The Plant Cell:福建农大唐定中研究组发表植物免疫新进展
2017年3月28日，国际植物科学顶级期刊《The plant Cell》在线发表了福建农林大学海峡联合研究院植物免疫中心唐定中教授研究组题为“CALCIUM-DEPENDENT PROTEIN KINASE5 associates with the truncated NLR protein TIR-NBS2 to contribute to exo70B1-mediated immunity”的研究论文。免疫中心讲师刘娜为第一作者，唐定中教授为通讯作者。
受病原菌的攻击，胞质内钙离子浓度的变化是植物免疫反应早期响应事件之一，在植物的PTI和ETI免疫途径中都是一种重要的反应信号。钙依赖蛋白激酶(Calcium-dependent protein kinases , CPKs)是一种感知钙信号的蛋白，在植物免疫反应中发挥着重要的信号转导作用。本研究综合运用遗传学、生物化学、细胞生物学的研究手段，揭示了钙依赖蛋白激酶CDPK5与胞吐复合体成员EXO70B1以及非典型性免疫蛋白TN2之间的关系和在植物免疫中发挥的作用。
原文链接：
CALCIUM-DEPendENT PROTEIN KINASE5 associates with the truncated NLR protein TIR-NBS2 to contribute to exo70B1-mediated immunity
原文摘要：
Calcium-dependent protein kinases (CPKs) function as calcium sensors and play important roles in plant immunity. Loss of function of the exocyst complex subunit EXO70B1 leads to autoimmunity caused by activation of TN2, a truncated Toll/interleukin-1 receptor-nucleotide-binding sequence protein (TIR-NBS). Here we show, based on a screen for suppressors of exo70B1, that exo70B1-activated autoimmune responses require CPK5. However, the CPK5 homologs CPK4, CPK6, and CPK11, which were previously reported to function redundantly with CPK5 in effector-triggered immunity, did not contribute to exo70B1-associated phenotypes, indicating that CPK5 plays a unique role in plant immunity. Overexpressing CPK5 results in TN2-dependent autoimmunity and enhanced disease resistance, reminiscent of the exo70B1 phenotypes. Ectopic expression of CPK5 in the exo70B1 mutant led to constitutive CPK5 protein kinase activity, which was not detectable in tn2 mutants. Furthermore, TN2 interacts with the CPK5 N-terminal variable and kinase domains, stabilizing CPK5 kinase activity in vitro. This work uncovers a direct functional link between an atypical immune receptor and a crucial component of early immune signaling: increased immunity in exo70B1 depends on TN2 and CPK5 and, in a positive feedback loop, TN2 keeps CPK5 enzymatically active beyond the initiating stimulus.
作者：唐定中
