Genetics of Programmed Cell Death in Arabidopsis

描述(申请人提供)：植物，像所有高等真核生物一样，必须 控制细胞死亡的发生和蔓延。植物生物学中充满了 发育控制性细胞程序性死亡(POD)的例子。 此外，植物中的一种特殊形式的POD，称为过敏性 响应(HR)与成功识别、和 对病原体攻击的反应。因此，人力资源可能是 植物的先天免疫反应。然而，目前还不清楚HR在其中扮演了什么因果角色 在阻止病原体入侵方面发挥了作用，或者HR是否是 杀死病原体的植物防御反应。同样不清楚的是 HR的遗传控制是与机械相关，还是截然不同 在发育过程中控制植物PCD的机制。另外， 虽然对动物PCD控制的分子机制了解很多， 从本质上讲，植物中没有任何东西是已知的。 这项建议的重点是使用拟南芥作为遗传模型，用来 将HR的控制理解为植物POD的一个容易定义的模型。 拟南芥基因组已完全测序，几乎没有分子 动物POD关键调控因子在序列上的保守性证据 水平。我们是最早认识到利用拟南芥 从基因上剖析了细胞死亡控制并做出了重大贡献 到战场上去。我们鉴定并分析了一系列失控的突变体 无病原体时HR样细胞死亡。我们克隆了三个关键的HR 所有调节器都属于一个基因家族： LSD1及其相关基因LOL1(LSD One Like 1)和LOL2。我们也 证实LSD1与两类转录因子相互作用 这些蛋白在HA中具有生物学功能，并且它们 在viva中与LSD1相互作用。基于以前的工作和进展情况 报告如下，具体目标的主题，使用前进和 反向遗传学和生物化学是： 1.拟南芥LSD1蛋白：细胞死亡繁殖的调控。 2.isdi信号转导：基因外isdi的遗传特征 抑制者。 3.LSD1的分子同源物也控制细胞死亡。 4.Isd1 RCD与ROL、NO和SA的平衡之间的相互作用。

DESCRIPTION (provided by applicant): Plants, like all higher eukaryotes, must control the onset and spread of cell death. Plant biology is replete with examples of developmentally controlled programmed cell death (POD). Additionally, a specialized form of POD in plants, termed the Hypersensitive Response (HR) is tightly correlated with successful recognition of, and response to, pathogen attack. Thus, the HR is potentially an important part of the plant innate immune response. It is, however, unclear what causal role HR plays in stopping pathogen ingress, or whether HR is the consequence of the plant defense response that does kill the pathogen. It is equally unclear whether the genetic control of HR is mechanistically related to, or distinct from, the mechanisms that control plant PCD during development. Additionally, while much is known about the molecular mechanisms of PCD control in animals, essentially nothing is known in plants. This proposal is focused on using Arabidopsis as a genetic model with which to understand the control of HR as an easily definable model for POD in plants. The Arabidopsis genome is fully sequenced and there is little molecular evidence for conservation of key regulators of animal POD at the sequence level. We were among the first to recognize the use of Arabidopsis to genetically dissect cell death control and have made significant contributions to the field. We identified and analyzed a series of mutants that misregulate HR-like cell death in the absence of pathogen. We cloned three key HR regulators all belonging to one gene family: LSD1 and the related genes LOL 1 (LSD One Like 1) and LOL2. We also demonstrated that LSD1 interacts with two classes of transcriptional regulators, that these proteins have biological functions in HA, and that they interact with LSD1 in viva. Based on this previous work, and on the progress reported below, the topics for the Specific Aims, using both forward and reverse genetics, and biochemistry, are: 1. The Arabidopsis LSD1 protein: Control of cell death propagation. 2. isdi signal transduction: Genetic characterization of extragenic isdi suppressors. 3. Molecular homologues of LSD1 also control cell death. 4. The interplay between Isd1 rcd and balances of ROl, NO and SA.