Chitosan augments bioactive properties and drought resilience in drought-induced red kidney beans

Application of 0.25% chitosan during seed priming or its foliage spray on Phaseolus vulgaris L. grown under restricted irrigations was assessed for its role in the enhancement of bioactive properties like antioxidant potential of dry seed. Seven hydroxycinnamic acid and eleven hydroxybenzoic acid derivatives were identified and quantified in seeds collected from treated plants using LC-MS/MS. The major phenolics in all the treatments were in the order; ferulic acid > p-coumaric acid > o-coumaric acid > gallic acid and salicylic acid. However, the concentrations of each differed significantly at p < 0.01, with ferulic acid (324.304 µg/g) in red kidney bean seed grown under 30% irrigation with primed seed as the most predominant phenolic. Phenolics reported are representative of the phenylpropanoid pathway having a defined role in combating abiotic stress. The DPPH free radical scavenging activity, metal chelation, and reducing power antioxidant activities of the crude extract of seeds were investigated and found to elevate with increase in imposing more drought stress. Total soluble phenol content was found to have a strong correlation with the antioxidant activities with DPPH radical scavenging activity (-0.88), reducing power activity (0.87) and chelating power activity (-0.85). Principal components PC1 and PC2 accounted for almost 64.40% as the principal contributors in augmenting the bioactive properties and drought resilience. Overall, our findings indicate that 0.25% chitosan as seed and foliar spray augments bioactive properties and drought resilience in drought induced red kidney beans.