were significantly (P<0.001) smaller, indicating that quantification of the developmental process of VIVO embryos according to TCN and CD would be useful as criteria for numerical evaluation of the developmental process of bovine in vitro produced embryos.

Artificial intelligence techniques for embryo and oocyte classification.

PubMed

Manna, Claudio; Nanni, Loris; Lumini, Alessandra; Pappalardo, Sebastiana

2013-01-01

One of the most relevant aspects in assisted reproduction technology is the possibility of characterizing and identifying the most viable oocytes or embryos. In most cases, embryologists select them by visual examination and their evaluation is totally subjective. Recently, due to the rapid growth in the capacity to extract texture descriptors from a given image, a growing interest has been shown in the use of artificial intelligence methods for embryo or oocyte scoring/selection in IVF programmes. This work concentrates the efforts on the possible prediction of the quality of embryos and oocytes in order to improve the performance of assisted reproduction technology, starting from their images. The artificial intelligence system proposed in this work is based on a set of Levenberg-Marquardt neural networks trained using textural descriptors (the local binary patterns). The proposed system was tested on two data sets of 269 oocytes and 269 corresponding embryos from 104 women and compared with other machine learning methods already proposed in the past for similar classification problems. Although the results are only preliminary, they show an interesting classification performance. This technique may be of particular interest in those countries where legislation restricts embryo selection. One of the most relevant aspects in assisted reproduction technology is the possibility of characterizing and identifying the most viable oocytes or embryos. In most cases, embryologists select them by visual examination and their evaluation is totally subjective. Recently, due to the rapid growth in our capacity to extract texture descriptors from a given image, a growing interest has been shown in the use of artificial intelligence methods for embryo or oocyte scoring/selection in IVF programmes. In this work, we concentrate our efforts on the possible prediction of the quality of embryos and oocytes in order to improve the performance of assisted reproduction technology

Contribution of arbuscular mycorrhizal fungi to the development of maize (Zea mays L.) grown in three types of coal mine spoils.

PubMed

Guo, Wei; Zhao, Renxin; Fu, Ruiying; Bi, Na; Wang, Lixin; Zhao, Wenjing; Guo, Jiangyuan; Zhang, Jun

2014-03-01

Coal mine spoils are usually unfavorable for plant growth and have different properties according to dumping years, weathering degree, and the occurrence of spontaneous combustion. The establishment of plant cover in mine spoils can be facilitated by arbuscular mycorrhizal fungi (AMF). A greenhouse pot experiment was conducted to evaluate the importance of AMF in plant adaptation to different mine spoils and the potential role of AMF for revegetation practices. We investigated the effects of Glomus aggregatum, Rhizophagus intraradices (syn. Glomus intraradices), and Funneliformis mosseae (syn. Glomus mosseae) on the growth, nutritional status, and metal uptake of maize (Zea mays L.) grown in recent discharged (S1), weathered (S2), and spontaneous combusted (S3) coal mine spoils. Symbiotic associations were successfully established between AMF and maize in three substrates. Mycorrhizal colonization effectively promoted plant growth by significantly increasing the uptake of nitrogen (N), phosphorus (P), and potassium (K), adjusting C:N:P stoichiometry and alleviating toxic effects of heavy metals. G. aggregatum, R. intraradices, and F. mosseae exhibited different mycorrhizal effects in response to mine spoil types. F. mosseae was the most effective in the development of maize in S1 and may be the most appropriate for revegetation of this substrate, while R. intraradices played the most beneficial role in S2 and S3. Our results suggest that inoculation with AMF can enhance plant adaptation to different types of coal mine spoils and play a positive role in the revegetation of coal mine spoil banks.

Embryo aggregation does not improve the development of interspecies somatic cell nuclear transfer embryos in the horse.

PubMed

Gambini, Andrés; De Stéfano, Adrián; Jarazo, Javier; Buemo, Carla; Karlanian, Florencia; Salamone, Daniel Felipe

2016-09-01

The low efficiency of interspecies somatic cell nuclear transfer (iSCNT) makes it necessary to investigate new strategies to improve embryonic developmental competence. Embryo aggregation has been successfully applied to improve cloning efficiency in mammals, but it remains unclear whether it could also be beneficial for iSCNT. In this study, we first compared the effect of embryo aggregation over in vitro development and blastocyst quality of porcine, bovine, and feline zona-free (ZF) parthenogenetic (PA) embryos to test the effects of embryo aggregation on species that were later used as enucleated oocytes donors in our iSCNT study. We then assessed whether embryo aggregation could improve the in vitro development of ZF equine iSCNT embryos after reconstruction with porcine, bovine, and feline ooplasm. Bovine- and porcine-aggregated PA blastocysts had significantly larger diameters compared with nonaggregated embryos. On the other hand, feline- and bovine-aggregated PA embryos had higher blastocyst cell number. Embryo aggregation of equine-equine SCNT was found to be beneficial for embryo development as we have previously reported, but the aggregation of three ZF reconstructed embryos did not improve embryo developmental rates on iSCNT. In vitro embryo development of nonaggregated iSCNT was predominantly arrested around the stage when transcriptional activation of the embryonic genome is reported to start on the embryo of the donor species. Nevertheless, independent of embryo aggregation, equine blastocyst-like structures could be obtained in our study using domestic feline-enucleated oocytes. Taken together, these results reported that embryo aggregation enhance in vitro PA embryo development and embryo quality but effects vary depending on the species. Embryo aggregation also improves, as expected, the in vitro embryo development of equine-equine SCNT embryos; however, we did not observe positive effects on equine iSCNT embryo development. Among oocytes

Can reptile embryos influence their own rates of heating and cooling?

PubMed

Du, Wei-Guo; Tu, Ming-Chung; Radder, Rajkumar S; Shine, Richard

2013-01-01

Previous investigations have assumed that embryos lack the capacity of physiological thermoregulation until they are large enough for their own metabolic heat production to influence nest temperatures. Contrary to intuition, reptile embryos may be capable of physiological thermoregulation. In our experiments, egg-sized objects (dead or infertile eggs, water-filled balloons, glass jars) cooled down more rapidly than they heated up, whereas live snake eggs heated more rapidly than they cooled. In a nest with diel thermal fluctuations, that hysteresis could increase the embryo's effective incubation temperature. The mechanisms for controlling rates of thermal exchange are unclear, but may involve facultative adjustment of blood flow. Heart rates of snake embryos were higher during cooling than during heating, the opposite pattern to that seen in adult reptiles. Our data challenge the view of reptile eggs as thermally passive, and suggest that embryos of reptile species with large eggs can influence their own rates of heating and cooling.

Protein Phosphorylation during Coconut Zygotic Embryo Development1

PubMed Central

Islas-Flores, Ignacio; Oropeza, Carlos; Hernández-Sotomayor, S.M. Teresa

1998-01-01

Evidence was obtained on the occurrence of protein threonine, serine, and tyrosine (Tyr) kinases in developing coconut (Cocos nucifera L.) zygotic embryos, based on in vitro phosphorylation of proteins in the presence of [γ-32P]ATP, alkaline treatment, and thin-layer chromatography analysis, which showed the presence of [32P]phosphoserine, [32P]phosphothreonine, and [32P]phosphotyrosine in [32P]-labeled protein hydrolyzates. Tyr kinase activity was further confirmed in extracts of embryos at different stages of development using antiphosphotyrosine monoclonal antibodies and the synthetic peptide derived from the amino acid sequence surrounding the phosphorylation site in pp60src (RR-SRC), which is specific for Tyr kinases. Anti-phosphotyrosine western blotting revealed a changing profile of Tyr-phosphorylated proteins during embryo development. Tyr kinase activity, as assayed using RR-SRC, also changed during embryo development, showing two peaks of activity, one during early and another during late embryo development. In addition, the use of genistein, a Tyr kinase inhibitor, diminished the ability of extracts to phosphorylate RR-SRC. Results presented here show the occurrence of threonine, serine, and Tyr kinases in developing coconut zygotic embryos, and suggest that protein phosphorylation, and the possible inference of Tyr phosphorylation in particular, may play a role in the coordination of the development of embryos in this species. PMID:9733545

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

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

Application of image analysis techniques to evaluate the effect of urban residuals fertilization on corn (Zea mays) production

NASA Astrophysics Data System (ADS)

Menesatti, P.; D'Andrea, S.; Socciarelli, S.

2007-09-01

The work focused the application of an image analysis technique to determine corn leaves morphology as objective indicator of the growth performance of corn (Zea mays) resulting from the urban residual fertilization. The analyses were related to six fertilization plots: original soil; chemical fertilizer (160 and 200 kg ha-1 of nitrogen); organic fertilizer (32 t ha-1) and two different doses of urban residues (sewage sludges) (7.5 and 22.5 t ha-1, this last amount corresponds to is the maximum level permitted from the Italian law in three year of fertilization). Those tests were realized by full randomized plots, with two three repetitions for each treatment. Measurements were performed for the first year of the trials in the period proximate to harvest (Rome, Italy - July 2000). Four plants for each plot were harvested and stripped of all leaves, whose RGB images were acquired by a digital photo camera (Kodak Ltd). Image analysis was performed first through the separation of RGB channels into single monochromatic 8-bit distribution, than the blue channel images, the most informative, were then submitted to enhancement, low pass filtering to reduce noise, threshold of binarization (based on statistical parameter affected on Gaussian grey levels distribution), binary morphology and object measurement. For ach single leaf the length, the width, the area were measured. The test results indicated positive and significant responses in relation between the crop growth (leaves area, length and width greater) and the different doses of urban residues (sewage sludges).

Arbuscular mycorrhizal symbiosis affects the grain proteome of Zea mays: a field study

PubMed Central

Bona, Elisa; Scarafoni, Alessio; Marsano, Francesco; Boatti, Lara; Copetta, Andrea; Massa, Nadia; Gamalero, Elisa; D’Agostino, Giovanni; Cesaro, Patrizia; Cavaletto, Maria; Berta, Graziella

2016-01-01

Maize is one of the most important crops worldwide and is strongly dependent on arbuscular mycorrhiza (AM) fungi, organisms that form a mutualistic association with land plants. In maize, AM symbiosis enhances spike dry weight, spike length, spike circumference, and the dry weight and dimensions of the grain. Notwithstanding its ubiquitous nature, the detailed relationship between AM fungal colonization and plant development is not completely understood. To facilitate a better understanding of the effects of AM fungi on plants, the work reported here assessed the effects of a consortium of AM fungi on the kernel proteome of maize, cultivated in open-field conditions. To our knowledge, this is the first report of the modulation of a plant seed proteome following AM fungal inoculation in the field. Here, it was found that AM fungi modify the maize seed proteome by up-regulating enzymes involved in energetic metabolism, embryo development, nucleotide metabolism, seed storage and stress responses. PMID:27216714

Arbuscular mycorrhizal symbiosis affects the grain proteome of Zea mays: a field study.

PubMed

Bona, Elisa; Scarafoni, Alessio; Marsano, Francesco; Boatti, Lara; Copetta, Andrea; Massa, Nadia; Gamalero, Elisa; D'Agostino, Giovanni; Cesaro, Patrizia; Cavaletto, Maria; Berta, Graziella

2016-05-24

Maize is one of the most important crops worldwide and is strongly dependent on arbuscular mycorrhiza (AM) fungi, organisms that form a mutualistic association with land plants. In maize, AM symbiosis enhances spike dry weight, spike length, spike circumference, and the dry weight and dimensions of the grain. Notwithstanding its ubiquitous nature, the detailed relationship between AM fungal colonization and plant development is not completely understood. To facilitate a better understanding of the effects of AM fungi on plants, the work reported here assessed the effects of a consortium of AM fungi on the kernel proteome of maize, cultivated in open-field conditions. To our knowledge, this is the first report of the modulation of a plant seed proteome following AM fungal inoculation in the field. Here, it was found that AM fungi modify the maize seed proteome by up-regulating enzymes involved in energetic metabolism, embryo development, nucleotide metabolism, seed storage and stress responses.

Mouse Embryo Compaction.

PubMed

White, M D; Bissiere, S; Alvarez, Y D; Plachta, N

2016-01-01

Compaction is a critical first morphological event in the preimplantation development of the mammalian embryo. Characterized by the transformation of the embryo from a loose cluster of spherical cells into a tightly packed mass, compaction is a key step in the establishment of the first tissue-like structures of the embryo. Although early investigation of the mechanisms driving compaction implicated changes in cell-cell adhesion, recent work has identified essential roles for cortical tension and a compaction-specific class of filopodia. During the transition from 8 to 16 cells, as the embryo is compacting, it must also make fundamental decisions regarding cell position, polarity, and fate. Understanding how these and other processes are integrated with compaction requires further investigation. Emerging imaging-based techniques that enable quantitative analysis from the level of cell-cell interactions down to the level of individual regulatory molecules will provide a greater understanding of how compaction shapes the early mammalian embryo. © 2016 Elsevier Inc. All rights reserved.

Gibberella ear rot of maize (Zea mays) in Nepal: distribution of the mycotoxins nivalenol and deoxynivalenol in naturally and experimentally infected maize.

PubMed

Desjardins, Anne E; Busman, Mark; Manandhar, Gyanu; Jarosz, Andrew M; Manandhar, Hira K; Proctor, Robert H

2008-07-09

The fungus Fusarium graminearum (sexual stage Gibberella zeae) causes ear rot of maize (Zea mays) and contamination with the 8-ketotrichothecenes nivalenol (1) or 4-deoxynivalenol (2), depending on diversity of the fungal population for the 4-oxygenase gene (TRI13). To determine the importance of 1 and 2 in maize ear rot, a survey of naturally contaminated maize in Nepal was combined with experiments in the field and in a plant growth room. In the survey, 1 contamination was 4-fold more frequent than 2 contamination and 1-producers (TRI13) were isolated more than twice as frequently as 2-producers (Psi TRI13). In maize ear rot experiments, genetically diverse 1-producers and 2-producers caused ear rot and trichothecene contamination. Among strains with the same genetic background, however, 1-producers caused less ear rot and trichothecene contamination than did 2-producers. The high frequency of 1 contamination and the high virulence of many 1-producers are of concern because maize is a staple food of rural populations in Nepal and because 1 has proven to be more toxic than 2 to animals.

