Phytophthora sojae avirulence effector Avr3b is a secreted NADH and ADP-ribose pyrophosphorylase that modulates plant immunity.
Phytophthora sojae avirulence effector Avr3b is a secreted NADH and ADP-ribose pyrophosphorylase that modulates plant immunity.
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大豆疫霉无毒效应子 Avr3b 是一种分泌型 NADH 和 ADP-核糖焦磷酸化酶，可调节植物免疫
DOI：
10.1371/journal.ppat.1002353
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发表时间：
2011-11
期刊：
影响因子：
6.7
通讯作者：
Wang Y
中科院分区：
文献类型：
--
作者：
Dong S;Yin W;Kong G;Yang X;Qutob D;Chen Q;Kale SD;Sui Y;Zhang Z;Dou D;Zheng X;Gijzen M;Tyler BM;Wang Y
植物进化出病原体相关分子模式（PAMP）触发的免疫（PTI）和效应物触发的免疫（ETI），以保护自身免受不同病原体的感染。在许多植物病原性卵菌和真菌中已经鉴定出无毒效应子（Avr），其由于被植物抗性（R）基因产物识别而触发植物ETI。然而，卵菌和真菌Avr效应子的毒力功能在很大程度上仍然未知。在这里，我们结合生物信息学和遗传学，以确定Avr 3b，一个新的Avr基因从大豆疫霉，卵菌病原体，导致大豆根腐病。Avr 3b编码具有RXLR宿主靶向基序和C-末端W和Nutrient水解酶基序的分泌蛋白。大豆疫霉的一些分离物通过Avr 3b中的序列突变逃避大豆R基因Rps 3b的感知并降低转录物积累。Avr 3b在本氏烟草中的瞬时表达增加了对辣椒疫霉和寄生疫霉的易感性，显著减少了入侵位点周围活性氧（ROS）的积累。生物化学分析证实Avr 3b是ADP-核糖/NADH焦磷酸化酶，如从Nutrium基序预测的。缺失Avr 3b的Nutrient基序消除了酶活性。Nutrient基序中关键残基的突变显著损害了Avr 3b的毒力功能，但不影响其无毒力。一些营养素水解酶充当植物免疫的负调节剂，因此Avr 3b可能作为营养素水解酶递送到宿主细胞中以损害宿主免疫。Avr 3b同源物存在于几个已测序的疫霉属基因组中，表明疫霉属病原体可能具有相似的抑制植物免疫的策略。
Plants have evolved pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity (ETI) to protect themselves from infection by diverse pathogens. Avirulence (Avr) effectors that trigger plant ETI as a result of recognition by plant resistance (R) gene products have been identified in many plant pathogenic oomycetes and fungi. However, the virulence functions of oomycete and fungal Avr effectors remain largely unknown. Here, we combined bioinformatics and genetics to identify Avr3b, a new Avr gene from Phytophthora sojae, an oomycete pathogen that causes soybean root rot. Avr3b encodes a secreted protein with the RXLR host-targeting motif and C-terminal W and Nudix hydrolase motifs. Some isolates of P. sojae evade perception by the soybean R gene Rps3b through sequence mutation in Avr3b and lowered transcript accumulation. Transient expression of Avr3b in Nicotiana benthamiana increased susceptibility to P. capsici and P. parasitica, with significantly reduced accumulation of reactive oxygen species (ROS) around invasion sites. Biochemical assays confirmed that Avr3b is an ADP-ribose/NADH pyrophosphorylase, as predicted from the Nudix motif. Deletion of the Nudix motif of Avr3b abolished enzyme activity. Mutation of key residues in Nudix motif significantly impaired Avr3b virulence function but not the avirulence activity. Some Nudix hydrolases act as negative regulators of plant immunity, and thus Avr3b might be delivered into host cells as a Nudix hydrolase to impair host immunity. Avr3b homologues are present in several sequenced Phytophthora genomes, suggesting that Phytophthora pathogens might share similar strategies to suppress plant immunity.
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影响因子：
3.7
作者：
Dong S;Yu D;Cui L;Qutob D;Tedman-Jones J;Kale SD;Tyler BM;Wang Y;Gijzen M
通讯作者：
Gijzen M
影响因子：
3.7
作者：
Dong S;Qutob D;Tedman-Jones J;Kuflu K;Wang Y;Tyler BM;Gijzen M
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Gijzen M
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作者：
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通讯作者：
Valent, B
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作者：
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通讯作者：
Tyler, Brett M.
影响因子：
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作者：
Allen, RL;Bittner-Eddy, PD;Beynon, JL
通讯作者：
Beynon, JL