Impact of the unfolded protein response on the pathogenicity of the necrotrophic fungus Alternaria brassicicola
Impact of the unfolded protein response on the pathogenicity of the necrotrophic fungus Alternaria brassicicola
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DOI：
10.1111/j.1365-2958.2010.07522.x
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发表时间：
2011-03-01
影响因子：
3.6
通讯作者：
Guillemette, T.
中科院分区：
文献类型：
--
作者：
Joubert, A.;Simoneau, P.;Guillemette, T.
P>；未折叠蛋白反应(UPR)是参与真菌细胞发育和环境适应的重要胁迫信号途径。我们研究了UPR途径在引起广泛十字花科植物黑斑病的植物坏死性真菌油菜链格孢菌致病中的重要性。我们在甘蓝型油菜中发现了编码主要UPR转录调控因子的AbHacA基因。AbHacA的缺失阻止了内质网应激诱导UPR的发生。突变体中UPR的缺失导致毒力完全丧失，并与细胞壁缺陷和分泌能力降低有关。此外，我们的结果表明，用Camalexin处理菌丝体，即主要的拟南芥植物保卫素，可以触发UPR，并且缺乏功能性AbHacA的菌株在体外对抗菌植物代谢物的敏感性增加。我们推测，UPR通过改变细胞对宿主代谢物的保护和降低真菌吸收在宿主环境中生长所需的营养的能力，在真菌毒力中发挥重要作用。这项研究表明，靶向UPR途径将是一种有效的植物病害控制策略。
P>The unfolded protein response (UPR) is an important stress signalling pathway involved in the cellular development and environmental adaptation of fungi. We investigated the importance of the UPR pathway in the pathogenicity of the plant necrotrophic fungus Alternaria brassicicola, which causes black spot disease on a wide range of Brassicaceae. We identified the AbHacA gene encoding the major UPR transcription regulator in A. brassicicola. Deletion of AbHacA prevented induction of the UPR in response to endoplasmic reticulum stress. Loss of UPR in mutants resulted in a complete loss of virulence and was also associated with a cell wall defect and a reduced capacity for secretion. In addition, our results showed that the UPR was triggered by treatment of mycelia with camalexin, i.e. the major Arabidopsis thaliana phytoalexin, and that strains lacking functional AbHacA exhibited increased in vitro susceptibility to antimicrobial plant metabolites. We hypothesize that the UPR plays a major role in fungal virulence by altering cell protection against host metabolites and by reducing the ability of the fungus to assimilate nutrients required for growth in the host environment. This study suggests that targeting the UPR pathway would be an effective plant disease control strategy.