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

Abstract

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 <i>CsCBLs</i> and 18 <i>CsCIPKs</i> 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 <i>CsCBL4</i> contained 30 stress-related elements. PlantPAN2 shows that <i>CsCIPK6</i> contains 48 ABRELATERD1; <i>CsCIPK17</i> contains 37 GT1CONSENSUS; <i>CsCIPK3</i> contains 64 MYBCOREATCYCB1; <i>CsCBL3</i> contains 52 SORLIP1AT; <i>CsCBL5</i> contains 65 SURECOREATSULTR11; and <i>CsCIPK11</i> 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 <i>CsCBL4</i>, <i>CsCIPK2,</i> and <i>CsCIPK14</i> were similar, and they were homologous to <i>AtSOS3</i> and <i>AtSIP3</i> and <i>AtSIP4</i> 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.