State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou, 310058, Zhejiang Province, China.
State Key Laboratory for Rice Biology, College of Life Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang Province, China.
Curr Genet. 2020 Apr;66(2):385-395. doi: 10.1007/s00294-019-01030-5. Epub 2019 Aug 30.
Pyricularia oryzae (synonym Magnaporthe oryzae) is a plant pathogen causing major yield losses in cultivated rice and wheat. The P-type ATPases play important roles in cellular processes of fungi, plants, and animals via transporting specific substrates through ATP hydrolysis. Here, we characterized the roles of a P5-ATPase, Spf1, in the development and virulence of P. oryzae. Deletion of SPF1 led to decreased hyphal growth and conidiation, delayed spore germination and appressorium formation, reduced penetration and invasive hyphal extension, and attenuated virulence. Appressorium turgor, however, was not affected by deletion of SPF1. The co-localization of Spf1-GFP and an endoplasmic reticulum (ER) marker protein, Lhs1-DsRed2, indicated that Spf1 is an ER-localized P5-ATPase. An ER stress factor, 0.5 μg/ml tunicamycin (TUNI), inhibited the growth of ∆spf1, but another ER stress factor, 5 mM dithiothreitol (DTT), promoted the growth of ∆spf1. Treatment with chemicals for oxidative stress (5 mM HO and 0.8 mM paraquat) also promoted the growth of ∆spf1. Gene expression assays showed that unfolded protein response (UPR) components KAR2, OST1, PMT1, ERV29, PDI1, SCJ1, SEC61, a Ca channel-related P-type ATPase gene PMR1, and a calcineurin-dependent transcription factor CRZ1 were significantly up-regulated in ∆spf1, suggesting activation of UPR in the mutant. These lines of experimental evidence indicate that SPF1 is involved in some basal ER mechanisms of P. oryzae including UPR pathway and responses to ER related stresses, therefore, affecting fungal development and virulence. However, the detailed mechanism between Spf1 and virulence still awaits future researches.
稻瘟病菌（同义名：稻梨孢菌）是一种植物病原菌，会导致栽培水稻和小麦的重大产量损失。P 型 ATP 酶通过水解 ATP 来转运特定的底物，在真菌、植物和动物的细胞过程中发挥着重要作用。在这里，我们研究了 P 型 ATP 酶 Spf1 在稻瘟病菌发育和毒性中的作用。SPF1 缺失导致菌丝生长和分生孢子形成减少，孢子萌发和附着胞形成延迟，穿透和侵袭性菌丝延伸减少，毒力减弱。然而，附着胞膨压不受 Spf1 缺失的影响。Spf1-GFP 和内质网（ER）标记蛋白 Lhs1-DsRed2 的共定位表明 Spf1 是一种 ER 定位的 P 型 ATP 酶。ER 应激因子 0.5μg/ml 衣霉素（TUNI）抑制了 ∆spf1 的生长，但另一种 ER 应激因子 5mM 二硫苏糖醇（DTT）促进了 ∆spf1 的生长。氧化应激化学物质（5mM HO 和 0.8mM 百草枯）的处理也促进了 ∆spf1 的生长。基因表达分析表明， unfolded protein response (UPR) 成分 KAR2、OST1、PMT1、ERV29、PDI1、SCJ1、SEC61、一个与钙通道相关的 P 型 ATP 酶基因 PMR1 和一个 calcineurin-dependent transcription factor CRZ1 在 ∆spf1 中显著上调，表明 UPR 在突变体中被激活。这些实验证据表明，SPF1 参与了稻瘟病菌的一些基础 ER 机制，包括 UPR 途径和对 ER 相关应激的反应，因此影响真菌的发育和毒性。然而，Spf1 和毒性之间的详细机制仍有待未来的研究。
