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Sample records for elucidating grass flower

  1. The role of seasonal flowering responses in adaptation of grasses to temperate climates

    PubMed Central

    Fjellheim, Siri; Boden, Scott; Trevaskis, Ben

    2014-01-01

    Grasses of the subfamily Pooideae, including important cereal crops and pasture grasses, are widespread in temperate zones. Seasonal regulation of developmental transitions coordinates the life cycles of Pooideae with the passing seasons so that flowering and seed production coincide with favorable conditions in spring. This review examines the molecular pathways that control the seasonal flowering responses of Pooideae and how variation in the activity of genes controlling these pathways can adapt cereals or grasses to different climates and geographical regions. The possible evolutionary origins of the seasonal flowering responses of the Pooideae are discussed and key questions for future research highlighted. These include the need to develop a better understanding of the molecular basis for seasonal flowering in perennial Pooideae and in temperate grasses outside the core Pooideae group. PMID:25221560

  2. The effect of timing of growing season drought on flowering of a dominant C4 grass.

    PubMed

    Dietrich, John D; Smith, Melinda D

    2016-06-01

    Timing of precipitation is equally important as amount for determining ecosystem function, especially aboveground net primary productivity (ANPP), in a number of ecosystems. In tallgrass prairie of the Central Plains of North America, grass flowering stalks of dominant C4 grasses, such as Andropogon gerardii, can account for more than 70 % of ANPP, or almost none of it, as the number of flowering stalks produced is highly variable. Although growing season precipitation amount is important for driving variation in flowering stalk production, it remains unknown whether there are critical periods within the growing season in which sufficient rainfall must occur to allow for flowering. The effect of timing of rainfall deficit (drought) on flowering of A. gerardii, was tested by excluding rainfall during three periods within the growing season (starting in mid-April, mid-May and mid-June). Mid-summer drought (starting in mid-June) strongly reduced the flowering rate (e.g., density and biomass) of A. gerardii (e.g., as high as 94 % compared to the control), suggesting flowering is highly sensitive to precipitation at this time. This effect appeared to be related to plant water status at the time of flowering stalk initiation, rather than an indirect consequence of reduced C assimilation. Our results suggest that increased frequency of growing season drought forecast with climate change could reduce sexual reproduction in this dominant grass species, particularly if it coincides with timing of flowering stalk initiation, with important implications for ecosystem functioning. PMID:26886131

  3. Population structure in the model grass Brachypodium distachyon is highly correlated with flowering differences across broad geographic areas

    DOE PAGESBeta

    Tyler, Ludmila; Lee, Scott J.; Young, Nelson D.; DeIulio, Gregory A.; Benavente, Elena; Reagon, Michael; Sysopha, Jessica; Baldini, Riccardo M.; Troia, Angelo; Hazen, Samuel P.; et al

    2016-04-29

    The small, annual grass Brachypodium distachyon (L.) Beauv., a close relative of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.), is a powerful model system for cereals and bioenergy grasses. Genome-wide association studies (GWAS) of natural variation can elucidate the genetic basis of complex traits but have been so far limited in B. distachyon by the lack of large numbers of well-characterized and sufficiently diverse accessions. Here, we report on genotyping-by-sequencing (GBS) of 84 B. distachyon, seven B. hybridum, and three B. stacei accessions with diverse geographic origins including Albania, Armenia, Georgia, Italy, Spain, and Turkey. Over 90,000 high-qualitymore » single-nucleotide polymorphisms (SNPs) distributed across the Bd21 reference genome were identified. Our results confirm the hybrid nature of the B. hybridum genome, which appears as a mosaic of B. distachyon-like and B. stacei-like sequences. Analysis of more than 50,000 SNPs for the B. distachyon accessions revealed three distinct, genetically defined populations. Surprisingly, these genomic profiles are associated with differences in flowering time rather than with broad geographic origin. High levels of differentiation in loci associated with floral development support the differences in flowering phenology between B. distachyon populations. Genome-wide association studies combining genotypic and phenotypic data also suggest the presence of one or more photoperiodism, circadian clock, and vernalization genes in loci associated with flowering time variation within B. distachyon populations. As a result, our characterization elucidates genes underlying population differences, expands the germplasm resources available for Brachypodium, and illustrates the feasibility and limitations of GWAS in this model grass.« less

  4. PHYTOCHROME C is an essential light receptor for photoperiodic flowering in the temperate grass, Brachypodium distachyon.

    PubMed

    Woods, Daniel P; Ream, Thomas S; Minevich, Gregory; Hobert, Oliver; Amasino, Richard M

    2014-09-01

    We show that in the temperate grass, Brachypodium distachyon, PHYTOCHROME C (PHYC), is necessary for photoperiodic flowering. In loss-of-function phyC mutants, flowering is extremely delayed in inductive photoperiods. PHYC was identified as the causative locus by utilizing a mapping by sequencing pipeline (Cloudmap) optimized for identification of induced mutations in Brachypodium. In phyC mutants the expression of Brachypodium homologs of key flowering time genes in the photoperiod pathway such as GIGANTEA (GI), PHOTOPERIOD 1 (PPD1/PRR37), CONSTANS (CO), and florigen/FT are greatly attenuated. PHYC also controls the day-length dependence of leaf size as the effect of day length on leaf size is abolished in phyC mutants. The control of genes upstream of florigen production by PHYC was likely to have been a key feature of the evolution of a long-day flowering response in temperate pooid grasses. PMID:25023399

  5. Translational Biology: From Arabidopsis Flowers to Grass Inflorescence Architecture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the key events in plant development is the initiation of lateral organs from the flanks of the meristem. In grasses, the inflorescence meristem (IM) reiteratively initiates a series of lateral meristems with slightly different fates. Our understanding of the genes and networks that regulate g...

  6. Evolution of VRN2/Ghd7-Like Genes in Vernalization-Mediated Repression of Grass Flowering.

    PubMed

    Woods, Daniel P; McKeown, Meghan A; Dong, Yinxin; Preston, Jill C; Amasino, Richard M

    2016-04-01

    Flowering of many plant species is coordinated with seasonal environmental cues such as temperature and photoperiod. Vernalization provides competence to flower after prolonged cold exposure, and a vernalization requirement prevents flowering from occurring prior to winter. In winter wheat (Triticum aestivum) and barley (Hordeum vulgare), three genes VRN1, VRN2, and FT form a regulatory loop that regulates the initiation of flowering. Prior to cold exposure, VRN2 represses FT. During cold, VRN1 expression increases, resulting in the repression of VRN2, which in turn allows activation of FT during long days to induce flowering. Here, we test whether the circuitry of this regulatory loop is conserved across Pooideae, consistent with their niche transition from the tropics to the temperate zone. Our phylogenetic analyses of VRN2-like genes reveal a duplication event occurred before the diversification of the grasses that gave rise to a CO9 and VRN2/Ghd7 clade and support orthology between wheat/barley VRN2 and rice (Oryza sativa) Ghd7 Our Brachypodium distachyon VRN1 and VRN2 knockdown and overexpression experiments demonstrate functional conservation of grass VRN1 and VRN2 in the promotion and repression of flowering, respectively. However, expression analyses in a range of pooids demonstrate that the cold repression of VRN2 is unique to core Pooideae such as wheat and barley. Furthermore, VRN1 knockdown in B. distachyon demonstrates that the VRN1-mediated suppression of VRN2 is not conserved. Thus, the VRN1-VRN2 feature of the regulatory loop appears to have evolved late in the diversification of temperate grasses. PMID:26848096

  7. Regulation of Flowering in the Long-Day Grass Lolium temulentum by Gibberellins and the FLOWERING LOCUS T Gene

    PubMed Central

    King, Rod W.; Moritz, Thomas; Evans, Lloyd T.; Martin, Jerome; Andersen, Claus H.; Blundell, Cheryl; Kardailsky, Igor; Chandler, Peter M.

    2006-01-01

    Seasonal control of flowering often involves leaf sensing of daylength coupled to time measurement and generation and transport of florigenic signals to the shoot apex. We show that transmitted signals in the grass Lolium temulentum may include gibberellins (GAs) and the FLOWERING LOCUS T (FT) gene. Within 2 h of starting a florally inductive long day (LD), expression of a 20-oxidase GA biosynthetic gene increases in the leaf; its product, GA20, then increases 5.7-fold versus short day; its substrate, GA19, decreases equivalently; and a bioactive product, GA5, increases 4-fold. A link between flowering, LD, GAs, and GA biosynthesis is shown in three ways: (1) applied GA19 became florigenic on exposure to LD; (2) expression of LtGA20ox1, an important GA biosynthetic gene, increased in a florally effective LD involving incandescent lamps, but not with noninductive fluorescent lamps; and (3) paclobutrazol, an inhibitor of an early step of GA biosynthesis, blocked flowering, but only if applied before the LD. Expression studies of a 2-oxidase catabolic gene showed no changes favoring a GA increase. Thus, the early LD increase in leaf GA5 biosynthesis, coupled with subsequent doubling in GA5 content at the shoot apex, provides a substantial trail of evidence for GA5 as a LD florigen. LD signaling may also involve transport of FT mRNA or protein because expression of LtFT and LtCONSTANS increased rapidly, substantially (>80-fold for FT), and independently of GA. However, because a LD from fluorescent lamps induced LtFT expression but not flowering, the nature of the light response of FT requires clarification. PMID:16581877

  8. Flowering induction in the bioenergy grass Miscanthus sacchariflorus is a quantitative short-day response, whilst delayed flowering under long days increases biomass accumulation

    PubMed Central

    Donnison, Iain

    2013-01-01

    Miscanthus sacchariflorus is a fast-growing C4 perennial grass that can naturally hybridize with M. sinensis to produce interspecific hybrids, such as the sterile triploid M.× giganteus. The creation of such hybrids is essential for the rapid domestication of this novel bioenergy crop. However, progress has been hindered by poor understanding of the environmental cues promoting floral transition in M. sacchariflorus, which flowers less readily than M. sinensis. The purpose of this work was to identify the flowering requirements of M. sacchariflorus genotypes in order to expedite the introduction of new germplasm optimized to different environments. Six M. sacchariflorus accessions collected from a range of latitudes were grown under controlled photoperiod and temperature conditions, and flowering, biomass, and morphological phenotypic data were captured. Results indicated that M. sacchariflorus, irrespective of origin, is a quantitative short-day plant. Flowering under static long days (15.3h daylength), compared with shorter photoperiods, was delayed by an average 61 d, with an average associated increase of 52% of above-ground biomass (DM plant–1). Timing of floral initiation occurred between photoperiods of 14.2h and 12.1h, and accumulated temperatures of 553–1157 °C above a base temperature of 10 °C. Miscanthus sacchariflorus flowering phenology closely resembles that of Sorghum and Saccharum, indicating potentially similar floral pathways and suggesting that determination of the underlying genetic mechanisms will be facilitated by the syntenic relationships existing between these important C4 grasses. PMID:23183254

  9. Structural elucidation of a pectin from flowers of Lonicera japonica and its antipancreatic cancer activity.

    PubMed

    Lin, Liyan; Wang, Peipei; Du, Zhenyun; Wang, Wucheng; Cong, Qifei; Zheng, Changping; Jin, Can; Ding, Kan; Shao, Chenghao

    2016-07-01

    To investigate polysaccharide structure from Lonicera japonica, and study its effects on behavior of pancreatic cells, a homogenous polysaccharide, LJ-02-1, was extracted and purified from flowers of L. japonica by DEAE-cellulose and Sephacryl S-200HR column. The molecular weight was estimated to be 54kDa. Monosaccharide composition was determined to be rhamnose, galacturonic acid, galactose and arabinose in the molar ratio of 10.77:7.88:15.45:65.89 by analyzing the PMP derivatives of the monosaccharides from 2M trifluoracetic acid hydrolysis via HPLC. Based on methylation analysis, partial acid hydrolysis, and NMR spectra, the polysaccharide was elucidated to be a rhamnogalacturonan backbone and substituted partly at C-4 of rhamnose. The branches were determined to be T- and 1,4,6-linked β-d-Galp, T- and 1,5-linked α-l-Araf. The polysaccharide might inhibit BxPC-3 and PANC-1 pancreatic cancer cells growth at the concentration of 1mg/mL with inhibitory ratio of 66.7% and 52.1%, respectively. PMID:27000440

  10. Elucidation of the pathway to astaxanthin in the flowers of Adonis aestivalis.

    PubMed

    Cunningham, Francis X; Gantt, Elisabeth

    2011-08-01

    A few species in the genus Adonis are the only land plants known to produce the valuable red ketocarotenoid astaxanthin in abundance. Here, we ascertain the pathway that leads from the β-rings of β-carotene, a carotenoid ubiquitous in plants, to the 3-hydroxy-4-keto-β-rings of astaxanthin (3,3'-dihydroxy-β,β-carotene-4,4'-dione) in the blood-red flowers of Adonis aestivalis, an ornamental and medicinal plant commonly known as summer pheasant's eye. Two gene products were found to catalyze three distinct reactions, with the first and third reactions of the pathway catalyzed by the same enzyme. The pathway commences with the activation of the number 4 carbon of a β-ring in a reaction catalyzed by a carotenoid β-ring 4-dehydrogenase (CBFD), continues with the further dehydrogenation of this carbon to yield a carbonyl in a reaction catalyzed by a carotenoid 4-hydroxy-β-ring 4-dehydrogenase, and concludes with the addition of an hydroxyl group at the number 3 carbon in a reaction catalyzed by the erstwhile CBFD enzyme. The A. aestivalis pathway is both portable and robust, functioning efficiently in a simple bacterial host. Our elucidation of the pathway to astaxanthin in A. aestivalis provides enabling technology for development of a biological production process and reveals the evolutionary origin of this unusual plant pathway, one unrelated to and distinctly different from those used by bacteria, green algae, and fungi to synthesize astaxanthin. PMID:21862704

  11. Progress towards elucidating the mechanisms of self-incompatibility in the grasses: further insights from studies in Lolium

    PubMed Central

    Klaas, Manfred; Yang, Bicheng; Bosch, Maurice; Thorogood, Daniel; Manzanares, Chloe; Armstead, Ian P.; Franklin, F. C. H.; Barth, Susanne

    2011-01-01

    Background and Scope Self-incompatibility (SI) in flowering plants ensures the maintenance of genetic diversity by ensuring outbreeding. Different genetic and mechanistic systems of SI among flowering plants suggest either multiple origins of SI or considerable evolutionary diversification. In the grasses, SI is based on two loci, S and Z, which are both polyallelic: an incompatible reaction occurs only if both S and Z alleles are matched in individual pollen with alleles of the pistil on which they alight. Such incompatibility is referred to as gametophytic SI (GSI). The mechanics of grass GSI is poorly understood relative to the well-characterized S-RNase-based single-locus GSI systems (Solanaceae, Rosaceae, Plantaginaceae), or the Papaver recognition system that triggers a calcium-dependent signalling network culminating in programmed cell death. There is every reason to suggest that the grass SI system represents yet another mechanism of SI. S and Z loci have been mapped using isozymes to linkage groups C1 and C2 of the Triticeae consensus maps in Secale, Phalaris and Lolium. Recently, in Lolium perenne, in order to finely map and identify S and Z, more closely spaced markers have been developed based on cDNA and repeat DNA sequences, in part from genomic regions syntenic between the grasses. Several genes tightly linked to the S and Z loci were identified, but so far no convincing candidate has emerged. Research and Progress From subtracted Lolium immature stigma cDNA libraries derived from S and Z genotyped individuals enriched for SI potential component genes, kinase enzyme domains, a calmodulin-dependent kinase and a peptide with several calcium (Ca2+) binding domains were identified. Preliminary findings suggest that Ca2+ signalling and phosphorylation may be involved in Lolium GSI. This is supported by the inhibition of Lolium SI by Ca2+ channel blockers lanthanum (La3+) and verapamil, and by findings of increased phosphorylation activity during an SI

  12. Evolution of VRN2/Ghd7-Like Genes in Vernalization-Mediated Repression of Grass Flowering1[OPEN

    PubMed Central

    McKeown, Meghan A.

    2016-01-01

    Flowering of many plant species is coordinated with seasonal environmental cues such as temperature and photoperiod. Vernalization provides competence to flower after prolonged cold exposure, and a vernalization requirement prevents flowering from occurring prior to winter. In winter wheat (Triticum aestivum) and barley (Hordeum vulgare), three genes VRN1, VRN2, and FT form a regulatory loop that regulates the initiation of flowering. Prior to cold exposure, VRN2 represses FT. During cold, VRN1 expression increases, resulting in the repression of VRN2, which in turn allows activation of FT during long days to induce flowering. Here, we test whether the circuitry of this regulatory loop is conserved across Pooideae, consistent with their niche transition from the tropics to the temperate zone. Our phylogenetic analyses of VRN2-like genes reveal a duplication event occurred before the diversification of the grasses that gave rise to a CO9 and VRN2/Ghd7 clade and support orthology between wheat/barley VRN2 and rice (Oryza sativa) Ghd7. Our Brachypodium distachyon VRN1 and VRN2 knockdown and overexpression experiments demonstrate functional conservation of grass VRN1 and VRN2 in the promotion and repression of flowering, respectively. However, expression analyses in a range of pooids demonstrate that the cold repression of VRN2 is unique to core Pooideae such as wheat and barley. Furthermore, VRN1 knockdown in B. distachyon demonstrates that the VRN1-mediated suppression of VRN2 is not conserved. Thus, the VRN1-VRN2 feature of the regulatory loop appears to have evolved late in the diversification of temperate grasses. PMID:26848096

  13. Elucidation of the Pathway to Astaxanthin in the Flowers of Adonis aestivalis[C][W

    PubMed Central

    Cunningham, Francis X.; Gantt, Elisabeth

    2011-01-01

    A few species in the genus Adonis are the only land plants known to produce the valuable red ketocarotenoid astaxanthin in abundance. Here, we ascertain the pathway that leads from the β-rings of β-carotene, a carotenoid ubiquitous in plants, to the 3-hydroxy-4-keto-β-rings of astaxanthin (3,3′-dihydroxy-β,β-carotene-4,4’-dione) in the blood-red flowers of Adonis aestivalis, an ornamental and medicinal plant commonly known as summer pheasant’s eye. Two gene products were found to catalyze three distinct reactions, with the first and third reactions of the pathway catalyzed by the same enzyme. The pathway commences with the activation of the number 4 carbon of a β-ring in a reaction catalyzed by a carotenoid β-ring 4-dehydrogenase (CBFD), continues with the further dehydrogenation of this carbon to yield a carbonyl in a reaction catalyzed by a carotenoid 4-hydroxy-β-ring 4-dehydrogenase, and concludes with the addition of an hydroxyl group at the number 3 carbon in a reaction catalyzed by the erstwhile CBFD enzyme. The A. aestivalis pathway is both portable and robust, functioning efficiently in a simple bacterial host. Our elucidation of the pathway to astaxanthin in A. aestivalis provides enabling technology for development of a biological production process and reveals the evolutionary origin of this unusual plant pathway, one unrelated to and distinctly different from those used by bacteria, green algae, and fungi to synthesize astaxanthin. PMID:21862704

  14. Growth of 3-D flower/grass-like metal oxide nanoarchitectures based on catalyst-assisted oxidation method

    PubMed Central

    2014-01-01

    Cu2O grass-like and ZnO flower-like nanoarchitectures were fabricated directly on Cu powders and Zn powders using a novel thermal oxidation stress-induced (TOS) method based on catalyst assistance at a low temperature of 150°C under moderate humid atmosphere. The experiments of Al powder were also carried out based on TOS method. Overlapping migration (OLM) of Cu and Zn atoms and toothpaste squeezing migration (TSM) of Al atoms caused by different atom densities in metal oxide materials were studied. PACS 81. Materials science; 81.07.-b Nanoscale materials and structures: fabrication and characterization; 81.16.Hc Catalytic methods PMID:24624935

  15. Growth of 3-D flower/grass-like metal oxide nanoarchitectures based on catalyst-assisted oxidation method

    NASA Astrophysics Data System (ADS)

    Hu, Lijiao; Ju, Yang; Hosoi, Atsushi

    2014-03-01

    Cu2O grass-like and ZnO flower-like nanoarchitectures were fabricated directly on Cu powders and Zn powders using a novel thermal oxidation stress-induced (TOS) method based on catalyst assistance at a low temperature of 150°C under moderate humid atmosphere. The experiments of Al powder were also carried out based on TOS method. Overlapping migration (OLM) of Cu and Zn atoms and toothpaste squeezing migration (TSM) of Al atoms caused by different atom densities in metal oxide materials were studied.

  16. The surface condition effect of Cu2O flower/grass-like nanoarchitectures grown on Cu foil and Cu film

    NASA Astrophysics Data System (ADS)

    Hu, Lijiao; Ju, Yang; Hosoi, Atsushi; Tang, Yongpeng

    2013-10-01

    Cu2O flower/grass-like nanoarchitectures (FGLNAs) were fabricated directly on two category specimens of Cu foils and Cu film using thermal oxidation method. The FGLNAs are approximately 3.5 to 12 μm in size, and their petals are approximately 50 to 950 nm in width. The high compressive stress caused by a large oxide volume in the Cu2O layer on the specimen surface played an important role in the growth of FGLNAs. The effects of surface conditions, such as the surface stresses, grain size, and surface roughness of Cu foil and Cu film specimens, on the FGLNA growth were discussed in detail.

  17. Elucidation of Differential Accumulation of 1-Phenylethanol in Flowers and Leaves of Tea (Camellia sinensis) Plants.

    PubMed

    Dong, Fang; Zhou, Ying; Zeng, Lanting; Peng, Qiyuan; Chen, Yiyong; Zhang, Ling; Su, Xinguo; Watanabe, Naoharu; Yang, Ziyin

    2016-01-01

    1-Phenylethanol (1PE) is a major aromatic volatile in tea (Camellia sinensis) flowers, whereas it occurs in a much smaller amounts in leaves. Enzymes involved in the formation of 1PE in plants and the reason why 1PE differentially accumulates in plants is unknown. In the present study, enzymes in the last step leading from acetophenone to 1PE were isolated from tea flowers by traditional biochemical chromatography. The two types of partially purified enzymes were proposed to be responsible for formations of (R)-1PE and (S)-1PE, respectively. Tea leaves also contained such enzymes having equivalent activities with flowers. Stable isotope labeling experiments indicated that weak transformation from l-phenylalanine to acetophenone in leaves mainly resulted in little occurrence of 1PE in leaves. This study provided an example that differential distribution of some metabolites in plant tissues was not only determined by enzyme(s) in the last step of metabolite formation, but also can be due to substrate availability. PMID:27563859

  18. The evolution of photoperiod-sensitive flowering in sorghum, a genomic model for panicoid grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water loss from a plant is a direct consequence of photosynthesis, and diverse plants share maximal sensitivity to water deficit at flowering. Flowering under short daylength (e.g. less than 12 hr) coordinates fecundity and seed development with favorable rainfall, temperature, and solar radiation i...

  19. The surface condition effect of Cu2O flower/grass-like nanoarchitectures grown on Cu foil and Cu film

    PubMed Central

    2013-01-01

    Cu2O flower/grass-like nanoarchitectures (FGLNAs) were fabricated directly on two category specimens of Cu foils and Cu film using thermal oxidation method. The FGLNAs are approximately 3.5 to 12 μm in size, and their petals are approximately 50 to 950 nm in width. The high compressive stress caused by a large oxide volume in the Cu2O layer on the specimen surface played an important role in the growth of FGLNAs. The effects of surface conditions, such as the surface stresses, grain size, and surface roughness of Cu foil and Cu film specimens, on the FGLNA growth were discussed in detail. PACS 81. Materials science; 81.07.-b Nanoscale materials and structures: fabrication and characterization; 81.16.Hc Catalytic methods PMID:24164860

  20. The Evolution of Photoperiod-Insensitive Flowering in Sorghum, A Genomic Model for Panicoid Grasses

    PubMed Central

    Cuevas, Hugo E.; Zhou, Chengbo; Tang, Haibao; Khadke, Prashant P.; Das, Sayan; Lin, Yann-Rong; Ge, Zhengxiang; Clemente, Thomas; Upadhyaya, Hari D.; Hash, C. Thomas; Paterson, Andrew H.

    2016-01-01

    Of central importance in adapting plants of tropical origin to temperate cultivation has been selection of daylength-neutral genotypes that flower early in the temperate summer and take full advantage of its long days. A cross between tropical and temperate sorghums [Sorghum propinquum (Kunth) Hitchc.×S. bicolor (L.) Moench], revealed a quantitative trait locus (QTL), FlrAvgD1, accounting for 85.7% of variation in flowering time under long days. Fine-scale genetic mapping placed FlrAvgD1 on chromosome 6 within the physically largest centiMorgan in the genome. Forward genetic data from “converted” sorghums validated the QTL. Association genetic evidence from a diversity panel delineated the QTL to a 10-kb interval containing only one annotated gene, Sb06g012260, that was shown by reverse genetics to complement a recessive allele. Sb06g012260 (SbFT12) contains a phosphatidylethanolamine-binding (PEBP) protein domain characteristic of members of the “FT” family of flowering genes acting as a floral suppressor. Sb06g012260 appears to have evolved ∼40 Ma in a panicoid ancestor after divergence from oryzoid and pooid lineages. A species-specific Sb06g012260 mutation may have contributed to spread to temperate regions by S. halepense (“Johnsongrass”), one of the world’s most widespread invasives. Alternative alleles for another family member, Sb02g029725 (SbFT6), mapping near another flowering QTL, also showed highly significant association with photoperiod response index (P = 1.53×10 − 6). The evolution of Sb06g012260 adds to evidence that single gene duplicates play large roles in important environmental adaptations. Increased knowledge of Sb06g012260 opens new doors to improvement of sorghum and other grain and cellulosic biomass crops. PMID:27335143

  1. The Evolution of Photoperiod-Insensitive Flowering in Sorghum, A Genomic Model for Panicoid Grasses.

    PubMed

    Cuevas, Hugo E; Zhou, Chengbo; Tang, Haibao; Khadke, Prashant P; Das, Sayan; Lin, Yann-Rong; Ge, Zhengxiang; Clemente, Thomas; Upadhyaya, Hari D; Hash, C Thomas; Paterson, Andrew H

    2016-09-01

    Of central importance in adapting plants of tropical origin to temperate cultivation has been selection of daylength-neutral genotypes that flower early in the temperate summer and take full advantage of its long days. A cross between tropical and temperate sorghums [Sorghum propinquum (Kunth) Hitchc.×S. bicolor (L.) Moench], revealed a quantitative trait locus (QTL), FlrAvgD1, accounting for 85.7% of variation in flowering time under long days. Fine-scale genetic mapping placed FlrAvgD1 on chromosome 6 within the physically largest centiMorgan in the genome. Forward genetic data from "converted" sorghums validated the QTL. Association genetic evidence from a diversity panel delineated the QTL to a 10-kb interval containing only one annotated gene, Sb06g012260, that was shown by reverse genetics to complement a recessive allele. Sb06g012260 (SbFT12) contains a phosphatidylethanolamine-binding (PEBP) protein domain characteristic of members of the "FT" family of flowering genes acting as a floral suppressor. Sb06g012260 appears to have evolved ∼40 Ma in a panicoid ancestor after divergence from oryzoid and pooid lineages. A species-specific Sb06g012260 mutation may have contributed to spread to temperate regions by S. halepense ("Johnsongrass"), one of the world's most widespread invasives. Alternative alleles for another family member, Sb02g029725 (SbFT6), mapping near another flowering QTL, also showed highly significant association with photoperiod response index (P = 1.53×10 (-)  (6)). The evolution of Sb06g012260 adds to evidence that single gene duplicates play large roles in important environmental adaptations. Increased knowledge of Sb06g012260 opens new doors to improvement of sorghum and other grain and cellulosic biomass crops. PMID:27335143

  2. Elucidating the evolutionary history of the Southeast Asian, holoparasitic, giant-flowered Rafflesiaceae: pliocene vicariance, morphological convergence and character displacement.

    PubMed

    Bendiksby, Mika; Schumacher, Trond; Gussarova, Galina; Nais, Jamili; Mat-Salleh, Kamarudin; Sofiyanti, Nery; Madulid, Domingo; Smith, Stephen A; Barkman, Todd

    2010-11-01

    The aim of the present study is to elucidate the evolutionary history of the enigmatic holoparasitic Rafflesiaceae. More specifically, floral morphological evolution is interpreted in a molecular phylogenetic context, the biogeographic history of the family is investigated, and the possibility of character displacement to have been operating in this family is assessed. Parsimony and Bayesian methods are used to estimate phylogeny and divergence times among Rafflesiaceae species based on nuclear and mitochondrial DNA sequence data from Barkman et al. (2008) as well as new sequence data from additional samples and an additional genetic marker, the plastid 16S. Ancestral areas are inferred using dispersal-vicariance analysis (DIVA) as well a more recently developed parametric likelihood method (LAGRANGE), now including an update that allows for estimation over the posterior distribution of dated trees. Our extended molecular phylogeny of Rafflesiaceae implies a general lack of morphological synapomorphies as well as a high level of morphological homoplasy. In particular, a high level of floral morphological homoplasy is detected among Rafflesia species suggestive of similar patterns of pollinator-based selection in different geographic areas, and multiple instances of divergent floral size evolution is consistent with a model of character displacement. Initial diversification of Rafflesiaceae during the Late Cretaceous was followed by a long period of no-net diversification, likely due to extinctions caused by a Late Eocene to Miocene dramatic reduction in rainforest cover. A Late Miocene to Early Pliocene rise in sea-level probably caused the vicariant diversification observed between areas of endemism. The most recent species divergences are concordant with Pleistocene changes in climate and sea-levels, but apparently with no successful inter-area migrations, supportive of savannah, rather than rainforest, covered landbridges. An explosive increase in net

  3. Elucidation of Molecular Identity of the W3 Locus and Its Implication in Determination of Flower Colors in Soybean

    PubMed Central

    Park, Gyu Tae; Sundaramoorthy, Jagadeesh; Lee, Jeong-Dong; Kim, Jeong Hoe; Seo, Hak Soo; Song, Jong Tae

    2015-01-01

    The wide range of flower colors in soybean is controlled by six independent loci (W1, W2, W3, W4, Wm, and Wp). Among these loci, mutations in the W3 locus under the w4 allelic background (i.e., w3w4) produce near-white flowers, while the W3w4 genotype produces purple throat flowers. Although a gene encoding dihydroflavonol 4-reductase, DFR1, has been known to be closely associated with the W3 locus, its molecular identity has not yet been characterized. In the present study, we aimed to determine whether DFR1 is responsible for allelic variations in the W3 locus. On the basis of the sequence of a DFR probe, Glyma.14G072700 was identified as a candidate gene for DFR1, and nucleotide sequences of Glyma.14G072700 from cultivars with previously validated genotypes for the W3 locus were determined. As a result, a number of nucleotide polymorphisms, mainly single-base substitutions, between both coding and 5′-upstream region sequences of the W3 and w3 alleles were identified. Among them, an indel of 311-bp in the 5′-upstream region was noteworthy, since the Glyma.14G072700 in all the w3 alleles examined contained the indel, whereas that in all the W3 alleles did not; the former was barely expressed, but the latter was well expressed. These results suggest that Glyma.14G072700 is likely to correspond to DFR1 for the W3 locus and that its expression patterns may lead to allelic color phenotypes of W3 and w3 alleles under the w4 allelic background. PMID:26555888

  4. Elucidation of the biochemical pathway of 2-phenylethanol from shikimic acid using isolated protoplasts of rose flowers.

