The Arabidopsis gene SCI2 encodes a RNA-binding protein which regulates the suppression of plant response to abiotic stress

拟南芥基因 SCI2 编码一种 RNA 结合蛋白，可调节植物对非生物胁迫反应的抑制

• 批准号: BB/D013429/1
• 负责人: John Turner
• 金额: $ 42.9万
• 依托单位: University of East Anglia
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2006
• 资助国家: 英国
• 起止时间: 2006 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FD013429%2F1
• 关键词: Arabidopsis; gene; SCI2; encodes; RNA

Our agriculture focuses on the production of crops that will feed us and our animals. However, these crops are attractive food for the myriad of herbivore insects and nematodes that also wish to eat them. It is not generally known that plants are extraordinarily sophisticated organisms: although they may appear to unresponsive, they constantly monitor themselves and their environment, and when they sense they have been attacked by insect pests or pathogens, or exposed to an abiotic stress such as drought or salinity, they respond rapidly to defend themselves. These defence responses are not only physical, but also chemical. The chemical response is based on the fact that plants are the masters of synthetic organic chemistry: in response to attack by pests they synthesise a variety of toxic compounds that include volatile terpenes, and toxic alkaloids, phenolics, and flavonoids. The production of these compounds deters all but the most determined, or well-defended, of insects. An unexpected corollary is that because the early selection and breeding of our crop plants deliberately produced varieties that lacked the bitter flavours many of these compounds cause, our domesticated varieties have therefore also been bred, unintentionally, to be vulnerable to pests. Other important factors that reduce yield include drought, salinity, and mechanical damage. Research in my laboratory has shown that plant response to pests has many similarities to plant response to drought, salinity, and to mechanical damage: that is, there are common features in the ways in which plants respond to these stresses. We wish to understand how the plant detect the stress, and then converts this signal to induce a response that adapts the plant to resist that stress. We have shown that when plants are wounded by insects, or are subject to stress, they make a compound called jasmonate, which appears to travel through the plant and induce a signal pathway that induces responses to stress, including the production of secondary chemical products. We have identified a number of genes that regulate the jasmonate signal pathway. This project is to characterise a new component of this pathway we recently discovered, called SCI2. When SCI2 is mutated the plant has greatly enhanced response to wounding and to stress, and greatly enhanced resistance. This means that the normal function of SCI2 is to suppress these responses. Therefore, the stress response pathway includes both activators and suppressers of the response. Because the synthesis of SCI2 is itself activated by jasmonate, this indicates that the jasmonate signal activates a suppresser of the jasmonate response pathway. We suspect that such a mechanism could assist in regulating the tissue-specificity of plant response to jasmonate. SCI2 is a protein predicted to bind to RNA products of other genes. We anticipate therefore that SCI2 will function by regulating the processing of these RNAs, by enchancing or reducing their stability. Therefore we shall identify the RNAs that bind SCI2, determine whether the level of the SCI2 protein affects the stability of these RNAs, and discover how expression of the SCI2 gene is regulated, and what gene expression SCI2 regulates.

我们的农业重点是生产可以养活我们和我们的动物的农作物。但是，这些农作物是众多的草食动物昆虫和线虫也希望食用的农作物。通常不知道植物是非常复杂的生物：尽管它们似乎没有响应性，但它​​们会不断监测自己和环境，并且当他们感觉到自己受到虫害或病原体的攻击，或暴露于诸如干旱或盐分之类的非生物压力（例如干旱或盐度）时，他们会迅速反应以防御自己。这些防御反应不仅是物理的，而且是化学的。化学反应基于以下事实：植物是合成有机化学的大师：为了响应害虫的攻击，它们合成了包括挥发性萜烯和有毒的生物碱，酚类和黄酮的各种有毒化合物。这些化合物的产生阻止了除最确定或防御良好的昆虫外的所有产品。意外的推论是，因为我们的作物植物的早期选择和繁殖故意生产的品种缺乏苦味，因此许多这些化合物会引起许多这些化合物，因此，我们的驯化品种也无意间繁殖，以免受到害虫的影响。降低产量的其他重要因素包括干旱，盐度和机械损害。我的实验室的研究表明，植物对害虫的反应与植物对干旱，盐度和机械损害的反应有许多相似之处：也就是说，在植物应对这些压力的方式中，有一些共同的特征。我们希望了解植物如何检测应力，然后转换该信号以诱导适应植物以抵抗这种压力的反应。我们已经表明，当植物受到昆虫的伤害或承受压力时，它们制造了一种称为jasmonate的化合物，该化合物似乎通过植物传播并诱导一种引起对压力反应的信号途径，包括二级化学产品的产生。我们已经确定了许多调节纹纹盐信号途径的基因。该项目是为了表征我们最近发现的该途径的新组成部分，称为Sci2。当Sci2突变时，植物对伤害和压力的反应大大增强，并大大增强了抵抗力。这意味着SCI2的正常功能是抑制这些响应。因此，应力响应途径既包括激活剂和抑制器，又包括响应的抑制器。因为Sci2的合成本身是通过jasmonate激活的，所以这表明jasmonate信号激活了jasmonate响应途径的抑制剂。我们怀疑这种机制可以帮助调节植物对jasmonate的反应的组织特异性。 Sci2是一种预测与其他基因的RNA产物结合的蛋白质。因此，我们预计SCI2将通过纵容或降低其稳定性来调节这些RNA的处理来发挥作用。因此，我们将确定结合SCI2的RNA，确定SCI2蛋白的水平是否影响这些RNA的稳定性，并发现SCI2基因的表达如何受到调节，以及哪种基因表达SCI2调节。