Mechanism of signal transduction pathways for the host response to virus infection

宿主应对病毒感染的信号转导途径机制

• 批准号: 12052204
• 负责人: TAKAHASHI Hideki
• 金额: $ 41.28万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Priority Areas
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12052204/
• 关键词: Hypersensitive response; Signal transduction; Cucumber mosaic virus; Tobacco mosaic virus; Resistance gene; Diterpene; Calmodulin; MAP kinase cascade; ウイルス; 植物; MAPキナーゼ; ウイルス抵抗性; 傷害応答; パーオキシダーゼ; 植物ウイルス; シグナル伝達機構; WIPK; スペルミジン; サリチル酸; ジャ

Cucumber mosaic virus (CMV) and Tobacco mosaic virus (TMV) are the best-characterized positive-sense single-stranded RNA viruses. In this project, the signal transduction pathways for the resistance to CMV and TMV were studied. CMV-Arabidopsis system: A. thaliana ecotype C24 is resistant to a yellow strain of CMV [CMV(Y)]. This resistance to CMV(Y) was conferred by a single dominant gene, RCY1, which is a member of RPP8/HRT resistance gene family. Our analysis of Arabidopsis mutants deficient in SA, JA and ethylene signaling pathways indicated that an SA-and ethylene-dependent signaling pathway played an important role in the expression of the high level of resistance to CMV(Y) conferred by the RCY1 gene, However, the combined impairment of SA and ethylene signaling in the nahG etrl RCY1 double mutant did not completely abolish the RCY1-conferred resistance to CMV(Y). We therefore proposed that in addition to SA and ethylene signaling, a novel uncharacterized signaling pathway was requ … More ired for the full resistance to CMV(Y) conferred by the RCY1 gene. Moreover, cross-talk between the SA and JA signaling pathways is an important modulator of RCY1-conferred resistance to CMV(Y). The analysis of double Arabidopsis mutants indicated that a CO/1-dependent mechanism negatively modulated the RCY1-mediated activation of SA signaling pathway and resistance to CMV(Y). The gene-for-gene resistance to Turnip mosaic virus (TCV) conferred by HRT of ecotype Di-17 was dependent on the SA-mediated signaling pathway, but not on the JA and ethylene signaling pathways. Although RCY1 in ecotype C24 was an ortholog of HRT in the ecotype Di-17, the extent of the requirement for SA signaling in conferring resistance to CMV(Y) and TCV was different between RCY1-and HRT-containing plants. The difference in the requirement of defense mechanisms targeting these two viruses is further exemplified by studies with the Arabidopsis ssi2 mutant. While the ssi2 mutant exhibited enhanced resistance to CMV(Y), it did not confer enhanced resistance to TCV. In summary our results suggest that the Arabidopsis RCYI and HRT genes evolved to recruit different combinations of signal transduction pathways for conferring resistance to two different viruses. TMV-Tobacco system: The, signaling pathway for acquired resistance to pathogen infection has been examined using a synchronous HR cell-death-inducing system in TMV-infected tobacco plants carrying the temperature-sensitive N resistance gene, as well as the wound-signaling pathway which cross-talks with HR-signaling. We studied the function of genes whose expression were induced or repressed 3 h after HR triggering. WRK: A receptor-like protein kinase gene was induced rapidly after HR triggering and wounding. WRK was constitutively expressed at a low level, and induced by a simple temperature transfer from 30'C to 20'C independent of the N gene. In transgenic tobacco with suppressed WRK expression, wound-induced phenomena such as activation of defense-related MAPKS (WIPK and SIPK), JA accumulation, and expression of wound-inducible genes such as PI-II were inhibited, suggesting involvement of WRK at least in wound-signaling. HSP90 : In transgenic tobacco plants with suppressed HSP90 gene expression, the level of HR-induced electrolytic leakage, an indicator of cell death, was considerably inhibited with attenuated resistance to TMV. Treatment with geldanamycin, a specific inhibitor of Hsp90, reduced the ion leakage and wound-induced activation of WIPK and SIPK, indicating the involvement of HSP90 in HR-signaling. CaM (calmodulin) : We isolated 13 tobacco genes encoding three plant-specific types of CaMs, some of which were induced by HR-triggering or wounding. The amount of each type CaM dynamically changed after HR or wounding, Tobacco CaMs activates target enzymes specifically in a Ca^<2+>dependent and type-specific manner. As a new CaM-binding protein, a MAPK phosphatase (MKP1) was isolated. The gene product inactivated SIPK in vitro. In MKP1 overexpressors, wound-induced activation of WIPK and SIPK was inhibited, suggesting Ca^2/CaM signal functions upstream in MAPK-cascade at least in wound-signaling. WAF-1: WIPK is activated enzymatically in response to wounding and HR by TMV infection. (11E,13E)-labda-11,13-diene-8a,15-diol, designated WAF-1 was identified as WIPK-activating substance from TMV-infected tobacco leaves. WAF-1, a novel diterpene, functions as an endogenous signal mediating defense responses of tobacco plants to TMV infection and wounding. Less

