Roles of microbiota in autoimmunity in Arabidopsis.
Roles of microbiota in autoimmunity in Arabidopsis.
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微生物群在拟南芥自身免疫中的作用。
DOI：
10.1101/2023.03.06.531303
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
He,ShengYang
中科院分区：
文献类型：
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作者：
Cheng,YuTi;Thireault,CaitlinA;Paasch,BradleyC;Zhang,Li;He,ShengYang
在过去的三十年里，研究人员已经分离出植物突变体，这些突变体在没有病原体感染的情况下表现出组成型激活的防御反应。这些突变体被称为自身免疫突变体，通常是侏儒和/或轴承褪绿/坏死病变。通过对参与维持正常叶片微生物群的拟南芥基因的遗传筛选，我们确定了编码S-酰基转移酶的TIP生长缺陷1（TIP 1），作为在高湿度条件下保护叶片免受异常微生物群水平和组成的关键参与者。tip 1突变体具有几种典型自身免疫突变体的特征性表型，包括矮小身材、显示病变和具有高基础水平的防御基因表达。无菌实验表明，tip 1突变体的自身免疫表型在很大程度上依赖于微生物群的存在，因为无菌tip 1植物的自身免疫表型显著减少。我们发现，微生物群依赖性的自身免疫表型是共享的几个“病变模拟”型自身免疫突变体在拟南芥。有趣的是，由NLR基因突变引起的自身免疫表型不需要微生物群的存在，甚至可以通过微生物群部分缓解。因此，我们的研究结果表明，在植物中存在两类自身免疫（微生物群依赖与微生物群独立）。在自身免疫的病变模拟类中观察到的自身免疫和微生物群之间的相互作用让人想起动物王国中自身免疫和生态失调之间的相互作用。
Over the past three decades, researchers have isolated plant mutants that display constitutively activated defense responses in the absence of pathogen infection. These mutants are called autoimmune mutants and are typically dwarf and/or bearing chlorotic/necrotic lesions. From a genetic screen for Arabidopsis genes involved in maintaining a normal leaf microbiota, we identified TIP GROWTH DEFECTIVE 1 (TIP1), which encodes a S-acyltransferase, as a key player in guarding leaves against abnormal microbiota level and composition under high humidity conditions. The tip1 mutant has several characteristic phenotypes of classical autoimmune mutants, including a dwarf stature, displaying lesions, and having a high basal level of defense gene expression. Gnotobiotic experiments revealed that the autoimmune phenotypes of the tip1 mutant are largely dependent on the presence of microbiota as axenic tip1 plants have markedly reduced autoimmune phenotypes. We found that the microbiota dependency of autoimmune phenotypes is shared by several “lesion mimic”-type autoimmune mutants in Arabidopsis. Interestingly, autoimmune phenotypes caused by mutations in NLR genes do not require the presence of microbiota and can even be partially alleviated by microbiota. Our results therefore suggest the existence of two classes of autoimmunity (microbiota-dependent vs. microbiota-independent) in plants. The observed interplay between autoimmunity and microbiota in the lesion mimic class of autoimmunity is reminiscent of the interactions between autoimmunity and dysbiosis in the animal kingdom.