Evaluating the role of biopriming and nanopriming on the morphometric, biochemical, and yield parameters of Chickpea (Cicer arietinum L.) under drought stress

• Biopriming and nanopriming of DT and DS chickpea altered morphometric, biochemical, and yield parameters under drought. Priming effects were more prominent in DS variety as compared to control. • Highest improvement in fresh as well as dry weight of root and shoot was led by monocultures (B 1 & B 2 ) and N 1 X, respectively, in DT variety while N 2 X led maximum increment in all the morphometric traits of DS variety. • In DT variety, highest increase in TCC was observed with B 1 while TSC and TPC were maximum in N 2 X (MD) and B 1 +B 2 (SD) treated plants, respectively. Highest improvement in TCC, TSC, and TPC were led by B 1 (SD), B 2 (SD), and N 1 X (MD), respectively, in DS variety. • Biopriming treatments and lower concentration of biological cunps scored higher in the PCA of DS variety. • The most important yield parameter (120 DDS), harvesting index increased significantly in DS variety with highest increment led by B 2 and N 1 X. This study evaluated drought mitigation potential of biopriming with plant growth promoting endophytic bacteria (PGPEBs) and nanopriming with their biological copper nanoparticles (CuNPs) and chemical CuNPs under polyethylene glycol (PEG-6000) induced moderate (MD-5%) and severe drought (SD-10%) in chickpea ( Cicer arietinum L.). The crop harvested at 15 DDS (Days to drought stress) was analysed for morphometric and biochemical parameters of drought tolerant (DT), BG-4958 and drought sensitive (DS), ICC-1882 chickpea varieties. In morphometric traits of DT variety, N 1 X led 384% increase in shoot dry weight (SDW) under MD while B 2 in root dry weight (RDW) under SD (418%). For DS variety, N 2 X led 444% and 727% increase in SDW (MD) and RDW (SD), respectively. Amongst biochemical parameters, maximum increment was noticed in total chlorophyll content (TCC) by B 1 under MD (703%) as well as SD (1206%) in DT variety. B 1 also led highest increment (758%) in TCC of DS variety under SD while B 2 under MD (300%). B 2 resulted in 242% increment in total soluble carbohydrates (TSC) and 47% increase in total protein content (TPC) of DS variety under SD. N 1 X and N 1 Y led 318% and 100% increase in the activity of ascorbate peroxidase (APX) and peroxidase (POD) of DS variety. This variety exhibiting pronounced response was subjected to correlation analysis revealing highest correlation amongst morpho-biochemical traits under SD. Score plot in principal component analysis (PCA) of DS variety showed that biopriming and N 1 X having higher score values for PC 2 mainly influenced by biochemical parameters also improved the yield parameters to a greater extent as analyzed on 120 DDS. Harvesting index, the ultimate indicator of the agricultural output remained insignificant in DT variety. On the other hand, B 2 and N 1 X led highest harvesting indices under MD (94%) and SD (69%), respectively, in DS variety, owing to their higher grain yield than biological yield and higher score values influencing biochemical parameters under stress. The present study provides insights into the beneficial role of PGPEBs and biosynthesized CuNPs in mitigating the adverse effects of drought in chickpea.