Department of Biotechnology, Plant Improvement Division, Tea Research Association, Tocklai, Jorhat, Assam, India.
Funct Integr Genomics. 2012 Aug;12(3):543-63. doi: 10.1007/s10142-012-0277-0. Epub 2012 May 5.
Understanding the genes that govern tea plant (Camellia sinensis) architecture and response to drought stress is urgently needed to enhance breeding in tea with improved water use efficiency. Field drought is a slow mechanism and the plants go through an adaptive process in contrast to the drastic changes of rapid dehydration in case of controlled experiments. We identified a set of drought responsive genes under controlled condition using SSH, and validated the identified genes and their pattern of expression under field drought condition. The study was at three stages of water deficit stress viz., before wilting, wilting and recovery, which revealed a set of genes with higher expression at before wilting stage including dehydrin, abscissic acid ripening protein, glutathione peroxidase, cinnamoyl CoA reductase, calmodulin binding protein. The higher expression of these genes was related with increase tolerance character of DT/TS-463 before wilting, these five tolerant progenies could withstand drought stress and thus are candidates for breeding. We observed that physiological parameter like water use efficiency formed a close group with genes such as calmodulin related, DRM3, hexose transporter, hydrogen peroxide induced protein, ACC oxidase, lipase, ethylene responsive transcription factor and diaminopimelate decarboxylase, during wilting point. Our data provides valuable information for the gene components and the dynamics of gene expression in second and third leaf against drought stress in tea, which could be regarded as candidate targets potentially associated with drought tolerance. We propose that the identified five tolerant progenies on the basis of their drought tolerance can thus be utilised for future breeding programmes.
了解控制茶树（Camellia sinensis）结构和对干旱胁迫响应的基因，对于提高茶树的节水效率、开展茶树的遗传改良十分必要。田间干旱是一个缓慢的过程，与控制实验中快速脱水的剧烈变化相比，植物会经历一个适应过程。我们利用 SSH 技术在受控条件下鉴定了一组干旱响应基因，并验证了在田间干旱条件下鉴定基因及其表达模式。研究分为三个水分亏缺胁迫阶段，即萎蔫前、萎蔫中和恢复，揭示了一组在萎蔫前阶段表达较高的基因，包括脱水素、脱落酸成熟蛋白、谷胱甘肽过氧化物酶、肉桂酰辅酶 A 还原酶、钙调素结合蛋白。这些基因的高表达与 DT/TS-463 在萎蔫前的耐受性特征增加有关，这 5 个耐旱后代能够耐受干旱胁迫，因此是育种的候选者。我们观察到，在萎蔫点，生理参数（如水利用效率）与钙调素相关基因、DRM3、己糖转运蛋白、过氧化氢诱导蛋白、ACC 氧化酶、脂肪酶、乙烯响应转录因子和二氨基庚二酸脱羧酶等基因密切相关。我们的数据为茶树第二和第三叶在干旱胁迫下的基因组成和基因表达动态提供了有价值的信息，这些信息可以作为潜在与耐旱性相关的候选目标。我们提出，基于耐旱性鉴定的 5 个耐旱后代，因此可以用于未来的育种计划。