Time-lapse microscopy and image analysis in basic and clinical embryo development research.

PubMed

Wong, C; Chen, A A; Behr, B; Shen, S

2013-02-01

Mammalian preimplantation embryo development is a complex process in which the exact timing and sequence of events are as essential as the accurate execution of the events themselves. Time-lapse microscopy (TLM) is an ideal tool to study this process since the ability to capture images over time provides a combination of morphological, dynamic and quantitative information about developmental events. Here, we systematically review the application of TLM in basic and clinical embryo research. We identified all relevant preimplantation embryo TLM studies published in English up to May 2012 using PubMed and Google Scholar. We then analysed the technical challenges involved in embryo TLM studies and how these challenges may be overcome with technological innovations. Finally, we reviewed the different types of TLM embryo studies, with a special focus on how TLM can benefit clinical assisted reproduction. Although new parameters predictive of embryo development potential may be discovered and used clinically to potentially increase the success rate of IVF, adopting TLM to routine clinical practice will require innovations in both optics and image analysis. Combined with such innovations, TLM may provide embryologists and clinicians with an important tool for making critical decisions in assisted reproduction. In this review, we perform a literature search of all published early embryo development studies that used time-lapse microscopy (TLM). From the literature, we discuss the benefits of TLM over traditional time-point analysis, as well as the technical difficulties and solutions involved in implementing TLM for embryo studies. We further discuss research that has successfully derived non-invasive markers that may increase the success rate of assisted reproductive technologies, primarily IVF. Most notably, we extend our discussion to highlight important considerations for the practical use of TLM in research and clinical settings. Copyright © 2012 Reproductive

Effect of Emamectin Benzoate on Mortality, Proboscis Extension, Gustation and Reproduction of the Corn Earworm, Helicoverpa zea

PubMed Central

López, Juan D.; Latheef, M. A.; Hoffmann, W. C.

2010-01-01

Newly emerged corn earworm adults, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) require a carbohydrate source from plant or other exudates and nectars for dispersal and reproduction. Adults actively seek and forage at feeding sites upon eclosion in the habitat of the larval host plant or during dispersal to, or colonization of, a suitable reproductive habitat. This nocturnal behavior of H. zea has potential for exploitation as a pest management strategy for suppression using an adult feeding approach. This approach entails the use of a feeding attractant and stimulant in combination with a toxicant that when ingested by the adult will either reduce fecundity/fertility at sub-lethal dosages or kill the adult. The intent of this study was to assess reproductive inhibition and toxicity of emamectin benzoate on H. zea when ingested by the adults when mixed in ppm active ingredient (wt:vol) with 2.5 M sucrose as a feeding stimulant. Because the mixture has to be ingested to function, the effect of emamectin benzoate was also evaluated at sub-lethal and lethal concentrations on proboscis extension and gustatory response of H. zea in the laboratory. Feral males captured in sex pheromone-baited traps in the field were used for toxicity evaluations because they were readily available and were more representative of the field populations than laboratory-reared adults. Laboratory-reared female moths were used for reproduction effects because it is very difficult to collect newly emerged feral females from the field. Emamectin benzoate was highly toxic to feral H. zea males with LC50 values (95% CL) being 0.718 (0.532–0.878), 0.525 (0.316–0.751), and 0.182 (0.06–0.294) ppm for 24, 48 and 72 h responses, respectively. Sub-lethal concentrations of emamectin benzoate did not significantly reduce proboscis extension response of feral males and gustatory response of female H. zea. Sublethal concentrations of emamectin benzoate significantly reduced percent larval hatch

Effect of emamectin benzoate on mortality, proboscis extension, gustation and reproduction of the corn earworm, Helicoverpa zea.

PubMed

López, Juan D; Latheef, M A; Hoffmann, W C

2010-01-01

Newly emerged corn earworm adults, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) require a carbohydrate source from plant or other exudates and nectars for dispersal and reproduction. Adults actively seek and forage at feeding sites upon eclosion in the habitat of the larval host plant or during dispersal to, or colonization of, a suitable reproductive habitat. This nocturnal behavior of H. zea has potential for exploitation as a pest management strategy for suppression using an adult feeding approach. This approach entails the use of a feeding attractant and stimulant in combination with a toxicant that when ingested by the adult will either reduce fecundity/fertility at sub-lethal dosages or kill the adult. The intent of this study was to assess reproductive inhibition and toxicity of emamectin benzoate on H. zea when ingested by the adults when mixed in ppm active ingredient (wt:vol) with 2.5 M sucrose as a feeding stimulant. Because the mixture has to be ingested to function, the effect of emamectin benzoate was also evaluated at sub-lethal and lethal concentrations on proboscis extension and gustatory response of H. zea in the laboratory. Feral males captured in sex pheromone-baited traps in the field were used for toxicity evaluations because they were readily available and were more representative of the field populations than laboratory-reared adults. Laboratory-reared female moths were used for reproduction effects because it is very difficult to collect newly emerged feral females from the field. Emamectin benzoate was highly toxic to feral H. zea males with LC(50) values (95% CL) being 0.718 (0.532-0.878), 0.525 (0.316-0.751), and 0.182 (0.06-0.294) ppm for 24, 48 and 72 h responses, respectively. Sub-lethal concentrations of emamectin benzoate did not significantly reduce proboscis extension response of feral males and gustatory response of female H. zea. Sublethal concentrations of emamectin benzoate significantly reduced percent larval hatch of

Deep cytoplasmic rearrangements in ventralized Xenopus embryos

NASA Technical Reports Server (NTRS)

Brown, E. E.; Denegre, J. M.; Danilchik, M. V.

1993-01-01

Following fertilization in Xenopus, dramatic rearrangements of the egg cytoplasm relocalize maternally synthesized egg components. During the first cell cycle the vegetal yolk mass rotates relative to the egg surface, toward the sperm entry point (SEP) (J. P. Vincent, G. F. Oster, and J. C. Gerhart, 1986, Dev. Biol. 113, 484-500), while concomitant deep cytoplasmic rearrangements occur in the animal hemisphere (M. V. Danilchik and J. M. Denegre, 1991, Development 111, 845-856). In this paper we examine the role of vegetal yolk mass rotation in producing the animal cytoplasmic rearrangements. We inhibited rotation by uv-irradiating embryos during the first cell cycle, a treatment that yields an extremely ventralized phenotype. Both uv-irradiated embryos and unirradiated control embryos show cytoplasmic rearrangements in the animal hemisphere during the first cell cycle. Cytoplasmic rearrangements on the SEP side of the embryo associated with the path of the sperm pronucleus, plus a swirl on the anti-SEP (dorsal) side, are seen, whether or not yolk mass rotation has occurred. This result suggests a role for the expanding sperm aster in directing animal hemisphere cytoplasmic movements. In unirradiated control embryos the anti-SEP (dorsal) swirl is larger than that in uv-irradiated embryos and often extends into the vegetal hemisphere, consistent with the animal cytoplasm having been pulled dorsally and vegetally by the sliding vegetal yolk mass. Thus the yolk mass rotation may normally enhance the dorsalward cytoplasmic movement, begun by the sperm aster, enough to induce normal axis formation. We extended our observations of unirradiated control and uv-irradiated embryos through early cleavages. The vegetal extent of the anti-SEP (dorsal) swirl pattern seen in control embryos persists through the early cleavage period, such that labeled animal cytoplasm extends deep into dorsal third-tier blastomeres at the 32-cell stage. Significantly, in uv-irradiated embryos

Expression of microRNAs in bovine and human pre-implantation embryo culture media

PubMed Central

Kropp, Jenna; Salih, Sana M.; Khatib, Hasan

2014-01-01

MicroRNAs (miRNA) are short non-coding RNAs which act to regulate expression of genes driving numerous cellular processes. These RNAs are secreted within exosomes from cells into the extracellular environment where they may act as signaling molecules. In addition, they are relatively stable and are specifically expressed in association to certain cancers making them strong candidates as biological markers. Moreover, miRNAs have been detected in body fluids including urine, milk, saliva, semen, and blood plasma. However, it is unknown whether they are secreted by embryonic cells into the culture media. Given that miRNAs are expressed throughout embryonic cellular divisions and embryonic genome activation, we hypothesized that they are secreted from the embryo into the extracellular environment and may play a role in the developmental competence of bovine embryos. To test this hypothesis, bovine embryos were cultured individually from day 5 to day 8 of development in an in vitro fertilization system and gene expression of 5 miRNAs was analyzed in both embryos and culture media. Differential miRNA gene expression was observed between embryos that developed to the blastocyst stage and those that failed to develop from the morula to blastocyst stage, deemed degenerate embryos. MiR-25, miR-302c, miR-196a2, and miR-181a expression was found to be higher in degenerate embryos compared to blastocyst embryos. Interestingly, these miRNAs were also found to be expressed in the culture media of both bovine and human pre-implantation embryos. Overall, our results show for the first time that miRNAs are secreted from pre-implantation embryos into culture media and that miRNA expression may correlate with developmental competence of the embryo. Expression of miRNAs in in vitro culture media could allow for the development of biological markers for selection of better quality embryos and for subsequent successful pregnancy. PMID:24795753

Cold hardiness of Helicoverpa zea (Lepidoptera: Noctuidae) pupae

Treesearch

A.C. Morey; W.D. Hutchison; R.C. Venette; E.C. Burkness

2012-01-01

An insect's cold hardiness affects its potential to overwinter and outbreak in different geographic regions. In this study, we characterized the response of Helicoverpa zea (Boddie) pupae to low temperatures by using controlled laboratory measurements of supercooling point (SCP), lower lethal temperature (LT50), and lower...

Inhibition of non-enzymatic glycation by silk extracts from a Mexican land race and modern inbred lines of maize (Zea mays).

PubMed

Farsi, Darius Arthur; Harris, Cory S; Reid, Lana; Bennett, Steffany A L; Haddad, Pierre S; Martineau, Louis C; Arnason, John Thor

2008-01-01

Non-enzymatic glycation and the accumulation of advanced glycation end products (AGEs) are associated with various disease states, including complications of diabetes and aging. Secondary metabolites from several plant species are known to inhibit non-enzymatic glycation and the formation of AGEs, including flavonoids found in the style (silk) of Zea mays (maize). Thirteen modern maize inbreds and one land race were tested for in vitro inhibition of non-enzymatic glycation of bovine serum albumin. Many of the tested extracts exhibited inhibitory activity, in particular the newest inbreds, which were bred for resistance to gibberella ear rot (Fusarium graminearum) and common smut (Ustilago maydis). The most active maize genotype (CO441), displaying an IC50 of 9.5 microg/mL, was more effective than aminoguanidine, a known inhibitor of glycation. Zapalote chico, a land race with high maysin content, showed only moderate inhibitory activity compared with the modern maize genotypes. Antiglycation activity was highly correlated with the total phenolic content of silk extracts and mildly correlated with resistance to certain fungal infections. The results identify modern resistant and high phenolic maize inbreds as promising candidates for the development of natural AGE inhibitors for the prevention and treatment of diabetic complications and the degenerative effects of aging. Copyright (c) 2007 John Wiley & Sons, Ltd.

Modification of nitrogen remobilization, grain fill and leaf senescence in maize (Zea mays) by transposon insertional mutagenesis in a protease gene.

PubMed

Donnison, Iain S; Gay, Alan P; Thomas, Howard; Edwards, Keith J; Edwards, David; James, Caron L; Thomas, Ann M; Ougham, Helen J

2007-01-01

A maize (Zea mays) senescence-associated legumain gene, See2beta, was characterized at the physiological and molecular levels to determine its role in senescence and resource allocation. A reverse-genetics screen of a maize Mutator (Mu) population identified a Mu insertion in See2beta. Maize plants homozygous for the insertion were produced. These See2 mutant and sibling wild-type plants were grown under high or low quantities of nitrogen (N). The early development of both genotypes was similar; however, tassel tip and collar emergence occurred earlier in the mutant. Senescence of the mutant leaves followed a similar pattern to that of wild-type leaves, but at later sampling points mutant plants contained more chlorophyll than wild-type plants and showed a small extension in photosynthetic activity. Total plant weight was higher in the wild-type than in the mutant, and there was a genotype x N interaction. Mutant plants under low N maintained cob weight, in contrast to wild-type plants under the same treatment. It is concluded, on the basis of transposon mutagenesis, that See2beta has an important role in N-use and resource allocation under N-limited conditions, and a minor but significant function in the later stages of senescence.

Translocation of radiolabeled indole-3-acetic acid and indole-3-acetyl-myo-inositol from kernel to shoot of Zea mays L

NASA Technical Reports Server (NTRS)

Chisnell, J. R.; Bandurski, R. S.

1988-01-01

Either 5-[3H]indole-3-acetic acid (IAA) or 5-[3H]indole-3-acetyl-myo-inositol was applied to the endosperm of kernels of dark-grown Zea mays seedlings. The distribution of total radioactivity, radiolabeled indole-3-acetic acid, and radiolabeled ester conjugated indole-3-acetic acid, in the shoots was then determined. Differences were found in the distribution and chemical form of the radiolabeled indole-3-acetic acid in the shoot depending upon whether 5-[3H]indole-3-acetic acid or 5-[3H]indole-3-acetyl-myo-inositol was applied to the endosperm. We demonstrated that indole-3-acetyl-myo-inositol applied to the endosperm provides both free and ester conjugated indole-3-acetic acid to the mesocotyl and coleoptile. Free indole-3-acetic acid applied to the endosperm supplies some of the indole-3-acetic acid in the mesocotyl but essentially no indole-3-acetic acid to the coleoptile or primary leaves. It is concluded that free IAA from the endosperm is not a source of IAA for the coleoptile. Neither radioactive indole-3-acetyl-myo-inositol nor IAA accumulates in the tip of the coleoptile or the mesocotyl node and thus these studies do not explain how the coleoptile tip controls the amount of IAA in the shoot.

Embryo banking between induction and consolidation chemotherapy in women with leukemia.

