Influence of cold stress on expression of invertase and calcium dependent protein kinase genes in chickpea

Abstract

Chickpea (Cicer arietinum L.) is an important food grain legume. Chickpea is sensitive to newlinecold and suffers substantial yield losses due to cold stress. Invertases hydrolyse sucrose into newlineglucose and fructose and play an important role in plant growth and development as well as newlineplants responses to various stresses including cold. In addition to invertases, calciumdependent protein kinases (CDPKs) modify gene expression via transcription factors to newlineachieve systematic plant growth/development and reaction to stresses. Information on newlineinvertases and calcium-dependent protein kinases as well as the role of these genes in stress newlinetolerance/susceptibility in chickpea is unavailable. In this study, 19 invertase genes (11 cellwall invertase, one vacuolar invertase and seven alkaline/neutral invertase genes) and 31 newlineCDPKs genes were identified in the chickpea genome. These genes were located on 7 newlinechickpea chromosomes. A comprehensive analysis of invertase as well as CDPK genes and newlineproteins were performed, including gene structure, mRNA structure, cis-acting elements in newlinethe promoter regions, phylogeny, evolutionary relationships, gene duplication events, protein newlinestructure, motifs, domains, physiochemical properties, sub-cellular localization and newlineinteractions of invertases as well as CDPKs with other proteins. Phylogenetic analysis newlinerevealed that chickpea invertases were comprised of five major lineages whereas CDPKs had newlinefour lineages. The members within the same sub-groups shared conserved domains. newlineExpression analysis revealed that all the invertase genes were functional in chickpea however, newlinethese genes expressed differentially in contrasting chickpea genotype under cold stress and newlineAscochyta blight infection. Expression analysis revealed that cell wall invertases were newlineassociated in cold tolerance whereas majority of the CaCDPK genes were involved in low newlinetemperature responses by tolerant as well as sensitive genotypes of chickpea. Invertase genes newlineassociated with Ascochyta blight resistance in chickpea were also identified. The study laid newlinethe foundation for unravelling the complexity of chickpea responses to cold and Ascochyta newlinerabiei infection and develop protocols for mitigation of cold stress in chickpea. newline