Danger peptide receptor signaling in plants ensures basal immunity upon pathogen-induced depletion of BAK1
Danger peptide receptor signaling in plants ensures basal immunity upon pathogen-induced depletion of BAK1
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DOI：
10.15252/embj.201591807
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发表时间：
2016-01-01
期刊：
影响因子：
11.4
通讯作者：
Saijo, Yusuke
中科院分区：
文献类型：
--
作者：
Yamada, Kohji;Yamashita-Yamada, Misuzu;Saijo, Yusuke
病原体通过抑制识别微生物相关分子模式（MAMP）后诱导的防御反应来感染宿主。尽管有这种抑制，MAMP受体介导的基础阻力，限制宿主的易感性，通过一个过程，这是知之甚少。拟南芥富含亮氨酸重复序列（LRR）受体激酶BAK 1与包括MAMPs在内的多种配体的不同细胞表面LRR受体相关并发挥作用。我们报告说，BAK 1耗竭与防御激活通过内源性PROPEP肽（Pep表位）和LRR受体激酶PEPR 1/PEPR 2，尽管在MAMP信号转导的关键缺陷。在bak 1基因敲除植物中，PEPR诱导导致广泛的细胞死亡和基于水杨酸的防御优先于基于茉莉酸的防御，除了升高的前配体和受体积累。BAK 1破坏刺激PROPEP 3的释放，PROPEP 3是在响应Pep应用和病原体攻击期间产生的，并使PEPR成为基础抗性所必需的。这些发现是生物学相关的，因为特定的BAK 1消耗与PEPR依赖的抗真菌病原体Colletotrichum higginsianum相一致。因此，当MAMP触发的防御被BAK 1耗尽损害时，PEPR途径确保基础抗性。
Pathogens infect a host by suppressing defense responses induced upon recognition of microbe-associated molecular patterns (MAMPs). Despite this suppression, MAMP receptors mediate basal resistance to limit host susceptibility, via a process that is poorly understood. The Arabidopsis leucine-rich repeat (LRR) receptor kinase BAK1 associates and functions with different cell surface LRR receptors for a wide range of ligands, including MAMPs. We report that BAK1 depletion is linked to defense activation through the endogenous PROPEP peptides (Pep epitopes) and their LRR receptor kinases PEPR1/PEPR2, despite critical defects in MAMP signaling. In bak1-knockout plants, PEPR elicitation results in extensive cell death and the prioritization of salicylate-based defenses over jasmonate-based defenses, in addition to elevated proligand and receptor accumulation. BAK1 disruption stimulates the release of PROPEP3, produced in response to Pep application and during pathogen challenge, and renders PEPRs necessary for basal resistance. These findings are biologically relevant, since specific BAK1 depletion coincides with PEPR-dependent resistance to the fungal pathogen Colletotrichum higginsianum. Thus, the PEPR pathway ensures basal resistance when MAMP-triggered defenses are compromised by BAK1 depletion.