Biochemical and molecular responses of flax to 24-epibrassinosteroide seed priming under drought stress

ABSTRACT The effects of 24-epibrassinolide (24-epiBL 10？8 M) were investigated on antioxidant enzymes activity, lipid peroxidation, and genes expression in 10-day-old Linum usitatissimum L. seedlings subjected to 6%, 12%, and 18% polyethylene glycol (PEG). Water deficit significantly enhanced the activity of CAT, POD, and SOD enzymes as well as elevation in protein, proline, and MDA contents whereas decreased activity of APOX and NR in a concentration-dependent manner. 24-epiBL seed priming improved flax adaptability due to the induction of antioxidant enzymes activity and protein and proline contents with a reduction in MDA content and antioxidant capacity. Gene expression studies showed that Mn-SOD, POD1, POD3, ERF, and WRKY 40 transcript levels were generally upregulated. Application of 24-epiBL caused induction in mRNA abundance of Mn-SOD, POD3, KRP2, and WRKY 40 under at least one level of PEG imposition. In conclusion, 24-epiBL seed priming could be implemented in order to counteract consequences of water deficit in flax