    PubMed

    Yang, Ziyin; Sakai, Miwa; Sayama, Hironori; Shimeno, Taku; Yamaguchi, Koji; Watanabe, Naoharu

    2009-05-15

    The isolated protoplasts of rose flowers were used to investigate the metabolic pathway in rose flower leading from shikimic acid or L-phenylalanine (L-Phe) to 2-phenylethanol (2PE), a dominant volatile compound in hybrid roses such as Rosa damascena Mill., R. 'Hoh-Jun', and R. 'Yves Piaget'. Deuterium-labeled L-Phe ([2H8]L-Phe) was supplied to the protoplasts isolated from R. 'Yves Piaget' petals. The volatile end products ([2Hn]-2PE, n=6-8) and their related intermediates ([2Hn]phenylacetaldehyde, n=6-8) were detected in the protoplasts by gas chromatography-mass spectrometry (GC-MS). In addition, we chemically synthesized [2,3,4,5,6-13C5]shikimic acid, a new stable isotopomer, to investigate the formation of 2PE from shikimic acid by GC-MS and nuclear magnetic resonance. We proposed the hypothetical biochemical pathway of 2PE from shikimic acid via chorismic acid, L-Phe, and phenylacetaldehyde. This protoplast system facilitates findings of metabolic intermediates and simplifies the complex branching biosynthetic pathways of floral scents to distinct individual events. PMID:19097671

  5. Flowers, Beautiful Flowers

    ERIC Educational Resources Information Center

    School Arts: The Art Education Magazine for Teachers, 2005

    2005-01-01

    In the lesson described, the middle school students had been studying the artist Georgia O'Keeffe and the history of her work. Students enhanced their flower portraits by adding a matching border and connecting the lesson to other subject areas. Students dissected a flower and drew a small diagram of the flower and labeled the parts. This is an…

  6. Variation in Onset of Summer Dormancy and Flowering Capacity Along an Aridity Gradient in Poa bulbosa L., a Geophytic Perennial Grass

    PubMed Central

    OFIR, MICHA; KIGEL, JAIME

    2003-01-01

    Variation in the onset of summer dormancy and flowering capacity of 16 populations of Poa bulbosa, collected along a steep north–south aridity gradient in Israel (810–110 mm rain year–1), was studied under controlled conditions in a phytotron (16 h daylength, 22/16 °C day/night) and under natural conditions in a garden experiment in a net‐house. Plant age at the onset of dormancy varied markedly amongst populations (7–16 weeks under controlled conditions) and was positively correlated with mean annual precipitation at the site of origin of the population, i.e. dormancy was earlier as aridity increased. Flowering capacity in the different populations was negatively correlated with rainfall in the original habitat and, consequently, also with the age at onset of dormancy, i.e. the lower the mean annual precipitation, the earlier the onset of dormancy and the higher the proportion of flowering plants and panicles per plant. Differences in xeromorphic leaf traits were also observed among populations from locations differing in aridity. Plants from the more arid sites (110–310 mm year–1) generally had greyish and curved leaves, whereas plants from more humid sites (500–810 mm year–1) tended to have green and straight leaves. Thus, plants with curved and/or greyish leaves generally had a higher flowering capacity and entered dormancy earlier than plants with straight and/or green leaves. The significance of the association among these traits for the adaptation of P. bulbosa to increasing aridity is discussed. PMID:12547692

  7. UV induced visual cues in grasses

    PubMed Central

    Baby, Sabulal; Johnson, Anil John; Govindan, Balaji; Lukose, Sujith; Gopakumar, Bhaskaran; Koshy, Konnath Chacko

    2013-01-01

    Grasses are traditionally considered as wind pollinated, however, field observations confirmed frequent insect visits to grass flowers, suggesting insect pollination. Fruit and seed predators inflict heavy losses to cereals and millets during their growth, maturation and storage. The actual factors guiding insects and predators to grass flowers, fruits and seeds are not clear. Here, we report attractive blue fluorescence emissions on grass floral parts such as glumes, lemma, palea, lodicules, staminal filaments, pollens and fruits in ultraviolet (UV) 366 nm, whereas the stigmatic portions were not blue, but red fluorescent. We characterized the blue fluorescent constituent in grass reproductive structures as ferulic acid (FA). Fluorescence spectra of blue-emitting grass floral, seed extracts and isolated FA on excitation at 366 nm showed their emissions at 420–460 nm. We propose these FA-based blue fluorescence emissions in grass reproductive structures as visual cues that attract pollinators, predators and even pests towards them. PMID:24061408

  8. Flower Parts.

    ERIC Educational Resources Information Center

    Steinheimer, Margaret

    1997-01-01

    Presents ideas for spring flower displays. Has students constructing their own interactive flower displays as extra-credit assignments to reinforce vocabulary and scientific concepts, and modeling flowers with household items. (JRH)

  9. Grass allergy

    MedlinePlus

    Although the grass itself may not be harmful, fertilizers, insecticides , and herbicides applied to the grass can ... with a chemical of any sort such as fertilizer, insecticide, or herbicide, find out the product name ...

  10. Blob Flowers.

    ERIC Educational Resources Information Center

    Canfield, Elaine

    2003-01-01

    Describes an art project called blob flowers in which fifth-grade students created pictures of flowers using watercolor and markers. Explains that the lesson incorporates ideas from art and science. Discusses in detail how the students created their flowers. (CMK)

  11. Difference in flowering time can initiate speciation of nocturnally flowering species.

    PubMed

    Matsumoto, Tomotaka; Yasumoto, Akiko A; Nitta, Kozue; Hirota, Shun K; Yahara, Tetsukazu; Tachida, Hidenori

    2015-04-01

    Isolation mechanisms that prevent gene flow between populations prezygotically play important roles in achieving speciation. In flowering plants, the nighttime flowering system provides a mechanism for isolation from diurnally flowering species. Although this system has long been of interest in evolutionary biology, the evolutionary process leading to this system has yet to be elucidated because of the lack of good model species. However, the genetic mechanisms underlying the differences in flowering times and the traits that attract pollinators between a pair of diurnally and nocturnally flowering species have recently been identified in a few cases. This identification enables us to build a realistic model for theoretically studying the evolution of a nocturnally flowering species. In this study, based on previous experimental data, we assumed a model in which two loci control the flowering time and one locus determines a trait that attracts pollinators. Using this model, we evaluated the possibility of the evolution of a nocturnally flowering species from a diurnally flowering ancestor through simulations. We found that a newly emerging nighttime flowering flower exhibited a sufficiently high fitness, and the evolution of a nocturnally flowering species from a diurnally flowering species could be achieved when hybrid viability was intermediate to low, even in a completely sympatric situation. Our results suggest that the difference in flowering time can act as a magic trait that induces both natural selection and assortative mating and would play an important role in speciation between diurnally and nocturnally flowering species pairs. PMID:25665720

  12. Flower Development

    PubMed Central

    Alvarez-Buylla, Elena R.; Benítez, Mariana; Corvera-Poiré, Adriana; Chaos Cador, Álvaro; de Folter, Stefan; Gamboa de Buen, Alicia; Garay-Arroyo, Adriana; García-Ponce, Berenice; Jaimes-Miranda, Fabiola; Pérez-Ruiz, Rigoberto V.; Piñeyro-Nelson, Alma; Sánchez-Corrales, Yara E.

    2010-01-01

    Flowers are the most complex structures of plants. Studies of Arabidopsis thaliana, which has typical eudicot flowers, have been fundamental in advancing the structural and molecular understanding of flower development. The main processes and stages of Arabidopsis flower development are summarized to provide a framework in which to interpret the detailed molecular genetic studies of genes assigned functions during flower development and is extended to recent genomics studies uncovering the key regulatory modules involved. Computational models have been used to study the concerted action and dynamics of the gene regulatory module that underlies patterning of the Arabidopsis inflorescence meristem and specification of the primordial cell types during early stages of flower development. This includes the gene combinations that specify sepal, petal, stamen and carpel identity, and genes that interact with them. As a dynamic gene regulatory network this module has been shown to converge to stable multigenic profiles that depend upon the overall network topology and are thus robust, which can explain the canalization of flower organ determination and the overall conservation of the basic flower plan among eudicots. Comparative and evolutionary approaches derived from Arabidopsis studies pave the way to studying the molecular basis of diverse floral morphologies. PMID:22303253

  13. Underutilized Grasses.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perennial warm-season grasses have been recognized for having several properties, such as high rates of net photosynthesis, energy and labor savings, and reduced soil and nutrient losses that make them better suited for biofuel production than many annual crops. Prairie cordgrass (Spartina pectinat...

  14. Genome-wide associations with flowering time in switchgrass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Switchgrass is an emerging bioenergy crop and perennial grass native to North America. Improving biomass yields is critical for developing switchgrass into an economically viable crop. Flowering time has a major effect on biomass yields as delaying flowering time prolongs the period of vegetative gr...

  15. Flowers & Weeds.

    ERIC Educational Resources Information Center

    Flannery, Maura C.

    1996-01-01

    Describes the topics and teaching strategies employed in an Issues in Biology course. Discusses flowers, plant breeding, potatoes and tomatoes, the chocolate tree, weeds, Arabidopis, gene transfers, and plant genes/human genes. Contains 22 references. (JRH)

  16. Post senescent grass canopy remote sensing

    NASA Technical Reports Server (NTRS)

    Tucker, C. J.

    1978-01-01

    Analysis of in situ collected spectral reflectance data from a dormant or senescent grass canopy showed a direct relationship existed between spectral reflectance and biomass for the 0.50-0.80 micron spectral region. The data, collected four weeks after the end of the growing season, indicated that post senescent remote sensing of grass canopy biomass is possible and helps to elucidate the spectral contribution of recently dead vegetation in mixed live/dead canopy situations.

  17. Grass Lignocellulose

    NASA Astrophysics Data System (ADS)

    Akin, Danny E.

    Grass lignocelluloses are limited in bioconversion by aromatic constituents, which include both lignins and phenolic acids esters. Histochemistry, ultraviolet absorption microspectrophotometry, and response to microorganisms and specific enzymes have been used to determine the significance of aromatics toward recalcitrance. Coniferyl lignin appears to be the most effective limitation to biodegradation, existing in xylem cells of vascular tissues; cell walls with syringyl lignin, for example, leaf sclerenchyma, are less recalcitrant. Esterified phenolic acids, i.e., ferulic and p-coumaric acids, often constitute a major chemical limitation in nonlignified cell walls to biodegradation in grasses, especially warm-season species. Methods to improve biodegradability through modification of aromatics include: plant breeding, use of lignin-degrading white-rot fungi, and addition of esterases. Plant breeding for new cultivars has been especially effective for nutritionally improved forages, for example, bermudagrasses. In laboratory studies, selective white-rot fungi that lack cellulases delignified the lignocellulosic materials and improved fermentation of residual carbohydrates. Phenolic acid esterases released p-coumaric and ferulic acids for potential coproducts, improved the available sugars for fermentation, and improved biodegradation. The separation and removal of the aromatic components for coproducts, while enhancing the availability of sugars for bioconversion, could improve the economics of bioconversion.

  18. Flowers in Their Variety.

    ERIC Educational Resources Information Center

    Flannery, Maura C.

    2002-01-01

    Describes the diversity of flowers with regard to the flower paintings of Pierre-Joseph Redoute, books about flowers, and research in genetic studies. Discusses gardening flowers and flowering strategies and criticizes the fact that biology education has moved steadily away from plants. (KHR)

  19. Seeding cool-season grasses to suppress white locoweed (Oxytropis sericea) reestablishment and increase forage production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Livestock poisoning can occur on short-grass prairies when locoweeds (Astragalus and Oxytropis spp.) are actively growing in spring before warm-season grasses begin growth. White locoweed grows in early spring, completes flowering and seed production by early summer, and goes dormant. Perennial co...

  20. Response of Broom Snakeweed (Gutierrezia sarothrae) and Cool-Season Grasses to Defoliation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Livestock poisoning can occur on short-grass prairies when locoweeds (Astragalus and Oxytropis spp.) are actively growing in spring before warm-season grasses begin growth. White locoweed grows in early spring, completes flowering and seed production by early summer, and goes dormant. Perennial co...

  1. Evolution of Grasses and Grassland Ecosystems

    NASA Astrophysics Data System (ADS)

    Strömberg, Caroline A. E.

    2011-05-01

    The evolution and subsequent ecological expansion of grasses (Poaceae) since the Late Cretaceous have resulted in the establishment of one of Earth's dominant biomes, the temperate and tropical grasslands, at the expense of forests. In the past decades, several new approaches have been applied to the fossil record of grasses to elucidate the patterns and processes of this ecosystem transformation. The data indicate that the development of grassland ecosystems on most continents was a multistage process involving the Paleogene appearance of (C3 and C4) open-habitat grasses, the mid-late Cenozoic spread of C3 grass-dominated habitats, and, finally, the Late Neogene expansion of C4 grasses at tropical-subtropical latitudes. The evolution of herbivores adapted to grasslands did not necessarily coincide with the spread of open-habitat grasses. In addition, the timing of these evolutionary and ecological events varied between regions. Consequently, region-by-region investigations using both direct (plant fossils) and indirect (e.g., stable carbon isotopes, faunas) evidence are required for a full understanding of the tempo and mode of grass and grassland evolution.

  2. Flowering, Capsule and Seed Characteristics in Cuphea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We modeled the flowering and capsule set dynamics, quantified the level of variation in seed characteristics, elucidated the inter-relationships among seed and capsule physical dimensions, and quantified their impact on single seed weight as the main determinant of seed yield in the indeterminate, p...

  3. Associations with flowering time, latitude, and climate in switchgrass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Switchgrass is a North American perennial grass and emerging bioenergy feedstock, and increasing biomass yields will improve the economic viability of switchgrass as a bioenergy crop. Flowering time is an important determinant of biomass yields in switchgrass because the majority of biomass accumula...

  4. Flower opening and closure: an update.

    PubMed

    van Doorn, Wouter G; Kamdee, Chanattika

    2014-11-01

    This review is an update of a 2003 review (Journal of Experimental Botany 54,1801-1812) by the same corresponding author. Many examples of flower opening have been recorded using time-lapse photography, showing its velocity and the required elongation growth. Ethylene regulates flower opening, together with at least gibberellins and auxin. Ethylene and gibberellic acid often promote and inhibit, respectively, the expression of DELLA genes and the stability of DELLA proteins. DELLA results in growth inhibition. Both hormones also inhibited and promoted, respectively, the expression of aquaporin genes required for cell elongation. Arabidopsis miRNA319a mutants exhibited narrow and short petals, whereby miRNA319a indirectly regulates auxin effects. Flower opening in roses was controlled by a NAC transcription factor, acting through miRNA164. The regulatory role of light and temperature, in interaction with the circadian clock, has been further elucidated. The end of the life span in many flowers is determined by floral closure. In some species pollination resulted in earlier closure of turgid flowers, compared with unpollinated flowers. It is hypothesized that this pollination-induced effect is only found in flowers in which closure is regulated by ethylene. PMID:25135521

  5. Design a Hummingbird Flower.

    ERIC Educational Resources Information Center

    Bailey, Kim

    2002-01-01

    Presents an activity that engages students in designing and making an artificial flower adapted for pollination by hummingbirds. Students work in teams to design flowers that maximize the benefit from attracting hummingbirds. Examines characteristics of real flowers adapted to pollination by hummingbirds. (DLH)

  6. Pests in Ornamental Grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ornamental perennial grasses are becoming increasingly popular in the landscape due to their beauty and ease of care. Although few pest problems are encountered in ornamental grasses, they are not immune to insects and disease. Two lined spittlebugs (Prosapia bicincta) can cause damage to ornament...

  7. Temporal and intraclonal variation of flowering and pseudovivipary in Poa bulbosa

    PubMed Central

    Ofir, Micha; Kigel, Jaime

    2014-01-01

    Background and Aims Versatility in the reproductive development of pseudoviviparous grasses in response to growth conditions is an intriguing reproduction strategy. To better understand this strategy, this study examined variation in flowering and pseudovivipary among populations, co-occurring clones within populations, and among tillers in individual clones of Poa bulbosa, a summer-dormant geophytic grass that reproduces sexually by seed, and asexually by basal tiller bulbs and bulbils formed in proliferated panicles. Methods Clones were collected from 17 populations across a rainfall gradient. Patterns of reproduction were monitored for 11 years in a common garden experiment and related to interannual differences in climatic conditions. Intraclonal variation in flowering and pseudovivipary was studied in a phytotron, under daylengths marginal for flowering induction. Key Results Clones showed large temporal variability in their reproductive behaviour. They flowered in some years but not in others, produced normal or proliferated panicles in different years, or became dormant without flowering. Proliferating clones did not show a distinct time sequence of flowering and proliferation across years. Populations differed in incidence of flowering and proliferation. The proportion of flowering clones increased with decreasing rainfall at the site of population origin, but no consistent relationship was found between flowering and precipitation in the common garden experiment across years. In contrast, flowering decreased at higher temperatures during early growth stages after bulb sprouting. Pulses of soil fertilization greatly increased the proportion of flowering clones and panicle production. High intraclonal tiller heterogeneity was observed, as shown by the divergent developmental fates of daughter plants arising from bulbs from the same parent clone and grown under similar conditions. Panicle proliferation was enhanced by non-inductive 8 h short days, while

  8. Grass Rooting the System

    ERIC Educational Resources Information Center

    Perlman, Janice E.

    1976-01-01

    Suggests a taxonomy of the grass roots movement and gives a general descriptive over view of the 60 groups studied with respect to origin, constituency, size, funding, issues, and ideology. (Author/AM)

  9. GRASS GIS Vector Processing: Towards GRASS 7

    NASA Astrophysics Data System (ADS)

    Metz, Markus; Landa, Martin; Petrasova, Anna; Petras, Vaclav; Chemin, Yann; Neteler, Markus

    2014-05-01

    The upcoming GRASS GIS 7 release improves not only raster processing and general design but the vector processing in the first place. GRASS GIS, as a topological GIS, recognizes that the topology plays the key role in the vector processing and analysis. Topology ensures that adjacent geographic components in a single vector map are related. In contrast to non-topological GIS, a border common to two areas exists only once and is shared between the two areas. Topological representation of vector data helps to produce and maintain vector maps with clean geometry as well as enables the user to perform certain analyses that can not be conducted with non-topological or spaghetti data. Non-topological vector data are automatically converted to a topological representation upon import. Further more, various cleaning tools exist to remove non-trivial topological errors. In the upcoming GRASS GIS 7 release the vector library was particularly improved to make it faster and more efficient with an improved internal vector file format. This new topological format reduces memory and disk space requirements, leading to a generally faster processing. Opening an existing vector requires less memory providing additionally support for large files. The new spatial index performs queries faster (compared to GRASS GIS 6 more than 10 times for large vectors). As a new option the user can select a file-based version of the spatial index for large vector data. All topological cleaning tools have been optimized with regard to processing speed, robustness, and system requirements. The topological engine comes with a new prototype for direct read/write support of Simple Features API/OGR. Additionally vector data can be directly exchanged with topological PostGIS 2 databases. Considering the wide spread usage of ESRI Shapefile, a non-topological format for vector data exchange, it is particularly advantageous that GRASS GIS 7 offers advanced cleaning tools. For power users and programmers, the

  10. Genome-Wide Analysis of Syntenic Gene Deletion in the Grasses

    PubMed Central

    Schnable, James C.; Freeling, Michael; Lyons, Eric

    2012-01-01

    The grasses, Poaceae, are one of the largest and most successful angiosperm families. Like many radiations of flowering plants, the divergence of the major grass lineages was preceded by a whole-genome duplication (WGD), although these events are not rare for flowering plants. By combining identification of syntenic gene blocks with measures of gene pair divergence and different frequencies of ancient gene loss, we have separated the two subgenomes present in modern grasses. Reciprocal loss of duplicated genes or genomic regions has been hypothesized to reproductively isolate populations and, thus, speciation. However, in contrast to previous studies in yeast and teleost fishes, we found very little evidence of reciprocal loss of homeologous genes between the grasses, suggesting that post-WGD gene loss may not be the cause of the grass radiation. The sets of homeologous and orthologous genes and predicted locations of deleted genes identified in this study, as well as links to the CoGe comparative genomics web platform for analyzing pan-grass syntenic regions, are provided along with this paper as a resource for the grass genetics community. PMID:22275519

  11. Flower Constancy, Insect Psychology, and Plant Evolution

    NASA Astrophysics Data System (ADS)

    Chittka, Lars; Thomson, James D.; Waser, Nickolas M.

    Individuals of some species of pollinating insects tend to restrict their visits to only a few of the available plant species, in the process bypassing valuable food sources. The question of why this flower constancy exists is a rich and important one with implications for the organization of natural communities of plants, floral evolution, and our understanding of the learning processes involved in finding food. Some scientists have assumed that flower constancy is adaptive per se. Others argued that constancy occurs because memory capacity for floral features in insects is limited, but attempts to identify the limitations often remained rather simplistic. We elucidate now different sensory and motor memories from natural foraging tasks are stored and retrieved, using concepts from modern learning science and visual search, and conclude that flower constancy is likely to have multiple causes. Possible constraints favoring constancy are interference sensitivity of short-term memory, and temporal limitations on retrieving information from long-term memory as rapidly as from short-term memory, but further empirical evidence is needed to substantiate these possibilities. In addition, retrieving memories may be slower and more prone to errors when there are several options than when an insect copes with only a single task. In addition to memory limitations, we also point out alternative explanations for flower constancy. We then consider the way in which floral parameters, such as interplant distances, nectar rewards, flower morphology, and floral color (as seen through bees' eyes) affect constancy. Finally, we discuss the implications of pollinator constancy for plant evolution. To date there is no evidence that flowers have diverged to favor constancy, although the appropriate tests may not have yet been conducted. However, there is good evidence against the notion that pollinator constancy is involved in speciation or maintenance of plant species integrity.

  12. Circumnutation on the water surface: female flowers of Vallisneria.

    PubMed

    Kosuge, Keiko; Iida, Satoko; Katou, Kiyoshi; Mimura, Tetsuro

    2013-01-01

    Circumnutation, the helical movement of growing organ tips, is ubiquitous in land plants. The mechanisms underlying circumnutation have been debated since Darwin's time. Experiments in space and mutant analyses have revealed that internal oscillatory (tropism-independent) movement and gravitropic response are involved in circumnutation. Female flower buds of tape grass (Vallisneria asiatica var. biwaensis) circumnutate on the water surface. Our observations and experiments with an artificial model indicated that gravitropism is barely involved in circumnutation. Instead, we show that helical intercalary growth at the base of peduncle plays the primary role in all movements in Vallisneria. This growth pattern produces torsional bud rotation, and gravity and buoyancy forces have a physical effect on the direction of peduncle elongation, resulting in bud circumnutation on the water surface. In contrast to other water-pollinated hydrophilous plants, circumnutation in Vallisneria enables female flowers to actively collect male flowers from a larger surface area of water. PMID:23355948

  13. Say it with flowers

    PubMed Central

    Falik, Omer; Hoffmann, Ishay; Novoplansky, Ariel

    2014-01-01

    The timing of reproduction is a critical determinant of fitness, especially in organisms inhabiting seasonal environments. Increasing evidence suggests that inter-plant communication plays important roles in plant functioning. Here, we tested the hypothesis that flowering coordination can involve communication between neighboring plants. We show that soil leachates from Brassica rapa plants growing under long-day conditions accelerated flowering and decreased allocation to vegetative organs in target plants growing under non-inductive short-day conditions. The results suggest that besides endogenous signaling and external abiotic cues, flowering timing may involve inter-plant communication, mediated by root exudates. The study of flowering communication is expected to illuminate neglected aspects of plant reproductive interactions and to provide novel opportunities for controlling the timing of plant reproduction in agricultural settings. PMID:24598343

  14. LIGNIN ACYLATION IN GRASSES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acylation of lignin during growth and development is a commonly found among some plant species. Grasses form unique acylated lignins involving p-coumarate (pCA). In corn rind tissue, it is exclusively attached to the gamma-carbon of lignin monomers, with a strong preference (over 90%) for attachment...

  15. Stars and Flowers, Flowers and Stars

    NASA Astrophysics Data System (ADS)

    Minti, Hari

    2012-12-01

    The author, a graduated from the Bucharest University (1964), actually living and working in Israel, concerns his book to variable stars and flowers, two domains of his interest. The analogies includes double stars, eclipsing double stars, eclipses, Big Bang. The book contains 34 chapters, each of which concerns various relations between astronomy and other sciences and pseudosciences such as Psychology, Religion, Geology, Computers and Astrology (to which the author is not an adherent). A special part of the book is dedicated to archeoastronomy and ethnoastronomy, as well as to history of astronomy. Between the main points of interest of these parts: ancient sanctuaries in Sarmizegetusa (Dacia), Stone Henge(UK) and other. The last chapter of the book is dedicated to flowers. The book is richly illustrated. It is designed for a wide circle of readers.

  16. Flower development: the evolutionary history and functions of the AGL6 subfamily MADS-box genes.

    PubMed

    Dreni, Ludovico; Zhang, Dabing

    2016-04-01

    AGL6 is an ancient subfamily of MADS-box genes found in both gymnosperms and angiosperms. Its functions remained elusive despite the fact that the MADS-box genes and the ABC model have been studied for >20 years. Nevertheless, recent discoveries in petunia, rice, and maize support its involvement in the 'E' function of floral development, very similar to the closely related AGL2 (SEPALLATA) subfamily which has been well characterized. The known functions of AGL6 span from ancient conserved roles to new functions acquired in specific plant families. The AGL6 genes are involved in floral meristem regulation, in floral organs, and ovule (integument) and seed development, and have possible roles in both male and female germline and gametophyte development. In grasses, they are also important for the development of the first whorl of the flower, whereas in Arabidopsis they may play additional roles before floral meristem formation. This review covers these recent insights and some other aspects that are not yet fully elucidated, which deserve more studies in the future. PMID:26956504

  17. Attacking invasive grasses

    USGS Publications Warehouse

    Keeley, Jon E.

    2015-01-01

    In grasslands fire may play a role in the plant invasion process, both by creating disturbances that potentially favour non-native invasions and as a possible tool for controlling alien invasions. Havill et al. (Applied Vegetation Science, 18, 2015, this issue) determine how native and non-native species respond to different fire regimes as a first step in understanding the potential control of invasive grasses.

  18. Flower constancy in insect pollinators

    PubMed Central

    Ratnieks, Francis L.W.

    2011-01-01

    As first noted by Aristotle in honeybee workers, many insect pollinators show a preference to visit flowers of just one species during a foraging trip. This “flower constancy” probably benefits plants, because pollen is more likely to be deposited on conspecific stigmas. But it is less clear why insects should ignore rewarding alternative flowers. Many researchers have argued that flower constancy is caused by constraints imposed by insect nervous systems rather than because flower constancy is itself an efficient foraging method. We argue that this view is unsatisfactory because it both fails to explain why foragers flexibly adjust the degree of flower constancy and does not explain why foragers of closely related species show different degrees of constancy. While limitations of the nervous system exist and are likely to influence flower constancy to some degree, the observed behavioural flexibility suggests that flower constancy is a successful foraging strategy given the insect’s own information about different foraging options. PMID:22446521

  19. Origins of flower morphology.

    PubMed

    Endress, P K

    2001-08-15

    Flowers evolved in many steps, probably starting long before flowering plants (angiophytes) originated. Certain parts of flowers are conservative and have not changed much during evolution; others are evolutionarily highly plastic. Here conservative features are discussed and an attempt is made to trace them back through their evolutionary history. Microsporangia and ovules (which develop into seeds) are preangiophyte floral elements. Angiospermy, combined with postgenital fusion, was the most prominent key innovation in angiophytes. Angiospermy and thecal organization of stamens originated earlier than all clades of extant angiosperms (the crown group of angiophytes). Differentiation of a perianth into calyx and corolla and syncarpy appeared after the first branching of the basalmost clades of extant angiosperms. Sympetaly and floral tubes as well as tenuinucellar, unitegmic ovules originated as major innovations in the clade that led to asterids. An obvious trend in flower evolution is increased synorganisation of parts, which led to new structures. Fixation of floral organ number and position was a precondition for synorganization. Concomitantly, plasticity changed from number and position of organs to shape of the new structures. Character distribution mapped onto cladograms indicates that key innovations do not appear suddenly, but start with trials and only later become deeply rooted genetically in the organization. This is implied from the common occurrence of reversals in the early history of an innovation. J. Exp. Zool. (Mol. Dev. Evol.) 291:105-115, 2001. PMID:11479912

  20. Vulnerability of the northern Mongolian steppe to climate change: insights from flower production and phenology.

    PubMed

    Liancourt, Pierre; Spence, Laura A; Boldgiv, Bazartseren; Lkhagva, Ariuntsetseg; Helliker, Brent R; Casper, Brenda B; Petraitis, Peter S

    2012-04-01

    The semiarid, northern Mongolian steppe, which still supports pastoral nomads who have used the steppe for millennia, has experienced an average 1.7 degrees C temperature rise over the past 40 years. Continuing climate change is likely to affect flowering phenology and flower numbers with potentially important consequences for plant community composition, ecosystem services, and herder livelihoods. Over the growing seasons of 2009 and 2010, we examined flowering responses to climate manipulation using open-top passive warming chambers (OTCs) at two locations on a south-facing slope: one on the moister, cooler lower slope and the other on the drier, warmer upper slope, where a watering treatment was added in a factorial design with warming. Canonical analysis of principal coordinates (CAP) revealed that OTCs reduced flower production and delayed peak flowering in graminoids as a whole but only affected forbs on the upper slope, where peak flowering was also delayed. OTCs affected flowering phenology in seven of eight species, which were examined individually, either by altering the time of peak flowering and/or the onset and/or cessation of flowering, as revealed by survival analysis. In 2010, which was the drier year, OTCs reduced flower production in two grasses but increased production in an annual forb found only on the upper slope. The particular effects of OTCs on phenology, and whether they caused an extension or contraction of the flowering season, differed among species, and often depended on year, or slope, or watering treatment; however, a relatively strong pattern emerged for 2010 when four species showed a contraction of the flowering season in OTCs. Watering increased flower production in two species in 2010, but slope location more often affected flowering phenology than did watering. Our results show the importance of taking landscape-scale variation into account in climate change studies and also contrasted with those of several studies set in cold

  1. Transcriptome analysis of grass carp (Ctenopharyngodon idella) fed with animal and plant diets.

    PubMed

    Li, Ling; Liang, Xu-Fang; He, Shan; Sun, Jian; Wen, Zheng-Yong; He, Yu-Hui; Cai, Wen-Jing; Wang, Ya-Ping; Tao, Ya-Xiong

    2015-12-15

    Numerous studies have been focused on the replacement of fish meal by other alternative protein sources. However, little is currently known about the molecular mechanism of utilization of diets with different protein sources in fish. Grass carp is a typical herbivorous fish. To elucidate the relationship between gene expression and utilization of animal and plant diets, transcriptome sequencing was performed in grass carp fed with chironomid larvae and duckweed. Grass carp fed with duckweed had significantly higher relative length of gut than those fed with chironomid larvae. 4435 differentially expressed genes were identified between grass carp fed with chironomid larvae and duckweed in brain, liver and gut, involved in cell proliferation and differentiation, appetite control, circadian rhythm, digestion and metabolism pathways. These pathways might play important roles in utilization of diets with different protein sources in grass carp. And the findings could provide a new insight into the replacement of fish meal in artificial diets. PMID:26283148

  2. Production of sugarcane and tropical grasses as renewable energy source. Third annual report, 1979-1980

    SciTech Connect

    Not Available

    1980-01-01

    Research continued on tropical grasses from Saccharum and related genera as sources of intensively-propagated fiber and fermentable solids. Candidate screening for short-rotation grasses was expanded to include six sorghum x Sudan grass hybrids developed by the Dekalb Company. Sugacane and napier grass yield trends in year 3 include: (1) Increased yields with delay of harvest frequency; (2) lack of response to close spacing; (3) a superiority of napier grass over sugarcane when harvested at intervals of six months or less; and (4) a general superiority of the sugarcane variety NCo 310 over varieties PR 980 and PR 64-1791. Delayed tasseling of a wild, early-flowering S. spontaneum hybrid enabled three crosses to be made in December using commercial hybrids as female parents. Approximately 1000 seedlings were produced. The first field-scale minimum tillage experiment was completed. Sordan 77 produced 2.23 OD tons/acre/10 weeks, with winter growing conditions and a total moisture input of 4.75 inches. Mechanization trials included successful planting of napier grass with a sugarcane planter, and the mowing, solar-drying, and round--baling of napier grass aged three to six months. Production-cost and energy-balance studies were initiated during year 3 using first-ratoon data for intensively propagated sugarcane. Preliminary cost estimates for energy cane (sugarcane managed for total biomass rather than sucrose) were in the order of $25.46/OD ton, or about $1.70/mm Btus.

  3. Positive Effects of Non-Native Grasses on the Growth of a Native Annual in a Southern California Ecosystem

    PubMed Central

    Pec, Gregory J.; Carlton, Gary C.

    2014-01-01

    Fire disturbance is considered a major factor in the promotion of non-native plant species. Non-native grasses are adapted to fire and can alter environmental conditions and reduce resource availability in native coastal sage scrub and chaparral communities of southern California. In these communities persistence of non-native grasses following fire can inhibit establishment and growth of woody species. This may allow certain native herbaceous species to colonize and persist beneath gaps in the canopy. A field manipulative experiment with control, litter, and bare ground treatments was used to examine the impact of non-native grasses on growth and establishment of a native herbaceous species, Cryptantha muricata. C. muricata seedling survival, growth, and reproduction were greatest in the control treatment where non-native grasses were present. C. muricata plants growing in the presence of non-native grasses produced more than twice the number of flowers and more than twice the reproductive biomass of plants growing in the treatments where non-native grasses were removed. Total biomass and number of fruits were also greater in the plants growing in the presence of non-native grasses. Total biomass and reproductive biomass was also greater in late germinants than early germinants growing in the presence of non-native grasses. This study suggests a potential positive effect of non-native grasses on the performance of a particular native annual in a southern California ecosystem. PMID:25379790

  4. PERENNIAL WARM-SEASON GRASSES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Warm-season grasses and can be used to augment the forage supply for grazing livestock operations in the northeastern U.S. Much of what is known about warm season grass production and management in the northeastern US was obtained from a soil conservation or wildlife habitat perspective. Warm-seas...

  5. Ornamental Landscape Grasses. Slide Script.

    ERIC Educational Resources Information Center

    Still, Steven M.; Adams, Denise W.

