Identification of the lysine and histidine transporter family in Camellia sinensis and the characterizations in nitrogen utilization

Abstract

In plants, the lysine and histidine transporter (LHT) family represent a class of proteins that mediate the uptake, translocation, and utilization of amino acids. The tea plant (Camellia sinensis) is a perennial evergreen with a relatively high level of amino acids. However, systematic identification and molecular characterization of the LHT gene family has rarely been reported in tea plants. In this study, 22 CsLHTs were identified from the ‘Shuchazao’ genome and classified into two groups. The modeled three-dimensional structure and the conserved domains presented a high similarity among the LHTs proteins. Moreover, it was predicted that a few genes were conserved through the analysis of the physiochemical characters, structures and cis-elements in promoters. The expression patterns in tea plants revealed that CsLHT7 was mainly expressed in the roots, and CsLHT4 and CsLHT11 exhibited relatively high expression in both the roots and leaves. Moreover, the expression of all three genes could be induced by organic nitrogen. Additionally, heterogeneous expression of CsLHT4, CsLHT7 and CsLHT11 in Arabidopsis thaliana decreased the aerial parts biomass compared with that in WT plants while significantly increased the rosette biomass only for CsLHT11 transgenic plants versus WT plants. Overall, our results provide fundamental information about CsLHTs and potential genes in N utilization for further analysis in tea plants.