Cloning and Expression Analysis of Ring-type E3 Ubiquitin Ligase Gene in Camellia sinensis cv. Tieguanyin Under Drought Stress

The E3 ubiquitin ligase gene from Camellia sinensis cv.Tieguanyin tea plants were cloned and subjected to a bioinformatics analysis. Under varied drought conditions on the plants, the quantitative expressions of the gene was determined using qPCR. The gene sequence (GenBank accession number, KR819177) was found to be 1 138 bp long containing an open reading frame (ORF) of 810 bp and encoding 269 amino acids. The bioinformatics revealed that the ligase gene did not have a transmembrane or signal peptide but multiple phosphorylation sites, and that its subcellular cells located in the chloroplasts. Its nucleotide and deduced amino acid sequences showed 51%, 50%, 50%, 50%, and 49% homology with the E3 ubiquitin ligase genes from Nicotiana sylvestris, Camelina sativa, Vitis vinifera, Tarenaya hassleriana, and Brassica rapa, respectively; while its conserved functional domains related to the translated protein sequences had a RING-finger structure. Consequently, it was preliminarily identified as the E3 ubiquitin ligase gene of C. sinensis cv. Tieguanyin. Subsequently, the qPCR analysis indicated that the transcript of this gene, when the tea plant was under varied drought stresses, was significantly more up-regulated than control. Hence, it was concluded that the previously identified RING-type E3 ubiquitin ligase gene found in C.sinensis cv. Tieguanyin indeed involved in the drought response mechanism of the plant.