helianthus

Summary

Summary: A genus herbs of the Asteraceae family. The SEEDS yield oil and are used as food and animal feed; the roots of Helianthus tuberosum (Jerusalem artichoke) are edible.

Top Publications

  1. Blackman B, Rasmussen D, Strasburg J, Raduski A, Burke J, Knapp S, et al. Contributions of flowering time genes to sunflower domestication and improvement. Genetics. 2011;187:271-87 pubmed publisher
    ..involved in the evolution of flowering time during early domestication and modern improvement of the sunflower (Helianthus annuus). Sunflower homologs of many genes with known functions in flowering time were isolated and cataloged...
  2. Bachlava E, Taylor C, Tang S, Bowers J, Mandel J, Burke J, et al. SNP discovery and development of a high-density genotyping array for sunflower. PLoS ONE. 2012;7:e29814 pubmed publisher
    ..Herein, we describe the development of a SNP genotyping resource for use in sunflower (Helianthus annuus L.)...
  3. Talia P, Greizerstein E, Hopp H, Paniego N, Poggio L, Heinz R. Detection of single copy sequences using BAC-FISH and C-PRINS techniques in sunflower chromosomes. Biocell. 2011;35:19-28 pubmed
    ..in situ labeling (C-PRINS) techniques were evaluated for integration of physical and genetic maps of sunflower (Helianthus annuus L.)...
  4. Donovan L, Rosenthal D, Sanchez Velenosi M, Rieseberg L, Ludwig F. Are hybrid species more fit than ancestral parent species in the current hybrid species habitats?. J Evol Biol. 2010;23:805-16 pubmed publisher
    ..Here, we ask whether two homoploid hybrid plant species (Helianthus anomalus, H. deserticola) diverged sufficiently from their ancestral parent species (H. annuus, H...
  5. Chaki M, Valderrama R, Fernández Ocaña A, Carreras A, Gómez Rodríguez M, Pedrajas J, et al. Mechanical wounding induces a nitrosative stress by down-regulation of GSNO reductase and an increase in S-nitrosothiols in sunflower (Helianthus annuus) seedlings. J Exp Bot. 2011;62:1803-13 pubmed publisher
    ..Consequently a process of nitrosative stress is induced in sunflower seedlings and SNOs constitute a new wound signal in plants. ..
  6. Marques A, Moreira H, Franco A, Rangel A, Castro P. Inoculating Helianthus annuus (sunflower) grown in zinc and cadmium contaminated soils with plant growth promoting bacteria--effects on phytoremediation strategies. Chemosphere. 2013;92:74-83 pubmed publisher
    ..work the effects of inoculating metal resistant and plant growth promoting bacterial strains on the growth of Helianthus annuus grown in Zn and Cd spiked soils were assessed...
  7. Bowers J, Bachlava E, Brunick R, Rieseberg L, Knapp S, Burke J. Development of a 10,000 locus genetic map of the sunflower genome based on multiple crosses. G3 (Bethesda). 2012;2:721-9 pubmed publisher
    ..Here, we describe the analysis and integration of genotypic data from four sunflower (Helianthus annuus L.) mapping populations to produce a consensus linkage map of the sunflower genome...
  8. Qi L, Seiler G, Vick B, Gulya T. Genetics and mapping of the R?? gene conferring resistance to recently emerged rust races, tightly linked to male fertility restoration, in sunflower (Helianthus annuus L.). Theor Appl Genet. 2012;125:921-32 pubmed publisher
    ..Rf ANN-1742, an 'HA 89' backcross restorer line derived from wild annual sunflower (Helianthus annuus L.), was identified as resistant to the newly emerged rust races...
  9. Sun L, Ouyang C, Kou S, Wang S, Yao Y, Peng T, et al. Cloning and characterization of a cDNA encoding type 1 diacylglycerol acyltransferase from sunflower (Helianthus annuus L.). Z Naturforsch C. 2011;66:63-72 pubmed
    ..3.1.20) was obtained from sunflower (Helianthus annuus L.) seeds...

