Abstract: Phosphate transporter proteins (Phts) play important roles in plant phosphorus (P) absorption and transportation. Furthermore, Phts affect usage efficiency of the tea garden fertilizer. A full-length phosphate transporter complementary DNA (cDNA) CsPht1:4 (also named CsPT4) was cloned from tea plant (Camellia sinensis cv. Longjingchangye) by rapid amplification of cDNA ends (RACE) techniques. CsPT4 had an open reading frame of 1β620βbp (GenBank accession No. KY132100) and encoded a 539 amino acid polypeptide. Bioinformatic analyses showed that CsPT4 had a molecular weight of 59.12βkD and a theoretical isoelectric point of 8.51. The protein secondary structure was a “6+Hydrophilic+6” configuration,which was consistent with the typical structure of Phts. Subcellular localization assay showed that the CsPT4 protein localized in plasma membrane, which was consistent with the predicted results of Softberry. The expression pattern of CsPT4 gene was tissue-specific. Its transcript abundance in old leaves was much higher than that in tender leaves, stems and roots. The lowest expression of CsPT4 gene was identified in roots. Quantitative real-time PCR showed that the gene expression trends in root and leaves were different under low-P and P-deficiency treatments. Under low-P treatment, its induced level was first increased and then decreased, with higher expression in roots than leaves. While under P-deficiency treatment, the induced expression of CsPT4 gene kept stable, with its peak in roots and leaves at 72 h and 48 h, respectively. The results of this study provided a reference for the study of the molecular mechanism of tea adaptation to low P.

Key words: tea plant (Camellia sinensis), phosphate transporter protein, gene cloning, subcellular localization, expression analysis