PubMed

Rossi, Brooke V; Ashby, Rachel K; Srouji, Serene S

2011-12-01

To report the results of controlled ovarian hyperstimulation (COH) after long-acting GnRH agonist (GnRH-a) and chemotherapy for the purposes of embryo cryopreservation. Case report. University medical center. Two premenopausal women with acute myelogenous leukemia with recent treatment with GnRH-a and induction chemotherapy for hematopoietic cell transplantation (HCT). COH with embryo cryopreservation. Numbers of oocytes and embryos cryopreserved. Both patients responded to gonadotropin stimulation and cryopreserved embryos. Women who have received recent long-acting GnRH-a and chemotherapy may respond to gonadotropin stimulation. The option of embryo banking can be offered to leukemia patients who are preparing for HCT. Copyright © 2011. Published by Elsevier Inc.

Global transcriptome analysis of the maize (Zea mays L.) inbred line 08LF during leaf senescence initiated by pollination-prevention

PubMed Central

Wang, Shunxi; Wu, Liuji; Ku, Lixia; Zhang, Jun; Song, Xiaoheng; Liu, Haiping

2017-01-01

In maize (Zea mays), leaf senescence acts as a nutrient recycling process involved in proteins, lipids, and nucleic acids degradation and transport to the developing sink. However, the molecular mechanisms of pre-maturation associated with pollination-prevention remain unclear in maize. To explore global gene expression changes during the onset and progression of senescence in maize, the inbred line 08LF, with severe early senescence caused by pollination prevention, was selected. Phenotypic observation showed that the onset of leaf senescence of 08LF plants occurred approximately 14 days after silking (DAS) by pollination prevention. Transcriptional profiling analysis of the leaf at six developmental stages during induced senescence revealed that a total of 5,432 differentially expressed genes (DEGs) were identified, including 2314 up-regulated genes and 1925 down-regulated genes. Functional annotation showed that the up-regulated genes were mainly enriched in multi-organism process and nitrogen compound transport, whereas down-regulated genes were involved in photosynthesis. Expression patterns and pathway enrichment analyses of early-senescence related genes indicated that these DEGs are involved in complex regulatory networks, especially in the jasmonic acid pathway. In addition, transcription factors from several families were detected, particularly the CO-like, NAC, ERF, GRAS, WRKY and ZF-HD families, suggesting that these transcription factors might play important roles in driving leaf senescence in maize as a result of pollination-prevention. PMID:28973044

Global transcriptome analysis of the maize (Zea mays L.) inbred line 08LF during leaf senescence initiated by pollination-prevention.

PubMed

Wu, Liancheng; Li, Mingna; Tian, Lei; Wang, Shunxi; Wu, Liuji; Ku, Lixia; Zhang, Jun; Song, Xiaoheng; Liu, Haiping; Chen, Yanhui

2017-01-01

In maize (Zea mays), leaf senescence acts as a nutrient recycling process involved in proteins, lipids, and nucleic acids degradation and transport to the developing sink. However, the molecular mechanisms of pre-maturation associated with pollination-prevention remain unclear in maize. To explore global gene expression changes during the onset and progression of senescence in maize, the inbred line 08LF, with severe early senescence caused by pollination prevention, was selected. Phenotypic observation showed that the onset of leaf senescence of 08LF plants occurred approximately 14 days after silking (DAS) by pollination prevention. Transcriptional profiling analysis of the leaf at six developmental stages during induced senescence revealed that a total of 5,432 differentially expressed genes (DEGs) were identified, including 2314 up-regulated genes and 1925 down-regulated genes. Functional annotation showed that the up-regulated genes were mainly enriched in multi-organism process and nitrogen compound transport, whereas down-regulated genes were involved in photosynthesis. Expression patterns and pathway enrichment analyses of early-senescence related genes indicated that these DEGs are involved in complex regulatory networks, especially in the jasmonic acid pathway. In addition, transcription factors from several families were detected, particularly the CO-like, NAC, ERF, GRAS, WRKY and ZF-HD families, suggesting that these transcription factors might play important roles in driving leaf senescence in maize as a result of pollination-prevention.

Time to take human embryo culture seriously.

PubMed

Sunde, Arne; Brison, Daniel; Dumoulin, John; Harper, Joyce; Lundin, Kersti; Magli, M Cristina; Van den Abbeel, Etienne; Veiga, Anna

2016-10-01

Is it important that end-users know the composition of human embryo culture media? We argue that there is as strong case for full transparency concerning the composition of embryo culture media intended for human use. Published data suggest that the composition of embryo culture media may influence the phenotype of the offspring. A review of the literature was carried out. Data concerning the potential effects on embryo development of culture media were assessed and recommendations for users made. The safety of ART procedures, especially with respect to the health of the offspring, is of major importance. There are reports from the literature indicating a possible effect of culture conditions, including culture media, on embryo and fetal development. Since the introduction of commercially available culture media, there has been a rapid development of different formulations, often not fully documented, disclosed or justified. There is now evidence that the environment the early embryo is exposed to can cause reprogramming of embryonic growth leading to alterations in fetal growth trajectory, birthweight, childhood growth and long-term disease including Type II diabetes and cardiovascular problems. The mechanism for this is likely to be epigenetic changes during the preimplantation period of development. In the present paper the ESHRE working group on culture media summarizes the present knowledge of potential effects on embryo development related to culture media, and makes recommendations. There is still a need for large prospective randomized trials to further elucidate the link between the composition of embryo culture media used and the phenotype of the offspring. We do not presently know if the phenotypic changes induced by in vitro embryo culture represent a problem for long-term health of the offspring. Published data indicate that there is a strong case for demanding full transparency concerning the compositions of and the scientific rationale behind the

Molecular cloning of the pheromone biosynthesis-activating neuropeptide in Helicoverpa zea.

PubMed Central

Davis, M T; Vakharia, V N; Henry, J; Kempe, T G; Raina, A K

1992-01-01

Pheromone biosynthesis-activating neuropeptide (PBAN) regulates sex pheromone biosynthesis in female Helicoverpa (Heliothis) zea. Two oligonucleotide probes representing two overlapping amino acid regions of PBAN were used to screen 2.5 x 10(5) recombinant plaques, and a positive recombinant clone was isolated. Sequence analysis of the isolated clone showed that the PBAN gene is interrupted after the codon encoding amino acid 14 by a 0.63-kilobase (kb) intron. Preceding the PBAN amino acid sequence is a 10-amino acid sequence containing a pentapeptide Phe-Thr-Pro-Arg-Leu, which is followed by a Gly-Arg-Arg processing site. Immediately after the PBAN amino acid sequence is a Gly-Arg processing site and a short stretch of 10 amino acids. This 10-amino acid sequence contains a repeat of the PBAN C-terminal pentapeptide Phe-Ser-Pro-Arg-Leu and is terminated by another Gly-Arg processing site. It is suggested that the PBAN gene in H. zea might carry, besides PBAN, a 7- and an 8-residue amidated peptide, which share with PBAN the core C-terminal pentapeptide Phe-(Ser or Thr)-Pro-Arg-Leu-NH2. The C-terminal pentapeptide sequence of PBAN represents the minimum sequence required for pheromonotropic activity in H. zea and also bears a high degree of homology to the pyrokinin family of insect peptides with myotropic activity. It is possible that the putative heptapeptide and octapeptide might be new members of the pyrokinin family, with pheromonotropic and/or myotropic activities. Thus, the PBAN gene products, besides affecting sexual behavior, might have broad influence on many biological processes in H. zea. Images PMID:1729680

Toxicity of chlorine to zebrafish embryos

PubMed Central

Kent, Michael L.; Buchner, Cari; Barton, Carrie; Tanguay, Robert L.

2014-01-01

Surface disinfection of fertilized fish eggs is widely used in aquaculture to reduce extraovum pathogens that may be released from brood fish during spawning, and this is routinely used in zebrafish (Danio rerio) research laboratories. Most laboratories use approximately 25 – 50 ppm unbuffered chlorine solution for 5 – 10 min. Treatment of embryos with chlorine has significant germicidal effects for many Gram-negative bacteria, viruses, and trophozoite stages of protozoa, it has reduced efficacy against cyst or spore stages of protozoa and certain Mycobacterium spp. Therefore, we evaluated the toxicity of unbufferred and buffered chlorine solution to embryos exposed at 6 or 24 hours post-fertilization (hpf) to determine if higher concentrations can be used for treating zebrafish embryos. Most of our experiments entailed using an outbred line (5D), with both mortality and malformations as endpoints. We found that 6 hpf embryos consistently were more resistant than 24 hpf embryos to the toxic effects of chlorine. Chlorine is more toxic and germicidal at lower pHs, and chlorine causes elevated pH. Consistent with this, we found that unbufferred chlorine solutions (pH ca 8–9) were less toxic at corresponding concentrations than solutions buffered to pH 7. Based on our findings here, we recommend treating 6 hpf embryos for 10 min and 24 hpf for 5 min with unbuffered chlorine solution at 100 ppm. One trial indicated that AB fish, a popular outbred line, are more susceptible to toxicity than 5Ds. This suggests that variability between zebrafish lines occurs, and researchers should evaluate each line or strain under their particular laboratory conditions for selection of the optimum chlorine treatment procedure. PMID:24429474

Is it time for a paradigm shift in understanding embryo selection?

PubMed

Gleicher, Norbert; Kushnir, Vitaly A; Barad, David H

2015-01-11

Embryo selection has been an integral feature of in vitro fertilization (IVF) almost since its inception. Since the advent of extended blastocyst stage embryo culture, and especially with increasing popularity of elective single embryo transfer (eSET), the concept of embryo selection has increasingly become a mainstay of routine IVF. We here, however, argue that embryo selection via blastocyst stage embryo transfer (BSET), as currently practiced, at best improves IVF outcomes only for a small minority of patients undergoing IVF cycles. For a large majority BSET is either ineffective or, indeed, may actually be harmful by decreasing IVF pregnancy chances. Overall, only a small minority of patients, thus, benefit from prolonged embryo culture, while BSET, as a tool to enhance IVF outcomes, is increasingly utilized as routine care in IVF for all patients. Since newer methods of embryo selection, like preimplantation genetic screening (PGS) and closed system embryo incubation with time-lapse photography are practically dependent on BSET, these concepts of embryo selection, currently increasingly adopted in mainstream IVF, require reconsideration. They, automatically, transfer the downsides of BSET, including decreases in IVF pregnancy chances in some patients, to these new procedures, and in addition raise serious questions about cost-effectiveness.

Radial extracorporeal shock wave treatment harms developing chicken embryos

PubMed Central

Kiessling, Maren C.; Milz, Stefan; Frank, Hans-Georg; Korbel, Rüdiger; Schmitz, Christoph

2015-01-01

Radial extracorporeal shock wave treatment (rESWT) has became one of the best investigated treatment modalities for cellulite, including the abdomen as a treatment site. Notably, pregnancy is considered a contraindication for rESWT, and concerns have been raised about possible harm to the embryo when a woman treated with rESWT for cellulite is not aware of her pregnancy. Here we tested the hypothesis that rESWT may cause serious physical harm to embryos. To this end, chicken embryos were exposed in ovo to various doses of radial shock waves on either day 3 or day 4 of development, resembling the developmental stage of four- to six-week-old human embryos. We found a dose-dependent increase in the number of embryos that died after radial shock wave exposure on either day 3 or day 4 of development. Among the embryos that survived the shock wave exposure a few showed severe congenital defects such as missing eyes. Evidently, our data cannot directly be used to draw conclusions about potential harm to the embryo of a pregnant woman treated for cellulite with rESWT. However, to avoid any risks we strongly recommend applying radial shock waves in the treatment of cellulite only if a pregnancy is ruled out. PMID:25655309

Humic acid effect on catalase activity and the generation of reactive oxygen species in corn (Zea mays).

PubMed

Cordeiro, Flávio Couto; Santa-Catarina, Claudete; Silveira, Vanildo; de Souza, Sonia Regina

2011-01-01

Humic acids (HAs) have positive effects on plant physiology, but the molecular mechanisms underlying these events are only partially understood. The induction of root growth and emission of lateral roots (LRs) promoted by exogenous auxin is a natural phenomenon. Exogenous auxins are also associated with HA. Gas nitric oxide (NO) is a secondary messenger produced endogenously in plants. It is associated with metabolic events dependent on auxin. With the application of auxin, NO production is significantly increased, resulting in positive effects on plant physiology. Thus it is possible to evaluate the beneficial effects of the application of HA as an effect of auxin. To investigate the effects of HA the parameters of root growth, Zea mays was studied by evaluating the application of 3 mM C L⁻¹ of HA extracted from Oxisol and 100 µM SNP (sodium nitroprusside) and the NO donor, subject to two N-NO₃⁻, high dose (5.0 mM N-NO₃⁻) and low dose (5.0 mM N-NO₃⁻). Treatments with HA and NO were positively increased, regardless of the N-NO₃⁻ taken, as assessed by fresh weight and dry root, issue of LRs. The effects were more pronounced in the treatment with a lower dose of N-NO₃⁻. Detection of reactive oxygen species (ROS) in vivo and catalase activity were evaluated; these tests were associated with root growth. Under application of the bioactive substances tested, detection of ROS and catalase activity increased, especially in treatments with lower doses of N-NO₃⁻. The results of this experiment indicate that the effects of HA are dependent on ROS generation, which act as a messenger that induces root growth and the emission of LRs.

Photoautotrophic Culture of Coffea arabusta Somatic Embryos: Photosynthetic Ability and Growth of Different Stage Embryos

PubMed Central

AFREEN, F.; ZOBAYED, S. M. A.; KOZAI, T.