黄瓜花叶病毒（CMV）和烟草花叶病毒（TMV）是目前已知的两种正链RNA病毒。本课题主要研究了烟草抗CMV和TMV的信号转导途径。CMV-Arabidopsis系统：A.拟南芥生态型C24对黄瓜花叶病毒黄色株系[CMV（Y）]具有抗性。该抗病基因是由一个显性基因RCY 1控制的，RCY 1是RPP 8/HRT抗性基因家族的成员。我们对SA、JA和乙烯信号途径缺失的拟南芥突变体的分析表明，SA和乙烯依赖的信号途径在RCY 1基因赋予的高水平CMV抗性（Y）的表达中起重要作用。然而，在nahG eigenase RCY 1双突变体中，SA和乙烯信号途径的联合损伤并没有完全消除RCY 1赋予的CMV抗性（Y）。因此，我们认为除了SA和乙烯信号外，还需要一种新的未表征的信号途径。 ...更多信息 RCY 1基因赋予的对CMV（Y）的完全抗性。此外，SA和JA信号传导途径之间的串扰是RCY 1赋予的对CMV（Y）的抗性的重要调节剂。对拟南芥双突变体的分析表明，CO/1依赖的机制负调控RCY 1介导的SA信号通路的激活和对CMV（Y）的抗性。HRT诱导的Di-17对芜菁花叶病毒（Turnip mosaic virus，TCV）的基因对基因抗性依赖于SA介导的信号通路，而不依赖于JA和乙烯信号通路。尽管C24生态型中的RCY 1是Di-17生态型中HRT的直系同源物，但在赋予对CMV（Y）和TCV的抗性中，对SA信号传导的需求程度在含RCY 1和HRT的植物之间是不同的。针对这两种病毒的防御机制的需求的差异进一步通过拟南芥ssi 2突变体的研究来举例说明。虽然ssi 2突变体表现出对CMV（Y）的增强的抗性，但它不赋予对TCV的增强的抗性。总之，我们的研究结果表明，拟南芥RCYI和HRT基因进化招募不同的信号转导途径的组合，赋予两种不同的病毒的抗性。TMV-烟草系统：利用同步HR细胞死亡诱导系统研究了携带温敏N抗性基因的TMV感染烟草植株获得病原体感染抗性的信号途径，以及与HR信号交叉的伤口信号途径。我们研究了HR触发后3 h表达被诱导或抑制的基因的功能。WRK：在HR触发和创伤后迅速诱导受体样蛋白激酶基因。WRK在低水平上组成型表达，并且通过从30 ℃到20 ℃的简单温度转移诱导，而不依赖于N基因。在转基因烟草与抑制WRK表达，伤口诱导的现象，如激活的防御相关的MAPKS（WIPK和SIPK），JA积累，和表达的伤口诱导基因，如PI-II的抑制，这表明WRK参与至少在伤口信号。HSP 90：HSP 90基因表达被抑制的转基因烟草植株中，HR诱导的电解质渗漏水平（细胞死亡的指标）被大大抑制，对TMV的抗性减弱。热休克蛋白90的特异性抑制剂格尔德霉素可降低离子渗漏和创伤诱导的WIPK和SIPK活化，表明热休克蛋白90参与了HR信号传导。CaM（钙调素）：我们分离了13个烟草基因编码三种植物特异性类型的CaM，其中一些是由HR触发或创伤诱导的。在HR或创伤后，各类型CaM的含量动态变化，烟草CaM以Ca^2+依赖性和类型特异性方式特异性激活靶酶。MAPK磷酸酶（MKP 1）是一种新的钙调素结合蛋白。该基因产物在体外使SIPK失活。在MKP 1过表达者中，创伤诱导的WIPK和SIPK活化受到抑制，表明Ca^2/CaM信号至少在创伤信号传导中在MAPK级联的上游发挥作用。WAF-1：WIPK响应于TMV感染的创伤和HR而被酶促激活。(11E 13 E）-labda-11，13-diene-8a，15-diol，命名为WAF-1，是从TMV侵染的烟草叶片中鉴定出的WIPK激活物质。WAF-1是一种新的二萜类化合物，是烟草对TMV侵染和伤害的内源信号调节因子。少

