College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350000, China.
Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350000, China.
Int J Mol Sci. 2022 Dec 10;23(24):15661. doi: 10.3390/ijms232415661.
Ammonium (NH), as a major inorganic source of nitrogen (N) for tea plant growth, is transported and distributed across membranes by the proteins of ammonium transporters (AMTs). However, the AMT2-type AMTs from tea plants remain poorly understood. In this study, five subfamily genes were identified in tea plant genomes, and their full-length coding sequences (CDS) were isolated from roots. Then, a NH uptake kinetic comparison of Fudingdabaicha (FD), Huangdan (HD), and Maoxie (MX) showed that FD was a high N efficiency (HNE) cultivar that had a wide range of adaptability to NH, HD was a high N efficiency under high N conditions (HNEH) cultivar, in which it was easy to obtain higher yield in a high N environment, and MX was a high N efficiency under low N conditions (HNEL) cultivar, which had a higher affinity for NH than the other two. Tissue-specific expression analysis suggested that and were highly expressed in the roots, indicating that these two members may be unique in the subfamily. This is further supported by our findings from the temporal expression profiles in the roots among these three different N adaptation cultivars. Expression levels of and in FD and HD were upregulated by a short time (2 h) under high NH treatment, while under low NH treatment, and were highly expressed at 0 h and 2 h in the HNEL-type cultivar-MX. Furthermore, the functional analysis illustrated that and could make a functional complementation of NH-defective mutant yeast cells at low NH levels, and the transport efficiency of was higher than that of . Thus, we concluded that and might play roles in controlling the NH uptake from the soil to the roots. These results will further the understanding of the NH signal networks of AMT2-type proteins in tea plants.
铵（NH）是茶树生长的主要氮（N）无机来源，其通过铵转运蛋白（AMT）的蛋白在膜间运输和分布。然而，茶树的 AMT2 型 AMT 仍知之甚少。本研究在茶树基因组中鉴定了 5 个亚家族基因，并从根部分离其全长编码序列（CDS）。然后，对福鼎大白茶（FD）、黄丹（HD）和毛蟹（MX）的 NH 吸收动力学比较表明，FD 是一种高氮效率（HNE）品种，对 NH 具有广泛的适应性；HD 是一种高氮条件下的高氮效率（HNEH）品种，在高氮环境中容易获得更高的产量；MX 是一种低氮条件下的高氮效率（HNEL）品种，对 NH 的亲和力高于其他两个品种。组织特异性表达分析表明，和在根部高表达，表明这两个成员可能在亚家族中具有独特性。这进一步得到了我们在这三个不同氮适应品种的根部中时间表达谱研究结果的支持。在高 NH 处理下，FD 和 HD 中的和在短时间（2 h）内上调表达，而在低 NH 处理下，HNEL 型品种-MX 中的和在 0 h 和 2 h 时高度表达。此外，功能分析表明，和可以在低 NH 水平下使 NH 缺陷型酵母细胞功能互补，并且的转运效率高于。因此，我们得出结论，和可能在控制 NH 从土壤到根部的吸收中发挥作用。这些结果将进一步加深对茶树 AMT2 型蛋白 NH 信号网络的理解。