    This slide script to accompany the slide series, Ornamental Landscape Grasses, contains photographs of the 167 slides and accompanying narrative text intended for use in the study and identification of commercially important ornamental grasses and grasslike plants. Narrative text is provided for slides of 62 different perennial and annual species…

  6. Summer Dormancy in Perennial Temperate Grasses

    PubMed Central

    VOLAIRE, FLORENCE; NORTON, MARK

    2006-01-01

    • Background and Aims Dormancy has been extensively studied in plants which experience severe winter conditions but much less so in perennial herbaceous plants that must survive summer drought. This paper reviews the current knowledge on summer dormancy in both native and cultivated perennial temperate grasses originating from the Mediterranean Basin, and presents a unified terminology to describe this trait. • Scope Under severe drought, it is difficult to separate the responses by which plants avoid and tolerate dehydration from those associated with the expression of summer dormancy. Consequently, this type of endogenous (endo-) dormancy can be tested only in plants that are not subjected to moisture deficit. Summer dormancy can be defined by four criteria, one of which is considered optional: (1) reduction or cessation of leaf production and expansion; (2) senescence of mature foliage; (3) dehydration of surviving organs; and (4, optional) formation of resting organs. The proposed terminology recognizes two levels of summer dormancy: (a) complete dormancy, when cessation of growth is associated with full senescence of foliage and induced dehydration of leaf bases; and (b) incomplete dormancy, when leaf growth is partially inhibited and is associated with moderate levels of foliage senescence. Summer dormancy is expressed under increasing photoperiod and temperature. It is under hormonal control and usually associated with flowering and a reduction in metabolic activity in meristematic tissues. Dehydration tolerance and dormancy are independent phenomena and differ from the adaptations of resurrection plants. • Conclusions Summer dormancy has been correlated with superior survival after severe and repeated summer drought in a large range of perennial grasses. In the face of increasing aridity, this trait could be used in the development of cultivars that are able to meet agronomic and environmental goals. It is therefore important to have a better

  7. Differentiation of plant age in grasses using remote sensing

    NASA Astrophysics Data System (ADS)

    Knox, Nichola M.; Skidmore, Andrew K.; van der Werff, Harald M. A.; Groen, Thomas A.; de Boer, Willem F.; Prins, Herbert H. T.; Kohi, Edward; Peel, Mike

    2013-10-01

    Phenological or plant age classification across a landscape allows for examination of micro-topographical effects on plant growth, improvement in the accuracy of species discrimination, and will improve our understanding of the spatial variation in plant growth. In this paper six vegetation indices used in phenological studies (including the newly proposed PhIX index) were analysed for their ability to statistically differentiate grasses of different ages in the sequence of their development. Spectra of grasses of different ages were collected from a greenhouse study. These were used to determine if NDVI, NDWI, CAI, EVI, EVI2 and the newly proposed PhIX index could sequentially discriminate grasses of different ages, and subsequently classify grasses into their respective age category. The PhIX index was defined as: (AVNIRn+log(ASWIR2n))/(AVNIRn-log(ASWIR2n)), where AVNIRn and ASWIR2n are the respective normalised areas under the continuum removed reflectance curve within the VNIR (500-800 nm) and SWIR2 (2000-2210 nm) regions. The PhIX index was found to produce the highest phenological classification accuracy (Overall Accuracy: 79%, and Kappa Accuracy: 75%) and similar to the NDVI, EVI and EVI2 indices it statistically sequentially separates out the developmental age classes. Discrimination between seedling and dormant age classes and the adult and flowering classes was problematic for most of the tested indices. Combining information from the visible near infrared (VNIR) and shortwave infrared region (SWIR) region into a single phenological index captures the phenological changes associated with plant pigments and the ligno-cellulose absorption feature, providing a robust method to discriminate the age classes of grasses. This work provides a valuable contribution into mapping spatial variation and monitoring plant growth across savanna and grassland ecosystems.

  8. A high loading overland flow system: Impacts on soil characteristics, grass constituents, yields and nutrient removal.

    PubMed

    Wen, C G; Chen, T H; Hsu, F H; Lu, C H; Lin, J B; Chang, C H; Chang, S P; Lee, C S

    2007-04-01

    The objectives of this paper are to determine effects of different grass species and their harvests on pollutant removal, elucidate impacts on soil characteristics and grass constituents, observe grass yield and quantify nutrient uptake by vegetation in an overland flow system (OLFS). Polluted creek water was applied to eight channels in the OLFS, which were planted with Paragrass, Nilegrass, Cattail, and Vetiver, with each two channels being randomly planted with a given grass species. The grass in one channel was harvested while that in the other channel was not. At a high rate of 27.8 m d(-1) hydraulic loading, the removal efficiencies of conventional pollutants such as BOD, COD, suspended solids (SS), and total coliforms in wastewater are not affected by the type of the grasses species, but those of nitrogen and phosphorus are affected by different species. Overall average removal efficiencies of BOD, COD, SS, ammonia, total nitrogen, total phosphorus and total coliforms through the OLFS are 42%, 48%, 78%, 47%, 40%, 33% and 89%, respectively. The concentration of nitrate, however, increases due to nitrification. Soil characteristics in OLFS have been changed significantly; specific conductivity, organic matter, exchangeable magnesium, extractable copper and zinc in soils all increase with time while pHs decrease. During the winter season, there is a significant accumulation of nitrate in grass with the subsequent reduction during the active growing season (Spring). The contents of nitrate and phosphorus in grass tissue are higher than those of grass in general pastureland, probably due to nutrient luxury uptake by grass. The overall grass yield, growth rate and nutrient uptake are quantified and implication of such high rate OLFS discussed. PMID:17234253

  9. γ-Lactam alkaloids from the flower buds of daylily.

    PubMed

    Matsumoto, Takahiro; Nakamura, Seikou; Nakashima, Souichi; Ohta, Tomoe; Yano, Mamiko; Tsujihata, Junichiro; Tsukioka, Junko; Ogawa, Keiko; Fukaya, Masashi; Yoshikawa, Masayuki; Matsuda, Hisashi

    2016-07-01

    Four new alkaloids, hemerocallisamines IV-VII, were isolated from the methanol extract of flower buds of daylily. The chemical structures of the new compounds were elucidated on the basis of chemical and physicochemical evidence. The absolute stereochemistry of the hemerocallisamines IV-VI was elucidated by the application of the modified Mosher's method, HPLC analysis, and optical rotation. In the present study, the isolated alkaloids significantly inhibited the aggregation of Aβ42 in vitro. This is the first report about bioactive alkaloids with a γ-lactam ring from daylily. In addition, isolated nucleosides showed accelerative effects on neurite outgrowth under the non-fasting condition. PMID:26849229

  10. Ixoroid: a new triterpenoid from the flowers of Ixora coccinea.

    PubMed

    Versiani, Muhammad Ali; Ikram, Ambreen; Khalid, Salman; Faizi, Shaheen; Tahiri, Iftikhar Ahmed

    2012-07-01

    A new natural terpenoid, ixoroid (1), was isolated from the flower of Ixora coccinea, along with the known constituents stigmast-5-en-3-O-beta-D-glucoside (2), 5-O-caffeoylquinic acid (3) and D-mannitol (4). The structure of ixoroid was elucidated on the basis of extensive 1D- and 2D-NMR studies and mass spectrometry as 21,23-epoxy-tirucall-7-en-3beta-ol (1). PMID:22908558

  11. Divergent Evolutionary Pattern of Sugar Transporter Genes is Associated with the Difference in Sugar Accumulation between Grasses and Eudicots.

    PubMed

    Wang, Wei; Zhou, Hui; Ma, Baiquan; Owiti, Albert; Korban, Schuyler S; Han, Yuepeng

    2016-01-01

    Sugars play a variety of roles in plants, and their accumulation in seeds and/or surrounding pericarp tissues is distinctly different between grasses and eudicots. However, little is known about the evolutionary pattern of genes involved in sugar accumulation in these two major groups of flowering plants. Here, we compared evolutionary rates, gene duplication, and selective patterns of genes involved in sugar metabolism and transport between grasses and eudicots using six grass species and seven eudicot species as materials. Overall, sugar transporter genes exhibit divergent evolutionary patterns, whereas, sugar metabolism genes showing similar evolutionary pattern between monocots and eudicots. Sugar transporter genes have higher frequencies of recent duplication in eudicots than in grasses and their patterns of evolutionary rate are different. Evidence for divergent selection of these two groups of flowering plants is also observed in sugar transporter genes, wherein, these genes have undergone positive selection in eudicots, but not in grasses. Taken together, these findings suggest that sugar transporter genes rather than sugar metabolism genes play important roles in sugar accumulation in plants, and that divergent evolutionary patterns of sugar transporter genes are associated with the difference of sugar accumulation in storage tissues of grasses and eudicots. PMID:27356489

  12. Divergent Evolutionary Pattern of Sugar Transporter Genes is Associated with the Difference in Sugar Accumulation between Grasses and Eudicots

    PubMed Central

    Wang, Wei; Zhou, Hui; Ma, Baiquan; Owiti, Albert; Korban, Schuyler S.; Han, Yuepeng

    2016-01-01

    Sugars play a variety of roles in plants, and their accumulation in seeds and/or surrounding pericarp tissues is distinctly different between grasses and eudicots. However, little is known about the evolutionary pattern of genes involved in sugar accumulation in these two major groups of flowering plants. Here, we compared evolutionary rates, gene duplication, and selective patterns of genes involved in sugar metabolism and transport between grasses and eudicots using six grass species and seven eudicot species as materials. Overall, sugar transporter genes exhibit divergent evolutionary patterns, whereas, sugar metabolism genes showing similar evolutionary pattern between monocots and eudicots. Sugar transporter genes have higher frequencies of recent duplication in eudicots than in grasses and their patterns of evolutionary rate are different. Evidence for divergent selection of these two groups of flowering plants is also observed in sugar transporter genes, wherein, these genes have undergone positive selection in eudicots, but not in grasses. Taken together, these findings suggest that sugar transporter genes rather than sugar metabolism genes play important roles in sugar accumulation in plants, and that divergent evolutionary patterns of sugar transporter genes are associated with the difference of sugar accumulation in storage tissues of grasses and eudicots. PMID:27356489

  13. Occupational allergy caused by flowers.

    PubMed

    de Jong, N W; Vermeulen, A M; Gerth van Wijk, R; de Groot, H

    1998-02-01

    We describe 14 consecutive patients with complaints due to the handling of flowers. The symptoms varied from allergic rhinoconjunctivitis and asthma to urticaria. Most patients had professions in the flower industry. Skin prick tests (SPT) were performed with home-made pollen extracts from 17 different flowers known to be the most commonly grown and sold in The Netherlands RAST against mugwort, chrysanthemum, and solidago was performed. The diagnosis of atopy against flowers was based on work-related symptoms due to the handling of flowers, positive SPT with flower extracts, and positive RAST. The concordance between SPT and case history was 74%, and that between SPT and RAST was 77% Extensive cross-sensitization was seen to pollen of several members of the Compositae family (e.g., Matricaria, chrysanthemum, solidago) and to pollen of the Amaryllidaceae family (Alstroemeria and Narcissus). Homemade flower extracts can be used to confirm IgE-mediated flower allergy. Mugwort can be used as a screening test for possible flower allergy. For most patients, the allergy led to a change of profession. PMID:9534922

  14. Grass fungal endophytes and uses thereof

    SciTech Connect

    Craven, Kelly

    2015-03-10

    The invention provides isolated fungal endophytes and synthetic combinations thereof with host grass plants. Methods for inoculating grass plant with the endophytes, for propagating the grass-endophyte combinations, and for producing feeds and biofuels from grass-endophyte combinations are also provided.

  15. Flowers that threaten Funza.

    PubMed

    Kendall, S

    1993-01-01

    Water shortages have resulted from agricultural development in a rural area outside Bogota, Colombia. These shortages have increased women's work load and caused problems in managing households because the water must be boiled before ingestion. In the community of Funza, women must obtain clean water in buckets at night from the main valve, which has insufficient water pressure and a slow stream. Some barrios collect water on a weekly basis. The local restaurant in town obtains water once a week from a tanker; the town is lucky to receive water three times a week. Men assume that women will take care of the problem. The mayor says that the piped water from Bogota will soon be connected and that each barrio will have its own valve. Women are concerned that the supply, even with new valves, will be limited and mixed with dirty lagoon water. Experts are saying that the water shortage and quality problems that began seven years ago will lead to rationing within three to six years. The flower companies, that came to the area 22 years age, are blamed for the water problems. People say that the flower companies have piped clean water from the area's supply in the San Patricia and that underground sources of water have been used up as well. The industry provides jobs and income, which have improved the standard of living, but there is little consideration given to the water supply. The community shifted water sources to the lagoon at a time when the water was being contaminated by sewage and pesticides and chemicals from the flower companies. PMID:12287011

  16. Projected Carbon Dioxide to Increase Grass Pollen and Allergen Exposure Despite Higher Ozone Levels

    PubMed Central

    Albertine, Jennifer M.; Manning, William J.; DaCosta, Michelle; Stinson, Kristina A.; Muilenberg, Michael L.; Rogers, Christine A.

    2014-01-01

    One expected effect of climate change on human health is increasing allergic and asthmatic symptoms through changes in pollen biology. Allergic diseases have a large impact on human health globally, with 10–30% of the population affected by allergic rhinitis and more than 300 million affected by asthma. Pollen from grass species, which are highly allergenic and occur worldwide, elicits allergic responses in 20% of the general population and 40% of atopic individuals. Here we examine the effects of elevated levels of two greenhouse gases, carbon dioxide (CO2), a growth and reproductive stimulator of plants, and ozone (O3), a repressor, on pollen and allergen production in Timothy grass (Phleum pratense L.). We conducted a fully factorial experiment in which plants were grown at ambient and/or elevated levels of O3 and CO2, to simulate present and projected levels of both gases and their potential interactive effects. We captured and counted pollen from flowers in each treatment and assayed for concentrations of the allergen protein, Phl p 5. We found that elevated levels of CO2 increased the amount of grass pollen produced by ∼50% per flower, regardless of O3 levels. Elevated O3 significantly reduced the Phl p 5 content of the pollen but the net effect of rising pollen numbers with elevated CO2 indicate increased allergen exposure under elevated levels of both greenhouse gases. Using quantitative estimates of increased pollen production and number of flowering plants per treatment, we estimated that airborne grass pollen concentrations will increase in the future up to ∼200%. Due to the widespread existence of grasses and the particular importance of P. pratense in eliciting allergic responses, our findings provide evidence for significant impacts on human health worldwide as a result of future climate change. PMID:25372614

  17. Identifying urban sources as cause of elevated grass pollen concentrations using GIS and remote sensing

    NASA Astrophysics Data System (ADS)

    Skjøth, C. A.; Ørby, P. V.; Becker, T.; Geels, C.; Schlünssen, V.; Sigsgaard, T.; Bønløkke, J. H.; Sommer, J.; Søgaard, P.; Hertel, O.

    2013-01-01

    We examine here the hypothesis that during flowering, the grass pollen concentrations at a specific site reflect the distribution of grass pollen sources within a few kilometres of this site. We perform this analysis on data from a measurement campaign in the city of Aarhus (Denmark) using three pollen traps and by comparing these observations with a novel inventory of grass pollen sources. The source inventory is based on a new methodology developed for urban-scale grass pollen sources. The new methodology is believed to be generally applicable for the European area, as it relies on commonly available remote sensing data combined with management information for local grass areas. The inventory has identified a number of grass pollen source areas present within the city domain. The comparison of the measured pollen concentrations with the inventory shows that the atmospheric concentrations of grass pollen in the urban zone reflect the source areas identified in the inventory, and that the pollen sources that are found to affect the pollen levels are located near or within the city domain. The results also show that during days with peak levels of pollen concentrations there is no correlation between the three urban traps and an operational trap located just 60 km away. This finding suggests that during intense flowering, the grass pollen concentration mirrors the local source distribution and is thus a local-scale phenomenon. Model simulations aimed at assessing population exposure to pollen levels are therefore recommended to take into account both local sources and local atmospheric transport, and not to rely only on describing regional to long-range transport of pollen. The derived pollen source inventory can be entered into local-scale atmospheric transport models in combination with other components that simulate pollen release in order to calculate urban-scale variations in the grass pollen load. The gridded inventory with a resolution of 14 m is therefore

  18. Identifying urban sources as cause to elevated grass pollen concentrations using GIS and remote sensing

    NASA Astrophysics Data System (ADS)

    Skjøth, C. A.; Ørby, P. V.; Becker, T.; Geels, C.; Schlünssen, V.; Sigsgaard, T.; Bønløkke, J. H.; Sommer, J.; Søgaard, P.; Hertel, O.

    2012-10-01

    We examine here the hypothesis that during flowering, the grass pollen concentrations at a specific site reflect the distribution of grass pollen sources within a few kilometres from this site. We perform this analysis on data from a measurement campaign in the city of Aarhus (Denmark) using three pollen traps and by comparing these observations with a novel inventory of grass pollen sources. The source inventory is based on a new methodology developed for urban scale grass pollen sources. The new methodology is believed to be generally applicable for the European area, as it relies on commonly available remote sensing data combined with management information for local grass areas. The inventory has identified a number of grass pollen source areas present within the city domain. The comparison of the measured pollen concentrations with the inventory shows that the atmospheric concentrations of grass pollen in the urban zone reflects the source areas identified in the inventory, and that these pollen sources that are found to affect the pollen levels are located near and within the city domain. The results also show that during days with peak levels of pollen concentrations, there is no correlation between the three urban traps and an operational trap located just 60 km away. This finding suggests that during intense flowering, the grass pollen concentration mirrors the local source distribution, and is thus a local scale phenomenon. Model simulations aiming at assessment of population exposure to pollen levels are therefore recommended to take into account both local sources and local atmospheric transport, and not rely only on describing regional to long-range transport of pollen. The derived pollen source inventory can be entered into local scale atmospheric transport models in combination with other components that simulates pollen release in order to calculate urban scale variations in the grass pollen load. The gridded inventory with a resolution of 14 m is

  19. CONSTANS and ASYMMETRIC LEAVES 1 complex is involved in the induction of FLOWERING LOCUS T in photoperiodic flowering in Arabidopsis

    PubMed Central

    Song, Young Hun; Lee, Ilha; Lee, Sang Yeol; Imaizumi, Takato; Hong, Jong Chan

    2011-01-01

    Summary Plants monitor changes in day length to coordinate flowering with favorable seasons to increase their fitness. The day-length specific induction of FLOWERING LOCUS T (FT) regulated by CONSTANS (CO) is the crucial aspect of photoperiodic flowering in Arabidopsis thaliana. Recent studies elucidated some mechanisms of CO-dependent FT induction. Here, we demonstrate another mechanism of CO-dependent FT regulation. Our results indicate that CO protein regulates FT transcription partially by forming a complex with ASYMMETRIC LEAVES 1 (AS1) protein, which regulates leaf development partly by controlling gibberellin (GA) levels. We identified AS1 as a CO-interacting protein in yeast and verified their interaction in vitro and in planta. We also showed that the AS1 temporal and spatial expression pattern overlapped with that of CO. In addition, as1 mutants showed GA-independent delayed flowering under different light/dark conditions. FT expression levels in the as1 mutants and the SUC2:CO-HA/as1 line under long-day and 12-h light/12-h dark conditions were reduced compared to wild-type plants and the SUC2:HA-CO line, respectively. Moreover, AS1 directly bound to the specific regions of the FT promoter in vivo. These results indicate that CO forms a functional complex with AS1 to regulate FT expression and that AS1 plays different roles in two regulatory pathways, both of which concomitantly regulate a precise timing of flowering. PMID:21950734

  20. Abundance of mixed linkage glucan in mature tissues and secondary cell walls of grasses.

    PubMed

    Vega-Sánchez, Miguel E; Verhertbruggen, Yves; Scheller, Henrik V; Ronald, Pamela C

    2013-02-01

    (1,3; 1,4)-β-D-glucan, also known as mixed linkage glucan (MLG), is a polysaccharide that in flowering plants is unique to the cell walls of grasses and other related members of Poales. MLG is highly abundant in endosperm cell walls, where it is considered a storage carbohydrate. In vegetative tissues, MLG transiently accumulates in the primary cell walls of young, elongating organs. In evolutionary distant species such as Equisetum, MLG accumulates predominantly in old tissues in the stems. Similarly, we have recently shown that rice accumulates a large amount of MLG in mature stems, which prompted us to re-evaluate the hypothesis that MLG is solely related to growth in grass vegetative tissues. Here, we summarize data that confirms the presence of MLG in secondary cell walls and mature tissues in rice and other grasses. Along with these results, we discuss additional evidence indicating a broader role for MLG than previously considered. PMID:23299432

  1. Stop and Paint the Flowers.

    ERIC Educational Resources Information Center

    Phillips, Shelley

    2002-01-01

    Describes an art lesson where students used watercolors to paint a flower bouquet arranged in a vase. Explains that the students viewed examples of flower bouquets by artists such as Vincent van Gogh and Odilon Redon. Discusses, in detail, the process of creating the artworks. (CMK)

  2. Molecular phylogenetic relationships of the brown leaf rust fungi on wheat, rye and other grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phylogenetic analyses were conducted with DNA sequence data from the rDNA internal transcribed spacer region and elongation factor 1–alpha to elucidate the species complex of brown leaf rust fungi infecting wheat, rye and other grasses. Three phylogenetic lineages were recovered within the complex o...

  3. Interaction of Photoperiod and Vernalization Determines Flowering Time of Brachypodium distachyon1[C][W][OPEN

    PubMed Central

    Ream, Thomas S.; Woods, Daniel P.; Schwartz, Christopher J.; Sanabria, Claudia P.; Mahoy, Jill A.; Walters, Eric M.; Kaeppler, Heidi F.; Amasino, Richard M.

    2014-01-01

    Timing of flowering is key to the reproductive success of many plants. In temperate climates, flowering is often coordinated with seasonal environmental cues such as temperature and photoperiod. Vernalization is an example of temperature influencing the timing of flowering and is defined as the process by which a prolonged exposure to the cold of winter results in competence to flower during the following spring. In cereals, three genes (VERNALIZATION1 [VRN1], VRN2, and FLOWERING LOCUS T [FT]) have been identified that influence the vernalization requirement and are thought to form a regulatory loop to control the timing of flowering. Here, we characterize natural variation in the vernalization and photoperiod responses in Brachypodium distachyon, a small temperate grass related to wheat (Triticum aestivum) and barley (Hordeum vulgare). Brachypodium spp. accessions display a wide range of flowering responses to different photoperiods and lengths of vernalization. In addition, we characterize the expression patterns of the closest homologs of VRN1, VRN2 (VRN2-like [BdVRN2L]), and FT before, during, and after cold exposure as well as in different photoperiods. FT messenger RNA levels generally correlate with flowering time among accessions grown in different photoperiods, and FT is more highly expressed in vernalized plants after cold. VRN1 is induced by cold in leaves and remains high following vernalization. Plants overexpressing VRN1 or FT flower rapidly in the absence of vernalization, and plants overexpressing VRN1 exhibit lower BdVRN2L levels. Interestingly, BdVRN2L is induced during cold, which is a difference in the behavior of BdVRN2L compared with wheat VRN2 during cold. PMID:24357601

  4. Interaction of photoperiod and vernalization determines flowering time of Brachypodium distachyon.

    PubMed

    Ream, Thomas S; Woods, Daniel P; Schwartz, Christopher J; Sanabria, Claudia P; Mahoy, Jill A; Walters, Eric M; Kaeppler, Heidi F; Amasino, Richard M

    2014-02-01

    Timing of flowering is key to the reproductive success of many plants. In temperate climates, flowering is often coordinated with seasonal environmental cues such as temperature and photoperiod. Vernalization is an example of temperature influencing the timing of flowering and is defined as the process by which a prolonged exposure to the cold of winter results in competence to flower during the following spring. In cereals, three genes (VERNALIZATION1 [VRN1], VRN2, and FLOWERING LOCUS T [FT]) have been identified that influence the vernalization requirement and are thought to form a regulatory loop to control the timing of flowering. Here, we characterize natural variation in the vernalization and photoperiod responses in Brachypodium distachyon, a small temperate grass related to wheat (Triticum aestivum) and barley (Hordeum vulgare). Brachypodium spp. accessions display a wide range of flowering responses to different photoperiods and lengths of vernalization. In addition, we characterize the expression patterns of the closest homologs of VRN1, VRN2 (VRN2-like [BdVRN2L]), and FT before, during, and after cold exposure as well as in different photoperiods. FT messenger RNA levels generally correlate with flowering time among accessions grown in different photoperiods, and FT is more highly expressed in vernalized plants after cold. VRN1 is induced by cold in leaves and remains high following vernalization. Plants overexpressing VRN1 or FT flower rapidly in the absence of vernalization, and plants overexpressing VRN1 exhibit lower BdVRN2L levels. Interestingly, BdVRN2L is induced during cold, which is a difference in the behavior of BdVRN2L compared with wheat VRN2 during cold. PMID:24357601

  5. Interactions between grass distribution and land surface form in a semiarid region with complex terrain

    NASA Astrophysics Data System (ADS)

    Bras, R. L.; Flores Cervantes, J. H.

    2008-12-01

    We analyze the spatial distribution of grass biomass and topographic features in two semiarid region in the Southwestern USA. We find that: 1) north-facing terrain has more grass biomass and higher slopes than south-facing terrain; 2) in north-facing hillslopes, grass biomass abundance increases with slope, and in south-facing hillslopes, grass biomass is least abundant at intermediate slopes; 3) grass biomass inversely correlates to solar irradiation that varies as a function of terrain orientation and slope; and 4) biomass distribution is also controlled by the spatial distribution of the channel network. These findings indicate that water availability, as a function of terrain form, controls vegetation growth in the water-limited region, leading to topographically-controlled spatial vegetation patterns that affect terrain form at a local scale. The effects of topography on grass biomass distribution and vice versa are largely dependent on the water fluxes on the surface of the terrain. A model that represents the erosion processes, grass biomass dynamics, and water fluxes in small watersheds is used to elucidate the observations discussed in the previous paragraph.

  6. Molecular characterization of mutations in white-flowered torenia plants

    PubMed Central

    2014-01-01

    Background Torenia (Torenia fournieri Lind.) is a model plant increasingly exploited in studies in various disciplines, including plant engineering, biochemistry, physiology, and ecology. Additionally, cultivars with different flower colors have been bred and made commercially available. Flower color in torenia is mainly attributed to the accumulation of anthocyanins, but the molecular mechanisms inducing flower color mutations in torenia have not been well elucidated. In this study, we therefore attempted to identify the cause of white coloration in torenia by comparing the white-flowered cultivar Crown White (CrW) with Crown Violet (CrV), a violet-flowered variety. Results In an expression analysis, no flavanone 3-hydroxylase (TfF3H) transcript accumulation was detected in CrW petals. Sequence analyses revealed that a novel long terminal repeat (LTR)-type retrotransposable element, designated as TORE1 (Torenia retrotransposon 1), is inserted into the 5′-upstream region of the TfF3H gene in CrW. A transient expression assay using torenia F3H promoters with or without TORE1 insertion showed that the TORE1 insertion substantially suppressed F3H promoter activity, suggesting that this insertion is responsible for the absence of F3H transcripts in white petals. Furthermore, a transformation experiment demonstrated that the introduction of a foreign gentian F3H cDNA, GtF3H, into CrW was able to recover pink-flower pigmentation, indicating that F3H deficiency is indeed the cause of the colorless flower phenotype in CrW. Detailed sequence analysis also identified deletion mutations in flavonoid 3′-hydroxylase (TfF3′H) and flavonoid 3′,5′- hydroxylase (TfF3′5′H) genes, but these were not directly responsible for white coloration in this cultivar. Conclusions Taken together, a novel retrotransposable element, TORE1, inserted into the F3H 5′-upstream region is the cause of deficient F3H transcripts in white-flowered torenia, thereby leading to reduced petal

  7. Say it with flowers: Flowering acceleration by root communication.

    PubMed

    Falik, Omer; Hoffmann, Ishay; Novoplansky, Ariel

    2014-01-01

    The timing of reproduction is a critical determinant of fitness, especially in organisms inhabiting seasonal environments. Increasing evidence suggests that inter-plant communication plays important roles in plant functioning. Here, we tested the hypothesis that flowering coordination can involve communication between neighboring plants. We show that soil leachates from Brassica rapa plants growing under long-day conditions accelerated flowering and decreased allocation to vegetative organs in target plants growing under non-inductive short-day conditions. The results suggest that besides endogenous signaling and external abiotic cues, flowering timing may involve inter-plant communication, mediated by root exudates. The study of flowering communication is expected to illuminate neglected aspects of plant reproductive interactions and to provide novel opportunities for controlling the timing of plant reproduction in agricultural settings. PMID:25764422

  8. Say it with flowers: flowering acceleration by root communication.

    PubMed

    Falik, Omer; Hoffmann, Ishay; Novoplansky, Ariel

    2014-01-01

    The timing of reproduction is a critical determinant of fitness, especially in organisms inhabiting seasonal environments. Increasing evidence suggests that inter-plant communication plays important roles in plant functioning. Here, we tested the hypothesis that flowering coordination can involve communication between neighboring plants. We show that soil leachates from Brassica rapa plants growing under long-day conditions accelerated flowering and decreased allocation to vegetative organs in target plants growing under non-inductive short-day conditions. The results suggest that besides endogenous signaling and external abiotic cues, flowering timing may involve inter-plant communication, mediated by root exudates. The study of flowering communication is expected to illuminate neglected aspects of plant reproductive interactions and to provide novel opportunities for controlling the timing of plant reproduction in agricultural settings. PMID:24598343

  9. Spirit Has Flower Power

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The Mars Exploration Rover Spirit took this image with its hazard-avoidance camera on sol 86 (March 31, 2004), after the rover's rock abrasion tool had brushed for three minutes on each of six locations on the rock named 'Mazatzal' to create a flower-shaped mosaic.

    The goal for this operation was to create a brushed area big enough for the miniature thermal emission spectrometer to capture within one of its pixels, which are 11 centimeters (4.3 inches) in diameter at the distance between the rock and the instrument. Because the rock abrasion tool creates individual brushed areas only about 5 centimeters (2 inches) in diameter, the team designed this six-location series of tool placements in order to brush 92 percent to 95 percent of the spectrometer's pixel size.

    This operation was only the second time the rock abrasion tool has created a brushing mosaic. The first time was a three-spot brushing on the rock called 'Humphrey.' The brush was originally designed to be used as an aide during full grinding operations, however it has been very effective in brushing the top layer off of dusty martian rocks to allow scientists a multi-depth look into the rocks on Mars.

  10. Chemicals Reduce Need To Mow Grass

    NASA Technical Reports Server (NTRS)

    Humphrys, Brooks; Farley, Max; Gast, Larry J.

    1993-01-01

    Brief report discusses use of herbicides Roundup(R), Campaign(R), and Oust(R) to retard growth of Argentine bahia grass. Herbicide applied by use of spraying apparatus pulled by tractor. "Chemical mowing" keeps grass at "freshly mowed" height with less mechanical mowing. Applied to grass on shoulders of roads, reducing time spent on mowing.

  11. VARIABILITY OF GRASS LIGNIN ACYLATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grasses are being championed as biomass sources for bioenergy production. Their ultimate use would be as a source of carbohydrate for fermentation to ethanol, conversion to oils via pyrolysis, or direct conversion to energy through combustion. In the latter case, increasing lignin content would enha...

  12. Grass pollen allergens globally: the contribution of subtropical grasses to burden of allergic respiratory diseases.

    PubMed

    Davies, J M

    2014-06-01

    Grass pollens of the temperate (Pooideae) subfamily and subtropical subfamilies of grasses are major aeroallergen sources worldwide. The subtropical Chloridoideae (e.g. Cynodon dactylon; Bermuda grass) and Panicoideae (e.g. Paspalum notatum; Bahia grass) species are abundant in parts of Africa, India, Asia, Australia and the Americas, where a large and increasing proportion of the world's population abide. These grasses are phylogenetically and ecologically distinct from temperate grasses. With the advent of global warming, it is conceivable that the geographic distribution of subtropical grasses and the contribution of their pollen to the burden of allergic rhinitis and asthma will increase. This review aims to provide a comprehensive synthesis of the current global knowledge of (i) regional variation in allergic sensitivity to subtropical grass pollens, (ii) molecular allergenic components of subtropical grass pollens and (iii) allergic responses to subtropical grass pollen allergens in relevant populations. Patients from subtropical regions of the world show higher allergic sensitivity to grass pollens of Chloridoideae and Panicoideae grasses, than to temperate grass pollens. The group 1 allergens are amongst the allergen components of subtropical grass pollens, but the group 5 allergens, by which temperate grass pollen extracts are standardized for allergen content, appear to be absent from both subfamilies of subtropical grasses. Whilst there are shared allergenic components and antigenic determinants, there are additional clinically relevant subfamily-specific differences, at T- and B-cell levels, between pollen allergens of subtropical and temperate grasses. Differential immune recognition of subtropical grass pollens is likely to impact upon the efficacy of allergen immunotherapy of patients who are primarily sensitized to subtropical grass pollens. The literature reviewed herein highlights the clinical need to standardize allergen preparations for both

  13. Biosynthesis of floral scent 2-phenylethanol in rose flowers.

    PubMed

    Hirata, Hiroshi; Ohnishi, Toshiyuki; Watanabe, Naoharu

    2016-10-01

    Plants emit chemically diverse volatile compounds for attracting pollinators or putting up a chemical defense against herbivores. 2-Phenylethanol (2PE) is one of the abundantly emitted scent compounds in rose flowers. Feeding experiments with l-[(2)H8]phenylalanine into rose flowers and subsequent analysis using gas chromatography-mass spectrometry analysis revealed the hypothetical biosynthetic intermediates to [(2)H8]-2PE, and the biochemical and genetic analyses elucidated the principal pathway to [(2)H8]-2PE. We recently found season-specific 2PE pathway producing [(2)H7]-2PE from l-[(2)H8]phenylalanine. This is a unique example where the dominant pathway to a specific compound changes with the seasons. This review focuses on the biosynthesis of floral volatiles and their regulation to adapt to the changes in the environment. PMID:27297332

  14. Phenylbenzoisoquinolindione alkaloids accumulate in stamens of Xiphidium caeruleum Aubl. flowers.

    PubMed

    Chen, Yu; Paetz, Christian; Menezes, Riya C; Schneider, Bernd

    2016-08-01

    Xiphidium caeruleum (Haemodoraceae) flower organs such as carpels, pedicels, petals, and stamens were separately investigated for their phytochemical profile. The stamens appeared to be a rich source of previously undescribed phenylbenzoisoquinolindiones, a group of phenylphenalenone-derived alkaloids, also named aza-phenylphenalenones. Nine previously undescribed compounds with an identical aza-phenylphenalenone core structure but different amino acid-derived side chains at position 2 were isolated and their structures elucidated by nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). In addition, some previously reported phenylbenzoisoquinolindiones, phenylbenzoisochromenones and flavonoids were found in stamens and other parts of the flowers. The specific occurrence of heterocyclic phenylphenalenone-type compounds in X. caeruleum suggests these are involved in physiological or ecological processes. PMID:27179683

  15. Inter-specific variation in headspace scent volatiles composition of four commercially cultivated jasmine flowers.

    PubMed

    Bera, Paramita; Kotamreddy, Jhansi Narmada Reddy; Samanta, Tanmoy; Maiti, Saborni; Mitra, Adinpunya

    2015-01-01

    Jasmines are commercially grown for their fragrant flowers and essential oil production. The flowers of jasmine emit sweet-smelling fragrance from evening till midnight. This study was designed to study the composition and inter-specific variation of the emitted scent volatiles from flowers of four commercially cultivated Jasminum species namely, Jasminum sambac, Jasminum auriculatum, Jasminum grandiflorum and Jasminum multiflorum. Gas chromatography-mass spectrometry analysis revealed that the scent volatiles composition of these flowers was predominantly enriched with both terpenoid and benzenoid compounds. Linalool and (3E,6E)-α-farnesene were identified as the major monoterpene and sesquiterpene in all the four species, respectively. The most abundant benzenoid detected in all flowers was benzyl acetate. Comparison of volatile profiles indicated a variation in fragrance contents and types emitted from these four jasmine flowers. The outcome of this study shall help in elucidating the enzymes and genes of fragrance biosynthesis in jasmines and in aiming to create flowers with improved scent quality. PMID:25583067

  16. Competition for water between deep- and shallow-rooted grasses

    SciTech Connect

    Healy, J.L.; Black, R.A. ); Link, S.O. )

    1994-06-01

    Competition between root systems of neighboring plants may be altered by seasonal variation in precipitation and soil moisture. Competitive effects of a deep-rooted, perennial grass, Pseudoroegneria spicata, on a shallow-rooted, perennial grass, Poa sandbergii, were monitored over two growing seasons by isolating the root system of P. sandbergii individuals within PVC tubes and comparing plant and soil characteristics to controls. When isolated for the entire growing season, P. sandbergii continued vegetative growth three weeks longer and later season soil water content was significantly greater than controls. Differences in soil water content were greatest between 30 and 50cm, below P. sandbergii's typical rooting depth. Flowering phenology was unchanged. When plants were isolated late in the season, treated plants showed more negative predown xylem pressure potential the morning after isolatron. Compared to controls, soil water content was reduced the day after tube insertion. These immediate effects on plant and soil water status may be due to removal of water supplied nightly by hydraulic lift.