More Information

Publications62

  1. Troncoso Ponce M, Rivoal J, Dorion S, Moisan M, Garc s R, Mart nez Force E. Cloning, biochemical characterization and expression of a sunflower (Helianthus annuus L.) hexokinase associated with seed storage compounds accumulation. J Plant Physiol. 2011;168:299-308 pubmed publisher
    A full-length hexokinase cDNA, HaHXK1, was cloned and characterized from Helianthus annuus L. developing seeds. Based on its sequence and phylogenetic relationships, HaHXK1 is a membrane-associated (type-B) hexokinase...
  2. Brouillette L, Donovan L. Nitrogen stress response of a hybrid species: a gene expression study. Ann Bot. 2011;107:101-8 pubmed publisher
    ..b>Helianthus anomalus is an annual sunflower of hybrid origin that is adapted to desert sand-dune substrates with lower ..
  3. Kawakami T, Dhakal P, Katterhenry A, Heatherington C, Ungerer M. Transposable element proliferation and genome expansion are rare in contemporary sunflower hybrid populations despite widespread transcriptional activity of LTR retrotransposons. Genome Biol Evol. 2011;3:156-67 pubmed publisher
    ..species from North America that have arisen via ancient hybridization between the same two parental taxa, Helianthus annuus and H. petiolaris...
  4. Cieślik E, Gębusia A, Florkiewicz A, Mickowska B. The content of protein and of amino acids in Jerusalem artichoke tubers (Helianthus tuberosus L.) of red variety Rote Zonenkugel. Acta Sci Pol Technol Aliment. 2011;10:433-41 pubmed
    Jerusalem artichoke (Helianthus tuberosus L.) is grown primarily for its edible tubers, which were first cultivated by native Americans before the arrival of the Europeans...
  5. Blackman B, Scascitelli M, Kane N, Luton H, Rasmussen D, Bye R, et al. Sunflower domestication alleles support single domestication center in eastern North America. Proc Natl Acad Sci U S A. 2011;108:14360-5 pubmed publisher
    ..Our evidence from multiple evolutionarily important loci and from neutral markers supports a single domestication event for extant cultivated sunflower in eastern North America. ..
  6. Beninati S, Iorio R, Tasco G, Serafini Fracassini D, Casadio R, Del Duca S. Expression of different forms of transglutaminases by immature cells of Helianthus tuberosus sprout apices. Amino Acids. 2013;44:271-83 pubmed publisher
    Immature cells of etiolated apices of sprouts growing from Helianthus tuberosus (H. t.) tubers showed Ca(2+)-dependent transglutaminase (TG, EC 2.3.2.13) activity on fibronectin (more efficiently) and dimethylcasein as substrates...
  7. Troncoso Ponce M, Garcés R, Martínez Force E. Glycolytic enzymatic activities in developing seeds involved in the differences between standard and low oil content sunflowers (Helianthus annuus L.). Plant Physiol Biochem. 2010;48:961-5 pubmed publisher
    ..These data together point to these last two enzymatic activities, phosphoglycerate kinase and enolase, as being responsible for the lower fat content in the ZEN-8 line. ..
  8. Ikezawa N, G pfert J, Nguyen D, Kim S, O Maille P, Spring O, et al. Lettuce costunolide synthase (CYP71BL2) and its homolog (CYP71BL1) from sunflower catalyze distinct regio- and stereoselective hydroxylations in sesquiterpene lactone metabolism. J Biol Chem. 2011;286:21601-11 pubmed publisher
    ..Evolution and homology models of these two P450s are discussed...
  9. Del Moral L, Fernández Martínez J, Pérez Vich B, Velasco L. Expression of modified tocopherol content and profile in sunflower tissues. J Sci Food Agric. 2012;92:351-7 pubmed publisher
    ..The expression of tocopherol mutations in other plant tissues will enable further studies on the physiological role of tocopherols and could be of interest for early selection for these traits in breeding programmes. ..
  10. Sambatti J, Strasburg J, Ortiz Barrientos D, Baack E, Rieseberg L. Reconciling extremely strong barriers with high levels of gene exchange in annual sunflowers. Evolution. 2012;66:1459-73 pubmed publisher
    ..Here, we contrast these two measures in two species of sunflower, Helianthus annuus and H. petiolaris...
  11. Mayrose M, Kane N, Mayrose I, Dlugosch K, Rieseberg L. Increased growth in sunflower correlates with reduced defences and altered gene expression in response to biotic and abiotic stress. Mol Ecol. 2011;20:4683-94 pubmed publisher
    ..to test for growth-defence trade-offs in agricultural weeds, crops and native varieties of common sunflower (Helianthus annuus L...
