National Center for Tea Improvement-Hunan Branch, Tea Research Institute, Hunan Academy of Agricultural Science, 702 Yuanda Road, Changsha, 410125, P. R. China.
Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, 650201, P. R. China.
Sci Rep. 2017 May 10;7(1):1693. doi: 10.1038/s41598-017-01949-0.
Applied nitrogen (N) fertilizer significantly increases the leaf yield. However, most N is not utilized by the plant, negatively impacting the environment. To date, little is known regarding N utilization genes and mechanisms in the leaf production. To understand this, we investigated transcriptomes using RNA-seq and amino acid levels with N treatment in tea (Camellia sinensis), the most popular beverage crop. We identified 196 and 29 common differentially expressed genes in roots and leaves, respectively, in response to ammonium in two tea varieties. Among those genes, AMT, NRT and AQP for N uptake and GOGAT and GS for N assimilation were the key genes, validated by RT-qPCR, which expressed in a network manner with tissue specificity. Importantly, only AQP and three novel DEGs associated with stress, manganese binding, and gibberellin-regulated transcription factor were common in N responses across all tissues and varieties. A hypothesized gene regulatory network for N was proposed. A strong statistical correlation between key genes' expression and amino acid content was revealed. The key genes and regulatory network improve our understanding of the molecular mechanism of N usage and offer gene targets for plant improvement.
施加氮肥（N）可显著提高叶片产量。然而，大部分 N 并未被植物利用，对环境造成负面影响。迄今为止，人们对叶片生产中 N 利用基因和机制知之甚少。为了了解这一点，我们使用 RNA-seq 技术和 N 处理后的氨基酸水平，对茶树（Camellia sinensis）进行了转录组研究，茶树是最受欢迎的饮料作物。我们在两个茶树品种中分别鉴定出 196 个和 29 个在铵胁迫下的共同差异表达基因。在这些基因中，用于氮吸收的 AMT、NRT 和 AQP，以及用于氮同化的 GOGAT 和 GS 是关键基因，通过 RT-qPCR 验证，它们以具有组织特异性的网络方式表达。重要的是，只有 AQP 和三个与应激、锰结合和赤霉素调节转录因子相关的新的差异表达基因是所有组织和品种中对 N 响应的共有基因。提出了一个假设的 N 基因调控网络。关键基因表达与氨基酸含量之间存在很强的统计学相关性。这些关键基因和调控网络有助于我们理解 N 利用的分子机制，并为植物改良提供基因靶点。
