Calcium signal transduction network in plant innate immunity

植物先天免疫中的钙信号转导网络

• 批准号: 20200060
• 负责人: NAKAHIRA Yoichi
• 金额: $ 20.47万
• 依托单位: Kyoto Prefectural University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Innovative Areas (Research a proposed research project)
• 财政年份: 2008
• 资助国家: 日本
• 起止时间: 2008 至 2010
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-20200060/
• 关键词: 葉緑体; Ca^<2+>; 過敏感細胞死; 植物・病原体相互作用; PR-1; CAS; サリチル酸; プラスチドシグナル

Mitochondria and chloroplasts are not only energy source for eukaryotic cells, but also play additional important roles to modulate cellular functions. For example, mammal mitochondria contribute to the initiation of apoptosis, diseases and aging. Plant chloroplast also serves several important functions in plant immunity, including biosynthesis of salicylic acid (SA) and the generation of reactive oxygen species (ROS), key signaling molecules in plant immune response. Interestingly, previous studies have shown that chloroplasts contain proteins involved in plant immune responses. Furthermore, several pathogen effectors target chloroplasts to suppress chloroplast-derived defense signals. Therefore, it is anticipated that chloroplasts play a role in plant innate immunity. However, how chloroplasts sense pathogen signals and control immune signaling network remains unclear. This study illustrates a previously unknown crosstalk between chloroplasts and innate immunity through chloroplast … More Ca^<2+> signaling in plants.Mitochondrial Ca^<2+> homeostasis plays a key role in apoptosis by switching Ca^<2+>-induced release of cytochrome C (caspase cofactor). However, very little is known about Ca^<2+> homeostasis in chloroplasts. Here, we report that pathogen associated molecular pattern (PAMP) signals induce a rapid increase in the stromal Ca^<2+> concentration. Pharmacological studies demonstrate that the cytoplasmic Ca^<2+> signal is transferred to the chloroplasts and induces the stromal Ca^<2+> transient. We further demonstrate that chloroplast-localized putative Ca^<2+> binding protein, CAS is involved in the generation of stromal Ca^<2+> signals. These studies suggest a novel mechanism relaying PAMP signals into chloroplasts at the beginning of the immune process.The PAMP-induced stromal Ca^<2+> signaling may control or activate the innate immune response. Thus, we examined the role of CAS in plant innate immunity. Remarkably, CAS deficient plants (cas-1) are compromised in broad range of innate immune responses including PAMP-induced basal defense and R-gene mediated hypersensitive cell death. It is unlikely that the compromised immunity of cas-1 plants is caused by limited cellular resources, since CAS deficient mutant lines exhibit normal phenotype and photosynthetically competent. Furthermore, a comprehensive analysis of plant hormone dynamics demonstrated that CAS is specifically required for PAMP-induced accumulation of SA, a key signal molecule in plant immune responses. These results suggest that chloroplast protein CAS acts as a positive regulator of plant innate immunity through SA-dependent signaling.CAS regulates SA biosynthesis most likely at transcriptional level. It is therefore anticipated that chloroplasts release retrograde signals that control defense gene expression during immune responses. PAMP induces expression of numerous defense related genes in nucleus. Using a genome wide transcriptome analysis we show that CAS is indispensable for the global induction of defense gene expression before SA biosynthesis starts, suggesting that CAS is involved in the chloroplast-to-nucleus retrograde signaling and mediates chloroplast control of plant innate immunity. Chloroplast-derived ^1O_2^- signaling has been implicated with the control of stress defense-related gene expression. Here we show that most genes downregulated in CAS deficient plants were enriched for ^1O_2^- responsive genes, providing evidence for a role of CAS in ^1O_2^- signaling to control nuclear-encoded defense genes.Collectively this study illustrates previously unknown mechanisms that coordinate chloroplast functions with nuclear-encoded defense gene expression. Upon infection, PAMP signals are relayed to chloroplasts through the cytoplasmic Ca^<2+>-induced stromal Ca^<2+> signaling pathway. This study further implicates a role of ^1O_2^- retrograde signaling as underlying mechanisms of chloroplast control of plant innate immunity. Chloroplast protein CAS plays a critical role in both processes. Identification of the chloroplast-dependent immune pathway may provide a novel strategy for the disease control of plants. Less

