Table_2_Transcriptome analysis of tea (Camellia sinensis) leaves in response to ammonium starvation and recovery.xlsx

The tea plant is a kind of ammonium-preferring crop, but the mechanism whereby ammonium (NH4+) regulate its growth is not well understood. The current study focused on the effects of NH4+ on tea plants. Transcriptomic analysis was performed to investigate the early- and late-stage NH4+ deprivation and resupply in tea plants shoots. Through short- and long-term NH4+ deficiency, the dynamic response to NH4+ stress was investigated. The most significant effects of NH4+ deficiency were found to be on photosynthesis and gene ontology (GO) enrichment varied with the length of NH4+ deprivation. Enriched KEGG pathways were also different when NH4+ was resupplied at different concentrations which may indicate reasons for tolerance of high NH4+ concentration. Using weighted gene co-expression network analysis (WGCNA), modules related to significant tea components, tea polyphenols and free amino acids, were identified. Hence, NH4+ could be regarded as a signaling molecule with the response of catechins shown to be higher than that of amino acids. The current work represents a comprehensive transcriptomic analysis of plant responses to NH4+ and reveals many potential genes regulated by NH4+ in tea plants. Such findings may lead to improvements in nitrogen efficiency of tea plants.

茶树是偏好铵态氮的作物，但铵态氮（NH₄⁺）调控其生长的分子机制目前仍未被完全阐明。本研究聚焦铵态氮对茶树的调控效应，通过转录组学分析，探究了茶树枝条在铵态氮剥夺与复供条件下的早期及晚期响应过程。通过设置短期与长期铵态氮匮乏处理，本研究解析了茶树对铵态氮胁迫的动态响应模式。研究发现，铵态氮匮乏对茶树光合作用的影响最为显著，且基因本体（Gene Ontology, GO）富集分析结果随铵态氮剥夺时长呈现动态变化。不同浓度铵态氮复供条件下，富集的京都基因与基因组百科全书（Kyoto Encyclopedia of Genes and Genomes, KEGG）通路亦存在差异，这或可为解析茶树对高浓度铵态氮的耐受机制提供线索。本研究通过加权基因共表达网络分析（Weighted Gene Co-expression Network Analysis, WGCNA），筛选得到与茶树关键次生代谢产物——茶多酚及游离氨基酸相关的基因共表达模块。综上，铵态氮可被视为一种信号分子，且茶树中儿茶素对铵态氮的响应强度高于氨基酸。本研究完成了茶树响应铵态氮的全面转录组学分析，揭示了茶树中众多受铵态氮调控的潜在功能基因。上述研究结果可为提升茶树氮素利用效率提供理论支撑。