5 min mechanical wounding

Plants are continuously exposed to a myriad of abiotic and biotic stresses. However, the molecular mechanisms by which these stress signals are perceived and transduced are poorly understood. To begin to identify primary stress signal transduction components we have focused on genes that respond rapidly (within 5 min) to stress signals. Because it has been hypothesized that detection of physical stress is a mechanism common to mounting a response against a broad range of environmental stresses, we have utilized mechanical wounding as the stress stimulus and performed whole genome microarray analysis of Arabidopsis thaliana leaf tissue. This led to the identification of a number of rapid wound responsive (RWR) genes. Comparison of RWR genes with published abiotic and biotic stress microarray datasets demonstrates a large overlap across a wide range of environmental stresses. Interestingly, RWR genes also exhibit a striking level and pattern of circadian regulation, with induced and repressed genes displaying antiphasic rhythms. Using bioinformatic analysis, we identified a novel motif overrepresented in the promoters of RWR genes, herein designated as the Rapid Stress Response Element (RSRE). We demonstrate in transgenic plants that multimerized RSREs are sufficient to confer a rapid response to both biotic and abiotic stresses in vivo, thereby establishing the functional involvement of this motif in primary transcriptional stress responses. Collectively, our data provide evidence for a novel cis-element that is distributed across the promoters of an array of diverse stress-responsive genes, poised to respond immediately and coordinately to stress signals. This structure suggests that plants may have a transcriptional network resembling the general stress signaling pathway in yeast and that the RSRE element may provide the key to this coordinate regulation. Keywords: Stress response, wounding Three biological replicates of pooled plants were used for each treatment (Not wounded vs 5 min wounded). Each biological replicate is comprised of 2 technical replicates and a dye swap was performed for each technical replicate.

植物始终暴露于多种多样的非生物胁迫与生物胁迫之中，但目前学界对这些胁迫信号的感知与转导分子机制仍缺乏深入了解。为初步鉴定初始胁迫信号转导组分，我们将研究重点置于可在胁迫信号刺激后5分钟内快速响应的基因上。
鉴于已有假说提出，物理胁迫的检测是植物针对广谱环境胁迫构建应答反应的共有机制，因此我们选用机械创伤作为胁迫刺激源，对拟南芥（Arabidopsis thaliana）叶片组织开展全基因组微阵列（microarray）分析。该分析成功鉴定出一批快速创伤响应基因（RWR）。
将RWR基因与已发表的非生物、生物胁迫微阵列数据集进行比对后发现，其在多种环境胁迫下存在显著的基因重叠。有趣的是，RWR基因还表现出显著的昼夜节律调控水平与模式，其中被诱导与被抑制的基因呈现出反相节律。
通过生物信息学分析，我们在RWR基因的启动子区域中鉴定出一个富集的新型基序，本文将其命名为快速胁迫响应元件（Rapid Stress Response Element, RSRE）。我们在转基因植物中证实，多聚化的RSRE足以在活体中介导对生物与非生物胁迫的快速应答，由此确立了该基序在初始转录水平胁迫应答中的功能性作用。
综上，本研究数据为一种新型顺式作用元件（cis-element）提供了实验证据：该元件广泛分布于一系列不同胁迫响应基因的启动子区域，可即时且协同地响应胁迫信号。这一结构表明，植物可能拥有一类与酵母通用胁迫信号通路相似的转录调控网络，而RSRE元件或许正是该协同调控机制的关键所在。
关键词：胁迫应答、创伤
每组处理（未创伤组 vs 创伤5分钟组）均采用3份混合植株的生物学重复样本。每份生物学重复包含2份技术重复，且对每一份技术重复均开展了染料互换实验。