Abstract:In order to investigate the effect of aquaporin in tea plant under water stress, two aquaporin genes (AQPs, aquaporins) were cloned from Camellia sinensis ‘Fuding Dabai’, and their expression patterns under simulated drought, exogenous application of ABA, natural drought and rehydration were analyzed. Amino acid sequence analysis showed that both aquaporins contained SGGHINPAVT, a conserved signal sequence of MIP protein family, and two highly conserved NPA (Asn-Pro-Ala) units, both of which contained six transmembrane regions. Based on the results of homologous alignment and the prediction of cell localization, they were assigned to the plasma membrane aquaporin (PIPs, plasma membrane intrinsic proteins) subfamily. The results of real-time fluorescence quantitative PCR showed that the gene expression of the two CsPIPs was tissue-specific, the expression level of CsPIP2;7 was the highest in leaves, and CsPIP2;8 was the highest in flowers and leaves. After 20% PEG simulated drought stress,CsPIP2;7 was significantly down-regulated, CsPIP2;8 fluctuated, and was slightly up-regulated 24 hours later. After exogenous application of ABA, CsPIP2;7 was significantly down-regulated, while CsPIP2;8 was significantly up-regulated. In addition, experiments of natural drought and rehydration showed that the expression of the two aquaporin genes was up-regulated by drought stress and reached the maximum 24 days after irrigation stopped, CsPIP2;7 and CsPIP2;8 were up-regulated by 7.13 times and 3.68 times respectively, and the two genes were down-regulated 29 days after irrigation stopped, and were down-regulated or remained stable after rehydration. Different from the expression pattern of leaves, CsPIP2;7 decreased slowly in the process of slow drought and was up-regulated significantly after rehydration, and CsPIP2;8 fluctuated as with PEG treatment, but was down-regulated after rehydration.