  17. Videographic enhancement of GRASS imagery: Recent advances

    SciTech Connect

    Sullivan, R.G.

    1992-06-01

    The Geographic Resource Analysis Support System (GRASS), a geographic information system, has been fielded at approximately 50 US Army training installations as a land-management decision-making tool. Use of the GRASS geographic information system involves the production of numerous digital maps of environmental parameters, such as elevation, soils, hydrography, etc. A recently emerging technology called computer videographics can be used to graphically enhance GRASS images, thereby creating new ways to visualize GRASS analysis results. The project described in this report explored the enhancement of GRASS images through the use of videographic technology. General image quality of videographically enhanced GRASS images was improved through the use of high-resolution imagery and improved software. Several new types of geographic data visualizations were developed, including three-dimensional shaded-relief maps of GRASS data, overlay of GRASS images with satellite images, and integration of computer-aided-design imagery with GRASS images. GRASS images were successfully enhanced using Macintosh hardware and software, rather than the DOS-based equipment used previously. Images scanned with a document scanner were incorporated into GRASS imagery, and enhanced images were output in an S-VHS high-resolution video format.

  18. Elucidation of the Teixobactin Pharmacophore.

    PubMed

    Yang, Hyunjun; Chen, Kevin H; Nowick, James S

    2016-07-15

    This paper elucidates the teixobactin pharmacophore by comparing the arginine analogue of teixobactin Arg10-teixobactin to seven homologues with varying structure and stereochemistry. The roles of the guanidinium group at position 10, the stereochemistry of the macrolactone ring, and the "tail" comprising residues 1-5 are investigated. The guanidinium group is not necessary for activity; Lys10-teixobactin is more active than Arg10-teixobactin against Gram-positive bacteria in minimum inhibitory concentration (MIC) assays. The relative stereochemistry of the macrolactone ring is important. Diastereomer l-Thr8,Arg10-teixobactin is inactive, and diastereomer d-allo-Ile11,Arg10-teixobactin is less active. The macrolactone ring is critical; seco-Arg10-teixobactin is inactive. The absolute stereochemistry is not important; the enantiomer ent-Arg10-teixobactin is comparable in activity. The hydrophobic N-terminal tail is important. Truncation of residues 1-5 results in loss of activity, and replacement of residues 1-5 with a dodecanoyl group partially restores activity. These findings pave the way for developing simpler homologues of teixobactin with enhanced pharmacological properties. PMID:27232661

  19. Bioactivity, proximate, mineral and volatile profiles along the flowering stages of Opuntia microdasys (Lehm.): defining potential applications.

    PubMed

    Chahdoura, Hassiba; Barreira, João C M; Fernández-Ruiz, Virginia; Morales, Patricia; Calhelha, Ricardo C; Flamini, Guido; Soković, Marina; Ferreira, Isabel C F R; Achour, Lotfi

    2016-03-01

    Opuntia spp. flowers have been traditionally used for medical purposes, mostly because of their diversity in bioactive molecules with health promoting properties. The proximate, mineral and volatile compound profiles, together with the cytotoxic and antimicrobial properties were characterized in O. microdasys flowers at different maturity stages, revealing several statistically significant differences. O. microdasys stood out mainly for its high contents of dietary fiber, potassium and camphor, and its high activities against HCT15 cells, Staphylococcus aureus, Aspergillus versicolor and Penicillium funiculosum. The vegetative stage showed the highest cytotoxic and antifungal activities, whilst the full flowering stage was particularly active against bacterial species. The complete dataset has been classified by principal component analysis, achieving clearly identifiable groups for each flowering stage, elucidating also the most distinctive features, and comprehensively profiling each of the assayed stages. The results might be useful to define the best flowering stage considering practical application purposes. PMID:26876160

  20. Bumblebee preference for symmetrical flowers.

    PubMed

    Møller, A P

    1995-03-14

    Fluctuating asymmetry, which represents small random deviations from otherwise bilateral symmetry, is a measure of the phenotypic quality of individuals indicating the ability of controlled development under given environmental and genetic conditions. I tested whether floral symmetry reliably reflects phenotypic quality measured in terms of pollinator rewards and whether pollinators respond to floral symmetry in a series of observations and experiments on Epilobium angustifolium (Onagraceae). Lower petal asymmetry was negatively related to mean lower petal length, whereas asymmetry in leaf width was positively related to mean leaf width. Flowers visited by bumblebees were larger and more symmetrical than the nearest neighboring flower. This relationship between pollinator preference for large and symmetrical flowers was demonstrated to be causal in experiments in which the lower petals were manipulated symmetrically or asymmetrically. Nectar production was larger in symmetrical flowers, and this may explain the bumblebee preference for flower symmetry. Floral symmetry therefore reliably reflects nectar production and hence enhances pollen transport. Extensive embryo abortion has been documented in E. angustifolium and other outcrossing plant species. Floral fluctuating asymmetry, which reflects general developmental homeostasis, may explain such developmental selection in these plants. PMID:11607519

  1. Ectopic expression of Jatropha curcas APETALA1 (JcAP1) caused early flowering in Arabidopsis, but not in Jatropha.

    PubMed

    Tang, Mingyong; Tao, Yan-Bin; Xu, Zeng-Fu

    2016-01-01

    Jatropha curcas is a promising feedstock for biofuel production because Jatropha oil is highly suitable for the production of biodiesel and bio-jet fuels. However, Jatropha exhibits a low seed yield as a result of unreliable and poor flowering. APETALA1 (AP1) is a floral meristem and organ identity gene in higher plants. The flower meristem identity genes of Jatropha have not yet been identified or characterized. To better understand the genetic control of flowering in Jatropha, an AP1 homolog (JcAP1) was isolated from Jatropha. An amino acid sequence analysis of JcAP1 revealed a high similarity to the AP1 proteins of other perennial plants. JcAP1 was expressed in inflorescence buds, flower buds, sepals and petals. The highest expression level was observed during the early developmental stage of the flower buds. The overexpression of JcAP1 using the cauliflower mosaic virus (CaMV) 35S promoter resulted in extremely early flowering and abnormal flowers in transgenic Arabidopsis plants. Several flowering genes downstream of AP1 were up-regulated in the JcAP1-overexpressing transgenic plant lines. Furthermore, JcAP1 overexpression rescued the phenotype caused by the Arabidopsis AP1 loss-of-function mutant ap1-11. Therefore, JcAP1 is an ortholog of AtAP1, which plays a similar role in the regulation of flowering in Arabidopsis. However, the overexpression of JcAP1 in Jatropha using the same promoter resulted in little variation in the flowering time and floral organs, indicating that JcAP1 may be insufficient to regulate flowering by itself in Jatropha. This study helps to elucidate the function of JcAP1 and contributes to the understanding of the molecular mechanisms of flower development in Jatropha. PMID:27168978

  2. Ectopic expression of Jatropha curcas APETALA1 (JcAP1) caused early flowering in Arabidopsis, but not in Jatropha

    PubMed Central

    Tang, Mingyong; Tao, Yan-Bin

    2016-01-01

    Jatropha curcas is a promising feedstock for biofuel production because Jatropha oil is highly suitable for the production of biodiesel and bio-jet fuels. However, Jatropha exhibits a low seed yield as a result of unreliable and poor flowering. APETALA1 (AP1) is a floral meristem and organ identity gene in higher plants. The flower meristem identity genes of Jatropha have not yet been identified or characterized. To better understand the genetic control of flowering in Jatropha, an AP1 homolog (JcAP1) was isolated from Jatropha. An amino acid sequence analysis of JcAP1 revealed a high similarity to the AP1 proteins of other perennial plants. JcAP1 was expressed in inflorescence buds, flower buds, sepals and petals. The highest expression level was observed during the early developmental stage of the flower buds. The overexpression of JcAP1 using the cauliflower mosaic virus (CaMV) 35S promoter resulted in extremely early flowering and abnormal flowers in transgenic Arabidopsis plants. Several flowering genes downstream of AP1 were up-regulated in the JcAP1-overexpressing transgenic plant lines. Furthermore, JcAP1 overexpression rescued the phenotype caused by the Arabidopsis AP1 loss-of-function mutant ap1-11. Therefore, JcAP1 is an ortholog of AtAP1, which plays a similar role in the regulation of flowering in Arabidopsis. However, the overexpression of JcAP1 in Jatropha using the same promoter resulted in little variation in the flowering time and floral organs, indicating that JcAP1 may be insufficient to regulate flowering by itself in Jatropha. This study helps to elucidate the function of JcAP1 and contributes to the understanding of the molecular mechanisms of flower development in Jatropha. PMID:27168978

  3. Synchronous Pulsed Flowering: Analysis of the Flowering Phenology in Juncus (Juncaceae)

    PubMed Central

    Michalski, Stefan G.; Durka, Walter

    2007-01-01

    Background and Aims The timing of flowering within and among individuals is of fundamental biological importance because of its influence on total seed production and, ultimately, fitness. Traditional descriptive parameters of flowering phenology focus on onset and duration of flowering and on synchrony among individuals. These parameters do not adequately account for variability in flowering across the flowering duration at individual and population level. This study aims to analyse the flowering phenology of wind-pollinated Juncus species that has been described as temporally highly variable (‘pulsed flowering’). Additionally, an attempt is made to identify proximate environmental factors that may cue the flowering, and ultimate causes for the flowering patterns are discussed. Methods Flowering phenology was examined in populations of nine Juncus species by estimating flowering synchrony and by using the coefficient of variation (CV) to describe the temporal variation in flowering on individual and population levels. Phenologies were compared with null models to test which patterns deviate from random flowering. All parameters assessed were compared with each other and the performance of the parameters in response to randomization and varying synchrony was evaluated using a model population. Flowering patterns were correlated with temperature and humidity. Key Results Most flowering patterns of Juncus were best described as synchronous pulsed flowering, characterized as population-wide concerted flowering events separated by days with no or few open flowers. Flowering synchrony and variability differed from a random pattern in most cases. CV values in combination with a measure of synchrony differentiated among flowering patterns found. Synchrony varied among species and was independent from variability in flowering. Neither temperature nor humidity could be determined as potential cues for the flowering pulses. Conclusions The results indicate that selection

  4. FLOBOTS: ROBOTIC FLOWERS FOR BEE BEHAVIOUR EXPERIMENTS

    PubMed Central

    Essenberg, Carla J.

    2015-01-01

    Studies of pollinator foraging behaviour often require artificial flowers that can refill themselves, allowing pollinators to forage for long periods of time under experimental conditions. Here I describe a design for inexpensive flowers that can refill themselves upon demand and that are easy enough to set up and clean that they can be used in arrays of 30 or more flowers. I also summarize of a variety of artificial flower designs developed by other researchers. PMID:25722755

  5. Spring Flowers: Harvest of a Sensitive Eye

    ERIC Educational Resources Information Center

    Clark, Eloise; Levin, Ted

    1978-01-01

    Defining and describing a number of spring flowers, this article includes illustrations and explanations that demonstrate "art and science are born of the same parents". The flowers discussed are skunk cabbage, bellwort, spring beauty, jack-in-the-pulpit, Solomon's seal, wild geranium, showy orchids, moccasin flower, bluets, apple, and Indian…

  6. Symbiotic grasses: A review of basic biology of forage grass fungal endophytes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungal endophytes associated with grasses are the fundamental reason for the basic successes of several pasture grasses, notable tall fescues, and perennial ryegrass. Tall fescue and perennial ryegrass fungal endophytes, Neotyphodium coenophialum and N. lolii, respectively, and their relatives ...

  7. Pyrethrum flowers and pyrethroid insecticides.

    PubMed Central

    Casida, J E

    1980-01-01

    The natural pyrethrins from the daisy-like flower, Tanacetum or Chrysanthemum cinerariifolium, are nonpersistent insecticides of low toxicity to mammals. Synthetic analogs or pyrethroids, evolved from the natural compounds by successive isosteric modifications, are more potent and stable and are the newest important class of crop protection chemicals. They retain many of the favorable properties of the pyrethrins. PMID:6993201

  8. Flowers and Landscape by Serendipity.

    ERIC Educational Resources Information Center

    Pippin, Sandi

    2003-01-01

    Describes an art lesson in which students sketch drawings of flowers and use watercolor paper and other materials to paint a landscape. Explains that the students also learn about impressionism in this lesson. Discusses how the students prepare the paper and create their artwork. (CMK)

  9. Andirolides W-Y from the flower oil of andiroba (Carapa guianensis, Meliaceae).

    PubMed

    Sakamoto, Asami; Tanaka, Yuji; Yamada, Takeshi; Kikuchi, Takashi; Muraoka, Osamu; Ninomiya, Kiyofumi; Morikawa, Toshio; Tanaka, Reiko

    2015-01-01

    Three new limonoids, andirolides W-Y (1-3), were isolated from the flower oil of Carapa guianasis AUBLET (Meliaceae). Their structures were elucidated on the basis of spectroscopic analyses using 1D and 2D NMR spectra and FABMS. Seven known limonoids: 7-deacetoxy-7-oxogedunin (4), 6α-acetoxygedunin (5), methylangolensate (6), 6α-hydroxygedunin (7), 6α-acetoxy-7α-deacetoxy-7α-hydroxygedunin (8), gedunin (9), and 7-deacetoxy-7-hydroxygedunin (10) from this flower oil were evaluated for the effects on the production of NO in LPS-activated mouse peritoneal macrophages. PMID:25200371

  10. Separation and Identification of Phenolic Acid and Flavonoids from Nerium indicum Flowers

    PubMed Central

    Vinayagam, A.; Sudha, P. N.

    2015-01-01

    Four major compounds were separated and identified from the methanol extracts of Nerium indicum flowers (Arali) using HPLC and mass spectral data. Through mass data, the chemical structures were elucidated as: trans5-O-caffeoylquinic acid (1), quercetin-3-O- rutinoside (2), luteolin-5-O-rutinoside (3) and luteolin-7-O-rutinoside (4). In addition, the cis isomers of 5-O-caffeoylquinic acid in Nerium indicum flowers were confirmed by Mass, HPLC and UV. The structures of these compounds confirmed with the help of liquid chromatography mass spectrometry. PMID:25767323

  11. L-band radar scattering from grass

    NASA Technical Reports Server (NTRS)

    Chauhan, N.; O'Neill, P.; Le Vine, D.; Lang, R.; Khadr, N.

    1992-01-01

    A radar system based on a network analyzer has been developed to study the backscatter from vegetation. The radar is operated at L-band. Radar measurements of a grass field were made in 1991. The radar returns from the grass were measured at three incidence angles. Ground truth and canopy parameters such as blade and stem dimensions, moisture content of the grass and the soil, and blade and stem density, were measured. These parameters are used in a distorted Born approximation model to compute the backscatter coefficients from the grass layer. The model results are compared with the radar data.

  12. Developmental changes in the metabolic network of snapdragon flowers.

    PubMed

    Muhlemann, Joëlle K; Maeda, Hiroshi; Chang, Ching-Yun; San Miguel, Phillip; Baxter, Ivan; Cooper, Bruce; Perera, M Ann; Nikolau, Basil J; Vitek, Olga; Morgan, John A; Dudareva, Natalia

    2012-01-01

    Evolutionary and reproductive success of angiosperms, the most diverse group of land plants, relies on visual and olfactory cues for pollinator attraction. Previous work has focused on elucidating the developmental regulation of pathways leading to the formation of pollinator-attracting secondary metabolites such as scent compounds and flower pigments. However, to date little is known about how flowers control their entire metabolic network to achieve the highly regulated production of metabolites attracting pollinators. Integrative analysis of transcripts and metabolites in snapdragon sepals and petals over flower development performed in this study revealed a profound developmental remodeling of gene expression and metabolite profiles in petals, but not in sepals. Genes up-regulated during petal development were enriched in functions related to secondary metabolism, fatty acid catabolism, and amino acid transport, whereas down-regulated genes were enriched in processes involved in cell growth, cell wall formation, and fatty acid biosynthesis. The levels of transcripts and metabolites in pathways leading to scent formation were coordinately up-regulated during petal development, implying transcriptional induction of metabolic pathways preceding scent formation. Developmental gene expression patterns in the pathways involved in scent production were different from those of glycolysis and the pentose phosphate pathway, highlighting distinct developmental regulation of secondary metabolism and primary metabolic pathways feeding into it. PMID:22808147

  13. Checklist of Serengeti Ecosystem Grasses

    PubMed Central

    Ficinski, Paweł; Vorontsova, Maria

    2016-01-01

    Abstract We present the first taxonomic checklist of the Poaceae species of the Serengeti, Tanzania. A review of the literature and herbarium specimens recorded 200 species of grasses, in line with similar studies in other parts of East Africa. The checklist is supported by a total of 939 herbarium collections. Full georeferenced collection data is made available alongside a summary checklist in pdf format. More than a quarter of the species are known from a single collection highlighting the need for further research, especially concerning the rare species and their distribution. PMID:27226761

  14. Checklist of Serengeti Ecosystem Grasses.

    PubMed

    Williams, Emma Victoria; Elia Ntandu, John; Ficinski, Paweł; Vorontsova, Maria

    2016-01-01

    We present the first taxonomic checklist of the Poaceae species of the Serengeti, Tanzania. A review of the literature and herbarium specimens recorded 200 species of grasses, in line with similar studies in other parts of East Africa. The checklist is supported by a total of 939 herbarium collections. Full georeferenced collection data is made available alongside a summary checklist in pdf format. More than a quarter of the species are known from a single collection highlighting the need for further research, especially concerning the rare species and their distribution. PMID:27226761

  15. Active anthocyanin degradation in Brunfelsia calycina (yesterday--today--tomorrow) flowers.

    PubMed

    Vaknin, Hila; Bar-Akiva, Ayelet; Ovadia, Rinat; Nissim-Levi, Ada; Forer, Izhak; Weiss, David; Oren-Shamir, Michal

    2005-09-01

    Anthocyanins are the largest group of plant pigments responsible for colors ranging from red to violet and blue. The biosynthesis of anthocyanins, as part of the larger phenylpropanoid pathway, has been characterized in great detail. In contrast to the detailed molecular knowledge available on anthocyanin synthesis, very little is known about the stability and catabolism of anthocyanins in plants. In this study we present a preliminary characterization of active in planta degradation of anthocyanins, requiring novel mRNA and protein synthesis, in Brunfelsia calycina flowers. Brunfelsia is a unique system for this study, since the decrease in pigment concentration in its flowers (from dark purple to white) is extreme and rapid, and occurs at a specific and well-defined stage of flower development. Treatment of detached flowers with protein and mRNA synthesis inhibitors, at specific stages of flower development, prevented degradation. In addition, treatment of detached flowers with cytokinins delayed senescence without changing the rate of anthocyanin degradation, suggesting that degradation of anthocyanins is not part of the general senescence process of the flowers but rather a distinctive and specific pathway. Based on studies on anthocyanin degradation in wine and juices, peroxidases are reasonable candidates for the in vivo degradation. A significant increase in peroxidase activity was shown to correlate in time with the rate of anthocyanin degradation. An additional indication that oxidative enzymes are involved in the process is the fact that treatment of flowers with reducing agents, such as DTT and glutathione, caused inhibition of degradation. This study represents the first step in the elucidation of the molecular mechanism behind in vivo anthocyanin degradation in plants. PMID:15918029

  16. Pistillate flowers experience more pollen limitation and less geitonogamy than perfect flowers in a gynomonoecious herb.

    PubMed

    Mamut, Jannathan; Xiong, Ying-Ze; Tan, Dun-Yan; Huang, Shuang-Quan

    2014-01-01

    Gynomonoecy, a sexual system in which plants have both pistillate (female) flowers and perfect (hermaphroditic) flowers, occurs in at least 15 families, but the differential reproductive strategies of the two flower morphs within one individual remain unclear. Racemes of Eremurus anisopterus (Xanthorrhoeaceae) have basal pistillate and distal perfect flowers. To compare sex allocation and reproductive success between the two flower morphs, we measured floral traits, pollinator preferences, and pollen movement in the field. Pollen limitation was more severe in pistillate flowers; bee pollinators preferred to visit perfect flowers, which were also capable of partial self-fertilization. Pollen-staining experiments indicated that perfect flowers received a higher proportion of intra-plant pollen (geitonogamy) than pistillate flowers. Plants with greater numbers of pistillate flowers received more outcross pollen. The differential reproductive success conformed with differential floral sex allocation, in which pistillate flowers produce fewer but larger ovules, resulting in outcrossed seeds. Our flower manipulations in these nectarless gynomonoecious plants demonstrated that perfect flowers promote seed quantity in that they are more attractive to pollinators, while pistillate flowers compensate for the loss of male function through better seed quality. These results are consistent with the outcrossing-benefit hypothesis for gynomonoecy. PMID:24111788

  17. Fruit load modulates flowering-related gene expression in buds of alternate-bearing ‘Moncada’ mandarin

    PubMed Central

    Muñoz-Fambuena, Natalia; Mesejo, Carlos; González-Mas, M. Carmen; Primo-Millo, Eduardo; Agustí, Manuel; Iglesias, Domingo J.

    2012-01-01

    Background and Aims Gene determination of flowering is the result of complex interactions involving both promoters and inhibitors. In this study, the expression of flowering-related genes at the meristem level in alternate-bearing citrus trees is analysed, together with the interplay between buds and leaves in the determination of flowering. Methods First defruiting experiments were performed to manipulate blossoming intensity in ‘Moncada’ mandarin, Citrus clementina. Further defoliation was performed to elucidate the role leaves play in the flowering process. In both cases, the activity of flowering-related genes was investigated at the flower induction (November) and differentiation (February) stages. Key Results Study of the expression pattern of flowering-genes in buds from on (fully loaded) and off (without fruits) trees revealed that homologues of FLOWERING LOCUS T (CiFT), TWIN SISTER OF FT (TSF), APETALA1 (CsAP1) and LEAFY (CsLFY) were negatively affected by fruit load. CiFT and TSF activities showed a marked increase in buds from off trees through the study period (ten-fold in November). By contrast, expression of the homologues of the flowering inhibitors of TERMINAL FLOWER 1 (CsTFL), TERMINAL FLOWER 2 (TFL2) and FLOWERING LOCUS C (FLC) was generally lower in off trees. Regarding floral identity genes, the increase in CsAP1 expression in off trees was much greater in buds than in leaves, and significant variations in CsLFY expression (approx. 20 %) were found only in February. Defoliation experiments further revealed that the absence of leaves completely abolished blossoming and severely affected the expression of most of the flowering-related genes, particularly decreasing the activity of floral promoters and of CsAP1 at the induction stage. Conclusions These results suggest that the presence of fruit affects flowering by greatly altering gene-expression not only at the leaf but also at the meristem level. Although leaves are required for flowering to

  18. Unique aspects of the grass cell wall

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grasses are amongst the most important crops worldwide, and the composition of their cell walls is critical for uses as food, feed, and energy crops. Grass cell walls differ dramatically from dicot cell walls in terms of the major structural polysaccharides present, how those polysaccharides are lin...

  19. Enhancing GRASS data communication with videographic technology

    SciTech Connect

    Sullivan, R.G. ); Gerdes, D.; Youngs, D. )

    1992-01-01

    Research at Argonne National Laboratory and the US Army Construction Engineering Research Laboratory has shown that computer videographic technology can be used to assist visualization and communication of GIS-generated geographic information. Videographic tools can be used to make results of GRASS analyses clear to decision-makers and to public interest groups, as well as to help GRASS users visualize geographic data more easily. Useful videographic visualization tools include graphic overlay of GRASS layers onto panchromatic images, allowing landscape features to be associated with GIS classifications; draping of GIS layers onto terrain models to create shaded relief maps; and incorporation of photographic imagery into GIS graphics. Useful videographic communications capabilities include convenient, direct interface to video formats, allowing incorporation of live video into GRASS graphics and output of GRASS graphics to video; convenient output of high-quality slides and prints; and enhanced labeling and editing of GRASS images. Conversion of GRASS imagery to standard videographic file formats also facilitates incorporation of GRASS images into other software programs, such as database and work-processing packages.

  20. Enhancing GRASS data communication with videographic technology

    SciTech Connect

    Sullivan, R.G.; Gerdes, D.; Youngs, D.

    1992-07-01

    Research at Argonne National Laboratory and the US Army Construction Engineering Research Laboratory has shown that computer videographic technology can be used to assist visualization and communication of GIS-generated geographic information. Videographic tools can be used to make results of GRASS analyses clear to decision-makers and to public interest groups, as well as to help GRASS users visualize geographic data more easily. Useful videographic visualization tools include graphic overlay of GRASS layers onto panchromatic images, allowing landscape features to be associated with GIS classifications; draping of GIS layers onto terrain models to create shaded relief maps; and incorporation of photographic imagery into GIS graphics. Useful videographic communications capabilities include convenient, direct interface to video formats, allowing incorporation of live video into GRASS graphics and output of GRASS graphics to video; convenient output of high-quality slides and prints; and enhanced labeling and editing of GRASS images. Conversion of GRASS imagery to standard videographic file formats also facilitates incorporation of GRASS images into other software programs, such as database and work-processing packages.

  1. Exploiting the Potential Differences in Pasture Grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Temperate grasses grown for pasture in Wisconsin exhibit a range of chemical and physical characteristics that influence their utilization by grazing cattle. Potential intake of all grasses declines with maturity due to decreasing cell wall digestiblity, but the leaves and stems of orchardgrass and...

  2. A Walk in the "Tall, Tall Grass"

    ERIC Educational Resources Information Center

    Kaatz, Kathryn

    2008-01-01

    This inquiry-based lesson was inspired by Denise Fleming's book entitled, "In the Tall, Tall Grass" (1991). The author used the book and a real study of prairie grasses to teach kindergartners how to make careful observations and record what they see. In addition, they learn how to "draw as scientists." Here the author describes her class's yearly…

  3. The Endophytic Niche and Grass Defense

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Much research has been done on the interactive nature of the tall fescue grass and its fungal partner. This research has established that this very valuable forage, turf and conservation grass, which occupies 30 million plus acres in the south-eastern USA, is toxic to most livestock and wild animal...

  4. Effects of flowering phenology and synchrony on the reproductive success of a long-flowering shrub.

    PubMed

    Rodríguez-Pérez, Javier; Traveset, Anna

    2016-01-01

    Flowering phenology and synchrony with biotic and abiotic resources are crucial traits determining the reproductive success in insect-pollinated plants. In seasonal climates, plants flowering for long periods should assure reproductive success when resources are more predictable. In this work, we evaluated the relationship between flowering phenology and synchrony and reproductive success in Hypericum balearicum, a shrub flowering all year round but mainly during spring and summer. We studied two contrasting localities (differing mostly in rainfall) during 3 years, and at different biological scales spanning from localities to individual flowers and fruits. We first monitored (monthly) flowering phenology and reproductive success (fruit and seed set) of plants, and assessed whether in the locality with higher rainfall plants had longer flowering phenology and synchrony and relatively higher reproductive success within or outside the flowering peak. Secondly, we censused pollinators on H. balearicum individuals and measured reproductive success along the flowering peak of each locality to test for an association between (i) richness and abundance of pollinators and (ii) fruit and seed set, and seed weight. We found that most flowers (∼90 %) and the highest fruit set (∼70 %) were produced during the flowering peak of each locality. Contrary to expectations, plants in the locality with lower rainfall showed more relaxed flowering phenology and synchrony and set more fruits outside the flowering peak. During the flowering peak of each locality, the reproductive success of early-flowering individuals depended on a combination of both pollinator richness and abundance and rainfall; by contrast, reproductive success of late-flowering individuals was most dependent on rainfall. Plant species flowering for long periods in seasonal climates, thus, appear to be ideal organisms to understand how flowering phenology and synchrony match with biotic and abiotic resources, and

  5. Effects of flowering phenology and synchrony on the reproductive success of a long-flowering shrub

    PubMed Central

    Rodríguez-Pérez, Javier; Traveset, Anna

    2016-01-01

    Flowering phenology and synchrony with biotic and abiotic resources are crucial traits determining the reproductive success in insect-pollinated plants. In seasonal climates, plants flowering for long periods should assure reproductive success when resources are more predictable. In this work, we evaluated the relationship between flowering phenology and synchrony and reproductive success in Hypericum balearicum, a shrub flowering all year round but mainly during spring and summer. We studied two contrasting localities (differing mostly in rainfall) during 3 years, and at different biological scales spanning from localities to individual flowers and fruits. We first monitored (monthly) flowering phenology and reproductive success (fruit and seed set) of plants, and assessed whether in the locality with higher rainfall plants had longer flowering phenology and synchrony and relatively higher reproductive success within or outside the flowering peak. Secondly, we censused pollinators on H. balearicum individuals and measured reproductive success along the flowering peak of each locality to test for an association between (i) richness and abundance of pollinators and (ii) fruit and seed set, and seed weight. We found that most flowers (∼90 %) and the highest fruit set (∼70 %) were produced during the flowering peak of each locality. Contrary to expectations, plants in the locality with lower rainfall showed more relaxed flowering phenology and synchrony and set more fruits outside the flowering peak. During the flowering peak of each locality, the reproductive success of early-flowering individuals depended on a combination of both pollinator richness and abundance and rainfall; by contrast, reproductive success of late-flowering individuals was most dependent on rainfall. Plant species flowering for long periods in seasonal climates, thus, appear to be ideal organisms to understand how flowering phenology and synchrony match with biotic and abiotic resources, and

  6. Early flower development in Arabidopsis.

    PubMed Central

    Smyth, D R; Bowman, J L; Meyerowitz, E M

    1990-01-01

    The early development of the flower of Arabidopsis thaliana is described from initiation until the opening of the bud. The morphogenesis, growth rate, and surface structure of floral organs were recorded in detail using scanning electron microscopy. Flower development has been divided into 12 stages using a series of landmark events. Stage 1 begins with the initiation of a floral buttress on the flank of the apical meristem. Stage 2 commences when the flower primordium becomes separate from the meristem. Sepal primordia then arise (stage 3) and grow to overlie the primordium (stage 4). Petal and stamen primordia appear next (stage 5) and are soon enclosed by the sepals (stage 6). During stage 6, petal primordia grow slowly, whereas stamen primordia enlarge more rapidly. Stage 7 begins when the medial stamens become stalked. These soon develop locules (stage 8). A long stage 9 then commences with the petal primordia becoming stalked. During this stage all organs lengthen rapidly. This includes the gynoecium, which commences growth as an open-ended tube during stage 6. When the petals reach the length of the lateral stamens, stage 10 begins. Stigmatic papillae appear soon after (stage 11), and the petals rapidly reach the height of the medial stamens (stage 12). This final stage ends when the 1-millimeter-long bud opens. Under our growing conditions 1.9 buds were initiated per day on average, and they took 13.25 days to progress through the 12 stages from initiation until opening. PMID:2152125

  7. One New Conjugate of a Secoiridoid Glucoside with a Sesquiterpene Glucoside from the Flower Buds of Lonicera japonica.

