THE FAMILY OF CHITINASES IN COTTON G. raimondii

Abstract

Chitinases are enzymes widely spread in plants with no endogenous substrate and play significant role to lyse the cell walls of many pathogens. Their role in defense is firmly established. Recently, their functions in plants have been extended to response to abiotic stresses and various developmental plant processes. The gene family of chitinases is well characterized in some model species. Few researches on their involvement in cotton defense against pathogens have been reported. Here were investigated Gossypium raimondii genome in the Phytozome database for the presence of homologues. BLAST similarity search, using five chitinase representatives from Arabidopsis belonging to different classes I-V, identified a total of 41 non-redundant chitinase gene sequences in cotton. We analysed them in silico using available bioinformatics software and characterized their basic molecular structures. Signal peptides, carbohydrate-binding domains, hinge regions were predicted, molecular weights and expected isoelectric points were calculated. Genes were divided into different chitinase classes based on homology clustering with genes from Arabidopsis. The individual family members were further linked to expression data and/or literary knowledge, which is in relation to cotton rather scarce. Knowledge on chitinase gene family members in cotton provides a basic for further basic- as well as applied cotton research as they are functionally validated.