Perturbation of Arabidopsis Amino Acid Metabolism Causes Incompatibility with the Adapted Biotrophic Pathogen Hyaloperonospora arabidopsidis
Perturbation of Arabidopsis Amino Acid Metabolism Causes Incompatibility with the Adapted Biotrophic Pathogen Hyaloperonospora arabidopsidis
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DOI：
10.1105/tpc.111.087684
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发表时间：
2011-07-01
期刊：
影响因子：
11.6
通讯作者：
Parker, Jane E.
中科院分区：
文献类型：
--
作者：
Stuttmann, Johannes;Hubberten, Hans-Michael;Parker, Jane E.
活体营养型病原菌对活植物组织的依赖性繁殖意味着宿主代谢和病原菌营养吸收之间存在很强的相互依赖性。然而，决定宿主适宜性和感染建立的因素在很大程度上是未知的。我们描述了一个天冬氨酸激酶2的抑制等位基因和一个二氢二吡啶合酶2的功能丧失等位基因，在筛选拟南芥突变体时发现了该突变体对专性生物营养卵菌阿拉伯透明霜霉（Hpa）的抗性增加。通过不同的分子机制，这些突变扰乱氨基酸的体内平衡，导致天冬氨酸衍生的氨基酸Met，Thr和Ile的过度积累。虽然对植物有害，但突变不会引起防御激活，并且两种突变体都保留对适应的专性活体营养真菌Golovinomyces orontii（Go）的完全易感性。模拟突变体代谢状态的化学处理将Thr鉴定为抑制Hpa而不是Go定殖的氨基酸。我们的结论是氨基酸稳态的扰动，使突变体植物不适合作为感染基板HPA。这可能是由于卵菌和植物具有相同的氨基酸生物合成途径。我们的数据表明，植物宿主的代谢状态可以以特定的方式影响适应的生物营养型菌株引起疾病的能力。
Reliance of biotrophic pathogens on living plant tissues to propagate implies strong interdependence between host metabolism and nutrient uptake by the pathogen. However, factors determining host suitability and establishment of infection are largely unknown. We describe a loss-of-inhibition allele of ASPARTATE KINASE2 and a loss-of-function allele of DIHYDRODIPICOLINATE SYNTHASE2 identified in a screen for Arabidopsis thaliana mutants with increased resistance to the obligate biotrophic oomycete Hyaloperonospora arabidopsidis (Hpa). Through different molecular mechanisms, these mutations perturb amino acid homeostasis leading to overaccumulation of the Asp-derived amino acids Met, Thr, and Ile. Although detrimental for the plant, the mutations do not cause defense activation, and both mutants retain full susceptibility to the adapted obligate biotrophic fungus Golovinomyces orontii (Go). Chemical treatments mimicking the mutants' metabolic state identified Thr as the amino acid suppressing Hpa but not Go colonization. We conclude that perturbations in amino acid homeostasis render the mutant plants unsuitable as an infection substrate for Hpa. This may be explained by deployment of the same amino acid biosynthetic pathways by oomycetes and plants. Our data show that the plant host metabolic state can, in specific ways, influence the ability of adapted biotrophic strains to cause disease.