The present study was carried out with the aim of (i) evaluating the effect of chitosan on the free radical scavenging activity, ferric reducing antioxidant power (FRAP) activity, 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and chitinase activity in T. aestivum L. and (ii) evaluating the effect of different concentration of chitosan on enzyme activities such as phenylalanine ammonia-lyase (PAL) activity and beta- 1, 3-glucanase activity in T. aestivum L. To achieve these goals, the 15-days-old wheat seedlings were treated with different concentrations of chitosan, such as 1-4 mg/mL and further, the enzyme assays were carried out. The results obtained showed that treatment with 0.5 mg/mL of chitosan induced the maximum free radical scavenging activity and DPPH activity in the plant, while treatment with 1.0 mg/mL of chitosan induced the maximum FRAP activity. The response of wheat seedlings to an increase in oxidative stress was correlated with chitosan treatment. Additionally, treatment with 1.0 mg/mL of chitosan to the plant also showed maximum chitinase enzymatic activity in wheat seedlings. Chitosan treatment also elicited enzyme activities such as PAL and beta-1, 3-glucanases. Different concentrations of chitosan treatment showed increasing patterns of PAL activity from 0 hr, which peaked between 24 - 48 hr and thereafter, started decreasing post 72 hr. Similarly, chitosan treatments in wheat seedlings showed an increasing activity of beta-1, 3-glucanase from 0 hr till 48 hr and started decreasing at 72 hr. Overall, the findings showed that chitosan exhibits a protective nature against oxidative stress.
Riddhi et al. (Wed,) studied this question.