Unveiling the protective role of chitosan in Plant Defense: A comprehensive review with emphasis on abiotic stress management

In agricultural scenario, chitosan, a naturally occurring biopolymer derived from chitins, has the ability to function as both a bio-stimulant and an elicitor. Chitosan is produced from chitins. It is suitable for a wide range of uses because it is non-toxic, does not contaminate the environment, and is biocompatible with living things. It improves physiological reactions and lessens the negative effects of abiotic stimuli through the stress transduction pathway and the use of secondary messengers. Through nitric oxide and hydrogen peroxide-based signalling pathways, chitosan treatment activates antioxidant enzymes. Additionally, it stimulates the production of organic acids, carbohydrates, amino acids, and other metabolites needed for osmotic regulation, stress signalling, and other processes. Additionally, it can combine with heavy metals to produce compounds, and it is used in both phytoremediation and biological remediation of polluted soil. Additionally, this is applied topically to a variety of plants as an anti-transpirant agent, which reduces the quantity of water needed while also providing protection from other negative effects. Due of chitosan's exceptional properties and the way the climate is changing, sustainable farming practises are increasingly incorporating it. Our study is a compendium of current chitosan research that emphasises abiotic stress reactions. These responses could be helpful in upcoming initiatives to increase crop productivity.