  12. Joel D, Chaudhuri S, Plakhine D, Ziadna H, Steffens J. Dehydrocostus lactone is exuded from sunflower roots and stimulates germination of the root parasite Orobanche cumana. Phytochemistry. 2011;72:624-34 pubmed publisher
    ..Orobanche aegyptiaca). DCL and other sesquiterpene lactones were found in various plant organs, but were previously not known to be exuded to the rhizosphere where they can interact with other organisms...
  13. Chapman M, Burke J. Evidence of selection on fatty acid biosynthetic genes during the evolution of cultivated sunflower. Theor Appl Genet. 2012;125:897-907 pubmed publisher
    ..analysis of 11 genes that underlie fatty acid biosynthesis and metabolism in wild and cultivated sunflower (Helianthus annuus)...
  14. Giordani T, Buti M, Natali L, Pugliesi C, Cattonaro F, Morgante M, et al. An analysis of sequence variability in eight genes putatively involved in drought response in sunflower (Helianthus annuus L.). Theor Appl Genet. 2011;122:1039-49 pubmed publisher
    ..The results are discussed in relation to the function of analysed genes, i.e. involved in gene regulation and signal transduction, or encoding enzymes and defence proteins. ..
  15. As Sadi F, Carrère S, Gascuel Q, Hourlier T, Rengel D, Le Paslier M, et al. Transcriptomic analysis of the interaction between Helianthus annuus and its obligate parasite Plasmopara halstedii shows single nucleotide polymorphisms in CRN sequences. BMC Genomics. 2011;12:498 pubmed publisher
    Downy mildew in sunflowers (Helianthus annuus L.) is caused by the oomycete Plasmopara halstedii (Farl.) Berlese et de Toni...
  16. Mandel J, Nambeesan S, Bowers J, Marek L, Ebert D, Rieseberg L, et al. Association mapping and the genomic consequences of selection in sunflower. PLoS Genet. 2013;9:e1003378 pubmed publisher
    ..Here, we describe the detailed genotypic and phenotypic analysis of a sunflower (Helianthus annuus L...
  17. Gong L, Hulke B, Gulya T, Markell S, Qi L. Molecular tagging of a novel rust resistance gene R(12) in sunflower (Helianthus annuus L.). Theor Appl Genet. 2013;126:93-9 pubmed publisher
    ..The gene conditioning rust resistance in RHA 464 originated from wild Helianthus annuus L., but has not been molecularly marked or determined to be independent from other rust loci...
  18. Cadic E, Coque M, Vear F, Grezes Besset B, Pauquet J, Piquemal J, et al. Combined linkage and association mapping of flowering time in Sunflower (Helianthus annuus L.). Theor Appl Genet. 2013;126:1337-56 pubmed publisher
    ..trait loci (QTL) and/or causative mutations involved in the control of flowering time in cultivated sunflower Helianthus annuus...
  19. Scascitelli M, Whitney K, Randell R, King M, Buerkle C, Rieseberg L. Genome scan of hybridizing sunflowers from Texas (Helianthus annuus and H. debilis) reveals asymmetric patterns of introgression and small islands of genomic differentiation. Mol Ecol. 2010;19:521-41 pubmed
    ..extent and direction of introgression between three sunflowers from the south-central USA: the common sunflower, Helianthus annuus ssp. annuus; a near-endemic to Texas, Helianthus debilis ssp...
  20. Kawakami T, Strakosh S, Zhen Y, Ungerer M. Different scales of Ty1/copia-like retrotransposon proliferation in the genomes of three diploid hybrid sunflower species. Heredity (Edinb). 2010;104:341-50 pubmed publisher
    ..These findings indicate that the genomic and/or environmental conditions associated with the origins of these sunflower hybrid taxa were conducive to derepression of at least two major groups of transposable elements...
