NPP1, a Phytophthora-associated trigger of plant defense in parsley and Arabidopsis
NPP1, a Phytophthora-associated trigger of plant defense in parsley and Arabidopsis
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DOI：
10.1046/j.1365-313x.2002.01454.x
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发表时间：
2002-11-01
期刊：
影响因子：
7.2
通讯作者：
Nürnberger, T
中科院分区：
文献类型：
--
作者：
Fellbrich, G;Romanski, A;Nürnberger, T
非品种特异性植物防御的激活是通过识别病原体衍生的诱导子介导的。在此之前，我们已经确定了一个肽片段（PEP-13）内的42 kDa的细胞壁转氨酶从各种疫霉属物种，触发了多方面的防御反应在欧芹细胞。许多这些卵菌物种现在已经被证明拥有另一种细胞壁蛋白（24 kDa），在欧芹中引起与Pep-13相同的反应模式。与Pep-13不同，从寄生疫霉中纯化的坏死诱导疫霉蛋白1（NPP 1）也会在欧芹中诱导过敏性细胞死亡样病变。在卵菌、真菌和细菌中发现了NPP 1结构同源物，但在植物中没有发现。结构-活性关系的研究表明，完整的蛋白质以及两个半胱氨酸残基是必不可少的激发子活性。NPP 1介导的欧芹病原体防御激活不使用Pep-13受体。然而，早期诱导的细胞反应涉及激发子信号传递（细胞质钙离子水平的增加，活性氧的产生，MAP激酶激活）的刺激任一激发子，表明收敛的信号通路在欧芹的存在。NPP 1渗入拟南芥Col-0植物叶片导致病程相关（PR）基因的转录积累，ROS和乙烯的产生，胼胝质沉积和HR样细胞死亡。NPP 1介导的PR 1基因的诱导是水杨酸依赖性的，并且，不像P.番茄DC 3000（avrRpm 1）诱导的PR 1基因表达需要功能性NDR 1和PAD 4。总之，渗透NPP 1的拟南芥植物构成了一个实验系统，该系统适合于正向遗传方法，旨在解剖涉及非品种特异性植物防御激活的信号通路。
Activation of non-cultivar-specific plant defense against attempted microbial infection is mediated through the recognition of pathogen-derived elicitors. Previously, we have identified a peptide fragment (Pep-13) within a 42-kDa cell wall transglutaminase from various Phytophthora species that triggers a multifacetted defense response in parsley cells. Many of these oomycete species have now been shown to possess another cell wall protein (24 kDa), that evoked the same pattern of responses in parsley as Pep-13. Unlike Pep-13, necrosis-inducing Phytophthora protein 1 (NPP1) purified from P. parasitica also induced hypersensitive cell death-like lesions in parsley. NPP1 structural homologs were found in oomycetes, fungi, and bacteria, but not in plants. Structure-activity relationship studies revealed the intact protein as well as two cysteine residues to be essential for elicitor activity. NPP1-mediated activation of pathogen defense in parsley does not employ the Pep-13 receptor. However, early induced cellular responses implicated in elicitor signal transmission (increased levels of cytoplasmic calcium, production of reactive oxygen species, MAP kinase activation) were stimulated by either elicitor, suggesting the existence of converging signaling pathways in parsley. Infiltration of NPP1 into leaves of Arabidopsis thaliana Col-0 plants resulted in transcript accumulation of pathogenesis-related (PR) genes, production of ROS and ethylene, callose apposition, and HR-like cell death. NPP1-mediated induction of the PR1 gene is salicylic acid-dependent, and, unlike the P. syringae pv. tomato DC3000(avrRpm1)-induced PR1 gene expression, requires both functional NDR1 and PAD4. In summary, Arabidopsis plants infiltrated with NPP1 constitute an experimental system that is amenable to forward genetic approaches aiming at the dissection of signaling pathways implicated in the activation of non-cultivar-specific plant defense.