    PubMed

    Yang, Biao; Meng, Zhaoqing; Ma, Yimin; Wang, Zhenzhong; Ding, Gang; Huang, Wenzhe; Sun, Lin; Hu, Yumei; Liu, Wenjun; Zhang, Chunxiao; Cao, Zeyu; Li, Jiachun; Zhong, Yan; Xiao, Wei

    2015-09-01

    Secosesquside (1), a new secoiridoid glucoside-sesquiterpene conjugate, together with three known secoiridoid derivatives, were isolated from flower buds of Lonicerajaponica. The isolated compounds were elucidated by extensive spectroscopic analyses, especially 2D NMR experiments. The anti-inflammatory activities of the new compound were also evaluated by enzyme-linked immunosorbent assay. PMID:26594743

  8. Senescence, dormancy and tillering in perennial C4 grasses.

    PubMed

    Sarath, Gautam; Baird, Lisa M; Mitchell, Robert B

    2014-03-01

    Perennial, temperate, C4 grasses, such as switchgrass and miscanthus have been tabbed as sources of herbaceous biomass for the production of green fuels and chemicals based on a number of positive agronomic traits. Although there is important literature on the management of these species for biomass production on marginal lands, numerous aspects of their biology are as yet unexplored at the molecular level. Perenniality, a key agronomic trait, is a function of plant dormancy and winter survival of the below-ground parts of the plants. These include the crowns, rhizomes and meristems that will produce tillers. Maintaining meristem viability is critical for the continued survival of the plants. Plant tillers emerge from the dormant crown and rhizome meristems at the start of the growing period in the spring, progress through a phase of vegetative growth, followed by flowering and eventually undergo senescence. There is nutrient mobilization from the aerial portions of the plant to the crowns and rhizomes during tiller senescence. Signals arising from the shoots and from the environment can be expected to be integrated as the plants enter into dormancy. Plant senescence and dormancy have been well studied in several dicot species and offer a potential framework to understand these processes in temperate C4 perennial grasses. The availability of latitudinally adapted populations for switchgrass presents an opportunity to dissect molecular mechanisms that can impact senescence, dormancy and winter survival. Given the large increase in genomic and other resources for switchgrass, it is anticipated that projected molecular studies with switchgrass will have a broader impact on related species. PMID:24467906

  9. Male flowers are better fathers than hermaphroditic flowers in andromonoecious Passiflora incarnata.

    PubMed

    Dai, Can; Galloway, Laura F

    2012-02-01

    • The diversity of plant breeding systems provides the opportunity to study a range of potential reproductive adaptations. Many mechanisms remain poorly understood, among them the evolution and maintenance of male flowers in andromonoecy. Here, we studied the role of morphologically male flowers ('male morph') in andromonoecious Passiflora incarnata. • We measured morphological differences between hermaphroditic and male morph flowers in P. incarnata and explored the fruiting and siring ability of both flower types. • Male morph flowers in P. incarnata were of similar size to hermaphroditic flowers, and there was little evidence of different resource allocation to the two flower types. Male morph flowers were less capable of producing fruit, even under ample pollen and resource conditions. By contrast, male morph flowers were more successful in siring seeds. On average, male morph flowers sired twice as many seeds as hermaphroditic flowers. This difference in male fitness was driven by higher pollen export from male morph flowers as a result of greater pollen production and less self-pollen deposition. • The production of male morph flowers in P. incarnata appears to be a flexible adaptive mechanism to enhance male fitness, which might be especially beneficial when plants face temporary resource shortages for nurturing additional fruits. PMID:22122433

  10. Flower size and longevity influence florivory in the large-flowered shrub Cistus ladanifer

    NASA Astrophysics Data System (ADS)

    Teixido, Alberto L.; Méndez, Marcos; Valladares, Fernando

    2011-09-01

    Plants with larger and longer-lived flowers receive more pollinator visits and increase reproductive success, though may also suffer more from antagonistic interactions with animals. Florivores can reduce fruit and seed production, so selection on flower size, floral longevity and/or number of flowers may thus be determined by the relative effects of both pollinators and florivores. In this study flowers of Cistus ladanifer, a large-flowered Mediterranean shrub, were monitored to evaluate the effects of flower size, floral longevity and number of flowers on levels of florivory in four populations. Number of flowers was variable but did not differ among populations. Both flower size and floral longevity of C. ladanifer showed broad variation and significantly differed among populations. Overall, 7% of flowers suffered attack by florivores, which were mainly ants picking the stamens and beetles consuming petals and pollen. Within-populations, larger and longer-lived flowers tended to be affected by florivores more frequently. The low overall incidence of florivores and its lack of between-population variation suggest that florivory may not influence intraspecific variation of these floral traits. However, moderate florivory levels on the largest and longest-lived flowers open the possibility of exerting selection towards smaller and shorter-lived flowers in some of the populations studied.

  11. Flower, fruit phenology and flower traits in Cordia boissieri (Boraginaceae) from northeastern Mexico.

    PubMed

    Martínez-Adriano, Cristian Adrian; Jurado, Enrique; Flores, Joel; González-Rodríguez, Humberto; Cuéllar-Rodríguez, Gerardo

    2016-01-01

    We characterized variations in Cordia boissieri flowers and established if these variations occur between plants or between flowering events. Flowering and fruiting was measured for 256 plants. A GLM test was used to determine the relationship between flowering and fruit set processes and rainfall. We performed measurements of floral traits to detect variations within the population and between flowering events. The position of the anthers with respect to the ovary was determined in 1,500 flowers. Three out of four flowering events of >80% C. boissieri plants occurred after rainfall events. Only one flowering event occurred in a drought. Most plants flowered at least twice a year. The overlapping of flowering and fruiting only occurred after rainfall. Anthesis lasted three-to-five days, and there were two flower morphs. Half of the plants had longistylus and half had brevistylus flowers. Anacahuita flower in our study had 1-4 styles; 2-9 stamens; 6.5-41.5 mm long corolla; sepals from 4.5-29.5 mm in length; a total length from 15.5-59 mm; a corolla diameter from 10.5-77 mm. The nectar guide had a diameter from 5-30.5 mm; 4-9 lobes; and 5 distinguishable nectar guide colors. The highest variation of phenotypic expression was observed between plants. PMID:27231656

  12. Flower, fruit phenology and flower traits in Cordia boissieri (Boraginaceae) from northeastern Mexico

    PubMed Central

    Martínez-Adriano, Cristian Adrian; Flores, Joel; González-Rodríguez, Humberto; Cuéllar-Rodríguez, Gerardo

    2016-01-01

    We characterized variations in Cordia boissieri flowers and established if these variations occur between plants or between flowering events. Flowering and fruiting was measured for 256 plants. A GLM test was used to determine the relationship between flowering and fruit set processes and rainfall. We performed measurements of floral traits to detect variations within the population and between flowering events. The position of the anthers with respect to the ovary was determined in 1,500 flowers. Three out of four flowering events of >80% C. boissieri plants occurred after rainfall events. Only one flowering event occurred in a drought. Most plants flowered at least twice a year. The overlapping of flowering and fruiting only occurred after rainfall. Anthesis lasted three-to-five days, and there were two flower morphs. Half of the plants had longistylus and half had brevistylus flowers. Anacahuita flower in our study had 1–4 styles; 2–9 stamens; 6.5–41.5 mm long corolla; sepals from 4.5–29.5 mm in length; a total length from 15.5–59 mm; a corolla diameter from 10.5–77 mm. The nectar guide had a diameter from 5–30.5 mm; 4–9 lobes; and 5 distinguishable nectar guide colors. The highest variation of phenotypic expression was observed between plants. PMID:27231656

  13. EARLY FLOWERING3 Regulates Flowering in Spring Barley by Mediating Gibberellin Production and FLOWERING LOCUS T Expression[C][W

    PubMed Central

    Boden, Scott A.; Weiss, David; Ross, John J.; Davies, Noel W.; Trevaskis, Ben; Chandler, Peter M.; Swain, Steve M.

    2014-01-01

    EARLY FLOWERING3 (ELF3) is a circadian clock gene that contributes to photoperiod-dependent flowering in plants, with loss-of-function mutants in barley (Hordeum vulgare), legumes, and Arabidopsis thaliana flowering early under noninductive short-day (SD) photoperiods. The barley elf3 mutant displays increased expression of FLOWERING LOCUS T1 (FT1); however, it remains unclear whether this is the only factor responsible for the early flowering phenotype. We show that the early flowering and vegetative growth phenotypes of the barley elf3 mutant are strongly dependent on gibberellin (GA) biosynthesis. Expression of the central GA biosynthesis gene, GA20oxidase2, and production of the bioactive GA, GA1, were significantly increased in elf3 leaves under SDs, relative to the wild type. Inhibition of GA biosynthesis suppressed the early flowering of elf3 under SDs independently of FT1 and was associated with altered expression of floral identity genes at the developing apex. GA is also required for normal flowering of spring barley under inductive photoperiods, with chemical and genetic attenuation of the GA biosynthesis and signaling pathways suppressing inflorescence development under long-day conditions. These findings illustrate that GA is an important floral promoting signal in barley and that ELF3 suppresses flowering under noninductive photoperiods by blocking GA production and FT1 expression. PMID:24781117

  14. The gated induction system of a systemic floral inhibitor, antiflorigen, determines obligate short-day flowering in chrysanthemums.

    PubMed

    Higuchi, Yohei; Narumi, Takako; Oda, Atsushi; Nakano, Yoshihiro; Sumitomo, Katsuhiko; Fukai, Seiichi; Hisamatsu, Tamotsu

    2013-10-15

    Photoperiodic floral induction has had a significant impact on the agricultural and horticultural industries. Changes in day length are perceived in leaves, which synthesize systemic flowering inducers (florigens) and inhibitors (antiflorigens) that determine floral initiation at the shoot apex. Recently, FLOWERING LOCUS T (FT) was found to be a florigen; however, the identity of the corresponding antiflorigen remains to be elucidated. Here, we report the identification of an antiflorigen gene, Anti-florigenic FT/TFL1 family protein (AFT), from a wild chrysanthemum (Chrysanthemum seticuspe) whose expression is mainly induced in leaves under noninductive conditions. Gain- and loss-of-function analyses demonstrated that CsAFT acts systemically to inhibit flowering and plays a predominant role in the obligate photoperiodic response. A transient gene expression assay indicated that CsAFT inhibits flowering by directly antagonizing the flower-inductive activity of CsFTL3, a C. seticuspe ortholog of FT, through interaction with CsFDL1, a basic leucine zipper (bZIP) transcription factor FD homolog of Arabidopsis. Induction of CsAFT was triggered by the coincidence of phytochrome signals with the photosensitive phase set by the dusk signal; flowering occurred only when night length exceeded the photosensitive phase for CsAFT induction. Thus, the gated antiflorigen production system, a phytochrome-mediated response to light, determines obligate photoperiodic flowering response in chrysanthemums, which enables their year-round commercial production by artificial lighting. PMID:24082137

  15. The gated induction system of a systemic floral inhibitor, antiflorigen, determines obligate short-day flowering in chrysanthemums

    PubMed Central

    Higuchi, Yohei; Narumi, Takako; Oda, Atsushi; Nakano, Yoshihiro; Sumitomo, Katsuhiko; Fukai, Seiichi; Hisamatsu, Tamotsu

    2013-01-01

    Photoperiodic floral induction has had a significant impact on the agricultural and horticultural industries. Changes in day length are perceived in leaves, which synthesize systemic flowering inducers (florigens) and inhibitors (antiflorigens) that determine floral initiation at the shoot apex. Recently, FLOWERING LOCUS T (FT) was found to be a florigen; however, the identity of the corresponding antiflorigen remains to be elucidated. Here, we report the identification of an antiflorigen gene, Anti-florigenic FT/TFL1 family protein (AFT), from a wild chrysanthemum (Chrysanthemum seticuspe) whose expression is mainly induced in leaves under noninductive conditions. Gain- and loss-of-function analyses demonstrated that CsAFT acts systemically to inhibit flowering and plays a predominant role in the obligate photoperiodic response. A transient gene expression assay indicated that CsAFT inhibits flowering by directly antagonizing the flower-inductive activity of CsFTL3, a C. seticuspe ortholog of FT, through interaction with CsFDL1, a basic leucine zipper (bZIP) transcription factor FD homolog of Arabidopsis. Induction of CsAFT was triggered by the coincidence of phytochrome signals with the photosensitive phase set by the dusk signal; flowering occurred only when night length exceeded the photosensitive phase for CsAFT induction. Thus, the gated antiflorigen production system, a phytochrome-mediated response to light, determines obligate photoperiodic flowering response in chrysanthemums, which enables their year-round commercial production by artificial lighting. PMID:24082137

  16. Tropical grasses as a renewable energy source

    SciTech Connect

    Samuels, G.; Alexander, A.G.; Rios, C.; Garcia, M.

    1983-01-01

    Agronomists, evaluating tropical grasses from Saccharum and allied genera as potential renewable energy sources for boiler fuel and alcohol, emphasized (1) maximizing sugar cane's total biomass rather than sucrose production, (2) utilizing alternative tropical grasses during sugar cane's offseason for year-round fuel production, and (3) mechanizing production technologies for fibrous, thin-stemmed tropical grasses that are to be managed as solar-dried fuels and feedstocks. Based on the time required to maximize their dry matter yields, three categories of grasses have emerged as potential energy crops: short rotation (2-3 months) with Sordan 70A (a sorghum/sudan grass hybrid), intermediate rotation (4-6 months) with napier grass, and long rotation (12-18 months) with sugar cane. Total oven-dried matter is 50 tons/acre-yr (114 metric tons /hectare-yr) for sugar cane, 33 tons (74 metric tons) from napier grass harvested at 6-month intervals, and 21 tons (47 metric tons) from Sordan 70A harvested every 14 weeks.

  17. Comprehensive analysis of the flowering genes in Chinese cabbage and examination of evolutionary pattern of CO-like genes in plant kingdom

    NASA Astrophysics Data System (ADS)

    Song, Xiaoming; Duan, Weike; Huang, Zhinan; Liu, Gaofeng; Wu, Peng; Liu, Tongkun; Li, Ying; Hou, Xilin

    2015-09-01

    In plants, flowering is the most important transition from vegetative to reproductive growth. The flowering patterns of monocots and eudicots are distinctly different, but few studies have described the evolutionary patterns of the flowering genes in them. In this study, we analysed the evolutionary pattern, duplication and expression level of these genes. The main results were as follows: (i) characterization of flowering genes in monocots and eudicots, including the identification of family-specific, orthologous and collinear genes; (ii) full characterization of CONSTANS-like genes in Brassica rapa (BraCOL genes), the key flowering genes; (iii) exploration of the evolution of COL genes in plant kingdom and construction of the evolutionary pattern of COL genes; (iv) comparative analysis of CO and FT genes between Brassicaceae and Grass, which identified several family-specific amino acids, and revealed that CO and FT protein structures were similar in B. rapa and Arabidopsis but different in rice; and (v) expression analysis of photoperiod pathway-related genes in B. rapa under different photoperiod treatments by RT-qPCR. This analysis will provide resources for understanding the flowering mechanisms and evolutionary pattern of COL genes. In addition, this genome-wide comparative study of COL genes may also provide clues for evolution of other flowering genes.

  18. Comprehensive analysis of the flowering genes in Chinese cabbage and examination of evolutionary pattern of CO-like genes in plant kingdom.

    PubMed

    Song, Xiaoming; Duan, Weike; Huang, Zhinan; Liu, Gaofeng; Wu, Peng; Liu, Tongkun; Li, Ying; Hou, Xilin

    2015-01-01

    In plants, flowering is the most important transition from vegetative to reproductive growth. The flowering patterns of monocots and eudicots are distinctly different, but few studies have described the evolutionary patterns of the flowering genes in them. In this study, we analysed the evolutionary pattern, duplication and expression level of these genes. The main results were as follows: (i) characterization of flowering genes in monocots and eudicots, including the identification of family-specific, orthologous and collinear genes; (ii) full characterization of CONSTANS-like genes in Brassica rapa (BraCOL genes), the key flowering genes; (iii) exploration of the evolution of COL genes in plant kingdom and construction of the evolutionary pattern of COL genes; (iv) comparative analysis of CO and FT genes between Brassicaceae and Grass, which identified several family-specific amino acids, and revealed that CO and FT protein structures were similar in B. rapa and Arabidopsis but different in rice; and (v) expression analysis of photoperiod pathway-related genes in B. rapa under different photoperiod treatments by RT-qPCR. This analysis will provide resources for understanding the flowering mechanisms and evolutionary pattern of COL genes. In addition, this genome-wide comparative study of COL genes may also provide clues for evolution of other flowering genes. PMID:26416765

  19. Comprehensive analysis of the flowering genes in Chinese cabbage and examination of evolutionary pattern of CO-like genes in plant kingdom

    PubMed Central

    Song, Xiaoming; Duan, Weike; Huang, Zhinan; Liu, Gaofeng; Wu, Peng; Liu, Tongkun; Li, Ying; Hou, Xilin

    2015-01-01

    In plants, flowering is the most important transition from vegetative to reproductive growth. The flowering patterns of monocots and eudicots are distinctly different, but few studies have described the evolutionary patterns of the flowering genes in them. In this study, we analysed the evolutionary pattern, duplication and expression level of these genes. The main results were as follows: (i) characterization of flowering genes in monocots and eudicots, including the identification of family-specific, orthologous and collinear genes; (ii) full characterization of CONSTANS-like genes in Brassica rapa (BraCOL genes), the key flowering genes; (iii) exploration of the evolution of COL genes in plant kingdom and construction of the evolutionary pattern of COL genes; (iv) comparative analysis of CO and FT genes between Brassicaceae and Grass, which identified several family-specific amino acids, and revealed that CO and FT protein structures were similar in B. rapa and Arabidopsis but different in rice; and (v) expression analysis of photoperiod pathway-related genes in B. rapa under different photoperiod treatments by RT-qPCR. This analysis will provide resources for understanding the flowering mechanisms and evolutionary pattern of COL genes. In addition, this genome-wide comparative study of COL genes may also provide clues for evolution of other flowering genes. PMID:26416765

  20. New 3,4-seco-Grayanane Diterpenoids from the Flowers of Pieris japonica.

    PubMed

    Cao, Lang; Li, Yanping; Li, Hongmei; Liu, Dan; Li, Rongtao

    2016-01-01

    Three new 3,4-seco-grayanane diterpenoids, neopierisoids D-F (2-4), and a new natural one, neopierisoid C (1), were isolated from the flowers of Pieris japonica. Their structures were elucidated on the basis of extensive spectroscopic analysis, including one and two dimensional (1- and 2D)-NMR, as well as high resolution-electron ionization (HR-EI)-MS. PMID:27477663

  1. A new highly oxygenated daphnane diterpene esters from the flower buds of Daphne genkwa.

    PubMed

    Jiang, Hai-Long; Wang, Rui; Li, Jian-Yong; Shi, Yan-Ping

    2015-01-01

    The phytochemical investigation of the flower buds of Daphne genkwa yielded eight highly oxygenated daphnane-type diterpene esters, including a new one, genkwanine N 20-palmitate (1) and seven known ones (2-8). The molecular structures of the isolated compounds were elucidated on the basis of extensive spectroscopic analysis, including UV, IR, NMR, and MS, and comparison with literature data. Furthermore, compound 1 showed potential cytotoxic activity in vitro, against A549 and Hep G2 tumour cell lines. PMID:25674674

  2. [Pathways of flowering regulation in plants].

    PubMed

    Liu, Yongping; Yang, Jing; Yang, Mingfeng

    2015-11-01

    Flowering, the floral transition from vegetative growth to reproductive growth, is induced by diverse endogenous and exogenous cues, such as photoperiod, temperature, hormones and age. Precise flowering time is critical to plant growth and evolution of species. The numerous renewal molecular and genetic results have revealed five flowering time pathways, including classical photoperiod pathway, vernalization pathway, autonomous pathway, gibberellins (GA) pathway and newly identified age pathway. These pathways take on relatively independent role, and involve extensive crosstalks and feedback loops. This review describes the complicated regulatory network of this floral transition to understand the molecular mechanism of flowering and provide references for further research in more plants. PMID:26939439

  3. Ploidy analysis of azalea flower colour sports.

    PubMed

    De Schepper, S; De Loose, M; Van Bockstaele, E; Debergh, P

    2001-01-01

    Flower colour variegation is not only a phenomenon of importance to horticulture, the phenotype involved is also often used as a scientific model system for the study of complex gene regulation processes. In the course of such studies on azalea, we observed a correlation between flower colour patterns, flower morphology and somatic polyploidy. Using high-resolution flow cytometry of nuclear DNA, the ploidy level was determined in flowers of different azalea sport families. Sports exhibiting variegated flowers with broad (> 7mm), differently coloured, petal edges (picotee type) proved to be tetraploid in the petal edge while diploid in the rest of the flower tissue. Neither flower colour pattern nor ploidy differences are chimeral in origin, but seem to be correlated with the topographic location of the cells within the flower tissue, i.e. the margin of the petals. The possible role of gene dosage effects and cell size involved in the remarkable correlation between somatic polyploidy, (flavonoid) gene expression and the flower morphology is discussed. PMID:15954634

  4. Genome sequence analysis of the model grass Brachypodium distachyon: insights into grass genome evolution

    SciTech Connect

    Schulman, Al

    2009-08-09

    Three subfamilies of grasses, the Erhardtoideae (rice), the Panicoideae (maize, sorghum, sugar cane and millet), and the Pooideae (wheat, barley and cool season forage grasses) provide the basis of human nutrition and are poised to become major sources of renewable energy. Here we describe the complete genome sequence of the wild grass Brachypodium distachyon (Brachypodium), the first member of the Pooideae subfamily to be completely sequenced. Comparison of the Brachypodium, rice and sorghum genomes reveals a precise sequence- based history of genome evolution across a broad diversity of the grass family and identifies nested insertions of whole chromosomes into centromeric regions as a predominant mechanism driving chromosome evolution in the grasses. The relatively compact genome of Brachypodium is maintained by a balance of retroelement replication and loss. The complete genome sequence of Brachypodium, coupled to its exceptional promise as a model system for grass research, will support the development of new energy and food crops

  5. North Dakota ''Flower Power'' project

    SciTech Connect

    Walter, J.; Aakre, P.; Derry, J.

    1982-05-01

    Flower Power Inc. was set up to study the long term effects of blends of sunflower oil and diesel fuel on engine components. Tests to date have indicated that farm diesel tractors can be operated on blends of up to 50% sunflower oil and diesel fuel but that its continued use would appear to cause premature engine problems. While the results of the tests are encouraging, use of sunflower oil as a fuel is not yet recommended. Continued long term testing is needed to evaluate the performance of sunflower oil-diesel blends.

  6. PHYTOCHROME C plays a major role in the acceleration of wheat flowering under long-day photoperiod

    PubMed Central

    Chen, Andrew; Li, Chengxia; Hu, Wei; Lau, Mei Yee; Lin, Huiqiong; Rockwell, Nathan C.; Martin, Shelley S.; Jernstedt, Judith A.; Lagarias, J. Clark; Dubcovsky, Jorge

    2014-01-01

    Phytochromes are dimeric proteins that function as red and far-red light sensors influencing nearly every phase of the plant life cycle. Of the three major phytochrome families found in flowering plants, PHYTOCHROME C (PHYC) is the least understood. In Arabidopsis and rice, PHYC is unstable and functionally inactive unless it heterodimerizes with another phytochrome. However, when expressed in an Arabidopsis phy-null mutant, wheat PHYC forms signaling active homodimers that translocate into the nucleus in red light to mediate photomorphogenic responses. Tetraploid wheat plants homozygous for loss-of-function mutations in all PHYC copies (phyCAB) flower on average 108 d later than wild-type plants under long days but only 19 d later under short days, indicating a strong interaction between PHYC and photoperiod. This interaction is further supported by the drastic down-regulation in the phyCAB mutant of the central photoperiod gene PHOTOPERIOD 1 (PPD1) and its downstream target FLOWERING LOCUS T1, which are required for the promotion of flowering under long days. These results implicate light-dependent, PHYC-mediated activation of PPD1 expression in the acceleration of wheat flowering under inductive long days. Plants homozygous for the phyCAB mutations also show altered profiles of circadian clock and clock-output genes, which may also contribute to the observed differences in heading time. Our results highlight important differences in the photoperiod pathways of the temperate grasses with those of well-studied model plant species. PMID:24961368

  7. Development and Genetic Control of Plant Architecture and Biomass in the Panicoid Grass, Setaria

    PubMed Central

    Mauro-Herrera, Margarita; Doust, Andrew N.

    2016-01-01

    The architecture of a plant affects its ability to compete for light and to respond to environmental stresses, thus affecting overall fitness and productivity. Two components of architecture, branching and height, were studied in 182 F7 recombinant inbred lines (RILs) at the vegetative, flowering and mature developmental stages in the panicoid C4 model grass system, Setaria. The RIL population was derived from a cross between domesticated S. italica (foxtail millet) and its wild relative S. viridis (green foxtail). In both field and greenhouse trials the wild parent was taller initially, started branching earlier, and flowered earlier, while the domesticated parent was shorter initially, but flowered later, producing a robust tall plant architecture with more nodes and leaves on the main culm and few or no branches. Biomass was highly correlated with height of the plant and number of nodes on the main culm, and generally showed a negative relationship with branch number. However, several of the RILs with the highest biomass in both trials were significantly more branched than the domesticated parent of the cross. Quantitative trait loci (QTL) analyses indicate that both height and branching are controlled by multiple genetic regions, often with QTL for both traits colocalizing in the same genomic regions. Genomic positions of several QTL colocalize with QTL in syntenic regions in other species and contain genes known to control branching and height in sorghum, maize, and switchgrass. Included in these is the ortholog of the rice SD-1 semi-dwarfing gene, which underlies one of the major Setaria height QTL. Understanding the relationships between height and branching patterns in Setaria, and their genetic control, is an important step to gaining a comprehensive knowledge of the development and genetic regulation of panicoid grass architecture. PMID:26985990

  8. Development and Genetic Control of Plant Architecture and Biomass in the Panicoid Grass, Setaria.

    PubMed

    Mauro-Herrera, Margarita; Doust, Andrew N

    2016-01-01

    The architecture of a plant affects its ability to compete for light and to respond to environmental stresses, thus affecting overall fitness and productivity. Two components of architecture, branching and height, were studied in 182 F7 recombinant inbred lines (RILs) at the vegetative, flowering and mature developmental stages in the panicoid C4 model grass system, Setaria. The RIL population was derived from a cross between domesticated S. italica (foxtail millet) and its wild relative S. viridis (green foxtail). In both field and greenhouse trials the wild parent was taller initially, started branching earlier, and flowered earlier, while the domesticated parent was shorter initially, but flowered later, producing a robust tall plant architecture with more nodes and leaves on the main culm and few or no branches. Biomass was highly correlated with height of the plant and number of nodes on the main culm, and generally showed a negative relationship with branch number. However, several of the RILs with the highest biomass in both trials were significantly more branched than the domesticated parent of the cross. Quantitative trait loci (QTL) analyses indicate that both height and branching are controlled by multiple genetic regions, often with QTL for both traits colocalizing in the same genomic regions. Genomic positions of several QTL colocalize with QTL in syntenic regions in other species and contain genes known to control branching and height in sorghum, maize, and switchgrass. Included in these is the ortholog of the rice SD-1 semi-dwarfing gene, which underlies one of the major Setaria height QTL. Understanding the relationships between height and branching patterns in Setaria, and their genetic control, is an important step to gaining a comprehensive knowledge of the development and genetic regulation of panicoid grass architecture. PMID:26985990

  9. Characterization of FLOWERING LOCUS T1 (FT1) Gene in Brachypodium and Wheat

    PubMed Central

    Han, Xiuli; Wang, Shuyun; Ni, Fei; Li, Kun; Pearce, Stephen; Wu, Jiajie; Dubcovsky, Jorge; Fu, Daolin

    2014-01-01

    The phase transition from vegetative to reproductive growth is a critical event in the life cycle of flowering plants. FLOWERING LOCUS T (FT) plays a central role in the regulation of this transition by integrating signals from multiple flowering pathways in the leaves and transmitting them to the shoot apical meristem. In this study, we characterized FT homologs in the temperate grasses Brachypodium distachyon and polyploid wheat using transgenic and mutant approaches. Downregulation of FT1 by RNAi was associated with a significant downregulation of the FT-like genes FT2 and FT4 in Brachypodium and FT2 and FT5 in wheat. In a transgenic wheat line carrying a highly-expressed FT1 allele, FT2 and FT3 were upregulated under both long and short days. Overexpression of FT1 caused extremely early flowering during shoot regeneration in both Brachypodium and hexaploid wheat, and resulted in insufficient vegetative tissue to support the production of viable seeds. Downregulation of FT1 transcripts by RNA interference (RNAi) resulted in non-flowering Brachypodium plants and late flowering plants (2–4 weeks delay) in wheat. A similar delay in heading time was observed in tetraploid wheat plants carrying mutations for both FT-A1 and FT-B1. Plants homozygous only for mutations in FT-B1 flowered later than plants homozygous only for mutations in FT-A1, which corresponded with higher transcript levels of FT-B1 relative to FT-A1 in the early stages of development. Taken together, our data indicate that FT1 plays a critical role in the regulation of flowering in Brachypodium and wheat, and that this role is associated with the simultaneous regulation of other FT-like genes. The differential effects of mutations in FT-A1 and FT-B1 on wheat heading time suggest that different allelic combinations of FT1 homoeologs could be used to adjust wheat heading time to improve adaptation to changing environments. PMID:24718312

  10. Exposure to grass pollen--but not birch pollen--affects lung function in Swedish children.

    PubMed

    Gruzieva, O; Pershagen, G; Wickman, M; Melén, E; Hallberg, J; Bellander, T; Lõhmus, M

    2015-09-01

    Allergic response to pollen is increasing worldwide, leading to high medical and social costs. However, the effect of pollen exposure on lung function has rarely been investigated. Over 1800 children in the Swedish birth cohort BAMSE were lung-function- and IgE-tested at the age of 8 and 16 years old. Daily concentrations for 9 pollen types together with measurements for ozone, NO2 , PM10 , PM2.5 were estimated for the index day as well as up to 6 days before the testing. Exposure to grass pollen during the preceding day was associated with a reduced forced expiratory volume in 8-yr-olds; -32.4 ml; 95% CI: -50.6 to -14.2, for an increase in three pollen counts/m³. Associations appeared stronger in children sensitized to pollen allergens. As the grass species flower late in the pollen season, the allergy care routines might be weakened during this period. Therefore, allergy information may need to be updated to increase awareness among grass pollen-sensitized individuals. PMID:26011717

  11. Airborne birch and grass pollen allergens in street-level shops.

    PubMed

    Holmquist, L; Weiner, J; Vesterberg, O

    2001-12-01

    Polluted urban outdoor air may be enriched with large amounts of submicronic respirable pollen allergen particles that penetrate into street-level shops. The objectives of the study were to map concentrations of birch and grass pollen allergens in indoor air of street-level shops and to explore the effect of electrostatic air cleaning under authentic working conditions, indoor air samples were collected in May and July 1999 in two shops. Allergens were quantified by a direct on sampling filter in solution (DOSIS) luminescence immunoassay. The average concentration of airborne indoor birch pollen allergen in the shop with air cleaning was estimated to be 20 +/- 9 SQ/m3 (mean +/- SD) compared to 31 +/- 17 SQ/m3 (mean +/- SD) of that without. The air cleaner reduced the indoor air birch pollen allergen concentration by on average 26 to 48% (P < 0.05). Corresponding figures for airborne indoor grass pollen allergen concentrations were 14 +/- 7 SQ/m3 and 17 +/- 8 SQ/m3, indicating a statistically non-significant (t-test) average 18% reduction of allergen by air cleaning. Excluding two observations with poor fit to the statistical model a significant (P < 0.05) average 27% reduction was obtained. Substantial amounts of airborne birch and grass pollen allergens may occur in street-level shops during flowering seasons. PMID:11761599

  12. Temperate grass response to timing of grazing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grazing management has a significant impact on pasture growth. We determined how timing of grazing influences grass productivity, yield distribution, and persistence. Meadow fescue [Schedonorus pratensis (Huds.) P. Beauv.], orchardgrass (Dactylis glomerata L.), quackgrass [Elymus repens (L.) Gould...

  13. New Developments in Grasses for Pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New forage varieties with improved traits are an essential component of best management practices for livestock agriculture. This paper discusses new varieties of several cool-season forage grasses used for pasture production....

  14. Watching Grass Grow: Biology Explorations Online.

    ERIC Educational Resources Information Center

    Puttick, Gillian

    2002-01-01

    Describes an online biology course for science teachers in a master's degree program that focuses on the adaptation and natural selection of grass under environmental challenges. Provides experience with how biologists use questioning and investigation in their research. (YDS)

  15. Estimation of pyrethrum flower number using digital imagery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flower number is a major determinant of pyrethrin yield in pyrethrum [Tanacetum cineariifolium (Trefi.) Sch. Bip.] production. Traditional estimates of flower numbers utilize physical harvesting of flowers which is time consuming and destructive. Physical harvest is complicated by constraints such...