2002-01-01

Coffea arabusta somatic embryos were cultured and development of stomata, rate of CO2 fixation or production, chlorophyll content and chlorophyll fluorescence were studied in embryos at different stages of development. Cotyledonary and germinated embryos have photosynthetic capacity, although pretreatment at a high photosynthetic photon flux (PPF) (100 µmol m–2 s–1) for 14 d increased photosynthetic ability. Except in a very small number of cases, stomata did not develop fully in precotyledonary stage embryos and were absent in torpedo stage embryos. Low chlorophyll content (90–130 µg g–1 fresh mass) was noted in torpedo and precotyledonary stage embryos compared with cotyledonary and germinated embryos (300–500 µg g–1 fresh mass). Due to the absence of stomata and low chlorophyll content in the torpedo and precotyledonary stage embryos, the photosynthetic rate was low and, in some cases, CO2 production was observed. These data suggest that the cotyledonary stage is the earliest stage that can be cultured photoautotrophically to ensure plantlet development. When grown photoautotrophically (in a sugar‐free medium with CO2 enrichment in the culture headspace and high photosynthetic photon flux), torpedo and precotyledonary stage embryos lost 20–25 % of their initial dry mass after 60 d of culture. However, in cotyledonary and germinated embryos, the dry mass of each embryo increased by 10 and 50 %, respectively. By using a porous supporting material, growth (especially root growth) was increased in cotyledonary stage embryos. In addition, photoautotrophic conditions, high PPF (100–150 µmol m–2 s–1) and increased CO2 concentration (1100 µmol mol–1) were found to be necessary for the development of plantlets from cotyledonary stage embryos. PMID:12125763

Air bubble migration is a random event post embryo transfer.

PubMed

Confino, E; Zhang, J; Risquez, F

2007-06-01

Air bubble location following embryo transfer (ET) is the presumable placement spot of embryos. The purpose of this study was to document endometrial air bubble position and migration following embryo transfer. Multicenter prospective case study. Eighty-eight embryo transfers were performed under abdominal ultrasound guidance in two countries by two authors. A single or double air bubble was loaded with the embryos using a soft, coaxial, end opened catheters. The embryos were slowly injected 10-20 mm from the fundus. Air bubble position was recorded immediately, 30 minutes later and when the patient stood up. Bubble marker location analysis revealed a random distribution without visible gravity effect when the patients stood up. The bubble markers demonstrated splitting, moving in all directions and dispersion. Air bubbles move and split frequently post ET with the patient in the horizontal position, suggestive of active uterine contractions. Bubble migration analysis supports a rather random movement of the bubbles and possibly the embryos. Standing up changed somewhat bubble configuration and distribution in the uterine cavity. Gravity related bubble motion was uncommon, suggesting that horizontal rest post ET may not be necessary. This report challenges the common belief that a very accurate ultrasound guided embryo placement is mandatory. The very random bubble movement observed in this two-center study suggests that a large "window" of embryo placement maybe present.

Encapsulation of Date Palm Somatic Embryos: Synthetic Seeds.

PubMed

Bekheet, Shawky A

2017-01-01

Synthetic seed or encapsulated somatic embryos may be used for propagation, storage, and exchange of plant germplasm and have many diverse applications in date palm cultivation. They have advantages over conventional use of offshoot material for germplasm propagation, maintenance, exchange, and transportation. This chapter describes a protocol for date palm synthetic seed production by encapsulation of somatic embryos with sodium alginate. Among three concentrations used, 3% sodium alginate followed by dropping into 2.5% calcium chloride (CaCl 2 ) solution shows the best concentration of gel matrix for both maintenance and recovery. In addition, storage of the encapsulated date palm somatic embryos at 5 °C improves the survival and conversion into plantlets; otherwise, 20 g/L sucrose in the culture medium enhances conversion of the recovered somatic embryos to plantlets. This protocol is promising for in vitro conservation and international exchange of date palm germplasm.

Noninvasive embryo assessment technique based on buoyancy and its association with embryo survival after cryopreservation.

PubMed

Wessels, Cara; Penrose, Lindsay; Ahmad, Khaliq; Prien, Samuel

2017-11-01

Embryo cryopreservation offers many benefits by allowing genetic preservation, genetic screening, cost reduction, global embryo transport and single embryo transfer. However, freezing of embryos decreases embryo viability, as intracellular ice crystal formation often damages embryos. Success rates of frozen embryo transfer are expected to be 15-20% less than fresh embryo transfer. We have developed a noninvasive embryo assessment technique (NEAT) which enables us to predict embryo viability based on buoyancy. The purpose of this research was twofold. First was to determine if a NEAT, through a specific gravity device can detect embryo survival of cryopreservation. Second, it was to relate embryo buoyancy to embryo viability for establishing pregnancies in sheep. Blastocysts descent times were measured on one-hundred sixty-nine mice blastocysts before cryopreservation, according to standard protocol and post-thawing blastocysts descent times were measured again. There was a significant difference in blastocyst post-thaw descent times with NEAT in those blastocysts which demonstrated viability from those that did not (P < 0.05). This suggests NEAT is successful in determining blastocysts viability in cryopreserved mice blastocysts. At a commercial ovine facility, NEAT was performed on fourteen frozen and thawed ovine blastocysts. Blastocysts of similar descent times were paired and transferred into recipient ewes as twins. Pregnancy was later confirmed by blood test and multiple gestation outcomes were determined at lambing. Six of seven recipient ewes were pregnant and all pregnant ewes delivered lambs without complication. Four ewes delivered twin lambs and two ewes delivered singletons, which totals ten of the fourteen (71%) blastocysts surviving to term. This pregnancy rate is comparable to expected to pregnancy rates in a commercial setting. The blastocysts which did not establish pregnancy demonstrated less buoyancy versus those blastocysts which established

Root-type-specific plasticity in response to localized high nitrate supply in maize (Zea mays)

PubMed Central

Yu, Peng; Hochholdinger, Frank; Li, Chunjian

2015-01-01

Background and Aims Shoot-borne roots contribute to most of the nutrient uptake throughout the life cycle of maize (Zea mays). Compared with numerous studies with embryonic roots, detailed information on the phenotypic plasticity of shoot-borne roots in response to a heterogeneous nitrogen supply is scarce. The present study therefore provides a comprehensive profile of fine-scale plastic responses of distinct root types to localized high nitrate supply. Methods Seedlings of the maize inbred line B73 were grown in split-root systems. The anatomy and morphological plasticity of the primary root and the roots initiated from the 2nd, 5th and 7th shoot nodes, and their lateral roots, were studied in response to local high nitrate supply to one side of the root system. Key Results In contrast to the insensitivity of axial roots, local high nitrate supply increased the length of 1st-order lateral roots on the primary root and the three whorls of shoot-borne roots at different growth stages, and increased the density of 1st-order lateral roots on the 7th shoot-borne root after silking. The length and density of 2nd-order lateral roots on the three whorls of shoot-borne roots displayed a more flexible response to local high nitrate than 1st-order lateral roots. Root diameter and number, and total area and diameter of metaxylem vessels increased from the primary root to early and then later developed shoot-borne roots, which showed a positive relationship with shoot growth and N accumulation. Conclusions Maize axial roots and lateral roots responded differently to local high nitrate, and this was related to their function. The extent of morphological plasticity of lateral roots in response to local high nitrate depended on the initiation time of the shoot-borne roots on which the lateral roots developed. Morphological plasticity was higher on 2nd-order than on 1st-order lateral roots. The results suggest that higher order lateral root branching might be a potential target

Root-type-specific plasticity in response to localized high nitrate supply in maize (Zea mays).

PubMed

Yu, Peng; Hochholdinger, Frank; Li, Chunjian

2015-10-01

Shoot-borne roots contribute to most of the nutrient uptake throughout the life cycle of maize (Zea mays). Compared with numerous studies with embryonic roots, detailed information on the phenotypic plasticity of shoot-borne roots in response to a heterogeneous nitrogen supply is scarce. The present study therefore provides a comprehensive profile of fine-scale plastic responses of distinct root types to localized high nitrate supply. Seedlings of the maize inbred line B73 were grown in split-root systems. The anatomy and morphological plasticity of the primary root and the roots initiated from the 2nd, 5th and 7th shoot nodes, and their lateral roots, were studied in response to local high nitrate supply to one side of the root system. In contrast to the insensitivity of axial roots, local high nitrate supply increased the length of 1st-order lateral roots on the primary root and the three whorls of shoot-borne roots at different growth stages, and increased the density of 1st-order lateral roots on the 7th shoot-borne root after silking. The length and density of 2nd-order lateral roots on the three whorls of shoot-borne roots displayed a more flexible response to local high nitrate than 1st-order lateral roots. Root diameter and number, and total area and diameter of metaxylem vessels increased from the primary root to early and then later developed shoot-borne roots, which showed a positive relationship with shoot growth and N accumulation. Maize axial roots and lateral roots responded differently to local high nitrate, and this was related to their function. The extent of morphological plasticity of lateral roots in response to local high nitrate depended on the initiation time of the shoot-borne roots on which the lateral roots developed. Morphological plasticity was higher on 2nd-order than on 1st-order lateral roots. The results suggest that higher order lateral root branching might be a potential target for genetic improvement in future maize breeding. �

Bacterial Communities in the Rhizosphere of Amilaceous Maize (Zea mays L.) as Assessed by Pyrosequencing.

PubMed

Correa-Galeote, David; Bedmar, Eulogio J; Fernández-González, Antonio J; Fernández-López, Manuel; Arone, Gregorio J

2016-01-01

Maize (Zea mays L.) is the staple diet of the native peasants in the Quechua region of the Peruvian Andes who continue growing it in small plots called chacras following ancestral traditions. The abundance and structure of bacterial communities associated with the roots of amilaceous maize has not been studied in Andean chacras. Accordingly, the main objective of this study was to describe the rhizospheric bacterial diversity of amilaceous maize grown either in the presence or the absence of bur clover cultivated in soils from the Quechua maize belt. Three 16S rRNA gene libraries, one corresponding to sequences of bacteria from bulk soil of a chacra maintained under fallow conditions, the second from the rhizosphere of maize-cultivated soils, and the third prepared from rhizospheric soil of maize cultivated in intercropping with bur clover were examined using pyrosequencing tags spanning the V4 and V5 hypervariable regions of the gene. A total of 26031 sequences were found that grouped into 5955 distinct operational taxonomic units which distributed in 309 genera. The numbers of OTUs in the libraries from the maize-cultivated soils were significantly higher than those found in the libraries from bulk soil. One hundred ninety seven genera were found in the bulk soil library and 234 and 203 were in those from the maize and maize/bur clover-cultivated soils. Sixteen out of the 309 genera had a relative abundance higher than 0.5% and the were (in decreasing order of abundance) Gp4, Gp6, Flavobacterium, Subdivision3 genera incertae sedis of the Verrucomicrobia phylum, Gemmatimonas, Dechloromonas, Ohtaekwangia, Rhodoferax, Gaiella, Opitutus, Gp7, Spartobacteria genera incertae sedis, Terrimonas, Gp5, Steroidobacter and Parcubacteria genera incertae sedis. Genera Gp4 and Gp6 of the Acidobacteria, Gemmatimonas and Rhodoferax were the most abundant in bulk soil, whereas Flavobacterium, Dechloromonas and Ohtaekwangia were the main genera in the rhizosphere of maize

Bacterial Communities in the Rhizosphere of Amilaceous Maize (Zea mays L.) as Assessed by Pyrosequencing

PubMed Central

Correa-Galeote, David; Bedmar, Eulogio J.; Fernández-González, Antonio J.; Fernández-López, Manuel; Arone, Gregorio J.

2016-01-01

Maize (Zea mays L.) is the staple diet of the native peasants in the Quechua region of the Peruvian Andes who continue growing it in small plots called chacras following ancestral traditions. The abundance and structure of bacterial communities associated with the roots of amilaceous maize has not been studied in Andean chacras. Accordingly, the main objective of this study was to describe the rhizospheric bacterial diversity of amilaceous maize grown either in the presence or the absence of bur clover cultivated in soils from the Quechua maize belt. Three 16S rRNA gene libraries, one corresponding to sequences of bacteria from bulk soil of a chacra maintained under fallow conditions, the second from the rhizosphere of maize-cultivated soils, and the third prepared from rhizospheric soil of maize cultivated in intercropping with bur clover were examined using pyrosequencing tags spanning the V4 and V5 hypervariable regions of the gene. A total of 26031 sequences were found that grouped into 5955 distinct operational taxonomic units which distributed in 309 genera. The numbers of OTUs in the libraries from the maize-cultivated soils were significantly higher than those found in the libraries from bulk soil. One hundred ninety seven genera were found in the bulk soil library and 234 and 203 were in those from the maize and maize/bur clover-cultivated soils. Sixteen out of the 309 genera had a relative abundance higher than 0.5% and the were (in decreasing order of abundance) Gp4, Gp6, Flavobacterium, Subdivision3 genera incertae sedis of the Verrucomicrobia phylum, Gemmatimonas, Dechloromonas, Ohtaekwangia, Rhodoferax, Gaiella, Opitutus, Gp7, Spartobacteria genera incertae sedis, Terrimonas, Gp5, Steroidobacter and Parcubacteria genera incertae sedis. Genera Gp4 and Gp6 of the Acidobacteria, Gemmatimonas and Rhodoferax were the most abundant in bulk soil, whereas Flavobacterium, Dechloromonas and Ohtaekwangia were the main genera in the rhizosphere of maize

Stable isotope biogeochemistry of seabird guano fertilization: results from growth chamber studies with maize (Zea mays).

PubMed

Szpak, Paul; Longstaffe, Fred J; Millaire, Jean-François; White, Christine D

2012-01-01

Stable isotope analysis is being utilized with increasing regularity to examine a wide range of issues (diet, habitat use, migration) in ecology, geology, archaeology, and related disciplines. A crucial component to these studies is a thorough understanding of the range and causes of baseline isotopic variation, which is relatively poorly understood for nitrogen (δ(15)N). Animal excrement is known to impact plant δ(15)N values, but the effects of seabird guano have not been systematically studied from an agricultural or horticultural standpoint. This paper presents isotopic (δ(13)C and δ(15)N) and vital data for maize (Zea mays) fertilized with Peruvian seabird guano under controlled conditions. The level of (15)N enrichment in fertilized plants is very large, with δ(15)N values ranging between 25.5 and 44.7‰ depending on the tissue and amount of fertilizer applied; comparatively, control plant δ(15)N values ranged between -0.3 and 5.7‰. Intraplant and temporal variability in δ(15)N values were large, particularly for the guano-fertilized plants, which can be attributed to changes in the availability of guano-derived N over time, and the reliance of stored vs. absorbed N. Plant δ(13)C values were not significantly impacted by guano fertilization. High concentrations of seabird guano inhibited maize germination and maize growth. Moreover, high levels of seabird guano greatly impacted the N metabolism of the plants, resulting in significantly higher tissue N content, particularly in the stalk. The results presented in this study demonstrate the very large impact of seabird guano on maize δ(15)N values. The use of seabird guano as a fertilizer can thus be traced using stable isotope analysis in food chemistry applications (certification of organic inputs). Furthermore, the fertilization of maize with seabird guano creates an isotopic signature very similar to a high-trophic level marine resource, which must be considered when interpreting isotopic data

Stable Isotope Biogeochemistry of Seabird Guano Fertilization: Results from Growth Chamber Studies with Maize (Zea Mays)

PubMed Central

Szpak, Paul; Longstaffe, Fred J.; Millaire, Jean-François; White, Christine D.

