Defence mechanism through a biochemical pathway in Kabuli chickpea genotypes against Ascochyta blight

Abstract

Abstract Chickpea (Cicer arietinum L.), the second-largest global pulse crop, plays a crucial role in providing essential minerals and dietary fiber. Ascochyta blight, caused by the necrotrophic pathogen Ascochyta rabiei, poses a substantial threat to chickpea cultivation. Contemporary cultivars often lose resistance to this disease, necessitating improved management strategies. In this study, six Kabuli chickpea genotypes underwent at treated and controlled conditions, identifying GLK 10–40, GLK 20055, FLIP 09-194C, FLIP 04-219C, and ICCV 55215 resistant and GLK 17301 susceptible to Ascochyta blight. The exploration into the biochemical responses of these genotypes revealed dynamic shifts in enzymatic activities and biochemical components post-fungal infection. PAL enzyme activity witnessed a remarkable 45.5-fold increase at 96 hours post inoculation in the resistant genotype GLK 10–40, underscoring its essential role in the early defense cascade against Ascochyta blight. TAL and PPO activity peaked at 96 hours post inoculation notably in GLK 20055 and GLK 10–40 respectively, emphasizing its participation in the initial defense response. POD activity, a crucial element in plant immunity, reached its peak at 96 hours post inoculation, particularly in the resistant line GLK 20055, signifying prolonged defense mechanisms. Lignin content exhibited a consistent increase till 144 hour post inoculation notably in GLK 20055, highlighting its structural contribution to defense against Ascochyta blight. Total phenol content, crucial in resisting microbial infection, showed heightened levels till 144 hour post inoculation in resistant line FLIP 04-219C maintaining sustained high levels. These findings unveil the biochemical intricacies of chickpea defense mechanisms against Ascochyta blight, laying the groundwork for targeted breeding or genetic engineering. The identified genotypes, such as GLK 10–40, GLK 20055, and FLIP 04-219C, hold promise for developing resilient chickpea cultivars to counter this challenging disease, crucial for ensuring global food security.