  16. Evolution of herbicide resistance mechanisms in grass weeds.

    PubMed

    Matzrafi, Maor; Gadri, Yaron; Frenkel, Eyal; Rubin, Baruch; Peleg, Zvi

    2014-12-01

    Herbicide resistant weeds are becoming increasingly common, threatening global food security. Here, we present BrIFAR: a new model system for the functional study of mechanisms of herbicide resistance in grass weeds. We have developed a large collection of Brachypodium accessions, the BrI collection, representing a wide range of habitats. Wide screening of the responses of the accessions to four major herbicide groups (PSII, ACCase, ALS/AHAS and EPSPS inhibitors) identified 28 herbicide-resistance candidate accessions. Target-site resistance to PSII inhibitors was found in accessions collected from habitats with a known history of herbicide applications. An amino acid substitution in the psbA gene (serine264 to glycine) conferred resistance and also significantly affected the flowering and shoot dry weight of the resistant accession, as compared to the sensitive accession. Non-target site resistance to ACCase inhibitors was found in accessions collected from habitats with a history of herbicide application and from a nature reserve. In-vitro enzyme activity tests and responses following pre-treatment with malathion (a cytochrome-P450 inhibitor) indicated sensitivity at the enzyme level, and give strong support to diclofop-methyl and pinoxaden enhanced detoxification as NTS resistance mechanism. BrIFAR can promote better understanding of the evolution of mechanisms of herbicide resistance and aid the implementation of integrative management approaches for sustainable agriculture. PMID:25443832

  17. Scent glands in legume flowers.

    PubMed

    Marinho, C R; Souza, C D; Barros, T C; Teixeira, S P

    2014-01-01

    Scent glands, or osmophores, are predominantly floral secretory structures that secrete volatile substances during anthesis, and therefore act in interactions with pollinators. The Leguminosae family, despite being the third largest angiosperm family, with a wide geographical distribution and diversity of habits, morphology and pollinators, has been ignored with respect to these glands. Thus, we localised and characterised the sites of fragrance production and release in flowers of legumes, in which scent plays an important role in pollination, and also tested whether there are relationships between the structure of the scent gland and the pollinator habit: diurnal or nocturnal. Flowers in pre-anthesis and anthesis of 12 legume species were collected and analysed using immersion in neutral red, olfactory tests and anatomical studies (light and scanning electron microscopy). The main production site of floral scent is the perianth, especially the petals. The scent glands are distributed in a restricted way in Caesalpinia pulcherrima, Anadenanthera peregrina, Inga edulis and Parkia pendula, constituting mesophilic osmophores, and in a diffuse way in Bauhinia rufa, Hymenaea courbaril, Erythrostemon gilliesii, Poincianella pluviosa, Pterodon pubescens, Platycyamus regnellii, Mucuna urens and Tipuana tipu. The glands are comprised of cells of the epidermis and mesophyll that secrete mainly terpenes, nitrogen compounds and phenols. Relationships between the presence of osmophores and type of anthesis (diurnal and nocturnal) and the pollinator were not found. Our data on scent glands in Leguminosae are original and detail the type of diffuse release, which has been very poorly studied. PMID:23574349

  18. Delayed flowering and global warming

    NASA Astrophysics Data System (ADS)

    Cook, B. I.; Wolkovich, E. M.; Parmesan, C.

    2011-12-01

    Within general trends toward earlier spring, observed cases of species and ecosystems that have not advanced their phenology, or have even delayed it, appear paradoxical, especially when made in temperate regions experiencing significant warming. The typical interpretation of this pattern has been that non-responders are insensitive to relatively small levels of warming over the past 40 years, while species showing delays are often viewed as statistical noise or evidence for unknown confounding factors at play. However, plant physiology studies suggest that when winter chilling (vernalization) is required to initiate spring development, winter warming may retard spring events, masking expected advances caused by spring warming. Here, we analyzed long-term data on phenology and seasonal temperatures from 490 species on two continents and demonstrate that 1) apparent non-responders are indeed responding to warming, but their responses to winter and spring warming are opposite in sign, 2) observed trends in first flowering date depend strongly on the magnitude of a given species' response to autumn/winter versus spring warming, and 3) inclusion of these effects strongly improves hindcast predictions of long-term flowering trends. With a few notable exceptions, climate change research has focused on the overall mean trend towards phenological advance, minimizing discussion of apparently non-responding species. Our results illuminate an under-studied source of complexity in wild species responses and support the need for models incorporating diverse environmental cues in order to improve predictability of species responses to anthropogenic climate change.

  19. Separate elements of the TERMINAL FLOWER 1 cis-regulatory region integrate pathways to control flowering time and shoot meristem identity.

    PubMed

    Serrano-Mislata, Antonio; Fernández-Nohales, Pedro; Doménech, María J; Hanzawa, Yoshie; Bradley, Desmond; Madueño, Francisco

    2016-09-15

    TERMINAL FLOWER 1 (TFL1) is a key regulator of Arabidopsis plant architecture that responds to developmental and environmental signals to control flowering time and the fate of shoot meristems. TFL1 expression is dynamic, being found in all shoot meristems, but not in floral meristems, with the level and distribution changing throughout development. Using a variety of experimental approaches we have analysed the TFL1 promoter to elucidate its functional structure. TFL1 expression is based on distinct cis-regulatory regions, the most important being located 3' of the coding sequence. Our results indicate that TFL1 expression in the shoot apical versus lateral inflorescence meristems is controlled through distinct cis-regulatory elements, suggesting that different signals control expression in these meristem types. Moreover, we identified a cis-regulatory region necessary for TFL1 expression in the vegetative shoot and required for a wild-type flowering time, supporting that TFL1 expression in the vegetative meristem controls flowering time. Our study provides a model for the functional organisation of TFL1 cis-regulatory regions, contributing to our understanding of how developmental pathways are integrated at the genomic level of a key regulator to control plant architecture. PMID:27385013

  20. Molecular control of grass inflorescence development.

    PubMed

    Zhang, Dabing; Yuan, Zheng

    2014-01-01

    The grass family is one of the largest families in angiosperms and has evolved a characteristic inflorescence morphology, with complex branches and specialized spikelets. The origin and development of the highly divergent inflorescence architecture in grasses have recently received much attention. Increasing evidence has revealed that numerous factors, such as transcription factors and plant hormones, play key roles in determining reproductive meristem fate and inflorescence patterning in grasses. Moreover, some molecular switches that have been implicated in specifying inflorescence shapes contribute significantly to grain yields in cereals. Here, we review key genetic and molecular switches recently identified from two model grass species, rice (Oryza sativa) and maize (Zea mays), that regulate inflorescence morphology specification, including meristem identity, meristem size and maintenance, initiation and outgrowth of axillary meristems, and organogenesis. Furthermore, we summarize emerging networks of genes and pathways in grass inflorescence morphogenesis and emphasize their evolutionary divergence in comparison with the model eudicot Arabidopsis thaliana. We also discuss the agricultural application of genes controlling grass inflorescence development. PMID:24471834

  1. Genetic compatibility determines endophyte-grass combinations.

    PubMed

    Saikkonen, Kari; Wäli, Piippa R; Helander, Marjo

    2010-01-01

    Even highly mutually beneficial microbial-plant interactions, such as mycorrhizal- and rhizobial-plant exchanges, involve selfishness, cheating and power-struggles between the partners, which depending on prevailing selective pressures, lead to a continuum of interactions from antagonistic to mutualistic. Using manipulated grass-endophyte combinations in a five year common garden experiment, we show that grass genotypes and genetic mismatches constrain genetic combinations between the vertically (via host seeds) transmitted endophytes and the out-crossing host, thereby reducing infections in established grass populations. Infections were lost in both grass tillers and seedlings in F(1) and F(2) generations, respectively. Experimental plants were collected as seeds from two different environments, i.e., meadows and nearby riverbanks. Endophyte-related benefits to the host included an increased number of inflorescences, but only in meadow plants and not until the last growing season of the experiment. Our results illustrate the importance of genetic host specificity and trans-generational maternal effects on the genetic structure of a host population, which act as destabilizing forces in endophyte-grass symbioses. We propose that (1) genetic mismatches may act as a buffering mechanism against highly competitive endophyte-grass genotype combinations threatening the biodiversity of grassland communities and (2) these mismatches should be acknowledged, particularly in breeding programmes aimed at harnessing systemic and heritable endophytes to improve the agriculturally valuable characteristics of cultivars. PMID:20614034

  2. Madagascar's grasses and grasslands: anthropogenic or natural?

    PubMed Central

    Besnard, Guillaume; Forest, Félix; Malakasi, Panagiota; Moat, Justin; Clayton, W. Derek; Ficinski, Paweł; Savva, George M.; Nanjarisoa, Olinirina P.; Razanatsoa, Jacqueline; Randriatsara, Fetra O.; Kimeu, John M.; Luke, W. R. Quentin; Kayombo, Canisius; Linder, H. Peter

    2016-01-01

    Grasses, by their high productivity even under very low pCO2, their ability to survive repeated burning and to tolerate long dry seasons, have transformed the terrestrial biomes in the Neogene and Quaternary. The expansion of grasslands at the cost of biodiverse forest biomes in Madagascar is often postulated as a consequence of the Holocene settlement of the island by humans. However, we show that the Malagasy grass flora has many indications of being ancient with a long local evolutionary history, much predating the Holocene arrival of humans. First, the level of endemism in the Madagascar grass flora is well above the global average for large islands. Second, a survey of many of the more diverse areas indicates that there is a very high spatial and ecological turnover in the grass flora, indicating a high degree of niche specialization. We also find some evidence that there are both recently disturbed and natural stable grasslands: phylogenetic community assembly indicates that recently severely disturbed grasslands are phylogenetically clustered, whereas more undisturbed grasslands tend to be phylogenetically more evenly distributed. From this evidence, it is likely that grass communities existed in Madagascar long before human arrival and so were determined by climate, natural grazing and other natural factors. Humans introduced zebu cattle farming and increased fire frequency, and may have triggered an expansion of the grasslands. Grasses probably played the same role in the modification of the Malagasy environments as elsewhere in the tropics. PMID:26791612

  3. Madagascar's grasses and grasslands: anthropogenic or natural?

    PubMed

    Vorontsova, Maria S; Besnard, Guillaume; Forest, Félix; Malakasi, Panagiota; Moat, Justin; Clayton, W Derek; Ficinski, Paweł; Savva, George M; Nanjarisoa, Olinirina P; Razanatsoa, Jacqueline; Randriatsara, Fetra O; Kimeu, John M; Luke, W R Quentin; Kayombo, Canisius; Linder, H Peter

    2016-01-27

    Grasses, by their high productivity even under very low pCO2, their ability to survive repeated burning and to tolerate long dry seasons, have transformed the terrestrial biomes in the Neogene and Quaternary. The expansion of grasslands at the cost of biodiverse forest biomes in Madagascar is often postulated as a consequence of the Holocene settlement of the island by humans. However, we show that the Malagasy grass flora has many indications of being ancient with a long local evolutionary history, much predating the Holocene arrival of humans. First, the level of endemism in the Madagascar grass flora is well above the global average for large islands. Second, a survey of many of the more diverse areas indicates that there is a very high spatial and ecological turnover in the grass flora, indicating a high degree of niche specialization. We also find some evidence that there are both recently disturbed and natural stable grasslands: phylogenetic community assembly indicates that recently severely disturbed grasslands are phylogenetically clustered, whereas more undisturbed grasslands tend to be phylogenetically more evenly distributed. From this evidence, it is likely that grass communities existed in Madagascar long before human arrival and so were determined by climate, natural grazing and other natural factors. Humans introduced zebu cattle farming and increased fire frequency, and may have triggered an expansion of the grasslands. Grasses probably played the same role in the modification of the Malagasy environments as elsewhere in the tropics. PMID:26791612

  4. Ehd4 Encodes a Novel and Oryza-Genus-Specific Regulator of Photoperiodic Flowering in Rice

    PubMed Central

    Gao, He; Zheng, Xiao-Ming; Fei, Guilin; Chen, Jun; Jin, Mingna; Ren, Yulong; Wu, Weixun; Zhou, Kunneng; Sheng, Peike; Zhou, Feng; Jiang, Ling; Wang, Jie; Zhang, Xin; Guo, Xiuping; Wang, Jiu-Lin; Cheng, Zhijun; Wu, Chuanyin; Wang, Haiyang; Wan, Jian-Min

    2013-01-01

    Land plants have evolved increasingly complex regulatory modes of their flowering time (or heading date in crops). Rice (Oryza sativa L.) is a short-day plant that flowers more rapidly in short-day but delays under long-day conditions. Previous studies have shown that the CO-FT module initially identified in long-day plants (Arabidopsis) is evolutionary conserved in short-day plants (Hd1-Hd3a in rice). However, in rice, there is a unique Ehd1-dependent flowering pathway that is Hd1-independent. Here, we report isolation and characterization of a positive regulator of Ehd1, Early heading date 4 (Ehd4). ehd4 mutants showed a never flowering phenotype under natural long-day conditions. Map-based cloning revealed that Ehd4 encodes a novel CCCH-type zinc finger protein, which is localized to the nucleus and is able to bind to nucleic acids in vitro and transactivate transcription in yeast, suggesting that it likely functions as a transcriptional regulator. Ehd4 expression is most active in young leaves with a diurnal expression pattern similar to that of Ehd1 under both short-day and long-day conditions. We show that Ehd4 up-regulates the expression of the “florigen” genes Hd3a and RFT1 through Ehd1, but it acts independently of other known Ehd1 regulators. Strikingly, Ehd4 is highly conserved in the Oryza genus including wild and cultivated rice, but has no homologs in other species, suggesting that Ehd4 is originated along with the diversification of the Oryza genus from the grass family during evolution. We conclude that Ehd4 is a novel Oryza-genus-specific regulator of Ehd1, and it plays an essential role in photoperiodic control of flowering time in rice. PMID:23437005

  5. Putative sugarcane FT/TFL1 genes delay flowering time and alter reproductive architecture in Arabidopsis

    PubMed Central

    Coelho, Carla P.; Minow, Mark A. A.; Chalfun-Júnior, Antonio; Colasanti, Joseph

    2014-01-01

    Agriculturally important grasses such as rice, maize, and sugarcane are evolutionarily distant from Arabidopsis, yet some components of the floral induction process are highly conserved. Flowering in sugarcane is an important factor that negatively affects cane yield and reduces sugar/ethanol production from this important perennial bioenergy crop. Comparative studies have facilitated the identification and characterization of putative orthologs of key flowering time genes in sugarcane, a complex polyploid plant whose genome has yet to be sequenced completely. Using this approach we identified phosphatidylethanolamine-binding protein (PEBP) gene family members in sugarcane that are similar to the archetypical FT and TFL1 genes of Arabidopsis that play an essential role in controlling the transition from vegetative to reproductive growth. Expression analysis of ScTFL1, which falls into the TFL1-clade of floral repressors, showed transcripts in developing leaves surrounding the shoot apex but not at the apex itself. ScFT1 was detected in immature leaves and apical regions of vegetatively growing plants and, after the floral transition, expression also occurred in mature leaves. Ectopic over-expression of ScTFL1 in Arabidopsis caused delayed flowering in Arabidopsis, as might be expected for a gene related to TFL1. In addition, lines with the latest flowering phenotype exhibited aerial rosette formation. Unexpectedly, over-expression of ScFT1, which has greatest similarity to the florigen-encoding FT, also caused a delay in flowering. This preliminary analysis of divergent sugarcane FT and TFL1 gene family members from Saccharum spp. suggests that their expression patterns and roles in the floral transition has diverged from the predicted role of similar PEBP family members. PMID:24904616

  6. Making Flowers at the Right Time.

    PubMed

    Wagner, Doris

    2016-05-01

    Different plant species flower in different seasons, but there is also annual variability depending on environmental conditions. In this issue of Developmental Cell, Hyun et al. (2016) show that Arabidopsis plants can flower without proper seasonal cues if they have developed past the juvenile phase and have high levels of gibberellin. PMID:27165552

  7. Susceptibility of blackberry flowers to freezing temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Injury of tight buds, open flowers and green fruit often occur in fruit crops during spring frost events. In this study, freezing tolerance of ‘Triple Crown’ blackberry flowers at different reproductive stages of development (tight bud to green drupe) was determined using two methods. One method i...

  8. How the Flowers Came to Be.

    ERIC Educational Resources Information Center

    Skinner, Linda; Brescia, William, Ed.

    The booklet tells the story of Josephine, a little Choctaw girl, who picks wild flowers and hurts her Aunt's feelings. Josephine later learns from her grandmother the importance of respecting nature and how the flowers came to be. The story introduces constellations, how weaving came to the Choctaw, how the sick were prayed for, and why wild…

  9. Analysis of soybean flowering-time genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Control of soybean flowering time is important for geographic adaptation, and maximizing yield. RT-PCR analysis was performed using primers synthesized for a number of putative flowering-time genes based on homology of soybean EST and genomic sequences to Arabidopsis genes. RNA for cDNA synthesis ...

  10. 'DREAM CATCHER' AND 'FIRST LADY' FLOWERING CHERRY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ornamental flowering cherry trees (Prunus L. species) are popular landscape plants, made famous in the U.S. by the historic Tidal Basin cherries planted in Washington, D.C. Although planted primarily for their spring bloom, flowering cherries are also used as street or shade trees, and are valued fo...

  11. Postharvest: Cut flowers and potted plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the past fifty years, the cut flower market has changed dramatically, from a local market with growers located on city outskirts, to a global one; flowers and cut foliage sourced from throughout the world are sold as bunches or combined into arrangements and bouquets in the major target markets. ...

  12. Meta-analysis of phenotypic selection on flowering phenology suggests that early flowering plants are favoured.

    PubMed

    Munguía-Rosas, Miguel A; Ollerton, Jeff; Parra-Tabla, Victor; De-Nova, J Arturo

    2011-05-01

    Flowering times of plants are important life-history components and it has previously been hypothesized that flowering phenologies may be currently subject to natural selection or be selectively neutral. In this study we reviewed the evidence for phenotypic selection acting on flowering phenology using ordinary and phylogenetic meta-analysis. Phenotypic selection exists when a phenotypic trait co-varies with fitness; therefore, we looked for studies reporting an association between two components of flowering phenology (flowering time or flowering synchrony) with fitness. Data sets comprising 87 and 18 plant species were then used to assess the incidence and strength of phenotypic selection on flowering time and flowering synchrony, respectively. The influence of dependence on pollinators, the duration of the reproductive event, latitude and plant longevity as moderators of selection were also explored. Our results suggest that selection favours early flowering plants, but the strength of selection is influenced by latitude, with selection being stronger in temperate environments. However, there is no consistent pattern of selection on flowering synchrony. Our study demonstrates that phenotypic selection on flowering time is consistent and relatively strong, in contrast to previous hypotheses of selective neutrality, and has implications for the evolution of temperate floras under global climate change. PMID:21332621

  13. Analysis of biochemical compounds and differentially expressed genes of the anthocyanin biosynthetic pathway in variegated peach flowers.

    PubMed

    Hassani, D; Liu, H L; Chen, Y N; Wan, Z B; Zhuge, Q; Li, S X

    2015-01-01

    Variegated plants are highly valuable in the floricultural market, yet the genetic mechanism underlying this attractive phenomenon has not been completely elucidated. In this study, we identified and measured different compounds in pink and white flower petals of peach (Prunus persica) by high-performance liquid chromatography and liquid chromatography/mass spectrometry analyses. No cyanidin-based or pelargonidin-based compounds were detected in white petals, but high levels of these compounds were found in pink petals. Additionally, we sequenced and analyzed the expression of six key structural genes in the anthocyanin biosynthesis pathway (CHI, CHS, DFR, F3'H, ANS, and UFGT) in both white and pink petals. Quantitative real-time polymerase chain reaction revealed all six genes to be expressed at greatly reduced levels in white flower petals, relative to pink. No allelic variations were found in the transcribed sequences. However, alignment of transcribed and genomic sequences of the ANS gene detected alternative splicing, resulting in transcripts of 1.071 and 942 bp. Only the longer transcript was observed in white flower petals. Since ANS is the key intermediate enzyme catalyzing the colorless leucopelargonidin and leucocyanidin to substrates required for completion of anthocyanin biosynthesis, the ANS gene is implicated in flower color variegation and should be explored in future studies. This article, together with a previous transcriptome study, elucidates the mechanism underlying peach flower color variegation in terms of the key structural genes involved in anthocyanin biosynthesis. PMID:26535657

  14. Induction of flowering by 5-azacytidine in some plant species: relationship between the stability of photoperiodically induced flowering and flower-inducing effect of DNA demethylation.

    PubMed

    Kondo, Hiroshi; Miura, Takashi; Wada, Kaede C; Takeno, Kiyotoshi

    2007-11-01

    The flower-inducing effect of 5-azacytidine, a DNA demethylating reagent, was examined in several plant species with a stable or unstable photoperiodically induced flowering state under non-inductive photoperiodic conditions. The long day plant Silene armeria, whose flowering state is stable and the short day plant Pharbitis nil, whose flowering state is unstable were induced to flower by 5-azacytidine under a non-inductive condition. Thus, the replacement of photoinduction by 5-azacytidine treatment is not specific to Perilla frutescens. On the other hand, 5-azacytidine did not induce flowering in Xanthium strumarium whose flowering state is stable and Lemna paucicostata whose flowering state is unstable. Thus, epigenetics caused by DNA demethylation may be involved in the regulation of photoperiodic flowering irrespective of the stability of the photoperiodically induced flowering state. PMID:18251884

  15. Carbon dots derived from rose flowers for tetracycline sensing.

    PubMed

    Feng, Yuanjiao; Zhong, Dan; Miao, Hong; Yang, Xiaoming

    2015-08-01

    Herein, an innovative and simple method for synthesizing carbon dots (CDs) with satisfactory fluorescence has been successfully established while rose flowers served as carbon source for the first time. Meanwhile, the fluorescence (FL) mechanism of current CDs was elucidated in detail by fluorescence, UV-vis, HR-TEM, and FTIR-based analyses. Subsequently, this type of CDs was employed for detecting tetracycline (TC) on the basis of the interactions between TC and CDs, and allowed quenching their fluorescence. Moreover, the proposed analytical strategy permitted detecting TC in a linear range of 1.0×10(-8)-1.0×10(-4) mol/L with a detection limit of 3.3×10(-9) mol/L at a signal-to-noise ratio of 3. Significantly, the CDs described here were further applied for fluorescent coding, demonstrating their promising future towards various applications in analytic science. PMID:26048834

  16. Arabidopsis flower development-of protein complexes, targets, and transport.

    PubMed

    Becker, Annette; Ehlers, Katrin

    2016-03-01

    Tremendous progress has been achieved over the past 25 years or more of research on the molecular mechanisms of floral organ identity, patterning, and development. While collections of floral homeotic mutants of Antirrhinum majus laid the foundation already at the beginning of the previous century, it was the genetic analysis of these mutants in A. majus and Arabidopsis thaliana that led to the development of the ABC model of floral organ identity more than 20 years ago. This intuitive model kick-started research focused on the genetic mechanisms regulating flower development, using mainly A. thaliana as a model plant. In recent years, interactions among floral homeotic proteins have been elucidated, and their direct and indirect target genes are known to a large extent. Here, we provide an overview over the advances in understanding the molecular mechanism orchestrating A. thaliana flower development. We focus on floral homeotic protein complexes, their target genes, evidence for their transport in floral primordia, and how these new results advance our view on the processes downstream of floral organ identity, such as organ boundary formation or floral organ patterning. PMID:25845756

  17. Elucidation of wear mechanisms by ferrographic analysis

    NASA Technical Reports Server (NTRS)

    Jones, W. R., Jr.

    1981-01-01

    The use of ferrographic analysis in conjunction with light and scanning electron microscopy is described for the elucidation of wear mechanisms taking place in operating equipment. Example of adhesive wear, abrasive wear, corrosive wear, rolling element fatigue, lubricant breakdown, and other wear modes are illustrated. In addition, the use of magnetic solutions to precipitate nonmagnetic debris from aqueous and nonaqueous fluids is described.

  18. Does Pictorial Elucidation Foster Recollection of Idioms?

    ERIC Educational Resources Information Center

    Boers, Frank; Piquer Piriz, Ana Maria; Stengers, Helene; Eyckmans, June

    2009-01-01

    Experimental evidence suggests that pictorial elucidation helps learners comprehend and remember the meaning of second language (L2) idioms. In this article we address the question whether it also helps retention of the form of idioms, i.e. their precise lexical composition. In a small-scale experiment, the meaning of English idioms was clarified…

  19. Climate change: consequences on the pollination of grasses in Perugia (Central Italy). A 33-year-long study

    NASA Astrophysics Data System (ADS)

    Sofia, Ghitarrini; Emma, Tedeschini; Veronica, Timorato; Giuseppe, Frenguelli

    2016-06-01

    Many works carried out in the last decades have shown that the pollen season for taxa flowering in winter and spring, in temperate regions, has tended to be earlier, probably due to the continuous rise in temperature. The mean annual temperature in Perugia, Central Italy, was about 0.5 °C higher in the last three decades compared with that registered from 1952 to 1981. The increase of temperature took place mainly in winter and spring, while no significant variation was recorded during the summer and autumn. This scenario shows variations in the timing and behavior of flowering of many spontaneous plants such as grasses, whose phenology is strongly influenced by air temperature. This work reports fluctuations in the airborne grass pollen presence in Perugia over a 33-year period (1982-2014), in order to study the influence of the warming registered in recent years on the behavior of pollen release of this taxon. The grass pollen season in Perugia typically lasts from the beginning of May to late July. The start dates showed a marked trend to an earlier beginning of the season (-0.4 day/year), as well as a strong correlation with the average temperatures of March and April. The peak is reached around 30th May, but the annual pollen index (API) is following a decreasing trend. The correlation between starting dates and spring temperatures could be interesting for the constitution of a forecasting model capable of predicting the presence of airborne grass pollen, helping to plan therapies for allergic people.

  20. Photoperiodic flowering regulation in Arabidopsis thaliana

    PubMed Central

    Golembeski, Greg S.; Kinmonth-Schultz, Hannah A.; Song, Young Hun; Imaizumi, Takato

    2015-01-01

    Photoperiod, or the duration of light in a given day, is a critical cue that flowering plants utilize to effectively assess seasonal information and coordinate their reproductive development in synchrony with the external environment. The use of the model plant, Arabidopsis thaliana, has greatly improved our understanding of the molecular mechanisms that determine how plants process and utilize photoperiodic information to coordinate a flowering response. This mechanism is typified by the transcriptional activation of FLOWERING LOCUS T (FT) gene by the transcription factor CONSTANS (CO) under inductive long-day conditions in Arabidopsis. FT protein then moves from the leaves to the shoot apex, where floral meristem development can be initiated. As a point of integration from a variety of environmental factors in the context of a larger system of regulatory pathways that affect flowering, the importance of photoreceptors and the circadian clock in CO regulation throughout the day has been a key feature of the photoperiodic flowering pathway. In addition to these established mechanisms, the recent discovery of a photosynthate derivative trehalose-6-phosphate as an activator of FT in leaves has interesting implications for the involvement of photosynthesis in the photoperiodic flowering response that were suggested from previous physiological experiments in flowering induction. PMID:25684830

  1. Phylogenetic niche conservatism in C4 grasses.

    PubMed

    Liu, Hui; Edwards, Erika J; Freckleton, Robert P; Osborne, Colin P

    2012-11-01

    Photosynthetic pathway is used widely to discriminate plant functional types in studies of global change. However, independent evolutionary lineages of C(4) grasses with different variants of C(4) photosynthesis show different biogeographical relationships with mean annual precipitation, suggesting phylogenetic niche conservatism (PNC). To investigate how phylogeny and photosynthetic type differentiate C(4) grasses, we compiled a dataset of morphological and habitat information of 185 genera belonging to two monophyletic subfamilies, Chloridoideae and Panicoideae, which together account for 90 % of the world's C(4) grass species. We evaluated evolutionary variance and covariance of morphological and habitat traits. Strong phylogenetic signals were found in both morphological and habitat traits, arising mainly from the divergence of the two subfamilies. Genera in Chloridoideae had significantly smaller culm heights, leaf widths, 1,000-seed weights and stomata; they also appeared more in dry, open or saline habitats than those of Panicoideae. Controlling for phylogenetic structure showed significant covariation among morphological traits, supporting the hypothesis of phylogenetically independent scaling effects. However, associations between morphological and habitat traits showed limited phylogenetic covariance. Subfamily was a better explanation than photosynthetic type for the variance in most morphological traits. Morphology, habitat water availability, shading, and productivity are therefore all involved in the PNC of C(4) grass lineages. This study emphasized the importance of phylogenetic history in the ecology and biogeography of C(4) grasses, suggesting that divergent lineages need to be considered to fully understand the impacts of global change on plant distributions. PMID:22569558

  2. Widespread genome duplications throughout the history of flowering plants

    PubMed Central

    Cui, Liying; Wall, P. Kerr; Leebens-Mack, James H.; Lindsay, Bruce G.; Soltis, Douglas E.; Doyle, Jeff J.; Soltis, Pamela S.; Carlson, John E.; Arumuganathan, Kathiravetpilla; Barakat, Abdelali; Albert, Victor A.; Ma, Hong; dePamphilis, Claude W.

    2006-01-01

    Genomic comparisons provide evidence for ancient genome-wide duplications in a diverse array of animals and plants. We developed a birth–death model to identify evidence for genome duplication in EST data, and applied a mixture model to estimate the age distribution of paralogous pairs identified in EST sets for species representing the basal-most extant flowering plant lineages. We found evidence for episodes of ancient genome-wide duplications in the basal angiosperm lineages including Nuphar advena (yellow water lily: Nymphaeaceae) and the magnoliids Persea americana (avocado: Lauraceae), Liriodendron tulipifera (tulip poplar: Magnoliaceae), and Saruma henryi (Aristolochiaceae). In addition, we detected independent genome duplications in the basal eudicot Eschscholzia californica (California poppy: Papaveraceae) and the basal monocot Acorus americanus (Acoraceae), both of which were distinct from duplications documented for ancestral grass (Poaceae) and core eudicot lineages. Among gymnosperms, we found equivocal evidence for ancient polyploidy in Welwitschia mirabilis (Gnetales) and no evidence for polyploidy in pine, although gymnosperms generally have much larger genomes than the angiosperms investigated. Cross-species sequence divergence estimates suggest that synonymous substitution rates in the basal angiosperms are less than half those previously reported for core eudicots and members of Poaceae. These lower substitution rates permit inference of older duplication events. We hypothesize that evidence of an ancient duplication observed in the Nuphar data may represent a genome duplication in the common ancestor of all or most extant angiosperms, except Amborella. PMID:16702410

  3. Southern Florida's River of Grass

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Florida's Everglades is a region of broad, slow-moving sheets of water flowing southward over low-lying areas from Lake Okeechobeeto the Gulf of Mexico. In places this remarkable 'river of grass' is 80 kilometers wide. These images from the Multi-angle Imaging SpectroRadiometer show the Everglades region on January 16, 2002. Each image covers an area measuring 191 kilometers x 205 kilometers. The data were captured during Terra orbit 11072.

    On the left is a natural color view acquired by MISR's nadir camera. A portion of Lake Okeechobee is visible at the top, to the right of image center. South of the lake, whose name derives from the Seminole word for 'big water,' an extensive region of farmland known as the Everglades Agricultural Area is recognizable by its many clustered squares. Over half of the sugar produced in United States is grown here. Urban areas along the east coast and in the northern part of the image extend to the boundaries of Big Cypress Swamp, situated north of Everglades National Park.

    The image on the right combines red-band data from the 46-degree backward, nadir and 46-degree forward-viewing camera angles to create a red, green, blue false-color composite. One of the interesting uses of the composite image is for detecting surface water. Wet surfaces appear blue in this rendition because sun glitter produces a greater signal at the forward camera's view angle. Wetlands visible in these images include a series of shallow impoundments called Water Conservation Areas which were built to speed water flow through the Everglades in times of drought. In parts of the Everglades, these levees and extensive systems such as the Miami and Tamiami Canals have altered the natural cycles of water flow. For example, the water volume of the Shark River Slough, a natural wetland which feeds Everglades National Park, is influenced by the Tamiami Canal. The unique and intrinsic value of the Everglades is now widely recognized, and efforts to restore

  4. Using Genomics for Natural Product Structure Elucidation.

    PubMed

    Tietz, Jonathan I; Mitchell, Douglas A

    2016-01-01

    Natural products (NPs) are the most historically bountiful source of chemical matter for drug development-especially for anti-infectives. With insights gleaned from genome mining, interest in natural product discovery has been reinvigorated. An essential stage in NP discovery is structural elucidation, which sheds light not only on the chemical composition of a molecule but also its novelty, properties, and derivatization potential. The history of structure elucidation is replete with techniquebased revolutions: combustion analysis, crystallography, UV, IR, MS, and NMR have each provided game-changing advances; the latest such advance is genomics. All natural products have a genetic basis, and the ability to obtain and interpret genomic information for structure elucidation is increasingly available at low cost to non-specialists. In this review, we describe the value of genomics as a structural elucidation technique, especially from the perspective of the natural product chemist approaching an unknown metabolite. Herein we first introduce the databases and programs of interest to the natural products chemist, with an emphasis on those currently most suited for general usability. We describe strategies for linking observed natural product-linked phenotypes to their corresponding gene clusters. We then discuss techniques for extracting structural information from genes, illustrated with numerous case examples. We also provide an analysis of the biases and limitations of the field with recommendations for future development. Our overview is not only aimed at biologically-oriented researchers already at ease with bioinformatic techniques, but also, in particular, at natural product, organic, and/or medicinal chemists not previously familiar with genomic techniques. PMID:26456468

  5. Inheritance of pink flower color in Styrax japonicus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most Styrax japonicus (Japanese snowbell) cultivars produce white flowers, but a few pink-flowered forms have been reported. ‘Pink Chimes’ is the most widely grown pink-flowered form and the only S. japonicus cultivar with deep pink flowers that hold their color even under hot growing conditions. ...

  6. Seed Production from Non-flowering Orchardgrass: Proof of Concept

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Non-flowering or sparse flowering orchardgrass (Dactylis glomerata L.) would greatly simplify management of intensive rotational grazing systems in which flowering stems are an impediment to efficient pasture utilization. Our objective was to quantify seed production on non-flowering orchardgrass c...