2012-01-01

Background Stable isotope analysis is being utilized with increasing regularity to examine a wide range of issues (diet, habitat use, migration) in ecology, geology, archaeology, and related disciplines. A crucial component to these studies is a thorough understanding of the range and causes of baseline isotopic variation, which is relatively poorly understood for nitrogen (δ15N). Animal excrement is known to impact plant δ15N values, but the effects of seabird guano have not been systematically studied from an agricultural or horticultural standpoint. Methodology/Principal Findings This paper presents isotopic (δ13C and δ15N) and vital data for maize (Zea mays) fertilized with Peruvian seabird guano under controlled conditions. The level of 15N enrichment in fertilized plants is very large, with δ15N values ranging between 25.5 and 44.7‰ depending on the tissue and amount of fertilizer applied; comparatively, control plant δ15N values ranged between −0.3 and 5.7‰. Intraplant and temporal variability in δ15N values were large, particularly for the guano-fertilized plants, which can be attributed to changes in the availability of guano-derived N over time, and the reliance of stored vs. absorbed N. Plant δ13C values were not significantly impacted by guano fertilization. High concentrations of seabird guano inhibited maize germination and maize growth. Moreover, high levels of seabird guano greatly impacted the N metabolism of the plants, resulting in significantly higher tissue N content, particularly in the stalk. Conclusions/Significance The results presented in this study demonstrate the very large impact of seabird guano on maize δ15N values. The use of seabird guano as a fertilizer can thus be traced using stable isotope analysis in food chemistry applications (certification of organic inputs). Furthermore, the fertilization of maize with seabird guano creates an isotopic signature very similar to a high-trophic level marine resource, which must

The Roles of Glutathione Peroxidases during Embryo Development

PubMed Central

Ufer, Christoph; Wang, Chi Chiu

2011-01-01

Embryo development relies on the complex interplay of the basic cellular processes including proliferation, differentiation, and apoptotic cell death. Precise regulation of these events is the basis for the establishment of embryonic structures and the organ development. Beginning with fertilization of the oocyte until delivery the developing embryo encounters changing environmental conditions such as varying levels of oxygen, which can give rise to reactive oxygen species (ROS). These challenges are met by the embryo with metabolic adaptations and by an array of anti-oxidative mechanisms. ROS can be deleterious by modifying biological molecules including lipids, proteins, and nucleic acids and may induce abnormal development or even embryonic lethality. On the other hand ROS are vital players of various signaling cascades that affect the balance between cell growth, differentiation, and death. An imbalance or dysregulation of these biological processes may generate cells with abnormal growth and is therefore potentially teratogenic and tumorigenic. Thus, a precise balance between processes generating ROS and those decomposing ROS is critical for normal embryo development. One tier of the cellular protective system against ROS constitutes the family of selenium-dependent glutathione peroxidases (GPx). These enzymes reduce hydroperoxides to the corresponding alcohols at the expense of reduced glutathione. Of special interest within this protein family is the moonlighting enzyme glutathione peroxidase 4 (Gpx4). This enzyme is a scavenger of lipophilic hydroperoxides on one hand, but on the other hand can be transformed into an enzymatically inactive cellular structural component. GPx4 deficiency – in contrast to all other GPx family members – leads to abnormal embryo development and finally produces a lethal phenotype in mice. This review is aimed at summarizing the current knowledge on GPx isoforms during embryo development and tumor development with an emphasis

The Roles of Glutathione Peroxidases during Embryo Development.

PubMed

Ufer, Christoph; Wang, Chi Chiu

2011-01-01

Embryo development relies on the complex interplay of the basic cellular processes including proliferation, differentiation, and apoptotic cell death. Precise regulation of these events is the basis for the establishment of embryonic structures and the organ development. Beginning with fertilization of the oocyte until delivery the developing embryo encounters changing environmental conditions such as varying levels of oxygen, which can give rise to reactive oxygen species (ROS). These challenges are met by the embryo with metabolic adaptations and by an array of anti-oxidative mechanisms. ROS can be deleterious by modifying biological molecules including lipids, proteins, and nucleic acids and may induce abnormal development or even embryonic lethality. On the other hand ROS are vital players of various signaling cascades that affect the balance between cell growth, differentiation, and death. An imbalance or dysregulation of these biological processes may generate cells with abnormal growth and is therefore potentially teratogenic and tumorigenic. Thus, a precise balance between processes generating ROS and those decomposing ROS is critical for normal embryo development. One tier of the cellular protective system against ROS constitutes the family of selenium-dependent glutathione peroxidases (GPx). These enzymes reduce hydroperoxides to the corresponding alcohols at the expense of reduced glutathione. Of special interest within this protein family is the moonlighting enzyme glutathione peroxidase 4 (Gpx4). This enzyme is a scavenger of lipophilic hydroperoxides on one hand, but on the other hand can be transformed into an enzymatically inactive cellular structural component. GPx4 deficiency - in contrast to all other GPx family members - leads to abnormal embryo development and finally produces a lethal phenotype in mice. This review is aimed at summarizing the current knowledge on GPx isoforms during embryo development and tumor development with an emphasis on

In Amnio MRI of Mouse Embryos

PubMed Central

Roberts, Thomas A.; Norris, Francesca C.; Carnaghan, Helen; Savery, Dawn; Wells, Jack A.; Siow, Bernard; Scambler, Peter J.; Pierro, Agostino; De Coppi, Paolo; Eaton, Simon; Lythgoe, Mark F.

2014-01-01

Mouse embryo imaging is conventionally carried out on ex vivo embryos excised from the amniotic sac, omitting vital structures and abnormalities external to the body. Here, we present an in amnio MR imaging methodology in which the mouse embryo is retained in the amniotic sac and demonstrate how important embryonic structures can be visualised in 3D with high spatial resolution (100 µm/px). To illustrate the utility of in amnio imaging, we subsequently apply the technique to examine abnormal mouse embryos with abdominal wall defects. Mouse embryos at E17.5 were imaged and compared, including three normal phenotype embryos, an abnormal embryo with a clear exomphalos defect, and one with a suspected gastroschisis phenotype. Embryos were excised from the mother ensuring the amnion remained intact and stereo microscopy was performed. Embryos were next embedded in agarose for 3D, high resolution MRI on a 9.4T scanner. Identification of the abnormal embryo phenotypes was not possible using stereo microscopy or conventional ex vivo MRI. Using in amnio MRI, we determined that the abnormal embryos had an exomphalos phenotype with varying severities. In amnio MRI is ideally suited to investigate the complex relationship between embryo and amnion, together with screening for other abnormalities located outside of the mouse embryo, providing a valuable complement to histology and existing imaging methods available to the phenotyping community. PMID:25330230

Metabolomic Assessment of Embryo Viability

PubMed Central

Uyar, Asli; Seli, Emre

2014-01-01

Preimplantation embryo metabolism demonstrates distinctive characteristics associated with the developmental potential of embryos. On this basis, metabolite content of culture media was hypothesized to reflect the implantation potential of individual embryos. This hypothesis was tested in consecutive studies reporting a significant association between culture media metabolites and embryo development or clinical pregnancy. The need for a noninvasive, reliable, and rapid embryo assessment strategy promoted metabolomics studies in vitro fertilization (IVF) in an effort to increase success rates of single embryo transfers. With the advance of analytical techniques and bioinformatics, commercial instruments were developed to predict embryo viability using spectroscopic analysis of surplus culture media. However, despite the initial promising results from proof-of-principal studies, recent randomized controlled trials using commercial instruments failed to show a consistent benefit in improving pregnancy rates when metabolomics is used as an adjunct to morphology. At present, the application of metabolomics technology in clinical IVF laboratory requires the elimination of factors underlying inconsistent findings, when possible, and development of reliable predictive models accounting for all possible sources of bias throughout the embryo selection process. PMID:24515909

Molecular Characterization of a Recombinant Zea mays Phenylalanine Ammonia-Lyase (ZmPAL2) and Its Application in trans-Cinnamic Acid Production from L-Phenylalanine.

PubMed

Zang, Ying; Jiang, Ting; Cong, Ying; Zheng, Zhaojuan; Ouyang, Jia

2015-06-01

Phenylalanine ammonia-lyase (PAL) is one of the most extensively studied enzymes with its crucial role in secondary phenylpropanoid metabolism of plants. Recently, its demand has been increased for aromatic chemical production, but its applications in trans-cinnamic acid production were not much explored. In the present study, a putative PAL gene from Zea mays designated as ZmPAL2 was expressed and characterized in Escherichia coli BL21 (DE3). The recombinant ZmPAL2 exhibited a high PAL activity (7.14 U/mg) and a weak tyrosine ammonia-lyase activity. The optimal temperature of ZmPAL2 was 55 °C, and the thermal stability results showed that about 50 % of enzyme activity remained after a treatment at 60 °C for 6 h. The recombinant ZmPAL2 is a good candidate for the production of trans-cinnamic acid. The vitro conversion indicated that the recombinant ZmPAL2 could effectively catalyze the L-phenylalanine to trans-cinnamic acid, and the trans-cinnamic acid concentration can reach up to 5 g/l.

Donation of surplus frozen pre-embryos to research in Israel: underlying motivations.

PubMed

Raz, Aviad; Amer-Alshiek, Jonia; Goren-Margalit, Mor; Jacobi, Gal; Hochberg, Alyssa; Amit, Ami; Azem, Foad; Amir, Hadar

2016-01-01

The high number of IVF procedures performed in Israel has had an unforeseen consequence: accumulation of large amounts of surplus frozen embryos. After five years that the frozen embryos are kept for free, patients need to make an embryo disposition decision. One option is donation for research. The donation rate in Israel is very low. Our aim was to understand the attitudes, values and perceptions of female IVF patients that decided to donate their surplus frozen embryos to research. The study setting was a tertiary IVF unit which during the 2000-2009 period treated 241 patients who had their frozen pre-embryos stored for more than five years. The study population consists of the 12 patients (from among the 241) who had decided to donate their excess frozen pre-embryos to research. In-depth interviews were carried out with 8 of those 12 patients. IVF patients who donated their surplus frozen pre-embryos to research viewed the frozen embryo as a valuable resource that does not have human identity yet. The majority expressed a gradualist approach to the human status of the embryo as requiring successful implantation and development in the uterus. All the respondents chose donation to research not because it was their first choice but because they did not want or were unable to use the pre-embryos in the future, in addition to not willing to thaw them. For many of the respondents, donation to research was accompanied by a sense of uncertainty. All would have preferred to donate their pre-embryos to infertile women or couples, an option which is currently prohibited in Israel. The moral reasoning behind decisions that patients make regarding excess pre-embryos is important for health care practitioners to consider when offering decision-making alternatives and counseling. For our respondents, the scarcity of donating excess frozen pre-embryos to research may reflect patients' preference for embryo donation to infertile couples. Recommended ways to increase donation to

Embryo loss in cattle between Days 7 and 16 of pregnancy.

PubMed

Berg, D K; van Leeuwen, J; Beaumont, S; Berg, M; Pfeffer, P L

2010-01-15

Embryo loss between embryonic Days 7 and 16 (Day 0=day of IVF) in nonlactating cattle, Bos taurus, was analyzed using transfer of 2449 (in groups of 3 to 30) in vitro-produced (IVP) blastocysts. In 152 transfers, pregnancy losses attributable solely to recipient failings amounted to between 6% (beef heifers) and 16% (parous dairy cows), of which 3% were caused by uterine infections. Neither season, year, nor the age of the embryos on retrieval affected pregnancy rates. The latter observation indicated that the reason that a recipient failed to retain embryos was already present at the time of transfer. Notably, the proportion of embryos recovered decreased (P=0.03) as more embryos were transferred, particularly at later stages (Day 14, P<0.01). The average length of embryos decreased by approximately 5% for every additional embryo transferred (P<0.0001). These effects may be linked to embryonic migration. Embryo mortality inherent to the embryo during the second week of pregnancy was 24%. Additionally, 9% of Day 14 embryos were of inferior quality, as they did not contain an epiblast. Combining embryo and recipient causes but excluding infection effects, embryonic loss of IVP embryos during the second week of pregnancy amounted to 26% (heifers) or 34% (parous dairy cows). The length of embryos doubled every day between Days 9 and 16, with a 4.4-fold range in sizes representing two thirds of the variation in length. Embryos retrieved from heifers were twice the size of those incubated in parous cows (P<0.0001), indicating faster embryonic development/trophoblast proliferation in heifers. Whereas season did not affect embryo recoveries, length was lower (50%) in winter (winter-autumn, P<0.05; winter-spring, P<0.001). Lastly, transuterine migration in cattle, when transferring multiple embryos, commenced at Day 14 (4%) and had occurred in all recipients by Day 16 (38% of embryos found contralaterally).

Anomalous oxygen consumption in porcine somatic cell nuclear transfer embryos.

