title: The rice Osmyb4 gene enhances tolerance to frost and improves germination under unfavourable conditions in transgenic barley plants.
abstract: The Osmyb4 rice gene, coding for a transcription factor, proved to be efficient against different abiotic stresses as a trans(cis)gene in several plant species, although the effectiveness was dependent on the host genomic background. Eight barley transgenic lines carrying the rice Osmyb4 gene under the control of the Arabidopsis cold inducible promoter cor15a were produced to test the efficiency of this gene in barley. After a preliminary test, the best performing lines were subjected to freezing at -11°C and -12°C. Frost tolerance was assessed measured the F(v)/F(m) parameter widely used to indicate the maximum quantum yield of photosystem II photochemistry in the dark adapted state. Three transgenic lines showed significantly increased tolerance. These selected lines were further studied under a complex stress applying cold and hypoxia at germinating stage. In these conditions the three selected transgenic lines outperformed the wild type barley in terms of germination vigour. The transgenic plants also showed a significant modification of their metabolism under cold/hypoxia conditions as demonstrated through the assessment of the activity of key enzymes involved in anoxic stress response. None of the transgenic lines showed dwarfism, just a slight retarded growth. These results provide evidence that the cold dependent expression of Osmyb4 can efficiently improved frost tolerance and germination vigour at low temperature without deleterious effect on plant growth.
authors.affiliation: Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, 2462, Martonvásár, Brunszvik u. 2, Hungary.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Soltész
authors.forename: Attila
authors.initials: A
authors.lastname: Vágújfalvi
authors.forename: Fulvia
authors.initials: F
authors.lastname: Rizza
authors.forename: Ildikó
authors.initials: I
authors.lastname: Kerepesi
authors.forename: Gábor
authors.initials: G
authors.lastname: Galiba
authors.forename: Luigi
authors.initials: L
authors.lastname: Cattivelli
authors.forename: Immacolata
authors.initials: I
authors.lastname: Coraggio
authors.forename: Cristina
authors.initials: C
authors.lastname: Crosatti
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D000693:Anaerobiosis / Q000502:physiology; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics; D001219:Aspartate Aminotransferases / Q000235:genetics / Q000378:metabolism; D003080:Cold Temperature; D005615:Freezing; D018506:Gene Expression Regulation, Plant; D018525:Germination; D001467:Hordeum / Q000201:enzymology / Q000235:genetics*; D007770:L-Lactate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D012275:Oryza / Q000235:genetics* / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D000516:alpha-Amylases / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C116166:COR15 protein, Arabidopsis; D045332:Photosystem II Protein Complex; D014157:Transcription Factors; D007770:L-Lactate Dehydrogenase; D001219:Aspartate Aminotransferases; D000516:alpha-Amylases