线粒体和叶绿体不仅是真核细胞的能量来源，而且在调节细胞功能方面也发挥着重要作用。例如，哺乳动物线粒体有助于细胞凋亡、疾病和衰老的启动。植物叶绿体在植物免疫中也具有多种重要功能，包括水杨酸（SA）的生物合成和活性氧（ROS）的产生，活性氧是植物免疫反应中的关键信号分子。有趣的是，以前的研究表明，叶绿体含有参与植物免疫反应的蛋白质。此外，几种病原体效应物靶向叶绿体以抑制叶绿体衍生的防御信号。因此，预计叶绿体在植物先天免疫中发挥作用。然而，叶绿体如何感知病原体信号并控制免疫信号网络仍不清楚。这项研究阐明了一个以前未知的串扰之间的叶绿体和先天免疫通过叶绿体 ...更多信息 植物中的Ca ^<2 +>信号：线粒体Ca ^<2 +>稳态通过转换Ca ^<2 +>诱导的细胞色素C（半胱天冬酶辅因子）的释放在细胞凋亡中起关键作用。然而，人们对叶绿体中Ca ^2+的稳态知之甚少。在此，我们报道了病原体相关分子模式（PAMP）信号诱导间质Ca ^2+浓度迅速升高。药理学研究表明，细胞质Ca ^2+信号被传递到叶绿体，并诱导基质Ca ^2+瞬变。我们进一步证明了叶绿体定位的Ca ^2+结合蛋白CAS参与了基质Ca ^2+信号的产生。这些研究表明，PAMP信号在免疫过程的初期传递到叶绿体是一种新的机制，PAMP诱导的基质Ca ^2+信号可能控制或激活天然免疫应答。因此，我们研究了CAS在植物先天免疫中的作用。值得注意的是，CAS缺陷型植物（cas-1）在广泛的先天免疫应答中受到损害，包括PAMP诱导的基础防御和R基因介导的过敏性细胞死亡。由于CAS缺陷突变株表现出正常的表型和光合能力，因此CAS-1植物的免疫力受损不太可能是由有限的细胞资源引起的。此外，对植物激素动力学的综合分析表明，CAS是PAMP诱导的SA积累所必需的，SA是植物免疫反应中的关键信号分子。这些结果表明，叶绿体CAS蛋白通过SA依赖的信号转导途径参与植物天然免疫的正调控，CAS很可能在转录水平上调控SA的合成。因此，预计叶绿体在免疫应答期间释放控制防御基因表达的逆行信号。PAMP诱导细胞核中许多防御相关基因的表达。使用全基因组转录组分析，我们表明，CAS是必不可少的防御基因表达的全球诱导SA生物合成开始之前，这表明CAS参与叶绿体到核的逆行信号传导和介导叶绿体控制植物先天免疫。叶绿体来源的^1O_2 ^-信号与胁迫防御相关基因表达的调控有关。我们发现CAS缺陷植株中大多数下调的基因富含^1O_2 ^-应答基因，为CAS在^1O_2 ^-信号传导中控制核编码防御基因的作用提供了证据，从而阐明了协调叶绿体功能与核编码防御基因表达的未知机制。感染后，PAMP信号通过细胞质Ca ^2+诱导的基质Ca ^2+信号通路传递到叶绿体。本研究进一步揭示了^1O_2 ^-逆行信号作为叶绿体控制植物先天免疫的潜在机制的作用。叶绿体蛋白CAS在这两个过程中起着关键作用。叶绿体依赖性免疫途径的发现为植物病害的防治提供了新的策略。少

项目成果

Chloroplasts and Ca^<2+> : from stress responses to stomatal movement

叶绿体和 Ca^<2 >：从应激反应到气孔运动

• 发表时间: 2008
• 作者: Shiina;T
• 通讯作者: T

Possible involvement of CAS in Ca2+ communication between cytoplasm and chloroplasts

CAS 可能参与细胞质和叶绿体之间的 Ca2+通讯

• 发表时间: 2008
• 作者: Itoh M.;Kawamoto T.;Tatsukawa H.;Kojima S.;Yamanishi;K.;Hitomi. K.;Nomura et.al.
• 通讯作者: Nomura et.al.

Role of Arabidopsis CHL27 protein for photosynthesis, chloroplast development and gene expression profiling

• DOI: 10.1093/pcp/pcn111
• 发表时间: 2008-09-01
• 期刊: PLANT AND CELL PHYSIOLOGY
• 影响因子: 4.9
• 作者: Bang, Woo Young;Jeong, In Sil;Bahk, Jeong Dong
• 通讯作者: Bahk, Jeong Dong

An isoform of Arabidopsis myosin XI interacts with small GTPases in its C-terminal tail region.

拟南芥肌球蛋白XI的同工型与其C末端尾部区域的小GTPase相互作用。

• DOI: 10.1093/jxb/ern202
• 发表时间: 2008
• 期刊: JOURNAL OF EXPERIMENTAL BOTANY
• 影响因子: 6.9
• 作者: Hashimoto, Kohsuke;Igarashi, Hisako;Mano, Shoji;Takenaka, Chikako;Shiina, Takashi;Yamaguchi, Masatoshi;Demura, Taku;Nishimura, Mikio;Shimmen, Teruo;Yokota, Etsuo
• 通讯作者: Yokota, Etsuo

CAS is Chloroplast Protein Implicated in flg22-Induced Stomatal Closure and Defense Response in Plant

CAS 是叶绿体蛋白，与 flg22 诱导的植物气孔关闭和防御反应有关

• 发表时间: 2009
• 作者: Uemura S.;et al
• 通讯作者: et al