PubMed

Sugimura, Satoshi; Yokoo, Masaki; Yamanaka, Ken-ichi; Kawahara, Manabu; Moriyasu, Satoru; Wakai, Takuya; Nagai, Takashi; Abe, Hiroyuki; Sato, Eimei

2010-08-01

Oxygen consumption reflects overall metabolic activity of mammalian embryos. We measured oxygen consumption in individual porcine somatic cell nuclear transfer (SCNT) and in vitro-fertilized (IVF) embryos by modified scanning electrochemical microscopy. Oxygen consumption in IVF embryos rapidly increased at day 5 of the blastocyst stage (D5BL). IVF embryos that consumed >0.81 x 10(14)/mol sec(-1) of oxygen at D5BL exhibited significantly higher hatching and hatched rates at D7BL, whereas D5BL SCNT embryos using porcine fetal fibroblasts did not show an increase in oxygen consumption until D7BL. The numbers of inner cell mass and trophectoderm (TE) cells and incidence of apoptosis did not significantly differ between IVF and SCNT embryos at D5BL. At D7BL, a significant lower number of TE cell and higher incidence of apoptosis were observed in SCNT than in IVF embryos; this significantly correlated with their oxygen consumption at D5BL. Use of cumulus cells as donor cells neutralized the low oxygen consumption in SCNT embryos at D5BL, regardless of the difference between the recipient cytoplasm and donor nucleus. Some of SCNT embryos at D7BL were retrieved the hatching completion and were improved the number of TE cell and apoptosis incidence by using cumulus cells. Thus, anomalous oxygen consumption in porcine SCNT embryos at D5BL could be sign of limited hatchability, which may be responsible for the low TE cell number and high apoptosis incidence.

Frozen-Thawed Embryo Transfer Cycles Have a Lower Incidence of Ectopic Pregnancy Compared With Fresh Embryo Transfer Cycles.

PubMed

Zhang, Xinyu; Ma, Caihong; Wu, Zhangxin; Tao, Liyuan; Li, Rong; Liu, Ping; Qiao, Jie

2017-01-01

To evaluate the risk of ectopic pregnancy of embryo transfer. A retrospective cohort study on the incidence of ectopic pregnancy in fresh and frozen-thawed embryo transfer cycles from January 1 st , 2010, to January 1 st , 2015. Infertile women undergoing frozen-thawed transfer cycles or fresh transfer cycles. In-vitro fertilization, fresh embryo transfer, frozen-thawed embryo transfer, ectopic pregnancy. Ectopic pregnancy rate and clinical pregnancy rate. A total of 69 756 in vitro fertilization-embryo transfer cycles from 2010 to 2015 were analyzed, including 45 960 (65.9%) fresh and 23 796 (34.1%) frozen-thawed embryo transfer cycles. The clinical pregnancy rate per embryo transfer was slightly lower in fresh embryo transfer cycles compared with frozen-thawed embryo transfer cycles (40.8% vs 43.1%, P < .001). Frozen-thawed embryo transfer is associated with a lower incidence of ectopic pregnancy per clinical pregnancy, compared with fresh embryo transfers (odds ratio = 0.31; 95% confidence interval = 0.24-0.39). Female age and body mass index have no influence on ectopic pregnancy. In the frozen-thawed embryo transfer cycles, blastocyst transfer shows a significantly lower incidence of ectopic pregnancy (0.8% vs 1.8%, P = .002) in comparison with day 3 cleavage embryo transfer. The risk of ectopic pregnancy is lower in frozen-thawed embryo transfer cycles than fresh embryo transfer cycles, and blastocyst transfer could further decrease the ectopic pregnancy rate in frozen-thawed embryo transfer cycles.

Multigenerational exposure to dietary zearalenone (ZEA), an estrogenic mycotoxin, affects puberty and reproduction in female mice

PubMed Central

Zhao, Fei; Li, Rong; Xiao, Shuo; Honglu, Diao; El Zowalaty, Ahmed E.; Ye, Xiaoqin

2014-01-01

This study investigated potential cumulative effects of multiple pregnancy and multigenerational exposure to dietary ZEA (0, 0.8, 4, or 20 ppm) on female puberty and reproduction in C57BL/6J mice. Multiple pregnancies did not significantly affect litter size or offspring puberty. Significant effects were observed in 20 ppm ZEA-treated females: advanced puberty onset in F0, F1, and F2 generations; decreased implantation rate, pregnancy rate, and litter size, and increased pregnancy gap and gestation period in F1 and F2 generations; and reduced fertility index in F2 generation. F3 females from 0 and 20 ppm groups were split into 0 or 20 ppm ZEA diets at weaning, with advanced puberty onset seen in 0-20 and 20-20 groups and decreased implantation rate observed in 20-20 group. In summary, 20 ppm dietary ZEA advanced puberty onset without obvious cumulative effect and impaired fertility with multigenerational cumulative effect, which could be partially alleviated upon exposure cessation. PMID:24972337

Migration and growth of protoplanetary embryos. I. Convergence of embryos in protoplanetary disks

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

Zhang, Xiaojia; Lin, Douglas N. C.; Liu, Beibei

2014-12-10

According to the core accretion scenario, planets form in protostellar disks through the condensation of dust, coagulation of planetesimals, and emergence of protoplanetary embryos. At a few AU in a minimum mass nebula, embryos' growth is quenched by dynamical isolation due to the depletion of planetesimals in their feeding zone. However, embryos with masses (M{sub p} ) in the range of a few Earth masses (M {sub ⊕}) migrate toward a transition radius between the inner viscously heated and outer irradiated regions of their natal disk. Their limiting isolation mass increases with the planetesimals surface density. When M{sub p} >more » 10 M {sub ⊕}, embryos efficiently accrete gas and evolve into cores of gas giants. We use a numerical simulation to show that despite stream line interference, convergent embryos essentially retain the strength of non-interacting embryos' Lindblad and corotation torques by their natal disks. In disks with modest surface density (or equivalently accretion rates), embryos capture each other in their mutual mean motion resonances and form a convoy of super-Earths. In more massive disks, they could overcome these resonant barriers to undergo repeated close encounters, including cohesive collisions that enable the formation of massive cores.« less

[In vivo spetrometric analysis of the electrical impedance of the first leaf of maize (Zea mays L.) as a function of soil and atmosphere hydrous conditions].

PubMed

Laarabi, Saïd; El Kinani, Khalifa; Ettouhami, Aziz; Limouri, Mohammed

2005-05-01

In vivo spectrometric analysis of the electrical impedance of the first leaf of maize (Zea mays L.) as a function of soil and atmosphere hydrous conditions. We have measured the electrical resistance and capacitance of the first leaf of maize aged 14 days. The plants were cultivated at different levels of soil and atmospheric humidity and submitted to quiet or agitated air. In 'control' plants cultivated in quiet air under moderate relative humidity (HRA) (50 to 60%), the amplitude of the spectrometric bioimpedance spectrum (CSB) increased with the quantity of water available to the roots. Agitated air or elevated HRA increased the magnitude of the CSB in plants cultivated at 40% of the maximal retention capacity (CRM) of the soil. On the other hand, the CSB decreased in plants cultivated at 60% of the CRM or in hydroponics. This was accompanied by a dramatic decrease in the electrical resistance. The action of the atmospheric factors studied depends on the quantity of water where the roots are bathing.

Use of blue crab (Callinectes sapidus) embryos for toxicity testing

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

Lee, R.; O`Malley, K.

1995-12-31

After fertilization, blue crab embryos develop in egg sacs attached to the female pleopods, often referred to as the sponge. Lipovitellin and lipid droplets in the egg sacs provide energy and nutrition for the developing embryos. Embryos were removed from the sponge and transferred to 24 well culture plates containing sea water with or without toxicants, Each well contained 10 embryos. After 7 to 10 days, embryos hatched to swimming zoea. The effects of toxicants at various concentrations on hatching were determined and the EC{sub 50} calculated. For example, the EC{sub 50} for tributyltin, fenvalerate and mercuric chloride were 50,more » 30 and 90 ng/liter, respectively. The hatching success of control embryos ranged from 95 to 98%. Formation of the heart, eyespot formation, appendage formation and utilization rate of lipovitellin were also effected by exposure to toxicants. At a low concentration of mercuric ion (30ng/liter) the heart formed, but there was no heart beat. Eyespot formation was abnormal in the presence of high concentrations of cadmium (2 {micro}g/liter) and zinc (5 {micro}g/liter), Crab embryos offer many advantages for toxicity testing of pure compounds or mixtures in water, including toxicity testing of sediment pore water. The crab embryos may also serve as models to understand the effect of specific toxicants on the heart and eye spots of crustaceans.« less

Nitrogen transporter and assimilation genes exhibit developmental stage-selective expression in maize (Zea mays L.) associated with distinct cis-acting promoter motifs.

PubMed

Liseron-Monfils, Christophe; Bi, Yong-Mei; Downs, Gregory S; Wu, Wenqing; Signorelli, Tara; Lu, Guangwen; Chen, Xi; Bondo, Eddie; Zhu, Tong; Lukens, Lewis N; Colasanti, Joseph; Rothstein, Steven J; Raizada, Manish N

2013-10-01

Nitrogen is considered the most limiting nutrient for maize (Zea mays L.), but there is limited understanding of the regulation of nitrogen-related genes during maize development. An Affymetrix 82K maize array was used to analyze the expression of ≤ 46 unique nitrogen uptake and assimilation probes in 50 maize tissues from seedling emergence to 31 d after pollination. Four nitrogen-related expression clusters were identified in roots and shoots corresponding to, or overlapping, juvenile, adult, and reproductive phases of development. Quantitative real time PCR data was consistent with the existence of these distinct expression clusters. Promoters corresponding to each cluster were screened for over-represented cis-acting elements. The 8-bp distal motif of the Arabidopsis 43-bp nitrogen response element (NRE) was over-represented in nitrogen-related maize gene promoters. This conserved motif, referred to here as NRE43-d8, was previously shown to be critical for nitrate-activated transcription of nitrate reductase (NIA1) and nitrite reductase (NIR1) by the NIN-LIKE PROTEIN 6 (NLP6) in Arabidopsis. Here, NRE43-d8 was over-represented in the promoters of maize nitrate and ammonium transporter genes, specifically those that showed peak expression during early-stage vegetative development. This result predicts an expansion of the NRE-NLP6 regulon and suggests that it may have a developmental component in maize. We also report leaf expression of putative orthologs of nitrite transporters (NiTR1), a transporter not previously reported in maize. We conclude by discussing how each of the four transcriptional modules may be responsible for the different nitrogen uptake and assimilation requirements of leaves and roots at different stages of maize development.

Polar body based aneuploidy screening is poorly predictive of embryo ploidy and reproductive potential.

PubMed

Salvaggio, C N; Forman, E J; Garnsey, H M; Treff, N R; Scott, R T

2014-09-01

Polar body (polar body) biopsy represents one possible solution to performing comprehensive chromosome screening (CCS). This study adds to what is known about the predictive value of polar body based testing for the genetic status of the resulting embryo, but more importantly, provides the first evaluation of the predictive value for actual clinical outcomes after embryo transfer. SNP array was performed on first polar body, second polar body, and either a blastomere or trophectoderm biopsy, or the entire arrested embryo. Concordance of the polar body-based prediction with the observed diagnoses in the embryos was assessed. In addition, the predictive value of the polar body -based diagnosis for the specific clinical outcome of transferred embryos was evaluated through the use of DNA fingerprinting to track individual embryos. There were 459 embryos analyzed from 96 patients with a mean maternal age of 35.3. The polar body-based predictive value for the embryo based diagnosis was 70.3%. The blastocyst implantation predictive value of a euploid trophectoderm was higher than from euploid polar bodies (51% versus 40%). The cleavage stage embryo implantation predictive value of a euploid blastomere was also higher than from euploid polar bodies (31% versus 22%). Polar body based aneuploidy screening results were less predictive of actual clinical outcomes than direct embryo assessment and may not be adequate to improve sustained implantation rates. In nearly one-third of cases the polar body based analysis failed to predict the ploidy of the embryo. This imprecision may hinder efforts for polar body based CCS to improve IVF clinical outcomes.

Transcriptomic and proteomic analysis reveals mechanisms of embryo abortion during chrysanthemum cross breeding.

PubMed

Zhang, Fengjiao; Wang, Zhiquan; Dong, Wen; Sun, Chunqing; Wang, Haibin; Song, Aiping; He, Lizhong; Fang, Weimin; Chen, Fadi; Teng, Nianjun

2014-10-07

Embryo abortion is the main cause of failure in chrysanthemum cross breeding, and the genes and proteins associated with embryo abortion are poorly understood. Here, we applied RNA sequencing and isobaric tags for relative and absolute quantitation (iTRAQ) to analyse transcriptomic and proteomic profiles of normal and abortive embryos. More than 68,000 annotated unigenes and 700 proteins were obtained from normal and abortive embryos. Functional analysis showed that 140 differentially expressed genes (DEGs) and 41 differentially expressed proteins (DEPs) were involved in embryo abortion. Most DEGs and DEPs associated with cell death, protein degradation, reactive oxygen species scavenging, and stress-response transcriptional factors were significantly up-regulated in abortive embryos relative to normal embryos. In contrast, most genes and proteins related to cell division and expansion, the cytoskeleton, protein synthesis and energy metabolism were significantly down-regulated in abortive embryos. Furthermore, abortive embryos had the highest activity of three executioner caspase-like enzymes. These results indicate that embryo abortion may be related to programmed cell death and the senescence- or death-associated genes or proteins contribute to embryo abortion. This adds to our understanding of embryo abortion and will aid in the cross breeding of chrysanthemum and other crops in the future.

Effect of Piriformospora indica inoculation on root development and distribution of maize (Zea mays L.) in the presence of petroleum contaminated soil

NASA Astrophysics Data System (ADS)

Zamani, Javad; Hajabbasi, Mohammad Ali; Alaie, Ebrahim

2014-05-01

The root systems of most terrestrial plants are confronted to various abiotic and biotic stresses. One of these abiotic stresses is contamination of soil with petroleum hydrocarbon, which the efficiency of phytoremediation of petroleum hydrocarbons in soils is dependent on the ability of plant roots to development into the contaminated soils. Piriformospora indica represents a recently discovered fungus that transfers considerable beneficial impact to its host plants. A rhizotron experiment was conducted to study the effects of P. Indica inoculation on root distribution and root and shoot development of maize (Zea mays L.) in the presence of three patterns of petroleum contamination in the soil (subsurface contamination, continuous contamination and without contamination (control)). Root distribution and root and shoot development were monitored over time. The final root and shoot biomass and the final TPH concentration in the rhizosphere were determined. Analysis of digitized images which were prepared of the tracing of the appeared roots along the front rhizotrons showed the depth and total length of root network in the contamination treatments were significantly decreased. Although the degradation of TPH in the rhizosphere of maize was significant, but there were no significant differences between degradation of TPH in the rhizosphere of +P. indica plants in comparison to -P. indica plants.

