Identification of NAC transcription factor genes CsNAC79 and CsNAC9 in tea plant and their response to different abiotic stresses

Abstract

Abstract [Objective] The study aims to identify the NAC transcription factor genes CsNAC79 and Cs- NAC9 in tea plants and analyze their expression patterns under drought, salt, high temperature, and low temperature stresses as well as ABA and GA3 treatments in order to provide references for functional analysis of CsNAC79 and CsNAC9. [Methods] CsNAC79 and CsNAC9 were amplified by RT-PCR from tea plant ‘Longjing 43’ and analyzed by bioinformatics. The expression of CsNAC79 and CsNAC9 under abiotic stresses in tea plants was analyzed by qRT-PCR. [Results] (1) CsNAC79 and CsNAC9 encoded 409 and 282 amino acids, respectively, and contain the conserved NAM domain of the NAC family at 15-150 amino acids and 11-134 amino acids, respectively. (2) CsNAC79 protein was closely related to Actinidia chinensis, Diospyros kaki, and Cynara scolymus, while CsNAC9 protein was closely related to Amygdalus persica, Litchi chinensis, and Durio zibethinus. Both of the NAC transcription factors were hydrophilic proteins without signal peptides and transmembrane structures. The promoter regions of CsNAC79 and CsNAC9 contained abiotic stress- responsive elements. Protein structure analysis showed that Cs- NAC79 and CsNAC9 proteins were mainly composed of random coils and α-helixes. (3) Expression analysis showed that CsNAC79 and CsNAC9 genes were up-regulated under different abiotic stresses. [Conclusion] The CsNAC79 and CsNAC9 genes in tea plants responded to various abiotic stresses.

Keywords

• tea plants
• nac transcription factor
• aba
• ga3
• abiotic stress
• expression analysis