Genome-Wide Identification and Expression Analysis of Calcineurin B-Like Protein and Calcineurin B-Like Protein-Interacting Protein Kinase Family Genes in Tea Plant.

Tea plant is an important economic crop on a global scale. Its yield and quality are affected by abiotic stress. The calcineurin B-like protein (CBL) and CBL-interacting protein kinase (CIPK) family genes play irreplaceable roles in plant development and stress resistance. More and more CBL-CIPK genes have been identified, but a few CBL-CIPK genes have been cloned and characterized in tea plants. In this study, 7 CsCBLs and 18 CsCIPKs were identified based on the tea plant genome. Physicochemical properties, phylogenetic, conserved motifs, gene structure, homologous gene network, and promoter upstream elements of these 25 genes were analyzed. Conserved motifs of these genes varied with phylogenetic tree node. From the genetic structure, members of the tea plant CIPK gene family can be divided into two types: intron rich and no intron. Many stress-related elements were found in the 2000 bp upstream of the promoter, and PlantCARE predicted that CsCBL4 contained 30 stress-related elements. PlantPAN2 shows that CsCIPK6 contains 48 ABRELATERD1; CsCIPK17 contains 37 GT1CONSENSUS; CsCIPK3 contains 64 MYBCOREATCYCB1; CsCBL3 contains 52 SORLIP1AT; CsCBL5 contains 65 SURECOREATSULTR11; and CsCIPK11 contains 83 WBOXATNPR1. In addition, eight genes were selected for quantitative real-time PCR (RT-qPCR) to detect their expression profiles under high-temperature, low-temperature, salt, and drought treatments. These genes were found to be responsive to one or more abiotic stress treatments. The expression levels of CsCBL4, CsCIPK2, and CsCIPK14 were similar, and they were homologous to AtSOS3 and AtSIP3 and AtSIP4 in Arabidopsis, which were involved in the SOS pathway. This study provides insight into the potential functions of the CsCBL and CsCIPK of tea plant.