Effect of specific plant-growth-promoting rhizobacteria (PGPR) on growth and uptake of neonicotinoid insecticide thiamethoxam in corn (Zea mays L.) seedlings.

PubMed

Myresiotis, Charalampos K; Vryzas, Zisis; Papadopoulou-Mourkidou, Euphemia

2015-09-01

Corn (Zea mays L.) is one of the most important cereal crops in the world and is used for food, feed and energy. Inoculation with plant-growth-promoting rhizobacteria (PGPR) would reduce the use of chemical fertilisers and pesticides and could be suggested as an alternative practice for sustainable production of corn in modern agricultural systems. In this study, the effect of two Bacillus PGPR formulated products, Companion (B. subtilis GB03) and FZB24 (B. subtilis FZB24), on corn growth and root uptake of insecticide thiamethoxam was investigated. All bacterial treatments enhanced root biomass production by 38-65% compared with the uninoculated control, with no stimulatory effect of PGPR on above-ground biomass of corn. The uptake results revealed that, in plants inoculated with the PGPR B. subtilis FZB24 and B. subtilis GB03, singly or in combination, the uptake and/or systemic translocation of thiamethoxam in the above-ground corn parts was significantly higher at the different growth ages compared with the control receiving no bacterial treatment. The findings suggest that the PGPR-elicited enhanced uptake of thiamethoxam could lead to improved efficiency of thiamethoxam using reduced rates of pesticides in combination with PGPR as an alternative crop protection technique. © 2014 Society of Chemical Industry.

Phytoremediation potentials of cowpea (Vigina unguiculata) and maize (Zea mays) for hydrocarbon degradation in organic and inorganic manure-amended tropical typic paleustults.

PubMed

Jidere, C M; Akamigbo, F O R; Ugwuanyi, J O

2012-04-01

A field study on phytoremediation of hydrocarbon contaminated soil was designed to assess the effects of organic manures (poultry droppings and cassava peels) and NPK fertilization on the potentials of cowpea (Vigina unguiculata) and maize (Zea mays) to stimulate hydrocarbon degradation in soil. Cowpea and maize crops were established on the hydrocarbon contaminated soil amended with three rates (0, 4, and 8 ton/ha) of the soil amendments, and arranged in 3 x 3 x 3 factorial in Randomized Complete Block Design. Hydrocarbon was significantly (P < 0.05) reduced in plots treated with the combined forms of the soil amendments. While the treatment combinations of 8 t/ha Poultry Droppings (PD) + 8 t/ha Cassava Peels (CP) + 4 t/ha NPK fertilizer was optimal for hydrocarbon degradation in the cowpea plots, 4 t/ha PD + 8 t/ha CP + 8 t/ha NPK fertilizer was the most preferred in the maize plot. Cowpea showed greater potential for hydrocarbon degradation at the first year. The mean values of hydrocarbon concentrations at the cowpea and maize plots indicated no significant difference at the second year. Grain yield of cowpea increased by 87% at the second year, while maize was unable to grow to maturity in the first year.

Soil water capture trends over 50 years of single-cross maize (Zea mays L.) breeding in the US corn-belt

PubMed Central

Reyes, Andres; Messina, Carlos D.; Hammer, Graeme L.; Liu, Lu; van Oosterom, Erik; Lafitte, Renee; Cooper, Mark

2015-01-01

Breeders have successfully improved maize (Zea mays L.) grain yield for the conditions of the US corn-belt over the past 80 years, with the past 50 years utilizing single-cross hybrids. Long-term improvement for grain yield under water-limited conditions has also been reported. Grain yield under water-limited conditions depends on water use, water use efficiency, and harvest index. It has been hypothesized that long-term genetic gain for yield could be due, in part, to increased water capture from the soil. This hypothesis was tested using a set of elite single-cross hybrids that were released by DuPont Pioneer between 1963 and 2009. Eighteen hybrids were grown in the field during 2010 and 2011 growing seasons at Woodland, CA, USA. Crops grew predominantly on stored soil water and drought stress increased as the season progressed. Soil water content was measured to 300cm depth throughout the growing season. Significant water extraction occurred to a depth of 240–300cm and seasonal water use was calculated from the change in soil water over this rooting zone. Grain yield increased significantly with year of commercialization, but no such trend was observed for total water extraction. Therefore, the measured genetic gain for yield for the period represented by this set of hybrids must be related to either increased efficiency of water use or increased carbon partitioning to the grain, rather than increased soil water uptake. PMID:26428065

Roothairless5, which functions in maize (Zea mays L.) root hair initiation and elongation encodes a monocot-specific NADPH oxidase.

PubMed

Nestler, Josefine; Liu, Sanzhen; Wen, Tsui-Jung; Paschold, Anja; Marcon, Caroline; Tang, Ho Man; Li, Delin; Li, Li; Meeley, Robert B; Sakai, Hajime; Bruce, Wesley; Schnable, Patrick S; Hochholdinger, Frank

2014-09-01

Root hairs are instrumental for nutrient uptake in monocot cereals. The maize (Zea mays L.) roothairless5 (rth5) mutant displays defects in root hair initiation and elongation manifested by a reduced density and length of root hairs. Map-based cloning revealed that the rth5 gene encodes a monocot-specific NADPH oxidase. RNA-Seq, in situ hybridization and qRT-PCR experiments demonstrated that the rth5 gene displays preferential expression in root hairs but also accumulates to low levels in other tissues. Immunolocalization detected RTH5 proteins in the epidermis of the elongation and differentiation zone of primary roots. Because superoxide and hydrogen peroxide levels are reduced in the tips of growing rth5 mutant root hairs as compared with wild-type, and Reactive oxygen species (ROS) is known to be involved in tip growth, we hypothesize that the RTH5 protein is responsible for establishing the high levels of ROS in the tips of growing root hairs required for elongation. Consistent with this hypothesis, a comparative RNA-Seq analysis of 6-day-old rth5 versus wild-type primary roots revealed significant over-representation of only two gene ontology (GO) classes related to the biological functions (i.e. oxidation/reduction and carbohydrate metabolism) among 893 differentially expressed genes (FDR <5%). Within these two classes the subgroups 'response to oxidative stress' and 'cellulose biosynthesis' were most prominently represented. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

Genome-wide identification, expression analysis of auxin-responsive GH3 family genes in maize (Zea mays L.) under abiotic stresses.

PubMed

Feng, Shangguo; Yue, Runqing; Tao, Sun; Yang, Yanjun; Zhang, Lei; Xu, Mingfeng; Wang, Huizhong; Shen, Chenjia

2015-09-01

Auxin is involved in different aspects of plant growth and development by regulating the expression of auxin-responsive family genes. As one of the three major auxin-responsive families, GH3 (Gretchen Hagen3) genes participate in auxin homeostasis by catalyzing auxin conjugation and bounding free indole-3-acetic acid (IAA) to amino acids. However, how GH3 genes function in responses to abiotic stresses and various hormones in maize is largely unknown. Here, the latest updated maize (Zea mays L.) reference genome sequence was used to characterize and analyze the ZmGH3 family genes from maize. The results showed that 13 ZmGH3 genes were mapped on five maize chromosomes (total 10 chromosomes). Highly diversified gene structures and tissue-specific expression patterns suggested the possibility of function diversification for these genes in response to environmental stresses and hormone stimuli. The expression patterns of ZmGH3 genes are responsive to several abiotic stresses (salt, drought and cadmium) and major stress-related hormones (abscisic acid, salicylic acid and jasmonic acid). Various environmental factors suppress auxin free IAA contents in maize roots suggesting that these abiotic stresses and hormones might alter GH3-mediated auxin levels. The responsiveness of ZmGH3 genes to a wide range of abiotic stresses and stress-related hormones suggested that ZmGH3s are involved in maize tolerance to environmental stresses. © 2014 Institute of Botany, Chinese Academy of Sciences.

Independent effects of leaf growth and light on the development of the plastid and its DNA content in Zea species.

PubMed

Zheng, Qi; Oldenburg, Delene J; Bendich, Arnold J

2011-05-01

In maize (Zea mays L.), chloroplast development progresses from the basal meristem to the mature leaf tip, and light is required for maturation to photosynthetic competence. During chloroplast greening, it was found that chloroplast DNA (cpDNA) is extensively degraded, falling to undetectable levels in many individual chloroplasts for three maize cultivars, as well as Zea mexicana (the ancestor of cultivated maize) and the perennial species Zea diploperennis. In dark-grown maize seedlings, the proplastid-to-etioplast transition is characterized by plastid enlargement, cpDNA replication, and the retention of high levels of cpDNA. When dark-grown seedlings are transferred to white light, the DNA content per plastid increases slightly during the first 4 h of illumination and then declines rapidly to a minimum at 24 h during the etioplast-to-chloroplast transition. Plastid autofluorescence (from chlorophyll) continues to increase as cpDNA declines, whereas plastid size remains constant. It is concluded that the increase in cpDNA that accompanies plastid enlargement is a consequence of cell and leaf growth, rather than illumination, whereas light stimulates photosynthetic capacity and cpDNA instability. When cpDNA from total tissue was monitored by blot hybridization and real-time quantitative PCR, no decline following transfer from dark to light was observed. The lack of agreement between DNA per plastid and cpDNA per cell may be attributed to nupts (nuclear sequences of plastid origin).

Effects of water-saving superabsorbent polymer on antioxidant enzyme activities and lipid peroxidation in corn (Zea mays L.) under drought stress.

PubMed

Islam, M Robiul; Hu, Yuegao; Mao, Sishuai; Jia, Pengfei; Eneji, A Egrinya; Xue, Xuzhang

2011-03-30

Drought is the most important abiotic stress factor limiting corn (Zea mays L.) growth and productivity. Therefore efficient management of soil moisture and study of metabolic changes in response to drought are important for improved production of corn. The objective of the present study was to gain a better understanding of drought tolerance mechanisms and improve soil water management strategies using a water-saving superabsorbent polymer (SAP) at 30 kg ha(-1) under three irrigation levels (adequate, moderate and deficit) using a new type of hydraulic pressure-controlled auto-irrigator. The results showed that relative water content and leaf water potential were much higher in corn treated with SAP. Although application of SAP reduced biomass accumulation by 11.1% under adequate irrigation, it increased the biomass markedly by 39.0% under moderate irrigation and 98.7% under deficit irrigation. Plants treated with SAP under deficit irrigation showed a significant decrease in superoxide dismutase, catalase, peroxidase, ascorbate peroxidase and glutathione reductase activities in leaves compared with control plants. The results of this study suggest that drought stress causes the production of oxygen radicals, leading to increased lipid peroxidation and oxidative stress in plants, and the application of a superabsorbent polymer could conserve soil water, making it available to plants for quenching oxidative stress and increasing biomass accumulation, especially under severe water stress. Copyright © 2010 Society of Chemical Industry.

Fossilized embryos are widespread but the record is temporally and taxonomically biased

USGS Publications Warehouse

Donoghue, P.C.J.; Kouchinsky, A.; Waloszek, Dieter; Bengtson, S.; Dong, X.-P.; Val'Kov, A.K.; Cunningham, J.A.; Repetski, J.E.

2006-01-01

We report new discoveries of embryos and egg capsules from the Lower Cambrian of Siberia, Middle Cambrian of Australia and Lower Ordovician of North America. Together with existing records, embryos have now been recorded from four of the seven continents. However, the new discoveries highlight secular and systematic biases in the fossil record of embryonic stages. The temporal window within which the embryos and egg capsules are found is of relatively short duration; it ends in the Early Ordovician and is roughly coincident with that of typical "Orsten"-type faunas. The reduced occurrence of such fossils has been attributed to reducing levels of phosphate in marine waters during the early Paleozoic, but may also be owing to the increasing depth of sediment mixing by infaunal metazoans. Furthermore, most records younger than the earliest Cambrian are of a single kind - large eggs and embryos of the priapulid-like scalidophoran Markuelia. We explore alternative explanations for the low taxonomic diversity of embryos recovered thus far, including sampling, size, anatomy, ecology, and environment, concluding that the preponderance of Markuelia embryos is due to its precocious development of cuticle at an embryonic stage, predisposing it to preservation through action as a substrate on which microbially mediated precipitation of authigenic calcium phosphate may occur. The fossil record of embryos may be limited to a late Neoproterozoic to early Ordovician snapshot that is subject to dramatic systematic bias. Together, these biases must be considered seriously in attempts to use the fossil record to arbitrate between hypotheses of developmental and life history evolution implicated in the origin of metazoan clades. ?? 2006 Blackwell Publishing Ltd.

