Tea Research Institute, Chinese Academy of Agricultural Sciences; National Center for Tea Improvement, Key Laboratory of Tea Plant Biology and Resources Utilization, Ministry of Agriculture, Hangzhou 310008, China.
BMC Genomics. 2013 Jun 22;14:415. doi: 10.1186/1471-2164-14-415.
Tea is the most popular non-alcoholic health beverage in the world. The tea plant (Camellia sinensis (L.) O. Kuntze) needs to undergo a cold acclimation process to enhance its freezing tolerance in winter. Changes that occur at the molecular level in response to low temperatures are poorly understood in tea plants. To elucidate the molecular mechanisms of cold acclimation, we employed RNA-Seq and digital gene expression (DGE) technologies to the study of genome-wide expression profiles during cold acclimation in tea plants.
Using the Illumina sequencing platform, we obtained approximately 57.35 million RNA-Seq reads. These reads were assembled into 216,831 transcripts, with an average length of 356 bp and an N50 of 529 bp. In total, 1,770 differentially expressed transcripts were identified, of which 1,168 were up-regulated and 602 down-regulated. These include a group of cold sensor or signal transduction genes, cold-responsive transcription factor genes, plasma membrane stabilization related genes, osmosensing-responsive genes, and detoxification enzyme genes. DGE and quantitative RT-PCR analysis further confirmed the results from RNA-Seq analysis. Pathway analysis indicated that the "carbohydrate metabolism pathway" and the "calcium signaling pathway" might play a vital role in tea plants' responses to cold stress.
Our study presents a global survey of transcriptome profiles of tea plants in response to low, non-freezing temperatures and yields insights into the molecular mechanisms of tea plants during the cold acclimation process. It could also serve as a valuable resource for relevant research on cold-tolerance and help to explore the cold-related genes in improving the understanding of low-temperature tolerance and plant-environment interactions.
茶是世界上最受欢迎的非酒精性健康饮料。茶树（Camellia sinensis (L.) O. Kuntze）需要经历一个冷驯化过程，以提高其在冬季的抗冻能力。茶树对低温的分子水平响应变化知之甚少。为了阐明冷驯化的分子机制，我们采用 RNA-Seq 和数字基因表达（DGE）技术研究了茶树在冷驯化过程中的全基因组表达谱。
我们使用 Illumina 测序平台获得了约 5735 万条 RNA-Seq reads。这些 reads 被组装成 216831 个转录本，平均长度为 356bp，N50 为 529bp。总共鉴定出 1770 个差异表达的转录本，其中 1168 个上调，602 个下调。其中包括一组冷传感器或信号转导基因、冷响应转录因子基因、质膜稳定相关基因、渗透压响应基因和解毒酶基因。DGE 和定量 RT-PCR 分析进一步证实了 RNA-Seq 分析的结果。通路分析表明，“碳水化合物代谢途径”和“钙信号通路”可能在茶树应对低温胁迫中发挥重要作用。
本研究对茶树在低温非冻结条件下的转录组谱进行了全面的研究，为茶树在冷驯化过程中的分子机制提供了新的认识。它还可以作为耐冷性相关研究的宝贵资源，并有助于探索与低温相关的基因，以提高对低温耐受性和植物-环境相互作用的理解。
