Molecular Characterization Reveals the Involvement of Calcium Dependent Protein Kinases in Abiotic Stress Signaling and Development in Chickpea (Cicer arietinum)

Abstract

Calcium-dependent protein kinases (CDPKs) are a major group of calcium (Ca2+) sensors in plants. CDPKs play a dual function of “Ca2+ sensor and responder.” These sensors decode the “Ca2+ signatures” generated in response to adverse growth conditions such as drought, salinity, and cold and developmental processes. However, knowledge of the CDPK family in the legume crop chickpea is missing. Here, we have identified a total of 22 CDPK genes in the chickpea genome. The phylogenetic analysis of the chickpea CDPK family with other plants revealed their evolutionary conservation. Protein homology modeling described the three-dimensional structure of chickpea CDPKs. Defined arrangements of α-helix, β-strands, and transmembrane-helix represent important structures like kinase domain, inhibitory junction domain, N and C-lobes of EF-hand motifs. Subcellular localization analysis revealed that CaCDPK proteins are localized mainly at the cytoplasm and in the nucleus. Most of the CaCDPK promoters had abiotic stress and development-related cis-regulatory elements, suggesting the functional role of CaCDPKs in abiotic stress and development-related signaling. RNA sequencing (RNA-seq) expression analysis indicated the role of the CaCDPK family in various developmental stages, including vegetative, reproductive development, senescence stages, and during seed stages of early embryogenesis, late embryogenesis, mid and late seed maturity. The real-time quantitative PCR (qRT-PCR) analysis revealed that several CaCDPK genes are specifically as well as commonly induced by drought, salt, and Abscisic acid (ABA). Overall, these findings indicate that the CDPK family is probably involved in abiotic stress responses and development in chickpeas. This study provides crucial information on the CDPK family that will be utilized in generating abiotic stress-tolerant and high-yielding chickpea varieties.

Genome-Wide Identification and Characterization of CDPK Gene Family in Cultivated Peanut (Arachis hypogaea L.) Reveal Their Potential Roles in Response to Ca Deficiency

“…The total number of AhCDPK genes is equal to the sum of the genes in the two diploid parents, which indicates a translocation occurrence during allopolyploidization. When compared to several other plant species, the cultivated peanut stands out with a higher number of AhCDPK genes, such as Arabidopsis thaliana (34), rice (29), chickpea (22), Medicago truncatula (24), peach (17), and pineapple (17) [6,[21][22][23]27,60]. However, the peanut's total still falls short when compared to tetraploid sea-island cotton (84) and hexaploid wheat (85) [17,25].…”

Genomic and Transcriptomic Approaches to Developing Abiotic Stress-Resilient Crops

“…Besides rice, the genome-wide approach has been used to identify and analyze of a number of gene families in different crops like soybean [119,120]), cotton [121,122], Brassica Spp. [52], Chickpea [123][124][125][126] and Maize [127][128][129].…”