Altered methanol embryopathies in embryo culture with mutant catalase-deficient mice and transgenic mice expressing human catalase

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

Miller, Lutfiya; Wells, Peter G., E-mail: pg.wells@utoronto.ca; Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON

2011-04-01

The mechanisms underlying the teratogenicity of methanol (MeOH) in rodents, unlike its acute toxicity in humans, are unclear, but may involve reactive oxygen species (ROS). Embryonic catalase, although expressed at about 5% of maternal activity, may protect the embryo by detoxifying ROS. This hypothesis was investigated in whole embryo culture to remove confounding maternal factors, including metabolism of MeOH by maternal catalase. C57BL/6 (C57) mouse embryos expressing human catalase (hCat) or their wild-type (C57 WT) controls, and C3Ga.Cg-Catb/J acatalasemic (aCat) mouse embryos or their wild-type C3HeB/FeJ (C3H WT) controls, were explanted on gestational day (GD) 9 (plug = GD 1),more » exposed for 24 h to 4 mg/ml MeOH or vehicle, and evaluated for functional and morphological changes. hCat and C57 WT vehicle-exposed embryos developed normally. MeOH was embryopathic in C57 WT embryos, evidenced by decreases in anterior neuropore closure, somites developed and turning, whereas hCat embryos were protected. Vehicle-exposed aCat mouse embryos had lower yolk sac diameters compared to C3H WT controls, suggesting that endogenous ROS are embryopathic. MeOH was more embryopathic in aCat embryos than WT controls, with reduced anterior neuropore closure and head length only in catalase-deficient embryos. These data suggest that ROS may be involved in the embryopathic mechanism of methanol, and that embryonic catalase activity may be a determinant of teratological risk.« less

Near-infrared laser irradiation improves the development of mouse pre-implantation embryos

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

Yokoo, Masaki; Mori, Miho

The aim of the present study was to assess the effects of near-infrared laser irradiation on the in vitro development of mouse embryos. Female ICR mice were superovulated with pregnant mare serum gonadotropin and human chorionic gonadotropin (hCG), and mated with male mice. Two-cell stage embryos were collected 40 h after administering hCG and cultured in M16 medium. Two-cell embryos (0 h after culture), 8-cell embryos (approx. 30 h after culture), morula (approx. 48 h after culture), and blastocysts (approx. 73 h after culture) were irradiated at 904 nm for 60 s. These embryos were cultured in a time-lapse monitoring system and the timing ofmore » blastocyst hatching was evaluated. Some of the irradiated blastocysts were transferred to the uterine horns of pseudopregnant recipients immediately after irradiation. Pregnancy rates, and offspring growth and fertility, were evaluated. Near-infrared laser irradiation increased the speed of in vitro mouse embryo development. In irradiated blastocysts, hatching was faster than in control (non-irradiated) blastocysts (18.4 vs. 28.2 h, P < 0.05). When 195 irradiated blastocysts were transferred to 18 pseudopregnant mice, all became pregnant and 92 (47.2%) normal-looking pups were born alive. When 182 control blastocysts were transferred to 17 pseudopregnant mice, 14 (82.4%) became pregnant and 54 (29.7%) normal-looking pups were born alive. The growth trajectories (up to 5 weeks) of offspring from irradiated blastocysts were similar to those from control blastocysts. Second generation offspring from transplanted animals were all fertile. These results indicate that near-infrared laser irradiation improves the quality of mouse embryo development in vitro, and increases the live birth rate without affecting the normality of the offspring. Thus, the near-infrared laser method may enhance the quality of embryos and contribute to improvements in reproductive technologies in mammals. - Highlights: • Irradiation of

Can Reptile Embryos Influence Their Own Rates of Heating and Cooling?

PubMed Central

Du, Wei-Guo; Tu, Ming-Chung; Shine, Richard

2013-01-01

Previous investigations have assumed that embryos lack the capacity of physiological thermoregulation until they are large enough for their own metabolic heat production to influence nest temperatures. Contrary to intuition, reptile embryos may be capable of physiological thermoregulation. In our experiments, egg-sized objects (dead or infertile eggs, water-filled balloons, glass jars) cooled down more rapidly than they heated up, whereas live snake eggs heated more rapidly than they cooled. In a nest with diel thermal fluctuations, that hysteresis could increase the embryo’s effective incubation temperature. The mechanisms for controlling rates of thermal exchange are unclear, but may involve facultative adjustment of blood flow. Heart rates of snake embryos were higher during cooling than during heating, the opposite pattern to that seen in adult reptiles. Our data challenge the view of reptile eggs as thermally passive, and suggest that embryos of reptile species with large eggs can influence their own rates of heating and cooling. PMID:23826200

Planar embryos have poor prognosis in terms of blastocyst formation and implantation.

PubMed

Ebner, T; Maurer, M; Shebl, O; Moser, M; Mayer, R B; Duba, H C; Tews, G

2012-09-01

Normally, day-2 embryos show a crosswise arrangement of four cells with three blastomeres lying side by side. Cleavage anomalies include embryos that are characterized by a particular planar constellation of four blastomeres with presumed incomplete cleavage. Since little is known on the developmental fate of such conceptuses, within a 10-month period all consecutive patients were screened for day-2 planar embryos. A total of 64/2070 embryos with suboptimal blastomere configuration were detected (3.1%). In conventional IVF, planar embryos were significantly less frequent (0.7%) as compared with intracytoplasmic sperm injection (2.8%; P<0.05) and cases of testicular sperm extraction (5.4%; P<0.01). Interestingly, embryos with a cleavage anomaly showed better morphology both on day 2 (P<0.005) and day 3 (P<0.001). In contrast, blastocyst formation (P<0.001) and blastocyst quality (P=NS) was higher in tetrahedral embryos. There was a significant increase in implantation rate if tetrahedral embryos could be transferred compared with when planar embryos had to be transferred (P<0.01). It may be postulated that, in planar embryos, the mitotic spindle might have been affected, e.g. sperm centrosome composition or function, which in turn might have led to the observed cleavage anomaly. Normally, day-2 embryos show a crosswise arrangement of four cells with three blastomeres lying side by side. Cleavage anomalies include more planar embryos that are characterized by a particular flat constellation of four blastomeres with presumed premature cleavage (like a tetrafoliate clover). Since little is known on the developmental fate of such embryos within a 10-month study period, all consecutive patients were screened for the presence of day-2 planar embryos (study group). A total of 64 (out of 2070) embryos with abnormal blastomere configuration were detected (3.1%). Interestingly, in conventional IVF (0.7%), the presence of planar embryos was significantly less frequent as

Characterization of embryo-specific genes

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

Sung, Z.R.

1988-01-01

The objective of the proposed research is to characterize the structure and function of a set of genes whose expression is regulated in embryo development, and that are not expressed in mature tissues -- the embryogenic genes. In order to isolate these genes, we immunized a rabbit with total extracts of somatic embryos of carrot, and enriched the anti-embryo antiserum for antibodies reacting with extracts of carrot somatic embryos. Using this enriched antiserum, we screened a lambda gt11 cDNA library constructed from embryo poly A{sup +} RNA, and isolated 10 cDNA clones that detect embryogenic mRNAs. Monospecific antibodies have beenmore » purified for proteins corresponding to each cDNA sequence. Four cDNA clones were further characterized in terms of the expression of their corresponding mRNA and protein in somatic embryos of carrot. In some cases, comparable gene sequences or products have been detected in somatic and zygotic embryos of other plant species. The characteristics of these 4 cDNA clones -- clone Nos. 8, 59, and 66 -- are described in this report. 3 figs.« less

Setting up equine embryo gender determination by preimplantation genetic diagnosis in a commercial embryo transfer program.

PubMed

Herrera, C; Morikawa, M I; Bello, M B; von Meyeren, M; Centeno, J Eusebio; Dufourq, P; Martinez, M M; Llorente, J

2014-03-15

Preimplantation genetic diagnosis (PGD) allows identifying genetic traits in early embryos. Because in some equine breeds, like Polo Argentino, females are preferred to males for competition, PGD can be used to determine the gender of the embryo before transfer and thus allow the production of only female pregnancies. This procedure could have a great impact on commercial embryo production programs. The present study was conducted to adapt gender selection by PGD to a large-scale equine embryo transfer program. To achieve this, we studied (i) the effect on pregnancy rates of holding biopsied embryos for 7 to 10 hours in holding medium at 32 °C before transfer, (ii) the effect on pregnancy rates of using embryos of different sizes for biopsy, and (iii) the efficiency of amplification by heating biopsies before polymerase chain reaction. Equine embryos were classified by size (≤300, 300-1000, and >1000 μm), biopsied, and transferred 1 to 2 or 7 to 10 hours after flushing. Some of the biopsy samples obtained were incubated for 10 minutes at 95 °C and the rest remained untreated. Pregnancy rates were recorded at 25 days of gestation; fetal gender was determined using ultrasonography and compared with PGD results. Holding biopsied embryos for 7 to 10 hours before transfer produced pregnancy rates similar to those for biopsied embryos transferred within 2 hours (63% and 57%, respectively). These results did not differ from pregnancy rates of nonbiopsied embryos undergoing the same holding times (50% for 7-10 hours and 63% for 1-2 hours). Pregnancy rates for biopsied and nonbiopsied embryos did not differ between size groups or between biopsied and nonbiopsied embryos within the same size group (P > 0.05). Incubating biopsy samples for 10 minutes at 95 °C before polymerase chain reaction significantly increased the diagnosis rate (78.5% vs. 45.5% for treated and nontreated biopsy samples respectively). Gender determination using incubated biopsy samples matched the

Membrane Stabilization and Detoxification of Acetaminophen-Mediated Oxidative Onslaughts in the Kidneys of Wistar Rats by Standardized Fraction of Zea mays L. (Poaceae), Stigma maydis.

PubMed

Sabiu, S; O'Neill, F H; Ashafa, A O T

2016-01-01

This study evaluated membrane stabilization and detoxification potential of ethyl acetate fraction of Zea mays L., Stigma maydis in acetaminophen-induced oxidative onslaughts in the kidneys of Wistar rats. Nephrotoxic rats were orally pre- and posttreated with the fraction and vitamin C for 14 days. Kidney function, antioxidative and histological analyses were thereafter evaluated. The acetaminophen-mediated significant elevations in the serum concentrations of creatinine, urea, uric acid, sodium, potassium, and tissue levels of oxidized glutathione, protein-oxidized products, lipid peroxidized products, and fragmented DNA were dose-dependently assuaged in the fraction-treated animals. The fraction also markedly improved creatinine clearance rate, glutathione, and calcium concentrations as well as activities of superoxide dismutase, catalase, glutathione reductase, and glutathione peroxidase in the nephrotoxic rats. These improvements may be attributed to the antioxidative and membrane stabilization activities of the fraction. The observed effects compared favorably with that of vitamin C and are informative of the fraction's ability to prevent progression of renal pathological conditions and preserve kidney functions as evidently supported by the histological analysis. Although the effects were prominently exhibited in the fraction-pretreated groups, the overall data from the present findings suggest that the fraction could prevent or extenuate acetaminophen-mediated oxidative renal damage via fortification of antioxidant defense mechanisms.

Membrane Stabilization and Detoxification of Acetaminophen-Mediated Oxidative Onslaughts in the Kidneys of Wistar Rats by Standardized Fraction of Zea mays L. (Poaceae), Stigma maydis

PubMed Central

Sabiu, S.; O'Neill, F. H.

2016-01-01

This study evaluated membrane stabilization and detoxification potential of ethyl acetate fraction of Zea mays L., Stigma maydis in acetaminophen-induced oxidative onslaughts in the kidneys of Wistar rats. Nephrotoxic rats were orally pre- and posttreated with the fraction and vitamin C for 14 days. Kidney function, antioxidative and histological analyses were thereafter evaluated. The acetaminophen-mediated significant elevations in the serum concentrations of creatinine, urea, uric acid, sodium, potassium, and tissue levels of oxidized glutathione, protein-oxidized products, lipid peroxidized products, and fragmented DNA were dose-dependently assuaged in the fraction-treated animals. The fraction also markedly improved creatinine clearance rate, glutathione, and calcium concentrations as well as activities of superoxide dismutase, catalase, glutathione reductase, and glutathione peroxidase in the nephrotoxic rats. These improvements may be attributed to the antioxidative and membrane stabilization activities of the fraction. The observed effects compared favorably with that of vitamin C and are informative of the fraction's ability to prevent progression of renal pathological conditions and preserve kidney functions as evidently supported by the histological analysis. Although the effects were prominently exhibited in the fraction-pretreated groups, the overall data from the present findings suggest that the fraction could prevent or extenuate acetaminophen-mediated oxidative renal damage via fortification of antioxidant defense mechanisms. PMID:27579048

Surgical manipulation of mammalian embryos in vitro.

PubMed

Naruse, I; Keino, H; Taniguchi, M

1997-04-01

Whole-embryo culture systems are useful in the fields of not only embryology but also teratology, toxicology, pharmacology, and physiology. Of the many advantages of whole-embryo culture, we focus here on the surgical manipulation of mammalian embryos. Whole-embryo culture allows us to manipulate mammalian embryos, similarly to fish, amphibian and avian embryos. Many surgical experiments have been performed in mammalian embryos in vitro. Such surgical manipulation alters the destiny of morphogenesis of the embryos and can answer many questions concerning developmental issues. As an example of surgical manipulation using whole-embryo culture systems, one of our experiments is described. Microsurgical electrocauterization of the deep preaxial mesodermal programmed cell death zone (fpp) in the footplate prevented the manifestation of polydactyly in genetic polydactyly mouse embryos (Pdn/Pdn), in which fpp was abolished.

Arrested human embryos are more likely to have abnormal chromosomes than developing embryos from women of advanced maternal age.

PubMed

Qi, Shu-Tao; Liang, Li-Feng; Xian, Ye-Xing; Liu, Jian-Qiao; Wang, Weihua

2014-01-01

Aneuploidy is one of the major factors that result in low efficiency in human infertility treatment by in vitro fertilization (IVF). The development of DNA microarray technology allows for aneuploidy screening by analyzing all 23 pairs of chromosomes in human embryos. All chromosome screening for aneuploidy is more accurate than partial chromosome screening, as errors can occur in any chromosome. Currently, chromosome screening for aneuploidy is performed in developing embryos, mainly blastocysts. It has not been performed in arrested embryos and/or compared between developing embryos and arrested embryos from the same IVF cycle. The present study was designed to examine all chromosomes in blastocysts and arrested embryos from the same cycle in patients of advanced maternal ages. Embryos were produced by routine IVF procedures. A total of 90 embryos (45 blastocysts and 45 arrested embryos) from 17 patients were biopsied and analyzed by the Agilent DNA array platform. It was found that 50% of the embryos developed to blastocyst stage; however, only 15.6% of the embryos (both blastocyst and arrested) were euploid, and most (84.4%) of the embryos had chromosomal abnormalities. Further analysis indicated that 28.9% of blastocysts were euploid and 71.1% were aneuploid. By contrast, only one (2.2%) arrested embryo was euploid while others (97.8%) were aneuploid. The prevalence of multiple chromosomal abnormalities in the aneuploid embryos was also higher in the arrested embryos than in the blastocysts. These results indicate that high proportions of human embryos from patients of advanced maternal age are aneuploid, and the arrested embryos are more likely to have abnormal chromosomes than developing embryos.