  21. Wills D, Abdel Haleem H, Knapp S, Burke J. Genetic architecture of novel traits in the hopi sunflower. J Hered. 2010;101:727-36 pubmed publisher
  22. Bachlava E, Radwan O, Abratti G, Tang S, Gao W, Heesacker A, et al. Downy mildew (Pl ( 8 ) and Pl ( 14 )) and rust (R ( Adv )) resistance genes reside in close proximity to tandemly duplicated clusters of non-TIR-like NBS-LRR-encoding genes on sunflower chromosomes 1 and 13. Theor Appl Genet. 2011;122:1211-21 pubmed publisher
  23. Fulda S, Mikkat S, Stegmann H, Horn R. Physiology and proteomics of drought stress acclimation in sunflower (Helianthus annuus L.). Plant Biol (Stuttg). 2011;13:632-42 pubmed publisher
    ..05 MPa) and drought-stressed (-0.6 MPa) seedlings of Helianthus annuus L. cv. Peredovick...
  24. Qi L, Hulke B, Vick B, Gulya T. Molecular mapping of the rust resistance gene R ( 4 ) to a large NBS-LRR cluster on linkage group 13 of sunflower. Theor Appl Genet. 2011;123:351-8 pubmed publisher
    ..9 cM from the R ( 4 ) locus, indicating that R ( adv ) is not an allele of the R ( 4 ) locus. The markers tightly linked to the R ( 4 ) gene will facilitate gene pyramiding for rust resistance breeding of sunflower. ..
  25. Mandel J, Dechaine J, Marek L, Burke J. Genetic diversity and population structure in cultivated sunflower and a comparison to its wild progenitor, Helianthus annuus L. Theor Appl Genet. 2011;123:693-704 pubmed publisher
    ..Here, we report the results of a population genetic analysis of the primary gene pool of sunflower (Helianthus annuus L...
  26. Barozai M, Baloch I, Din M. Identification of MicroRNAs and their targets in Helianthus. Mol Biol Rep. 2012;39:2523-32 pubmed publisher
    ..A systematic search approach was used for inter-species homologs of miRNA precursors (pre-miRNAs), from known Helianthus expressed sequence tags (ESTs)...
  27. Staton S, Bakken B, Blackman B, Chapman M, Kane N, Tang S, et al. The sunflower (Helianthus annuus L.) genome reflects a recent history of biased accumulation of transposable elements. Plant J. 2012;72:142-53 pubmed publisher
    ..Thus, understanding the diversity and evolutionary dynamics of transposable elements in sunflower (Helianthus annuus L.), especially given its large genome size (?3...
  28. Whitney K, Randell R, Rieseberg L. Adaptive introgression of abiotic tolerance traits in the sunflower Helianthus annuus. New Phytol. 2010;187:230-9 pubmed publisher
    ..we examine introgression of abiotic tolerance traits between two hybridizing North American sunflower species, Helianthus annuus and Helianthus debilis...
  29. Talia P, Greizerstein E, Quijano C, Peluffo L, Fernandez L, Fernandez P, et al. Cytological characterization of sunflower by in situ hybridization using homologous rDNA sequences and a BAC clone containing highly represented repetitive retrotransposon-like sequences. Genome. 2010;53:172-9 pubmed publisher
    ..present work we report new tools for the characterization of the complete chromosome complement of sunflower (Helianthus annuus L...
  30. Chaki M, Valderrama R, Fern ndez Oca a A, Carreras A, G mez Rodr guez M, L pez Jaramillo J, et al. High temperature triggers the metabolism of S-nitrosothiols in sunflower mediating a process of nitrosative stress which provokes the inhibition of ferredoxin-NADP reductase by tyrosine nitration. Plant Cell Environ. 2011;34:1803-18 pubmed publisher
    ..In sunflower (Helianthus annuus L...
  31. Bazin J, Langlade N, Vincourt P, Arribat S, Balzergue S, El Maarouf Bouteau H, et al. Targeted mRNA oxidation regulates sunflower seed dormancy alleviation during dry after-ripening. Plant Cell. 2011;23:2196-208 pubmed publisher
    ..We show here that sunflower (Helianthus annuus) seed alleviation of dormancy during after-ripening is associated with mRNA oxidation and that this ..
  32. Buti M, Giordani T, Cattonaro F, Cossu R, Pistelli L, Vukich M, et al. Temporal dynamics in the evolution of the sunflower genome as revealed by sequencing and annotation of three large genomic regions. Theor Appl Genet. 2011;123:779-91 pubmed publisher
    ..Retrotransposon families related to those identified in the BAC clones are present also in other species of Helianthus, both annual and perennial, and even in other Asteraceae...
