Effect of low temperature acclimation on developmental regulation of redox responses and phytohormones metabolism in lines of crosses between spring and winter wheat

Low temperature (LT) acclimation in winter wheat (Triticum aestivum L.) was related to developmental regulation of transcriptome and metabolome for balancing growth and responses. In this study, six wheat lines from the F8 generation, derived from crosses between spring wheat (Pishtaz) and winter wheat (Claire) with distinct growth habits (based on the Vrn-1 loci) were planted under field conditions. The final leaf number (FLN) and double ridge (DR) formation showed that genotypes without vernalization requirement, including Pishtaz parent, and lines 8041 and 8044 transitioned rapidly into the reproductive stage. They also had lower LT tolerance, antioxidants activity and abscisic acid (ABA) content among genotypes. In these genotypes, cytokinin (CK) and gibberellin (GA3) contents and expression levels of gibberellin 20 oxidase (GA20ox) and gibberellin 3 oxidase (GA3ox) genes, were more active than other genotypes. Facultative lines 8020 and 8025 had higher antioxidants activity and lower hydrogen peroxide (H2O2) and malondialdehyde (MDA) contents compared to spring types. Winter genotypes, including Claire parent, lines 8011 and 8015 had a strong vernalization requirement resulted in prolonged vegetative phase, accompanied by increased LT tolerance, antioxidants activity and expression of ABA biosynthetic genes, confirming that the duration of the vegetative phase plays a key role in determining wheat's winter survival capacity. Higher LT tolerance was effectively related to retarded reproductive phase, minimized redox damages through co-regulating phytohormone-metabolites under developmental periods in winter wheat.