Synergistic effect of 24-epibrassinolide and salicylic acid on photosynthetic efficiency and gene expression in Brassica juncea L. under Pb stress

Abstract

Lead (Pb) has wide-ranging effects on various essential physiological processes in plants including seed germination, root/ shoot growth, photosynthetic efficiency, water status, and activities of enzymes. The effect of combined treatment of 24-epibrassinolide(107M, EBL) and salicylic acid (1 mM, SA) on growth, photosynthetic attributes, and phenolic compounds in 30-, 60-, and 90-day-oldplants ofBrassica junceaL. under Pb stress (0.25 mM, 0.50 mM, and 0.75 mM) were studied. It was observed that Pb toxicity resultedin lowered growth and photosynthetic efficiency. The expressions ofCHLASE ,PSY ,CHS , andPALgenes were altered. Presoakingtreatment with the combination of EBL and SA for metal-stressed plants mitigated the adverse effects of metal stress by improvinggrowth and levels of pigment and phenolic compounds.