Physiological and biochemical characterisation of watered and drought-stressed barley mutants in the HvDWARF gene encoding C6-oxidase involved in brassinosteroid biosynthesis.

摘要: Brassinosteroids (BR) are plant steroid hormones that were discovered more than thirty years ago, but their physiological function has yet to be fully explained. The aim of the study was answer question whether/how disturbances in production BR barley affects plant's metabolism and development under conditions optimal watering drought. Mutants with an impaired one best tools research aimed at understanding mechanisms action these hormones. used cultivars a normal synthesis (wild type) semi-dwarf allelic mutants activity C6-oxidase (mutation HvDWARF), which resulted decreased synthesis. Half plants subjected drought stress seedling stage other half watered optimally. Plants characterised by lower height developmental retardation. Under both drought, disorders caused reduced ABA cytokinins, not auxins. also produced less osmoprotectant (proline). optimally drought-stressed accumulated sucrose, accompanied changes soluble sugars. increased content fructooligosaccharide (kestose) would suggest is negative regulator kestose production. level nystose suggests involvement regulation this fructooligosaccharide. accumulation transcripts genes associated response (hsp90) BR-deficient mutants. In turn, efficiency photosystem II net photosynthetic rate revealed only conditions. presented allows for biochemical traits two BR-barley characterised, helps understood. knowledge can good starting point some breeding companies interested introducing new cultivars.