  7. Grass pollen immunotherapy: where are we now.

    PubMed

    Würtzen, Peter A; Gupta, Shashank; Brand, Stephanie; Andersen, Peter S

    2016-04-01

    During allergen immunotherapy (AIT), the allergic patient is exposed to the disease-inducing antigens (allergens) in order to induce clinical and immunological tolerance and obtain disease modification. Large trials of grass AIT with highly standardized subcutaneous and sublingual tablet vaccines have been conducted to document the clinical effect. Induction of blocking antibodies as well as changes in the balance between T-cell phenotypes, including induction of regulatory T-cell subtypes, have been demonstrated for both treatment types. These observations increase the understanding of the immunological mechanism behind the clinical effect and may make it possible to use the immunological changes as biomarkers of clinical effect. The current review describes the recent mechanistic findings for subcutaneous immunotherapy and sublingual immunotherapy/tablet treatment and discusses how the observed immunological changes translate into a scientific foundation for the observed clinical effects of grass pollen immunotherapy and lead to new treatment strategies for grass AIT. PMID:26973122

  8. Molecular biomarkers for grass pollen immunotherapy

    PubMed Central

    Popescu, Florin-Dan

    2014-01-01

    Grass pollen allergy represents a significant cause of allergic morbidity worldwide. Component-resolved diagnosis biomarkers are increasingly used in allergy practice in order to evaluate the sensitization to grass pollen allergens, allowing the clinician to confirm genuine sensitization to the corresponding allergen plant sources and supporting an accurate prescription of allergy immunotherapy (AIT), an important approach in many regions of the world with great plant biodiversity and/or where pollen seasons may overlap. The search for candidate predictive biomarkers for grass pollen immunotherapy (tolerogenic dendritic cells and regulatory T cells biomarkers, serum blocking antibodies biomarkers, especially functional ones, immune activation and immune tolerance soluble biomarkers and apoptosis biomarkers) opens new opportunities for the early detection of clinical responders for AIT, for the follow-up of these patients and for the development of new allergy vaccines. PMID:25237628

  9. "Say it...near the flower shop": further evidence of the effect of flowers on mating.

    PubMed

    Guéguen, Nicolas

    2012-01-01

    For millennia, flowers have been used to convey romance. In this study, 18-25-year-old women (N = 600) walking alone in a shopping mall were approached by an attractive 20-year-old male-confederate who solicited them for their phone number. The women were solicited as they were walking in the area of a flower shop, a cake shop, or a women's shoes shop. It was found that women agreed more favorably to the confederate's courtship solicitation when solicited in the area of the flower shop. Positive mood induced by exposure to flowers was used to explain these results. PMID:22930994

  10. Flowering responses to light and temperature.

    PubMed

    Li, Li; Li, Xu; Liu, Yawen; Liu, Hongtao

    2016-04-01

    Light and temperature signals are the most important environmental cues regulating plant growth and development. Plants have evolved various strategies to prepare for, and adapt to environmental changes. Plants integrate environmental cues with endogenous signals to regulate various physiological processes, including flowering time. There are at least five distinct pathways controlling flowering in the model plant Arabidopsis thaliana: the photoperiod pathway, the vernalization/thermosensory pathway, the autonomous floral initiation, the gibberellins pathway, and the age pathway. The photoperiod and temperature/ vernalization pathways mainly perceive external signals from the environment, while the autonomous and age pathways transmit endogenous cues within plants. In many plant species, floral transition is precisely controlled by light signals (photoperiod) and temperature to optimize seed production in specific environments. The molecular mechanisms by which light and temperature control flowering responses have been revealed using forward and reverse genetic approaches. Here we focus on the recent advances in research on flowering responses to light and temperature. PMID:26687726

  11. The evolutionary root of flowering plants.

    PubMed

    Goremykin, Vadim V; Nikiforova, Svetlana V; Biggs, Patrick J; Zhong, Bojian; Delange, Peter; Martin, William; Woetzel, Stefan; Atherton, Robin A; McLenachan, Patricia A; Lockhart, Peter J

    2013-01-01

    Correct rooting of the angiosperm radiation is both challenging and necessary for understanding the origins and evolution of physiological and phenotypic traits in flowering plants. The problem is known to be difficult due to the large genetic distance separating flowering plants from other seed plants and the sparse taxon sampling among basal angiosperms. Here, we provide further evidence for concern over substitution model misspecification in analyses of chloroplast DNA sequences. We show that support for Amborella as the sole representative of the most basal angiosperm lineage is founded on sequence site patterns poorly described by time-reversible substitution models. Improving the fit between sequence data and substitution model identifies Trithuria, Nymphaeaceae, and Amborella as surviving relatives of the most basal lineage of flowering plants. This finding indicates that aquatic and herbaceous species dominate the earliest extant lineage of flowering plants. [; ; ; ; ; .]. PMID:22851550

  12. Flexibility in the structure of spiral flowers and its underlying mechanisms.

    PubMed

    Wang, Peipei; Liao, Hong; Zhang, Wengen; Yu, Xianxian; Zhang, Rui; Shan, Hongyan; Duan, Xiaoshan; Yao, Xu; Kong, Hongzhi

    2015-01-01

    Spiral flowers usually bear a variable number of organs, suggestive of the flexibility in structure. The mechanisms underlying the flexibility, however, remain unclear. Here we show that in Nigella damascena, a species with spiral flowers, different types of floral organs show different ranges of variation in number. We also show that the total number of organs per flower is largely dependent on the initial size of the floral meristem, whereas the respective numbers of different types of floral organs are determined by the functional domains of corresponding genetic programmes. By conducting extensive expression and functional studies, we further elucidate the genetic programmes that specify the identities of different types of floral organs. Notably, the AGL6-lineage member NdAGL6, rather than the AP1-lineage members NdFL1/2, is an A-function gene, whereas petaloidy of sepals is not controlled by AP3- or PI-lineage members. Moreover, owing to the formation of a regulatory network, some floral organ identity genes also regulate the boundaries between different types of floral organs. On the basis of these results, we propose that the floral organ identity determination programme is highly dynamic and shows considerable flexibility. Transitions from spiral to whorled flowers, therefore, may be explained by evolution of the mechanisms that reduce the flexibility. PMID:27250746

  13. Why Is a Flower Five-Petaled?

    ERIC Educational Resources Information Center

    Nishiyama, Yutaka

    2004-01-01

    This paper examines why many flowers are five-petaled through the use of a five-petaled model that draws insights from the location of cell clusters at a shoot apex, rather than by way of the Fibonacci sequence or the golden ratio as in the past. The conclusion drawn is that flowers are most likely to be five-petaled, followed by six-petaled;…

  14. Synchrony in the phenology of a culturally iconic spring flower

    NASA Astrophysics Data System (ADS)

    Sparks, Tim H.; Mizera, Tadeusz; Wójtowicz, Wanda; Tryjanowski, Piotr

    2012-03-01

    We examine the flowering phenology of the cultural iconic Spring Snowflake Leucojum vernum, a considerable tourist attraction, recorded from two sites in western Poland. Flowering dates at the two sites were closely correlated but about 6 days later at the more natural area. The end of flowering was associated with the start of canopy leafing. Early flowering was related to a longer flowering season which may benefit ecotourism under future climate warming.

  15. Synchrony in the phenology of a culturally iconic spring flower.

    PubMed

    Sparks, Tim H; Mizera, Tadeusz; Wójtowicz, Wanda; Tryjanowski, Piotr

    2012-03-01

    We examine the flowering phenology of the cultural iconic Spring Snowflake Leucojum vernum, a considerable tourist attraction, recorded from two sites in western Poland. Flowering dates at the two sites were closely correlated but about 6 days later at the more natural area. The end of flowering was associated with the start of canopy leafing. Early flowering was related to a longer flowering season which may benefit ecotourism under future climate warming. PMID:21547445

  16. Guidelines for growing perennial grasses for biofuel and bioproducts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Guidelines for growing perennial grasses for biofuel and bioproducts Rob Mitchell Abstract: Switchgrass, big bluestem, and warm-season grass mixtures provide numerous benefits. Existing field equipment, herbicides, and cultivar improvement promote rapid establishment in the planting year. These gra...

  17. Pollination Services of Mango Flower Pollinators.

    PubMed

    Huda, A Nurul; Salmah, M R Che; Hassan, A Abu; Hamdan, A; Razak, M N Abdul

    2015-01-01

    Measuring wild pollinator services in agricultural production is very important in the context of sustainable management. In this study, we estimated the contribution of native pollinators to mango fruit set production of two mango cultivars Mangifera indica (L). cv. 'Sala' and 'Chok Anan'. Visitation rates of pollinators on mango flowers and number of pollen grains adhering to their bodies determined pollinator efficiency for reproductive success of the crop. Chok Anan failed to produce any fruit set in the absence of pollinators. In natural condition, we found that Sala produced 4.8% fruit set per hermaphrodite flower while Chok Anan produced 3.1% per flower. Hand pollination tremendously increased fruit set of naturally pollinated flower for Sala (>100%), but only 33% for Chok Anan. Pollinator contribution to mango fruit set was estimated at 53% of total fruit set production. Our results highlighted the importance of insect pollinations in mango production. Large size flies Eristalinus spp. and Chrysomya spp. were found to be effective pollen carriers and visited more mango flowers compared with other flower visitors. PMID:26246439

  18. Pollination Services of Mango Flower Pollinators

    PubMed Central

    Huda, A. Nurul; Salmah, M. R. Che; Hassan, A. Abu; Hamdan, A.; Razak, M. N. Abdul

    2015-01-01

    Measuring wild pollinator services in agricultural production is very important in the context of sustainable management. In this study, we estimated the contribution of native pollinators to mango fruit set production of two mango cultivars Mangifera indica (L). cv. ‘Sala’ and ‘Chok Anan’. Visitation rates of pollinators on mango flowers and number of pollen grains adhering to their bodies determined pollinator efficiency for reproductive success of the crop. Chok Anan failed to produce any fruit set in the absence of pollinators. In natural condition, we found that Sala produced 4.8% fruit set per hermaphrodite flower while Chok Anan produced 3.1% per flower. Hand pollination tremendously increased fruit set of naturally pollinated flower for Sala (>100%), but only 33% for Chok Anan. Pollinator contribution to mango fruit set was estimated at 53% of total fruit set production. Our results highlighted the importance of insect pollinations in mango production. Large size flies Eristalinus spp. and Chrysomya spp. were found to be effective pollen carriers and visited more mango flowers compared with other flower visitors. PMID:26246439

  19. Trees as huge flowers and flowers as oversized floral guides: the role of floral color change and retention of old flowers in Tibouchina pulchra

    PubMed Central

    Brito, Vinícius L. G.; Weynans, Kevin; Sazima, Marlies; Lunau, Klaus

    2015-01-01

    Floral color changes and retention of old flowers are frequently combined phenomena restricted to the floral guide or single flowers in few-flowered inflorescences. They are thought to increase the attractiveness over long distances and to direct nearby pollinators toward the rewarding flowers. In Tibouchina pulchra, a massively flowering tree, the whole flower changes its color during anthesis. On the first day, the flowers are white and on the next 3 days, they change to pink. This creates a new large-scale color pattern in which the white pre-changed flowers contrast against the pink post-changed ones over the entire tree. We describe the spectral characteristics of floral colors of T. pulchra and test bumblebees’ response to this color pattern when viewed at different angles (simulating long and short distances). The results indicated the role of different color components in bumblebee attraction and the possible scenario in which this flower color pattern has evolved. We tested bumblebees’ preference for simulated trees with 75% pink and 25% white flowers resembling the color patterns of T. pulchra, and trees with green leaves and pink flowers (control) in long-distance approach. We also compared an artificial setting with three pink flowers and one white flower (T. pulchra model) against four pink flowers with white floral guides (control) in short-distance approach. Bumblebees spontaneously preferred the simulated T. pulchra patterns in both approaches despite similar reward. Moreover, in short distances, pollinator visits to peripheral, non-rewarding flowers occurred only half as frequently in the simulated T. pulchra when compared to the control. Thefore, this exceptional floral color change and the retention of old flowers in T. pulchra favors the attraction of pollinators over long distances in a deception process while it honestly directs them toward the rewarding flowers at short distances possibly exploring their innate color preferences. PMID

  20. Ring Beholds a Delicate Flower

    NASA Technical Reports Server (NTRS)

    2005-01-01

    NASA's Spitzer Space Telescope finds a delicate flower in the Ring Nebula, as shown in this image. The outer shell of this planetary nebula looks surprisingly similar to the delicate petals of a camellia blossom. A planetary nebula is a shell of material ejected from a dying star. Located about 2,000 light years from Earth in the constellation Lyra, the Ring Nebula is also known as Messier Object 57 and NGC 6720. It is one of the best examples of a planetary nebula and a favorite target of amateur astronomers.

    The 'ring' is a thick cylinder of glowing gas and dust around the doomed star. As the star begins to run out of fuel, its core becomes smaller and hotter, boiling off its outer layers. The telescope's infrared array camera detected this material expelled from the withering star. Previous images of the Ring Nebula taken by visible-light telescopes usually showed just the inner glowing loop of gas around the star. The outer regions are especially prominent in this new image because Spitzer sees the infrared light from hydrogen molecules. The molecules emit infrared light because they have absorbed ultraviolet radiation from the star or have been heated by the wind from the star.

    Download the QuickTime movie for the animated version of this Ring Nebula image.

  1. Phytochrome, plant growth and flowering

    NASA Technical Reports Server (NTRS)

    King, R. W.; Bagnall, D. J.

    1994-01-01

    Attempts to use artificially lit cabinets to grow plants identical to those growing in sunlight have provided compelling evidence of the importance of light quality for plant growth. Changing the balance of red (R) to far-red (FR) radiation, but with a fixed photosynthetic input can shift the phytochrome photoequilibrium in a plant and generate large differences in plant growth. With FR enrichment the plants elongate, and may produce more leaf area and dry matter. Similar morphogenic responses are also obtained when light quality is altered only briefly (15-30 min) at the end-of-the-day. Conversely, for plants grown in natural conditions the response of plant form to selective spectral filtering has again shown that red and far-red wavebands are important as found by Kasperbauer and coworkers. Also, where photosynthetic photon flux densities (PPFD) of sunlight have been held constant, the removal of far-red alone alters plant growth. With FR depletion plants grown in sunlight are small, more branched and darker green. Here we examine the implications for plant growth and flowering when the far-red composition of incident radiation in plant growth chambers is manipulated.

  2. Native Grasses as a Management Alternative on Vegetated Closure Caps

    NASA Astrophysics Data System (ADS)

    Kwit, Charles; Collins, Beverly

    2008-06-01

    Capped waste sites often are vegetated with commercial turf grasses to increase evapotranspiration and prevent erosion and possible exposure of the barrier. Fertilizer, frequent watering, and mowing may be required to establish the turf grass and prevent invasion by trees and shrubs. Oldfield vegetation of grasses and forbs is a possible sustainable alternative to turf grass communities. To determine if oldfield vegetation can establish on caps, we (1) compared establishment of a dominant oldfield grass and a commercial turf grass under different combinations of new closure cap management: spring or summer planting and presence or absence of amendments to alleviate drought (watering, mulch) or increase soil fertility (fertilizer, lime, a nitrogen-fixing legume); (2) surveyed existing caps to determine if oldfield species establish naturally; and (3) performed a greenhouse experiment to compare growth of two native grasses under low and amended (added water, soil nutrients) conditions. Both the commercial grass and oldfield species established under new cap conditions; fertilizer, water, and mulch improved vegetation establishment in spring or summer, but legumes decreased grass cover. In the greenhouse, both native grasses grew best with amendments; however, substantial stem and root length were obtained with no fertilizer and only once-weekly watering. Existing vegetated caps supported planted grasses and naturally established oldfield species. Overall, the results indicate native grasses can establish on new caps and oldfields can serve as a management model; further work is needed to determine the management strategy to maintain herbaceous vegetation and slow woody species invasion.

  3. Native Warm Season Grasses in the National Plant Germplasm System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA National Plant Germplasm System (NPGS) warm-season grass collection which is maintained in Griffin, Georgia currently has over 7300 accessions of which less than ten percent of the collection can be classified as native grass material. This native grass material has been collected from dif...

  4. Isotopic signatures of vegetation change on northern mixed grass prairie

    Technology Transfer Automated Retrieval System (TEKTRAN)

    National analyses have shown invasion of northern mixed-grass prairie by nonnative grasses such as Kentucky bluegrass (Poa pratensis L.). Invasion of native prairie by nonnative grasses may compromise ecosystem function and limit potential ecosystem services. Recent data from a long-term (100 year) ...

  5. A Tensile Strength of Bermuda Grass and Vetiver Grass in Terms of Root Reinforcement Ability Toward Soil Slope Stabilization

    NASA Astrophysics Data System (ADS)

    Noorasyikin, M. N.; Zainab, M.

    2016-07-01

    An examination on root characteristics and root properties has been implemented in this study. Two types of bioengineering were chose which are Vetiver grass and Bermuda grass as these grasses were widely applied for slope stabilization. The root samples were taken to the laboratory to investigate its classification, characteristics and strength. The root of both grasses was found grow with fibrous root matrix system. In terms of root anchorage, the root matrix system of Vetiver grass was exhibits more strengthen than the Bermuda grass. However, observation on root image from Scanning Electron Microscope test reveals that the root of Vetiver grass becomes non-porous as the moisture content reduced. Meanwhile, the root tensile strength of Bermuda grass was obtained acquired low value with higher percentage of moisture content, root morphology and bonding strength. The results indicated that the root tensile strength is mainly influence by percentage of moisture content and root morphology.

  6. Grassroots e-floras in the Poaceae: growing GrassBase and GrassWorld

    PubMed Central

    Vorontsova, Maria S.; Clayton, Derek; Simon, Bryan K.

    2015-01-01

    Abstract GrassBase and GrassWorld are the largest structured descriptive datasets in plants, publishing descriptions of 11,290 species in the DELTA format. Twenty nine years of data compilation and maintenance have created a dataset which now underpins much of the Poaceae bioinformatics. GrassBase and GrassWorld can continue to grow productively if the proliferation of alternative classifications and datasets can be brought together into a consensus system. If the datasets are reconciled instead of diverging further apart a long term cumulative process can bring knowledge together for great future utility. This paper presents the Poaceae as the first and largest model system for e-taxonomy and the study of classification development in plants. The origin, development, and content of both datasets is described and key contributors are noted. The challenges of alternative classifications, data divergence, collaborative contribution mechanisms, and software are outlined. PMID:25941449

  7. Basin wildrye: the forgotten grass revisited

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Basin wildrye was once a very abundant and widely occurring species throughout the landscapes of northern Nevada. When Captain Simpson, of the topographical Engineers, explored the route for a wagon road across the central Great Basin he marveled at the grass in the valley bottoms that reached to h...

  8. Common Ground for Managing Invasive Annual Grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive annual grasses often reach their full biological potential in ecosystems of the western United States. This suggests that crucial ecosystem "checks and balances" are not functioning. In other words, invasion occurs because ecosystems have lost resistance to invasion, and invasive plants a...

  9. Challenging Cancer at the Grass Roots.

    ERIC Educational Resources Information Center

    Casto, James E.

    1997-01-01

    The National Cancer Institute created the Appalachia Leadership Initiative on Cancer, composed of four similar projects that focus on increasing screening for cervical and breast cancer among low-income, older women. The program relies on community coalitions that develop innovative grass roots methods to spread the message about the importance of…

  10. Annual grass as supplements for beef cows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research has shown when limit grazing cool-season annual grasses as a supplement in a complementary forage system, energy and CP supplementation are not required and hay requirements are reduced 23% for gestating beef cows. To further improve the sustainability of complementary forage systems, repla...

  11. Grass Woman Stories. Blackfeet Heritage Program.

    ERIC Educational Resources Information Center

    Ground, Mary

    During her lifetime Mary Ground, whose Indian name is Grass Woman, has experienced extreme changes in the life of Blackfeet Indians. Born in 1883, she remembers the travois and teepee days as well as the change to reservation life when the reservation was a fenced compound patrolled by the U.S. military. She has seen the decline in the use of…

  12. Project GRADS (Grass Roots Alternative Diploma Study).

    ERIC Educational Resources Information Center

    Kimmel, Harold S.; Lucas, Geoffrey S.

    A project to develop grass roots alternative diploma study (Project GRADS) was undertaken for the purpose of formulating and implementing a multimodal, systems approach to preparing rural adults to pass the General Educational Development (GED) Tests. During the year-long, countywide program, GED programming was developed and delivered via the…

  13. Wheatgrass and Wildrye Grasses (Triticeae) (Book Chapter)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheatgrass and wildrye grasses are valued throughout the temperature regions of the world as forage and habitat for livestock and wildlife as well as for other qualities relating to aesthetics, soil stabilization, weed control, and watershed management in semiarid environments. These perennial gras...

  14. Grasses and Legumes: Genetics and Plant Breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Humans have been breeding forage and turf species for over 100 years. This chapter explores the progress that has been made in improving grasses and legumes for human benefit and the evolution of breeding and selection systems that have brought about those changes....

  15. INTESPECIIC DIFFERENCES IN GRASS SEED IMBIBITION

    EPA Science Inventory

    Seeds from 12 grass species were studied relative to mode of wetting and time of exposure to water to document interspecific differences in imbibition characteristics. Imbibition causes seeds to become wet, and wet seeds are more detectable to consumers than dry seeds. Thus, ge...

  16. Grass roots of soil carbon sequestration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soils rooted with perennial grasses have high organic matter content, and therefore, can contribute to an agricultural future with high soil quality; a condition that can help to mitigate greenhouse gas emissions through soil carbon sequestration and improve a multitude of other ecosystem responses,...

  17. Exotic plant infestation is associated with decreased modularity and increased numbers of connectors in mixed-grass prairie pollination networks

    USGS Publications Warehouse

    Larson, Diane L.; Rabie, Paul A.; Droege, Sam; Larson, Jennifer L.; Haar, Milton

    2016-01-01

    The majority of pollinating insects are generalists whose lifetimes overlap flowering periods of many potentially suitable plant species. Such generality is instrumental in allowing exotic plant species to invade pollination networks. The particulars of how existing networks change in response to an invasive plant over the course of its phenology are not well characterized, but may shed light on the probability of long-term effects on plant-pollinator interactions and the stability of network structure. Here we describe changes in network topology and modular structure of infested and non-infested networks during the flowering season of the generalist non-native flowering plant, Cirsium arvense in mixed-grass prairie at Badlands National Park, South Dakota, USA. Objectives were to compare network-level effects of infestation as they propagate over the season in infested and non-infested (with respect to C. arvense) networks. We characterized plant-pollinator networks on 5 non-infested and 7 infested 1-ha plots during 4 sample periods that collectively covered the length of C. arvense flowering period. Two other abundantly-flowering invasive plants were present during this time: Melilotus officinalis had highly variable floral abundance in both C. arvense-infested and non-infested plots andConvolvulus arvensis, which occurred almost exclusively in infested plots and peaked early in the season. Modularity, including roles of individual species, and network topology were assessed for each sample period as well as in pooled infested and non-infested networks. Differences in modularity and network metrics between infested and non-infested networks were limited to the third and fourth sample periods, during flower senescence of C. arvenseand the other invasive species; generality of pollinators rose concurrently, suggesting rewiring of the network and a lag effect of earlier floral abundance. Modularity was lower and number of connectors higher in infested

  18. Exotic Plant Infestation Is Associated with Decreased Modularity and Increased Numbers of Connectors in Mixed-Grass Prairie Pollination Networks

    PubMed Central

    Larson, Diane L.; Rabie, Paul A.; Droege, Sam; Larson, Jennifer L.; Haar, Milton

    2016-01-01

    The majority of pollinating insects are generalists whose lifetimes overlap flowering periods of many potentially suitable plant species. Such generality is instrumental in allowing exotic plant species to invade pollination networks. The particulars of how existing networks change in response to an invasive plant over the course of its phenology are not well characterized, but may shed light on the probability of long-term effects on plant-pollinator interactions and the stability of network structure. Here we describe changes in network topology and modular structure of infested and non-infested networks during the flowering season of the generalist non-native flowering plant, Cirsium arvense in mixed-grass prairie at Badlands National Park, South Dakota, USA. Objectives were to compare network-level effects of infestation as they propagate over the season in infested and non-infested (with respect to C. arvense) networks. We characterized plant-pollinator networks on 5 non-infested and 7 infested 1-ha plots during 4 sample periods that collectively covered the length of C. arvense flowering period. Two other abundantly-flowering invasive plants were present during this time: Melilotus officinalis had highly variable floral abundance in both C. arvense-infested and non-infested plots and Convolvulus arvensis, which occurred almost exclusively in infested plots and peaked early in the season. Modularity, including roles of individual species, and network topology were assessed for each sample period as well as in pooled infested and non-infested networks. Differences in modularity and network metrics between infested and non-infested networks were limited to the third and fourth sample periods, during flower senescence of C. arvense and the other invasive species; generality of pollinators rose concurrently, suggesting rewiring of the network and a lag effect of earlier floral abundance. Modularity was lower and number of connectors higher in infested networks

  19. Exotic Plant Infestation Is Associated with Decreased Modularity and Increased Numbers of Connectors in Mixed-Grass Prairie Pollination Networks.

    PubMed

    Larson, Diane L; Rabie, Paul A; Droege, Sam; Larson, Jennifer L; Haar, Milton

    2016-01-01

    The majority of pollinating insects are generalists whose lifetimes overlap flowering periods of many potentially suitable plant species. Such generality is instrumental in allowing exotic plant species to invade pollination networks. The particulars of how existing networks change in response to an invasive plant over the course of its phenology are not well characterized, but may shed light on the probability of long-term effects on plant-pollinator interactions and the stability of network structure. Here we describe changes in network topology and modular structure of infested and non-infested networks during the flowering season of the generalist non-native flowering plant, Cirsium arvense in mixed-grass prairie at Badlands National Park, South Dakota, USA. Objectives were to compare network-level effects of infestation as they propagate over the season in infested and non-infested (with respect to C. arvense) networks. We characterized plant-pollinator networks on 5 non-infested and 7 infested 1-ha plots during 4 sample periods that collectively covered the length of C. arvense flowering period. Two other abundantly-flowering invasive plants were present during this time: Melilotus officinalis had highly variable floral abundance in both C. arvense-infested and non-infested plots and Convolvulus arvensis, which occurred almost exclusively in infested plots and peaked early in the season. Modularity, including roles of individual species, and network topology were assessed for each sample period as well as in pooled infested and non-infested networks. Differences in modularity and network metrics between infested and non-infested networks were limited to the third and fourth sample periods, during flower senescence of C. arvense and the other invasive species; generality of pollinators rose concurrently, suggesting rewiring of the network and a lag effect of earlier floral abundance. Modularity was lower and number of connectors higher in infested networks

  20. First flowering dates and flowering periods of prairie plants at Woodworth, North Dakota

    USGS Publications Warehouse

    Callow, J.M.; Kantrud, H.A.; Higgins, K.F.

    1992-01-01

    We recorded flowering events for 97 species of prairie plants for 2-6 years near Woodworth, ND. Earliest and latest flower initiation dates varied by year. Temperature seemed much more important than precipitation in influencing phenology of species that bloom from late March through May, but no strong climatic effect was evident for plants that bloom later in the growing season.

  1. A Stochastic Flowering Model Describing an Asynchronically Flowering Set of Trees

    PubMed Central

    NORMAND, F.; HABIB, R.; CHADŒUF, J.

    2002-01-01

    A general stochastic model is presented that simulates the time course of flowering of individual trees and populations, integrating the synchronization of flowering both between and within trees. Making some hypotheses, a simplified expression of the model, called the ‘shoot’ model, is proposed, in which the synchronization of flowering both between and within trees is characterized by specific parameters. Two derived models, the ‘tree’ model and the ‘population’ model, are presented. They neglect the asynchrony of flowering, respectively, within trees, and between and within trees. Models were fitted and tested using data on flowering of Psidium cattleianum observed at study sites at elevations of 200, 520 and 890 m in Réunion Island. The ‘shoot’ model fitted the data best and reproduced the strong irregularities in flowering shown by empirical data. The asynchrony of flowering in P. cattleianum was more pronounced within than between trees. Simulations showed that various flowering patterns can be reproduced by the ‘shoot’ model. The use of different levels of organization of the general model is discussed. PMID:12234153

  2. Thunderstorm asthma due to grass pollen.

    PubMed

    Suphioglu, C

    1998-08-01

    It is widely known and accepted that grass pollen is a major outdoor cause of hay fever. Moreover, grass pollen is also responsible for triggering allergic asthma, gaining impetus as a result of the 1987/1989 Melbourne and 1994 London thunderstorm-associated asthma epidemics. However, grass pollen is too large to gain access into the lower airways to trigger the asthmatic response and micronic particles <5 micro m are required to trigger the response. We have successfully shown that ryegrass pollen ruptures upon contact with water, releasing about 700 starch granules which not only contain the major allergen Lol p 5, but have been shown to trigger both in vitro and in vivo IgE-mediated responses. Furthermore, starch granules have been isolated from the Melbourne atmosphere with 50-fold increase following rainfall. Free grass pollen allergen molecules have been recently shown to interact with other particles including diesel exhaust carbon particles, providing a further transport mechanism for allergens to gain access into lower airways. In this review, implication and evidence for grass pollen as a trigger of thunderstorm-associated asthma is presented. Such information is critical and mandatory for patient education and training in their allergen avoidance programs. More importantly, patients with serum IgE to group 5 allergens are at high risk of allergic asthma, especially those not protected by medication. Therefore, a system to determine the total atmospheric allergen load and devising of an effective asthma risk forecast is urgently needed and is subject to current investigation. PMID:9693274

  3. Elucidating novel disease mechanisms in severe asthma.

    PubMed

    Kim, Richard Y; Rae, Brittany; Neal, Rachel; Donovan, Chantal; Pinkerton, James; Balachandran, Lohis; Starkey, Malcolm R; Knight, Darryl A; Horvat, Jay C; Hansbro, Philip M

    2016-07-01

    Corticosteroids are broadly active and potent anti-inflammatory agents that, despite the introduction of biologics, remain as the mainstay therapy for many chronic inflammatory diseases, including inflammatory bowel diseases, nephrotic syndrome, rheumatoid arthritis, chronic obstructive pulmonary disease and asthma. Significantly, there are cohorts of these patients with poor sensitivity to steroid treatment even with high doses, which can lead to many iatrogenic side effects. The dose-limiting toxicity of corticosteroids, and the lack of effective therapeutic alternatives, leads to substantial excess morbidity and healthcare expenditure. We have developed novel murine models of respiratory infection-induced, severe, steroid-resistant asthma that recapitulate the hallmark features of the human disease. These models can be used to elucidate novel disease mechanisms and identify new therapeutic targets in severe asthma. Hypothesis-driven studies can elucidate the roles of specific factors and pathways. Alternatively, 'Omics approaches can be used to rapidly generate new targets. Similar approaches can be used in other diseases. PMID:27525064

  4. Elucidating novel disease mechanisms in severe asthma

    PubMed Central

    Kim, Richard Y; Rae, Brittany; Neal, Rachel; Donovan, Chantal; Pinkerton, James; Balachandran, Lohis; Starkey, Malcolm R; Knight, Darryl A; Horvat, Jay C; Hansbro, Philip M

    2016-01-01

    Corticosteroids are broadly active and potent anti-inflammatory agents that, despite the introduction of biologics, remain as the mainstay therapy for many chronic inflammatory diseases, including inflammatory bowel diseases, nephrotic syndrome, rheumatoid arthritis, chronic obstructive pulmonary disease and asthma. Significantly, there are cohorts of these patients with poor sensitivity to steroid treatment even with high doses, which can lead to many iatrogenic side effects. The dose-limiting toxicity of corticosteroids, and the lack of effective therapeutic alternatives, leads to substantial excess morbidity and healthcare expenditure. We have developed novel murine models of respiratory infection-induced, severe, steroid-resistant asthma that recapitulate the hallmark features of the human disease. These models can be used to elucidate novel disease mechanisms and identify new therapeutic targets in severe asthma. Hypothesis-driven studies can elucidate the roles of specific factors and pathways. Alternatively, 'Omics approaches can be used to rapidly generate new targets. Similar approaches can be used in other diseases. PMID:27525064

  5. Identification of a R2R3-MYB gene regulating anthocyanin biosynthesis and relationships between its variation and flower color difference in lotus (Nelumbo Adans.)

    PubMed Central

    Sun, Shan-Shan

    2016-01-01

    The lotus (Nelumbonaceae: Nelumbo Adans.) is a highly desired ornamental plant, comprising only two extant species, the sacred lotus (N. nucifera Gaerten.) with red flowers and the American lotus (N. lutea Willd.) with yellow flowers. Flower color is the most obvious difference of two species. To better understand the mechanism of flower color differentiation, the content of anthocyanins and the expression levels of four key structural genes (e.g., DFR, ANS, UFGT and GST) were analyzed in two species. Our results revealed that anthocyanins were detected in red flowers, not yellow flowers. Expression analysis showed that no transcripts of GST gene and low expression level of three UFGT genes were detected in yellow flowers. In addition, three regulatory genes (NnMYB5, NnbHLH1 and NnTTG1) were isolated from red flowers and showed a high similarity to corresponding regulatory genes of other species. Sequence analysis of MYB5, bHLH1 and TTG1 in two species revealed striking differences in coding region and promoter region of MYB5 gene. Population analysis identified three MYB5 variants in Nelumbo: a functional allele existed in red flowers and two inactive forms existed in yellow flowers. This result revealed that there was an association between allelic variation in MYB5 gene and flower color difference. Yeast two-hybrid experiments showed that NnMYB5 interacts with NnbHLH1, NlbHLH1 and NnTTG1, and NnTTG1 also interacts with NnbHLH1 and NlbHLH1. The over-expression of NnMYB5 led to anthocyanin accumulation in immature seeds and flower stalks and up-regulation of expression of TT19 in Arabidopsis. Therefore, NnMYB5 is a transcription activator of anthocyanin synthesis. This study helps to elucidate the function of NnMYB5 and will contribute to clarify the mechanism of flower coloration and genetic engineering of flower color in lotus.

