Induction of β-1,3-glucanase and chitinase activity, cloning and their characterization in the defense response of Cuminum cyminum plant against the fungal pathogen Fusarium oxysporum

The activities of beta-1,3-glucanase and chitinase, two important PR proteins were measured on 15 days and one month old plants in two varieties viz. GC-4 (Resistant) and RZ-209 (Susceptible) as control and pathogenic state, respectively. The activities were found to be higher in the pathogen inoculated plants than the control plants. Varietal differences with respect to slightly higher beta-1,3-glucanase and chitinase activity in var. GC-4 than var. RZ-209 was obtained. The enzyme activity gradually increased throughout the experimental period of 168h in pathogen inoculated plants as compared to control. However, the increase in activity of beta-1,3-glucanase and chitinase was more rapid and to a greater extent in plants of var. GC-4 than in var. RZ-209. A number of protein bands were observed on SDS-Page, further Western blot analysis revealed the presence of 30 and 28 kDa bands of beta-1,3-glucanase and chitinase in induced cumin plants. The results indicate a distinct role of PR proteins in the defense response of Cumin plants. The isolation, cloning and characterization of beta-1,3-glucanase and chitinase were, then performed as a part of a wider study to enhance the resistance of cumin to fungal diseases. A phylogenetic analysis was done to investigate the pattern of functional divergence in these proteins.