The Arabidopsis microtubule-associated protein MAP65-3 supports infection by filamentous biotrophic pathogens by down-regulating salicylic acid-dependent defenses
The Arabidopsis microtubule-associated protein MAP65-3 supports infection by filamentous biotrophic pathogens by down-regulating salicylic acid-dependent defenses
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DOI：
10.1093/jxb/erv564
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发表时间：
2016-03-01
影响因子：
6.9
通讯作者：
Favery, Bruno
中科院分区：
文献类型：
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作者：
Quentin, Michael;Baures, Isabelle;Favery, Bruno
卵菌透明霜霉（Hyaloperonospora arabidopsidis）和子囊菌十字花科白粉菌（Erysiphe cruciferarum）分别是拟南芥上引起霜霉病和白粉病的专性活体营养型病原菌。在感染后，丝状病原体诱导称为吸器的细胞内球状结构的形成，吸器是活体营养生活方式所需的。我们以前表明，微管相关蛋白AtMAP 65 -3在有丝分裂和胞质分裂过程中组织细胞骨架微管阵列中起着至关重要的作用。这使得蛋白质对于巨细胞的发育是必需的，巨细胞是由根结线虫诱导的摄食位点。在这里，我们表明，AtMAP 65 -3的表达也诱导叶片感染后的霜霉病卵菌和白粉病真菌。在map 65 -3突变体中AtMAP 65 -3功能的丧失显著降低了两种病原体的感染，主要是在叶片渗透的阶段。全转录组分析显示，在map 65 -3中，参与水杨酸（SA）生物合成、信号传导和防御执行的基因被过度代表、组成性激活，而茉莉酸（JA）介导的信号传导被下调。防止SA合成和积累map 65 -3拯救植物对病原体的易感性，但不是由细胞骨架缺陷引起的发育表型。AtMAP 65 -3因此具有双重作用。它积极调节胞质分裂，从而植物的生长和发育，并负面干扰植物对丝状生物营养型防御。我们的数据表明，霜霉病和白粉病刺激AtMAP 65 -3表达下调SA信号转导的感染。
The oomycete Hyaloperonospora arabidopsidis and the ascomycete Erysiphe cruciferarum are obligate biotrophic pathogens causing downy mildew and powdery mildew, respectively, on Arabidopsis. Upon infection, the filamentous pathogens induce the formation of intracellular bulbous structures called haustoria, which are required for the biotrophic lifestyle. We previously showed that the microtubule-associated protein AtMAP65-3 plays a critical role in organizing cytoskeleton microtubule arrays during mitosis and cytokinesis. This renders the protein essential for the development of giant cells, which are the feeding sites induced by root knot nematodes. Here, we show that AtMAP65-3 expression is also induced in leaves upon infection by the downy mildew oomycete and the powdery mildew fungus. Loss of AtMAP65-3 function in the map65-3 mutant dramatically reduced infection by both pathogens, predominantly at the stages of leaf penetration. Whole-transcriptome analysis showed an over-represented, constitutive activation of genes involved in salicylic acid (SA) biosynthesis, signaling, and defense execution in map65-3, whereas jasmonic acid (JA)-mediated signaling was down-regulated. Preventing SA synthesis and accumulation in map65-3 rescued plant susceptibility to pathogens, but not the developmental phenotype caused by cytoskeleton defaults. AtMAP65-3 thus has a dual role. It positively regulates cytokinesis, thus plant growth and development, and negatively interferes with plant defense against filamentous biotrophs. Our data suggest that downy mildew and powdery mildew stimulate AtMAP65-3 expression to down-regulate SA signaling for infection.