Genome-wide characterization and expression analysis of the chitinase gene family in chickpea (Cicer arietinum L.) for fungal stress resistance.

Chitinases, enzymes responsible for hydrolyzing chitin, a significant component of fungal cell walls, play a crucial role in plant defense mechanisms, growth, symbiotic relationships, and stress resistance. In this study, we identified 27 chitinase genes in chickpeas (CaChi) and classified them into five classes based on phylogenetic analysis. Overall, chitinase genes are clustered on eight chromosomes. Among these chromosomes (Chr), Chr-2 displayed the maximum number of genes. Meanwhile, promoter analysis revealed that cis-elements are involved in responses to phytohormones, biotic stress, plant growth, and development. Tissue-based expression analysis indicated that CaChi genes are predominantly expressed in the seedling and floral parts. Furthermore, qRT-PCR analysis revealed that CaChi genes play diverse roles in plant-environment interactions. Notably, several CaChi members were strongly induced by Fusarium oxysporum f. sp. and fourteen genes (CaChi20, CaChi25, CaChi11, CaChi3, CaChi16, CaChi14, CaChi1, CaChi4, CaChi5, CaChi8, CaChi9, CaChi21, CaChi18, CaChi13) exhibited elevated expression levels after post-inoculation, depicting a significant function of Chi genes in chickpea resistance to Fusarium wilt. These findings enhance understanding of the chitinase family in chickpea crops and clarify the functions of chickpea chitinase in response to fungal stress.