  6. Flower volatiles, crop varieties and bee responses.

    PubMed

    Klatt, Björn K; Burmeister, Carina; Westphal, Catrin; Tscharntke, Teja; von Fragstein, Maximilian; von Fragstein, Maximillian

    2013-01-01

    Pollination contributes to an estimated one third of global food production, through both the improvement of the yield and the quality of crops. Volatile compounds emitted by crop flowers mediate plant-pollinator interactions, but differences between crop varieties are still little explored. We investigated whether the visitation of crop flowers is determined by variety-specific flower volatiles using strawberry varieties (Fragaria x ananassa Duchesne) and how this affects the pollination services of the wild bee Osmia bicornis L. Flower volatile compounds of three strawberry varieties were measured via headspace collection. Gas chromatography showed that the three strawberry varieties produced the same volatile compounds but with quantitative differences of the total amount of volatiles and between distinct compounds. Electroantennographic recordings showed that inexperienced females of Osmia bicornis had higher antennal responses to all volatile compounds than to controls of air and paraffin oil, however responses differed between compounds. The variety Sonata was found to emit a total higher level of volatiles and also higher levels of most of the compounds that evoked antennal responses compared with the other varieties Honeoye and Darselect. Sonata also received more flower visits from Osmia bicornis females under field conditions, compared with Honeoye. Our results suggest that differences in the emission of flower volatile compounds among strawberry varieties mediate their attractiveness to females of Osmia bicornis. Since quality and quantity of marketable fruits depend on optimal pollination, a better understanding of the role of flower volatiles in crop production is required and should be considered more closely in crop-variety breeding. PMID:23977347

  7. Flower power: Tree flowering phenology as a settlement cue for migrating birds

    USGS Publications Warehouse

    McGrath, L.J.; van Riper, Charles, III; Fontaine, J.J.

    2009-01-01

    1. Neotropical migrant birds show a clear preference for stopover habitats with ample food supplies; yet, the proximate cues underlying these decisions remain unclear. 2. For insectivorous migrants, cues associated with vegetative phenology (e.g. flowering, leaf flush, and leaf loss) may reliably predict the availability of herbivorous arthropods. Here we examined whether migrants use the phenology of five tree species to choose stopover locations, and whether phenology accurately predicts food availability. 3. Using a combination of experimental and observational evidence, we show migrant populations closely track tree phenology, particularly the flowering phenology of honey mesquite (Prosopis glandulosa), and preferentially forage in trees with more flowers. Furthermore, the flowering phenology of honey mesquite reliably predicts overall arthropod abundance as well as the arthropods preferred by migrants for food. 4. Together, these results suggest that honey mesquite flowering phenology is an important cue used by migrants to assess food availability quickly and reliably, while in transit during spring migration. ?? 2008 The Authors.

  8. Heat Shock Proteins in Association with Heat Tolerance in Grasses

    PubMed Central

    Xu, Yan; Zhan, Chenyang; Huang, Bingru

    2011-01-01

    The grass family Poaceae includes annual species cultivated as major grain crops and perennial species cultivated as forage or turf grasses. Heat stress is a primary factor limiting growth and productivity of cool-season grass species and is becoming a more significant problem in the context of global warming. Plants have developed various mechanisms in heat-stress adaptation, including changes in protein metabolism such as the induction of heat shock proteins (HSPs). This paper summarizes the structure and function of major HSPs, recent research progress on the association of HSPs with grass tolerance to heat stress, and incorporation of HSPs in heat-tolerant grass breeding. PMID:22084689

  9. Mineral and metabolic profiles in tea leaves and flowers during flower development.

    PubMed

    Jia, Sisi; Wang, Yu; Hu, Jianhui; Ding, Zhaotang; Liang, Qing; Zhang, Yinfei; Wang, Hui

    2016-09-01

    Tea [Camellia sinensis (L.) O. Kuntze] is one of the most popular non-alcoholic beverage crops in the world, and the physiological processes and gene regulations involved in development in tea plants have been well characterized. However, relatively little is known about the metabolic changes combined with mineral distributions that occur during flower development. Here we detected the contents of 11 elements in tea leaves and flowers and found that, some of them, especially phosphorus, sulfur and copper, showed significant changes during tea flowering. We also detected 122 metabolites in tea leaves and flowers and found that, 72 of them showed significant differences between flowers and leaves, of which sugars, organic acids, and flavonoids dominated. The sugars, such as trehalose and galactose, all accumulated in tea flowers, and the organic acids, such as malic acid, citric acid and fumaric acid involved in TCA cycle. The flavonoids, like epicatechin, catechin gallate and epigallocatechin, were more abundant in leaves. Furthermore, we found that the contents of 33 metabolites changed during the development of flowers. Especially, citric acid, phenylalanine and most flavonoids decreased while fructose and galactose increased during flowering stages in flowers. We also analyzed the correlations between the ions and metabolites and found that, some mineral nutrients including phosphorus, sulfur, manganese and zinc had close relations to organic acids, flavonoids, sugars and several amino acids during flowering. We mapped the metabolic pathway according to the KEGG database. This work will serve as the foundation for a systems biology approach to the understanding of mineral metabolism. PMID:27372442

  10. The contribution of trees and grasses to productivity of an Australian tropical savanna

    NASA Astrophysics Data System (ADS)

    Moore, C. E.; Beringer, J.; Evans, B.; Hutley, L. B.; McHugh, I.; Tapper, N. J.

    2015-12-01

    Savanna ecosystems cover 20 % of the global land surface and account for 25 % of global terrestrial carbon uptake. They support one fifth of the world's human population and are one of the most important ecosystems on our planet. Savanna productivity is a product of the interplay between trees and grass that co-dominate savanna landscapes and are maintained through interactions with climate and disturbance (fire, land use change, herbivory). In this study, we evaluate the temporally dynamic partitioning of overstory and understory carbon dioxide fluxes in Australian tropical savanna using overstory and understory eddy covariance measurements. Over a two year period (September 2012 to October 2014) the overall net ecosystem productivity (NEP) of the savanna was 506.2 (±22 SE) g C m-2 yr-1. The total gross primary productivity (GPP) was 2267.1 (±80 SE) g C m-2 yr-1, of which the understory contributed 32 %. The understory contribution was strongly seasonal, with most GPP occurring in the wet season (40 % of total ecosystem in the wet season and 18 % in the dry). This study is the first to elucidate the temporal dynamics of savanna understory and overstory carbon flux components explicitly using observational information. Understanding grass productivity is crucial for evaluating fuel loads, as is tree productivity for quantifying the tree carbon sink. This information will contribute to a significant refinement of the representation of savannas in models, as well as improved understanding of relative tree-grass productivity and competition for resources.

  11. The contribution of trees and grasses to productivity of an Australian tropical savanna

    NASA Astrophysics Data System (ADS)

    Moore, Caitlin E.; Beringer, Jason; Evans, Bradley; Hutley, Lindsay B.; McHugh, Ian; Tapper, Nigel J.

    2016-04-01

    Savanna ecosystems cover 20 % of the global land surface and account for 25 % of global terrestrial carbon uptake. They support one fifth of the world's human population and are one of the most important ecosystems on our planet. Savanna productivity is a product of the interplay between trees and grass that co-dominate savanna landscapes and are maintained through interactions with climate and disturbance (fire, land use change, herbivory). In this study, we evaluate the temporally dynamic partitioning of overstory and understory carbon dioxide fluxes in Australian tropical savanna using overstory and understory eddy covariance measurements. Over a 2-year period (September 2012 to October 2014) the overall net ecosystem productivity (NEP) of the savanna was 506.2 (±22 SE) g C m-2 yr-1. The total gross primary productivity (GPP) was 2267.1 (±80 SE) g C m-2 yr-1, of which the understory contributed 32 %. The understory contribution was strongly seasonal, with most GPP occurring in the wet season (40 % of total ecosystem in the wet season and 18 % in the dry). This study is the first to elucidate the temporal dynamics of savanna understory and overstory carbon flux components explicitly using observational information. Understanding grass productivity is crucial for evaluating fuel loads, as is tree productivity for quantifying the tree carbon sink. This information will contribute to a significant refinement of the representation of savannas in models, as well as improved understanding of relative tree-grass productivity and competition for resources.

  12. Infection of Brachypodium distachyon with selected grass rust pathogens.

    PubMed

    Ayliffe, Michael; Singh, Davinder; Park, Robert; Moscou, Matthew; Pryor, Tony

    2013-08-01

    The model temperate grass Brachypodium distachyon is considered a nonhost for wheat rust diseases caused by Puccinia graminis f. sp. tritici, P. triticina, and P. striiformis. Up to 140 Brachypodium accessions were infected with these three rust species, in addition to P. graminis ff. spp. avena and phalaridis. Related B. distachyon lines showed similar cytological nonhost resistance (NHR) phenotypes, and an inverse relationship between P. graminis f. sp. tritici and P. striiformis growth was observed in many lines, with accessions that allowed the most growth of P. graminis f. sp. tritici showing the least P. striiformis development and vice versa. Callose deposition patterns during infection by all three rust species showed similarity to the wheat basal defense response while cell death that resulted in autofluorescence did not appear to be a major component of the defense response. Infection of B. distachyon with P. graminis f. sp. avena and P. graminis f. sp. phalaridis produced much greater colonization, indicating that P. graminis rusts with Poeae hosts show greater ability to infect B. distachyon than those with Triticeae hosts. P. striiformis infection of progeny from two B. distachyon families demonstrated that these NHR phenotypes are highly heritable and appear to be under relatively simple genetic control, making this species a powerful tool for elucidating the molecular basis of NHR to cereal rust pathogens. PMID:23594350

  13. Nowcasting daily minimum air and grass temperature

    NASA Astrophysics Data System (ADS)

    Savage, M. J.

    2016-02-01

    Site-specific and accurate prediction of daily minimum air and grass temperatures, made available online several hours before their occurrence, would be of significant benefit to several economic sectors and for planning human activities. Site-specific and reasonably accurate nowcasts of daily minimum temperature several hours before its occurrence, using measured sub-hourly temperatures hours earlier in the morning as model inputs, was investigated. Various temperature models were tested for their ability to accurately nowcast daily minimum temperatures 2 or 4 h before sunrise. Temperature datasets used for the model nowcasts included sub-hourly grass and grass-surface (infrared) temperatures from one location in South Africa and air temperature from four subtropical sites varying in altitude (USA and South Africa) and from one site in central sub-Saharan Africa. Nowcast models used employed either exponential or square root functions to describe the rate of nighttime temperature decrease but inverted so as to determine the minimum temperature. The models were also applied in near real-time using an open web-based system to display the nowcasts. Extrapolation algorithms for the site-specific nowcasts were also implemented in a datalogger in an innovative and mathematically consistent manner. Comparison of model 1 (exponential) nowcasts vs measured daily minima air temperatures yielded root mean square errors (RMSEs) <1 °C for the 2-h ahead nowcasts. Model 2 (also exponential), for which a constant model coefficient ( b = 2.2) was used, was usually slightly less accurate but still with RMSEs <1 °C. Use of model 3 (square root) yielded increased RMSEs for the 2-h ahead comparisons between nowcasted and measured daily minima air temperature, increasing to 1.4 °C for some sites. For all sites for all models, the comparisons for the 4-h ahead air temperature nowcasts generally yielded increased RMSEs, <2.1 °C. Comparisons for all model nowcasts of the daily grass

  14. Photosynthetic carbon metabolism of a marine grass.

    PubMed

    Benedict, C R; Scott, J R

    1976-06-01

    The delta(13)C value of a tropical marine grass Thalassia testudinum is -9.04 per thousand. This value is similar to the delta(13)C value of terrestrial tropical grasses. The delta(13)C values of the organic acid fraction, the amino acid fraction, the sugar fraction, malic acid, and glucose are: -11.2 per thousand, -13.1 per thousand, -10.1 per thousand, -11.1 per thousand, and -11.5 per thousand, respectively. The delta(13)C values of malic acid and glucose of Thalassia are similar to the delta(13)C values of these intermediates in sorghum leaves and attest to the presence of the photosynthetic C(4)-dicarboxylic acid pathway in this marine grass. The inorganic HCO(3) (-) for the growth of the grass fluctuates between -6.7 to -2.7 per thousand during the day. If CO(2) fixation in Thalassia is catalyzed by phosphoenolpyruvate carboxylase (which would result in a -3 per thousand fractionation between HCO(3) (-) and malic acid), the predicted delta(13)C value for Thalassia would be -9.7 to -5.7 per thousand. This range is close to the observed range of -12.6 to -7.8 per thousand for Thalassia and agree with the operation of the C(4)-dicarboxylic acid pathway in this plant. The early products of the fixation of HCO(3) (-) in the leaf sections are malic acid and aspartic acid which are similar to the early products of CO(2) fixation in C(4) terrestrial plants.Electron microscopy of the leaves of Thalassia reveal thick walled epidermal cells exceedingly rich in mitochondria and C(3)-type chloroplasts. The mesophyll cells have many different shapes and surround air lacunae which contain O(2) and CO(2). The mesophyll cells are highly vacuolated and the parietal cytoplasm contains an occasional chloroplast. This chloroplast contains grana but the lamellar system is not as developed as the system in epidermal chloroplasts. Extensive phloem tissue is present but the xylem elements are reduced in this aquatic grass. The vascular tissue is not surrounded by bundle sheath cells

  15. Nowcasting daily minimum air and grass temperature.

    PubMed

    Savage, M J

    2016-02-01

    Site-specific and accurate prediction of daily minimum air and grass temperatures, made available online several hours before their occurrence, would be of significant benefit to several economic sectors and for planning human activities. Site-specific and reasonably accurate nowcasts of daily minimum temperature several hours before its occurrence, using measured sub-hourly temperatures hours earlier in the morning as model inputs, was investigated. Various temperature models were tested for their ability to accurately nowcast daily minimum temperatures 2 or 4 h before sunrise. Temperature datasets used for the model nowcasts included sub-hourly grass and grass-surface (infrared) temperatures from one location in South Africa and air temperature from four subtropical sites varying in altitude (USA and South Africa) and from one site in central sub-Saharan Africa. Nowcast models used employed either exponential or square root functions to describe the rate of nighttime temperature decrease but inverted so as to determine the minimum temperature. The models were also applied in near real-time using an open web-based system to display the nowcasts. Extrapolation algorithms for the site-specific nowcasts were also implemented in a datalogger in an innovative and mathematically consistent manner. Comparison of model 1 (exponential) nowcasts vs measured daily minima air temperatures yielded root mean square errors (RMSEs) <1 °C for the 2-h ahead nowcasts. Model 2 (also exponential), for which a constant model coefficient (b = 2.2) was used, was usually slightly less accurate but still with RMSEs <1 °C. Use of model 3 (square root) yielded increased RMSEs for the 2-h ahead comparisons between nowcasted and measured daily minima air temperature, increasing to 1.4 °C for some sites. For all sites for all models, the comparisons for the 4-h ahead air temperature nowcasts generally yielded increased RMSEs, <2.1 °C. Comparisons for all model nowcasts of the daily grass

  16. Native Perennial Grasses Show Evolutionary Response to Bromus tectorum (Cheatgrass) Invasion

    PubMed Central

    Goergen, Erin M.; Leger, Elizabeth A.; Espeland, Erin K.

    2011-01-01

    Invasive species can change selective pressures on native plants by altering biotic and abiotic conditions in invaded habitats. Although invasions can lead to native species extirpation, they may also induce rapid evolutionary changes in remnant native plants. We investigated whether adult plants of five native perennial grasses exhibited trait shifts consistent with evolution in response to invasion by the introduced annual grass Bromus tectorum L. (cheatgrass), and asked how much variation there was among species and populations in the ability to grow successfully with the invader. Three hundred and twenty adult plants were collected from invaded and uninvaded communities from four locations near Reno, Nevada, USA. Each plant was divided in two and transplanted into the greenhouse. One clone was grown with B. tectorum while the other was grown alone, and we measured tolerance (ability to maintain size) and the ability to reduce size of B. tectorum for each plant. Plants from invaded populations consistently had earlier phenology than those from uninvaded populations, and in two out of four sites, invaded populations were more tolerant of B. tectorum competition than uninvaded populations. Poa secunda and one population of E. multisetus had the strongest suppressive effect on B. tectorum, and these two species were the only ones that flowered in competition with B. tectorum. Our study indicates that response to B. tectorum is a function of both location and species identity, with some, but not all, populations of native grasses showing trait shifts consistent with evolution in response to B. tectorum invasion within the Great Basin. PMID:21479185

  17. Tiger cubs and little flowers.

    PubMed

    1993-01-01

    Short vignettes are related to show the conditions for girls and women in Morocco. Descriptions are given for child labor, literacy, the government's education campaign, youth group efforts to enhance family planning (FP) knowledge, the impact of FP outreach in rural areas, and unmarried mothers. In Morocco's cities, young boys can be seen hawking cigarettes and working in market stalls; in the countryside, boys herd goats or do other farm work. In rural areas girls are hidden by having them perform work around the house or on the farm primarily indoors. Women are supervised by women. 54% work as maids and 39% are apprentices in carpet factories. Parents prefer to have their daughters working and consider it protection from mischief as well as needed income. Only 60% of girls are enrolled in primary school vs. 80% of the boys. In rural areas, only 44% of girls are enrolled, and 20% stay to complete their primary education, while 76% of boys enroll and 63% complete primary school. Literacy of women has an effect on the ability to accurately take birth control pills. All ages of women gather at schools in the evening for lessons in reading and writing in a program supported by the King. Women are pleased with their success in just learning how to write their own names. Television advertisements promote sending children to school, as another part of the Ministry of Education's campaign to increase girl's educational status. There are still not enough schools; many schools are double shift, and communities are building their own schools. Youth clubs, which refer to boys as "tiger cubs" and girls as "little flowers," try to familiarize young people with some basic information about contraception. A traditional midwife relates some problems with girl's education: costs for clothing and supplies, worry about male teachers, and poor role models. In some remote areas, farm families do not send their children to school, because of the distance to schools and the need for

  18. Medicinal flowers. XII.(1)) New spirostane-type steroid saponins with antidiabetogenic activity from Borassus flabellifer.

    PubMed

    Yoshikawa, Masayuki; Xu, Fengming; Morikawa, Toshio; Pongpiriyadacha, Yutana; Nakamura, Seikou; Asao, Yasunobu; Kumahara, Akira; Matsuda, Hisashi

    2007-02-01

    The methanolic extract from the male flowers of Borassus flabellifer was found to inhibit the increase of serum glucose levels in sucrose-loaded rats at a dose of 250 mg/kg, p.o. From the methanolic extract, six new spirostane-type steroid saponins, borassosides A-F (1-6), were isolated together with 23 known constituents. The structures of borassosides (1-6) were elucidated on the basis of chemical and physicochemical evidences. In addition, the principal steroid saponin, dioscin (13), inhibited the increase of serum glucose levels in sucrose-loaded rats at a dose of 50 mg/kg, p.o. PMID:17268107

  19. Orchid flowers tolerance to gamma-radiation

    NASA Astrophysics Data System (ADS)

    Kikuchi, Olivia Kimiko

    2000-03-01

    Cut flowers are fresh goods that may be treated with fumigants such as methyl bromide to meet the needs of the quarantine requirements of importing countries. Irradiation is a non-chemical alternative to substitute the methyl bromide treatment of fresh products. In this research, different cut orchids were irradiated to examine their tolerance to gamma-rays. A 200 Gy dose did inhibit the Dendrobium palenopsis buds from opening, but did not cause visible damage to opened flowers. Doses of 800 and 1000 Gy were damaging because they provoked the flowers to drop from the stem. Cattleya irradiated with 750 Gy did not show any damage, and were therefore eligible for the radiation treatment. Cymbidium tolerated up to 300 Gy and above this dose dropped prematurely. On the other hand, Oncydium did not tolerate doses above 150 Gy.

  20. Tropism in azalea and lily flowers

    NASA Astrophysics Data System (ADS)

    Shimizu, M.; Tomita-Yokotani, K.; Nakamura, T.; Yamashita, M.

    Tropic responses were examined in azalea Rhododendrom pulchrum and lily Lilium cv. 'Casablanca' flowers. Orientation of the flowers in these two species depicts several up/down characteristics, such as angle of the corolla opening, alignment or configuration of a specific petal at the top, plus direction in the curved tip of the pistil and stamen. Gravity was found to be the prime factor, with light as a secondary signal that determines gravitropism in the pistil of the azalea. Within the azalea, sedimented amyloplasts were observed throughout the cells along the inner layers below the epidermis. In lily flowers, no sedimented amyloplasts were found in style cells, and phototropic responses caused upward bending of the pistil. Responses of lily pistils to monochromatic light were consistent with the action spectrum for phototropism in the shoots of monocotyledonous plants. We discuss how these features may increase the fitness for pollination in these two species.

  1. Unique Crystallization of Fullerenes: Fullerene Flowers

    PubMed Central

    Kim, Jungah; Park, Chibeom; Song, Intek; Lee, Minkyung; Kim, Hyungki; Choi, Hee Cheul

    2016-01-01

    Solution-phase crystallization of fullerene molecules strongly depends on the types of solvent and their ratios because solvent molecules are easily included in the crystal lattice and distort its structure. The C70 (solute)–mesitylene (solvent) system yields crystals with various morphologies and structures, such as cubes, tubes, and imperfect rods. Herein, using C60 and C70 dissolved in mesitylene, we present a novel way to grow unique flower-shaped crystals with six symmetric petals. The different solubility of C60 and C70 in mesitylene promotes nucleation of C70 with sixfold symmetry in the early stage, which is followed by co-crystallization of both C60 and C70 molecules, leading to lateral petal growth. Based on the growth mechanism, we obtained more complex fullerene crystals, such as multi-deck flowers and tube-flower complexes, by changing the sequence and parameters of crystallization. PMID:27561446

  2. Unique Crystallization of Fullerenes: Fullerene Flowers.

    PubMed

    Kim, Jungah; Park, Chibeom; Song, Intek; Lee, Minkyung; Kim, Hyungki; Choi, Hee Cheul

    2016-01-01

    Solution-phase crystallization of fullerene molecules strongly depends on the types of solvent and their ratios because solvent molecules are easily included in the crystal lattice and distort its structure. The C70 (solute)-mesitylene (solvent) system yields crystals with various morphologies and structures, such as cubes, tubes, and imperfect rods. Herein, using C60 and C70 dissolved in mesitylene, we present a novel way to grow unique flower-shaped crystals with six symmetric petals. The different solubility of C60 and C70 in mesitylene promotes nucleation of C70 with sixfold symmetry in the early stage, which is followed by co-crystallization of both C60 and C70 molecules, leading to lateral petal growth. Based on the growth mechanism, we obtained more complex fullerene crystals, such as multi-deck flowers and tube-flower complexes, by changing the sequence and parameters of crystallization. PMID:27561446

  3. Sensitivity of flowering phenology to changing temperature in China

    NASA Astrophysics Data System (ADS)

    Zhang, Haicheng; Yuan, Wenping; Liu, Shuguang; Dong, Wenjie; Fu, Yang

    2015-08-01

    Plant phenology is one of the preferred indicators of climate change, and its variation potentially impacts community dynamics and ecosystem functions. To better understand the responses of plants' flowering phenology to rising temperatures, we investigated the temperature sensitivity (expressed as the date of changes in phenology per change in temperature in degree Celsius, d °C-1) of flowering phenology for more than 220 plant species at 59 sites in China during the period 1963-1988. Our results indicated that most flowerings in China were significantly sensitive to the temperature in the 2 months (60 days) prior to the flowering dates. Plants in warmer regions showed larger sensitivities to increased temperatures. Species flowering in the late spring and early summer were generally less sensitive to changing temperature than species flowering at other times of the year. For plants flowering in the spring, species that flower earlier showed higher temperature sensitivity; however, for plants flowering in the summer and autumn, species that flower earlier showed lower temperature sensitivity. The responses of the first and last flowering times to changing temperature were mostly consistent, so flowering durations were rarely (6.1%) sensitive to changing temperature. We hypothesize that plants in cold regions may have adapted to the more variable temperatures and thus showed lower temperature sensitivities than plants in warm regions. Overall, the responses of flowering phenology to temperature varied significantly among temperature zones and plant species, so it should be considered carefully when estimating the impacts of climate warming on the terrestrial biosphere.

  4. Interception and retention of wet-deposited radiocaesium and radiostrontium on a ley mixture of grass and clover.

    PubMed

    Bengtsson, Stefan B; Gärdenäs, Annemieke I; Eriksson, Jan; Vinichuk, Mykhailo; Rosén, Klas

    2014-11-01

    The aims of this study were to assess the potential radioactive contamination of fodder in the case of accidental radionuclide fallout, and to analyse the relationship between interception and retention of radionuclides as a function of biomass and Leaf Area Index (LAI). The interception and the retention of wet deposited (134)Cs and (85)Sr in ley (a mixture of grass and clover) were measured after artificial wet deposition in a field trial in Uppsala (eastern central Sweden). The field trial had a randomised block design with three replicates. (134)Cs and (85)Sr were deposited at six different growth stages during two growing seasons (2010 and 2011) using a rainfall simulator. The biomass was sampled in the center of each parcel 2 to 3h after deposition and at later growth stages (1 to 5) during the growing season. The above ground biomass and LAI were measured as well. The interception of radionuclides by the ley was largest at the late growth stages; the spike and tassel/flowering (code 5:6) in the 1(st) year, and at flowering/initial flowering (code 6:5) in the 2(nd) year. There was a correlation between radionuclide interception and above ground plant biomass, as well as with LAI, for both radionuclides in both years. The highest activity concentrations of both radionuclides were measured after deposition at the late growth stages and were found to be higher in the 2(nd) year. The weathering half-lives were shorter at the earlier growth stages than at the later growth stages for both radionuclides. For the magnitude of deposition chosen in our experiment, it can be concluded that the above ground biomass is a good predictor and the LAI a more uncertain predictor of the interception of radiocaesium and radiostrontium by ley grass and clover. PMID:25146910

  5. Shorter flowering seasons and declining abundance of flower visitors in a warmer Arctic

    NASA Astrophysics Data System (ADS)

    Høye, Toke T.; Post, Eric; Schmidt, Niels M.; Trøjelsgaard, Kristian; Forchhammer, Mads C.

    2013-08-01

    Advancing phenology in response to global warming has been reported across biomes, raising concerns about the temporal uncoupling of trophic interactions. Concurrently, widely reported flower visitor declines have been linked to resource limitations. Phenological responses in the Arctic have been shown to outpace responses from lower latitudes and recent studies suggest that differences between such responses for plants and their flower visitors could be particularly pronounced in the Arctic. The evidence for phenological uncoupling is scant because relevant data sets are lacking or not available at a relevant spatial scale. Here, we present evidence of a climate-associated shortening of the flowering season and a concomitant decline in flower visitor abundance based on a long-term, spatially replicated (1996-2009) data set from high-Arctic Greenland. A unique feature of the data set is the spatial and temporal overlap of independent observations of plant and insect phenology. The shortening of the flowering season arose through spatial variation in phenological responses to warming. The shorter flowering seasons may have played a role in the observed decline in flower visitor abundance. Our results demonstrate that the dramatic climatic changes currently taking place in the Arctic are strongly affecting individual species and ecological communities, with implications for trophic interactions.

  6. Refuges, flower strips, biodiversity and agronomic interest.

    PubMed

    Roy, Grégory; Wateau, Karine; Legrand, Mickaël; Oste, Sandrine

    2008-01-01

    Several arthropods are natural predators of pests, and they are able to reduce and control their population development. FREDON Nord Pas-de-Calais (Federation Regionate de Defense contre les Organismes Nuisibles = Regional Federation for Pest Control) has begun for a long time to form farmers to the recognition of beneficial arthropods and to show them their usefulness. These beneficial insects or arachnids are present everywhere, in orchards and even in fields which are areas relatively poor in biodiversity. Adults feed in the flower strips instead larvae and some adults feed on preys such as aphids or caterpillars. Most of the time, beneficial insects can regulate pest but sometimes, in agricultural area, they can't make it early enough and efficiently. Their action begin too late and there biodiversity and number are too low. It's possible to enhance their action by manipulating the ecological infrastructures, like sewing flower strips or installing refuges. Flower strips increase the density of natural enemies and make them be present earlier in the field in order to control pests. Refuges permit beneficial's to spend winter on the spot. So they're able to be active and to grow in number earlier. From 2004 to 2007, on the one hand, FREDON Nord Pas-de-Calais has developed a research program. Its purpose was to inventory practices and also tools and means available and to judge the advisability of using such or such beneficial refuge in orchards. On the second hand, it studied the impact in orchard of refuges on population of beneficial's and the difference there were between manufactured refuges and homemade refuges. Interesting prospects were obtained with some of them. Otherwise, since 2003, FREDON has studied flower strips influence on beneficial population and their impact on pest control. In cabbage fields, results of trials have shown that flower strips lead to a reduction of aphid number under acceptable economic level, up to 50 meters from flower strips

  7. Flower Development and Perianth Identity Candidate Genes in the Basal Angiosperm Aristolochia fimbriata (Piperales: Aristolochiaceae)

    PubMed Central

    Pabón-Mora, Natalia; Suárez-Baron, Harold; Ambrose, Barbara A.; González, Favio

    2015-01-01

    Aristolochia fimbriata (Aristolochiaceae: Piperales) exhibits highly synorganized flowers with a single convoluted structure forming a petaloid perianth that surrounds the gynostemium, putatively formed by the congenital fusion between stamens and the upper portion of the carpels. Here we present the flower development and morphology of A. fimbriata, together with the expression of the key regulatory genes that participate in flower development, particularly those likely controlling perianth identity. A. fimbriata is a member of the magnoliids, and thus gene expression detected for all ABCE MADS-box genes in this taxon, can also help to elucidate patterns of gene expression prior the independent duplications of these genes in eudicots and monocots. Using both floral development and anatomy in combination with the isolation of MADS-box gene homologs, gene phylogenetic analyses and expression studies (both by reverse transcription PCR and in situ hybridization), we present hypotheses on floral organ identity genes involved in the formation of this bizarre flower. We found that most MADS-box genes were expressed in vegetative and reproductive tissues with the exception of AfimSEP2, AfimAGL6, and AfimSTK transcripts that are only found in flowers and capsules but are not detected in leaves. Two genes show ubiquitous expression; AfimFUL that is found in all floral organs at all developmental stages as well as in leaves and capsules, and AfimAG that has low expression in leaves and is found in all floral organs at all stages with a considerable reduction of expression in the limb of anthetic flowers. Our results indicate that expression of AfimFUL is indicative of pleiotropic roles and not of a perianth identity specific function. On the other hand, expression of B-class genes, AfimAP3 and AfimPI, suggests their conserved role in stamen identity and corroborates that the perianth is sepal and not petal-derived. Our data also postulates an AGL6 ortholog as a candidate

  8. Genetic variation in the flowering and yield formation of timothy (Phleum pratense L.) accessions after different photoperiod and vernalization treatments

    PubMed Central

    Jokela, Venla; Trevaskis, Ben; Seppänen, Mervi M.

    2015-01-01

    Timothy is a perennial forage grass grown commonly in Boreal regions. This study explored the effect of vernalization and photoperiod (PP) on flowering and growth characteristics and how this related to changes in expression of three flowering related genes in accessions from different geographic origin. Large variation was found in accessions in their vernalization and PP responses. In southern accessions vernalization response or requirement was not observed, the heading date remained unchanged, and plants flowered without vernalization. On the contrary, northern types had obligatory requirement for vernalization and long PP, but the tiller elongation did not require vernalization at 16-h PP. Longer vernalization or PP treatments reduced the genotypical differences in flowering. Moreover, the vernalization saturation progressed stepwise from main tiller to lateral tillers, and this process was more synchronized in southern accessions. The expression of PpVRN1 was associated with vernalization while PpVRN3 accumulated at long PP. A crucial role for PpVRN3 in the transition to flowering was supported as in southern accession the transcript accumulated in non-vernalized plants after transfer to 16-h PP, and the apices transformed to generative stage. Differences in vernalization requirements were associated with variation in expression levels of PpVRN1 and PpVRN3, with higher expression levels in southern type. Most divergent transcript accumulation of PpMADS10 was found under different vernalization conditions. These differences between accessions can be translated into agronomic traits, such as the tiller composition of canopy, which affects the forage yield. The southern types, with minimal vernalization response, have fast re-growth ability and rapidly decreasing nutritive value, whereas northern types grow slowly and have better quality. This information can be utilized in breeding for new cultivars for longer growing seasons at high latitudes. PMID:26175739

  9. Feasibility of Seed Production from Non-flowering Orchardgrass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Non-flowering or sparse flowering orchardgrass (Dactylis glomerata L.) would greatly simplify management of intensive rotational grazing systems. Our objective was to quantify seed production on non-flowering orchardgrass clones selected in cold-winter climates, but grown for seed in mild-winter cl...

  10. The evolution of flowering strategies in US weedy rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Local adaptation in plants often involves changes in flowering time in response to day length and temperature differences. Many crop varieties have been selected for uniformity in flowering time. In contrast, variable flowering may be important for increased competitiveness in weed species invading ...