生物谷报道：1月8日，北京生命科学研究所周俭民实验室在《当代生物学》（Current Biology）杂志上发表题为Pseudomonas syringae Effector AvrPto Blocks Innate Immunity by Targeting Receptor Kinases的文章。该文报道了丁香假单胞菌（Pseudomonas syringae）效应蛋白AvrPto帮助细菌侵染植物的分子机理。植物依赖包括FLS2和EFR在内的受体激酶感应细菌的入侵并激活免疫反应。该文工作发现，AvrPto进入植物细胞内后直接作用于FLS2和EFR等受体激酶，阻断信号传导，使植物丧失感受细菌的能力。而在某些抗病番茄中，AvrPto能被胞内蛋白激酶Pto识别，并激活另一条更为强烈的免疫反应通路。该文工作发现Pto-AvrPto和FLS2-AvrPto作用方式类似，表明Pto在进化上很可能模拟了受体激酶，作为一个假靶标吸引AvrPto，从而让植物获得抗病性。
向婷婷（博士研究生），宗娜（博士后），和邹燕（北京生命科学研究所博士毕业）为本文共同第一作者。其他参与此项工作的还有：吴勇，张杰（北京生命科学研究所博士毕业），邢维满（北京生命科学研究所博士毕业），李燕，堪撒斯州立大学的唐晓艳教授，中科院遗传发育所的朱立煌研究员和我所的柴继杰研究员。北京生命科学研究所研究员周俭民博士是本文的通讯作者。
此项研究为科技部863和北京市科委资助课题，在北京生命科学研究所完成。（来源：北京生命科学研究所）
生物谷推荐原始出处：
Current Biology, Vol 18, 74-80, 08 January 2008
Report
Pseudomonas syringae Effector AvrPto Blocks Innate Immunity by Targeting Receptor Kinases
Tingting Xiang,1,2,5 Na Zong,2,5 Yan Zou,2,3,5 Yong Wu,2 Jie Zhang,2 Weiman Xing,2 Yan Li,2 Xiaoyan Tang,4 Lihuang Zhu,3 Jijie Chai,2 and Jian-Min Zhou2,
1 State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100094, China
2 National Institute of Biological Sciences, Beijing 102206, China
3 Institute of Genetics, Chinese Academy of Sciences, Beijing 100864, China
4 Department of Plant Pathology, Kansas State University, Manhattan, Kansas 66506
Corresponding author
Jian-Min Zhou
zhoujianmin@nibs.ac.cn
Summary
Plants use receptor kinases, such as FLS2 and EFR, to perceive bacterial pathogens and initiate innate immunity. This immunity is often suppressed by bacterial effectors, allowing pathogen propagation. To counteract, plants have evolved disease resistance genes that detect the bacterial effectors and reinstate resistance. The Pseudomonas syringae effector AvrPto promotes infection in susceptible plants but triggers resistance in plants carrying the protein kinase Pto and the associated resistance protein Prf. Here we show that AvrPto binds receptor kinases, including Arabidopsis FLS2 and EFR and tomato LeFLS2, to block plant immune responses in the plant cell. The ability to target receptor kinases is required for the virulence function of AvrPto in plants. The FLS2-AvrPto interaction and Pto-AvrPto interaction appear to share similar sequence requirements, and Pto competes with FLS2 for AvrPto binding. The results suggest that the mechanism by which AvrPto recognizes virulence targets is linked to the evolution of Pto, which, in association with Prf, recognizes the bacterium and triggers strong resistance.
