Chitosan modulated antioxidant activity, inorganic ions homeostasis and endogenous melatonin to improve yield of Pisum sativum L. accessions under salt stress

Effects of NaCl stress and foliar treatment of chitosan (CTS) on growth, antioxidant activity, inorganic ions and yield attributes of two pea (Pisum sativum L.) accessions were analyzed in this study. Experimentation was done in total 36 pots with 2 accessions and in three way completely randomized design (CRD) with 3 replicates. P. sativum plants were supplied with three salt concentrations (0, 60 and 120 mM) and two concentrations of CTS (0 and 120 mg/L). Both P. sativum accessions performed notably different from each other under salt stress. On the basis of remarkable reduction in biomass and yield parameters of ccession 200-03 under NaCl stress, it is assumed that this accession might be sensitive against salt stress. Whereas accession 200-06 under NaCl stress showed non-significant reduction in yield and biomass indicating that this accession might be resistant against salt stress. Foliar treatment of CTS boosted antioxidant enzyme activities, enhanced secondary metabolites (leaf proline and total phenolics), lowered the level of H2O2 and improved the RMP and yield in both ccessions. Salt stress resulted in enhanced content of endogenous melatonin. Chitosan treatment further boosted melatonin synthesis. It is concluded that foliar treatment of CTS mitigated the deleterious effects of salt stress and modulated growth in P. sativum plants under salt stress. Therefore, it is recommended that chitosan induced growth modulation in plants may be exploited.