  33. Buti M, Giordani T, Vukich M, Gentzbittel L, Pistelli L, Cattonaro F, et al. HACRE1, a recently inserted copia-like retrotransposon of sunflower (Helianthus annuus L.). Genome. 2009;52:904-11 pubmed publisher
    ..of dicotyledons, this retrotransposon was assigned to the copia retrotransposon superfamily and named HACRE1 (Helianthus annuus copia-like retroelement 1)...
  34. Karrenberg S, Edelist C, Lexer C, Rieseberg L. Response to salinity in the homoploid hybrid species Helianthus paradoxus and its progenitors H. annuus and H. petiolaris. New Phytol. 2006;170:615-29 pubmed
    ..differentiation in speciation, we compared salinity responses of the halophytic diploid hybrid species Helianthus paradoxus and its glycophytic progenitors Helianthus annuus and Helianthus petiolaris...
  35. Radwan O, Gandhi S, Heesacker A, Whitaker B, Taylor C, Plocik A, et al. Genetic diversity and genomic distribution of homologs encoding NBS-LRR disease resistance proteins in sunflower. Mol Genet Genomics. 2008;280:111-25 pubmed publisher
    ..NBS-LRR homologs have only been isolated on a limited scale from sunflower (Helianthus annuus L...
  36. Fusari C, Lia V, Hopp H, Heinz R, Paniego N. Identification of single nucleotide polymorphisms and analysis of linkage disequilibrium in sunflower elite inbred lines using the candidate gene approach. BMC Plant Biol. 2008;8:7 pubmed publisher
    ..1) suggest that high resolution association mapping in sunflower could be achieved with marker densities lower than those usually reported in the literature. ..
  37. Timms L, Jimenez R, Chase M, Lavelle D, McHale L, Kozik A, et al. Analyses of synteny between Arabidopsis thaliana and species in the Asteraceae reveal a complex network of small syntenic segments and major chromosomal rearrangements. Genetics. 2006;173:2227-35 pubmed
    ..thaliana and regions of <5 cM in lettuce and sunflower. These syntenic patches are often not colinear, however, and form a network of regions that have likely evolved by duplications followed by differential gene loss. ..
  38. Rieseberg L, Raymond O, Rosenthal D, Lai Z, Livingstone K, Nakazato T, et al. Major ecological transitions in wild sunflowers facilitated by hybridization. Science. 2003;301:1211-6 pubmed
    ..The same combinations of parental chromosomal segments required to generate extreme phenotypes in synthetic hybrids also occurred in ancient hybrids. Thus, hybridization facilitated ecological divergence in sunflowers. ..
  39. Feng J, Vick B, Lee M, Zhang H, Jan C. Construction of BAC and BIBAC libraries from sunflower and identification of linkage group-specific clones by overgo hybridization. Theor Appl Genet. 2006;113:23-32 pubmed
    ..These BAC and BIBAC libraries and linkage group-specific clones provide resources essential for comprehensive research of the sunflower genome. ..
  40. Gerhardt B, Fischer K, Balkenhohl T, Pohnert G, Kuhn H, Wasternack C, et al. Lipoxygenase-mediated metabolism of storage lipids in germinating sunflower cotyledons and beta-oxidation of (9Z,11E,13S)-13-hydroxy-octadeca-9,11-dienoic acid by the cotyledonary glyoxysomes. Planta. 2005;220:919-30 pubmed
    During the early stages of germination, a lipid-body lipoxygenase is expressed in the cotyledons of sunflowers (Helianthus annuus L.)...
  41. Hewezi T, Léger M, El Kayal W, Gentzbittel L. Transcriptional profiling of sunflower plants growing under low temperatures reveals an extensive down-regulation of gene expression associated with chilling sensitivity. J Exp Bot. 2006;57:3109-22 pubmed
  42. Lai Z, Gross B, Zou Y, Andrews J, Rieseberg L. Microarray analysis reveals differential gene expression in hybrid sunflower species. Mol Ecol. 2006;15:1213-27 pubmed
    ..the creation of a cDNA microarray for annual sunflowers and its use to elucidate patterns of gene expression in Helianthus annuus, Helianthus petiolaris, and the homoploid hybrid species Helianthus deserticola...
