Cloning and expression of RING-finger E3 ubiquitin ligase CsSDIR1 gene in tea plant (Camellia sinensis)北大核心CSCD

Protein ubiquitination regulates many aspects of plant development and stress response. The RING-finger type E3 ubiquitin ligase SDIR1 (salt and drought induced ring finger 1) gene plays a key role in plant stress response. In this study, the full-length cDNA and the promoter sequences of CsSDIR1 were isolated from tea plants using the RT-PCR technology, and its bioinformatics characteristics were systematically analyzed. The expression patterns of CsSDIR1 in various tissues and in response to cold, drought, salt, and ABA treatments were also investigated by quantitative real-time RT-PCR (qRT-PCR). The sequence of CsSDIR1 contains a complete open reading frame of 831 bp, coding for a 276-long amino acid protein with a molecular weight of (Mr) 30.085 × 103 and a theoretical isoelectric point of 6.54. CsSDIR1 was predicted to be a hydrophobic protein localized on the intracellular membranes. The analysis of the amino acid sequence characteristics showed that CsSDIR1 contains two putative transmembrane domains at the N-terminus and a C3H2C3 RING-finger domain at the C-terminus; it shares high similarity with other plants' SDIR1, and has the closest relationship to Actinidia sinensis. A cis-acting regulatory elements prediction showed that the CsSDIR1 promoter contains many cis-acting elements, especially drought and salt stress response elements. The qRT-PCR analysis indicated that the CsSDIR1 gene has a high expression level in stems, followed by roots, leaves, and flowers; the expression of the CsSDIR1 gene is up-regulated by ABA, salt, and drought treatments, whereas it is down-regulated in response to cold stress. These results demonstrated that the CsSDIR1 gene might be involved in the plant stress response of tea trees. © 2018 Science Press. All rights reserved.