Key Components of Different Plant Defense Pathways Are Dispensable for Powdery Mildew Resistance of the Arabidopsis mlo2 mlo6 mlo12 Triple Mutant.
Key Components of Different Plant Defense Pathways Are Dispensable for Powdery Mildew Resistance of the Arabidopsis mlo2 mlo6 mlo12 Triple Mutant.
复制标题
DOI：
10.3389/fpls.2017.01006
复制
发表时间：
2017
影响因子：
5.6
通讯作者：
Panstruga R
中科院分区：
文献类型：
--
作者：
Kuhn H;Lorek J;Kwaaitaal M;Consonni C;Becker K;Micali C;Ver Loren van Themaat E;Bednarek P;Raaymakers TM;Appiano M;Bai Y;Meldau D;Baum S;Conrath U;Feussner I;Panstruga R
特定植物抗霉位点O （MLO）基因的功能突变丧失赋予了对白粉病真菌持久和广谱渗透抗性。在此，我们结合遗传、转录组学和代谢组学分析来探索完全抗性拟南芥mlo2 mlo6 mlo12三重突变体的防御机制。我们发现这种基因型出乎意料地克服了对吲哚抗菌剂和防御相关分泌的需求，这是mlo2单突变体不完全耐药的关键。mlo2、mlo6、mlo12突变体和野生型植物接种后的转录组比较微阵列分析显示，许多防御相关转录物的积累增加和加速。尽管相互作用具有生物营养性质，但这包括茉莉酸/乙烯依赖转录程序的非规范激活。与非适应性白粉病病原体相比，适应性白粉病真菌能够以MLO蛋白依赖的方式挫败防御相关吲哚代谢物的积累。我们认为，在mlo2、mlo6、mlo12植物中，广泛而快速的免疫应答激活可以弥补单一或少数防御途径的缺乏。此外，我们的研究结果表明拟南芥MLO2、MLO6和MLO12在适应性白粉真菌入侵时能够抑制防御作用。
Loss of function mutations of particular plant MILDEW RESISTANCE LOCUS O (MLO) genes confer durable and broad-spectrum penetration resistance against powdery mildew fungi. Here, we combined genetic, transcriptomic and metabolomic analyses to explore the defense mechanisms in the fully resistant Arabidopsis thaliana mlo2 mlo6 mlo12 triple mutant. We found that this genotype unexpectedly overcomes the requirement for indolic antimicrobials and defense-related secretion, which are critical for incomplete resistance of mlo2 single mutants. Comparative microarray-based transcriptome analysis of mlo2 mlo6 mlo12 mutants and wild type plants upon Golovinomyces orontii inoculation revealed an increased and accelerated accumulation of many defense-related transcripts. Despite the biotrophic nature of the interaction, this included the non-canonical activation of a jasmonic acid/ethylene-dependent transcriptional program. In contrast to a non-adapted powdery mildew pathogen, the adapted powdery mildew fungus is able to defeat the accumulation of defense-relevant indolic metabolites in a MLO protein-dependent manner. We suggest that a broad and fast activation of immune responses in mlo2 mlo6 mlo12 plants can compensate for the lack of single or few defense pathways. In addition, our results point to a role of Arabidopsis MLO2, MLO6, and MLO12 in enabling defense suppression during invasion by adapted powdery mildew fungi.