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 H2O2 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 Ca2+ 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.

中文翻译：

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P5型ATPase Spf1是稻瘟病菌Pyricularia oryzae的发育和毒性所必需的。

稻瘟病菌（Pyricularia oryzae）（植物稻瘟病菌（Magnaporthe oryzae）的别名）是一种植物病原体，在耕种的水稻和小麦中造成大量的产量损失。P型ATP酶通过ATP水解转运特定的底物，在真菌，植物和动物的细胞过程中发挥重要作用。在这里，我们表征了P5-ATPase Spf1在稻瘟病菌的发育和毒性中的作用。SPF1的删除导致菌丝生长和分生孢子减少，孢子萌发和附着层形成延迟，穿透力降低和侵入性菌丝延伸以及毒力减弱。然而，Appressorium turgor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是一个ER定位的P5-ATPase。ER应力因子0.5μg/ ml衣霉素（TUNI），抑制了∆spf1的生长，但另一个ER胁迫因子5 mM二硫苏糖醇（DTT）促进了∆spf1的生长。用化学物质处理氧化应激（5 mM H2O2和0.8 mM百草枯）也促进了∆spf1的生长。基因表达分析显示，未折叠的蛋白应答（UPR）组件KAR2，OST1，PMT1，ERV29，PDI1，SCJ1，SEC61，Ca2 +通道相关的P型ATPase基因PMR1和钙调磷酸酶依赖性转录因子CRZ1均显着升高。在Δspf1中调控，表明该突变体中UPR的激活。这些实验证据表明，SPF1参与了稻瘟病菌的一些基础内质网机制，包括UPR途径和对内质网相关应激的反应，因此影响了真菌的发育和毒力。然而，Spf1和毒力之间的详细机制仍在等待未来的研究。