  43. Cavallini A, Natali L, Zuccolo A, Giordani T, Jurman I, Ferrillo V, et al. Analysis of transposons and repeat composition of the sunflower (Helianthus annuus L.) genome. Theor Appl Genet. 2010;120:491-508 pubmed publisher
    ..The evolution of the repetitive component in the Helianthus genus and in other Asteraceae was studied by comparative analysis of the hybridization of total genomic DNAs ..
  44. Sun L, Wang X, Dai J, Xiu Z. Microbial production of 2,3-butanediol from Jerusalem artichoke tubers by Klebsiella pneumoniae. Appl Microbiol Biotechnol. 2009;82:847-52 pubmed publisher
    ..The results showed that Jerusalem artichoke tuber is a favorable substrate for 2,3-butanediol production, and the application of fed-batch SSF for its conversion can result in a more cost-effective process...
  45. Donovan L, Ludwig F, Rosenthal D, Rieseberg L, Dudley S. Phenotypic selection on leaf ecophysiological traits in Helianthus. New Phytol. 2009;183:868-79 pubmed publisher
    ..Here, we examined spatial and temporal variation in phenotypic selection on leaf ecophysiological traits for 10 Helianthus populations, including two species of hybrid origin, Helianthus anomalus and Helianthus deserticola, and ..
  46. Chapman M, Leebens Mack J, Burke J. Positive selection and expression divergence following gene duplication in the sunflower CYCLOIDEA gene family. Mol Biol Evol. 2008;25:1260-73 pubmed publisher
    ..The composite inflorescences of sunflower (Helianthus annuus L. Asteraceae) contain both zygomorphic and actinomorphic (i.e...
  47. Nehnevajova E, Herzig R, Federer G, Erismann K, Schwitzguebel J. Chemical mutagenesis--a promising technique to increase metal concentration and extraction in sunflowers. Int J Phytoremediation. 2007;9:149-65 pubmed publisher
    ..The main goal of the present study was the improvement of metal concentration and extraction properties of Helianthus annuus L by chemical mutagenesis (the non-GMO approach)...
  48. Fernandez P, Di Rienzo J, Fernandez L, Hopp H, Paniego N, Heinz R. Transcriptomic identification of candidate genes involved in sunflower responses to chilling and salt stresses based on cDNA microarray analysis. BMC Plant Biol. 2008;8:11 pubmed publisher
    ..This is the first organ-specific cDNA fluorescence microarray study addressing a simultaneous evaluation of concerted transcriptional changes in response to chilling and salinity stress in cultivated sunflower. ..
  49. Micic Z, Hahn V, Bauer E, Schön C, Melchinger A. QTL mapping of resistance to Sclerotinia midstalk rot in RIL of sunflower population NDBLOSsel x CM625. Theor Appl Genet. 2005;110:1490-8 pubmed
    ..The genetic effects and predictive quality of these two QTL are promising for application in marker-assisted selection to Sclerotinia midstalk-rot resistance. ..
  50. Lehner A, Corbineau F, Bailly C. Changes in lipid status and glass properties in cotyledons of developing sunflower seeds. Plant Cell Physiol. 2006;47:818-28 pubmed
    ..changes in thermal properties of lipid reserves, and intracellular glasses might play a role in sunflower (Helianthus annuus L.) seed development...
  51. Chechetkin I, Medvedeva N, Grechkin A. The novel pathway for ketodiene oxylipin biosynthesis in Jerusalem artichoke (Helianthus tuberosus) tubers. Biochim Biophys Acta. 2004;1686:7-14 pubmed
    ..specifically towards the ketodiene formation, was detected during in vitro experiments with Jerusalem artichoke (Helianthus tuberosus) tubers...
  52. Lai Z, Livingstone K, Zou Y, Church S, Knapp S, Andrews J, et al. Identification and mapping of SNPs from ESTs in sunflower. Theor Appl Genet. 2005;111:1532-44 pubmed
    More than 67,000 expressed sequence tags (ESTs) have recently been generated for sunflower (Helianthus), including 44,000 from cultivated confectionery (RHA280) and oilseed (RHA801) lines of Helianthus annuus and 23,000 from drought- and ..
  53. Evered C, Majevadia B, Thompson D. Cell wall water content has a direct effect on extensibility in growing hypocotyls of sunflower (Helianthus annuus L.). J Exp Bot. 2007;58:3361-71 pubmed
    ..a number of experiments in which the water potential of frozen and thawed growing hypocotyls of sunflower (Helianthus annuus L...