项目成果

Rapid down and up translocation of salicylic acid in tobacco plants.

烟草植物中水杨酸的快速向下和向上易位。

• 发表时间: 2004
• 期刊: Plant Biotech. 21
• 作者: Ohashi;Y.et al.
• 通讯作者: Y.et al.

The enhanced resistance to Cucumber mosaic virus in the Arabidopsis thaliana stearoyl-ACP desaturase-deficient ssi2 mutant is mediated by an SA-independent, but EDS5-dependent signaling mechanism

拟南芥硬脂酰-ACP去饱和酶缺陷的ssi2突变体对黄瓜花叶病毒的抵抗力增强是由不依赖SA但依赖EDS5的信号机制介导的

• 发表时间: 2004
• 期刊: Molecular Plant-Microbe Interaction 17・6
• 作者: Kazuhiro Ohta et al.;Kazuhisa Kato et al.;Yoshinori Kanayama et al.;Kazuhiro Ohta et al.;Hideki Takahashi et al.;Ming Shu Zheng et al.;Takeaki Ishihara;Ken-taro Sekine
• 通讯作者: Ken-taro Sekine

Honda.A.et al.: "Activation of defense-related gene expression and systemic acquired resistance in Cucumber mosaic virus-infected tobacco plants expressing the mammalian 2'5'oligoadenylate system"Archives of Virology. 148. 1017-1026 (2003)

Honda.A.等人：“表达哺乳动物 25寡腺苷酸系统的黄瓜花叶病毒感染的烟草植物中防御相关基因表达的激活和系统获得性抗性”病毒学档案。

Zheng.M.S.et al.: "Up-regulation of Arabidopsis thaliana NHL10 in the hypersensitive response to Cucumber mosaic virus infection and in senescing leaves is controlled by signaling pathways that differ in salicylate involvement"Planta. 218. 740-750 (2003)

Cheng.M.S.等人：“拟南芥NHL10在对黄瓜花叶病毒感染的过敏反应和衰老叶子中的上调是由水杨酸参与不同的信号通路控制的”Planta。

Yamakawa, H.et al.: "Plant mitogen-activated protein phosphatase interacts with calmodulins."J.Biol.Chem.. (in press). (2004)

Yamakawa, H.et al.：“植物丝裂原激活蛋白磷酸酶与钙调蛋白相互作用。”J.Biol.Chem..（正在出版）。