Fungi-induced plant diseases affect global food security and plant ecology. The biotrophic fungus Ustilago maydis causes smut disease in maize (Zea mays) plants by secreting numerous virulence effectors that reprogram plant metabolism and immune responses1,2. The secreted fungal chorismate mutase Cmu1 presumably affects biosynthesis of the plant immune signal salicylic acid by channelling chorismate into the phenylpropanoid pathway3. Here we show that one of the 20 maize-encoded kiwellins (ZmKWL1) specifically blocks the catalytic activity of Cmu1. ZmKWL1 hinders substrate access to the active site of Cmu1 through intimate interactions involving structural features that are specific to fungal Cmu1 orthologues. Phylogenetic analysis suggests that plant kiwellins have a versatile scaffold that can specifically counteract pathogen effectors such as Cmu1. We reveal the biological activity of a member of the kiwellin family, a widely conserved group of proteins that have previously been recognized only as important human allergens.A kiwellin protein in maize is found to inhibit the activity of the secreted enzyme chorismate mutase from a maize-infecting pathogenic fungus, suggesting a role for kiwellins in plant immunity.

中文翻译：

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kiwellin 解除分泌的真菌毒力因子的代谢活动

真菌引起的植物病害影响全球粮食安全和植物生态。生物营养真菌 Ustilago maydis 通过分泌大量毒力效应物来重新编程植物代谢和免疫反应 1,2，从而在玉米 (Zea mays) 植物中引起黑穗病。分泌的真菌分支酸变位酶 Cmu1 可能通过将分支酸引导到苯丙烷通路中来影响植物免疫信号水杨酸的生物合成。在这里，我们展示了 20 种玉米编码的 kiwellins (ZmKWL1) 中的一种，专门阻止了 Cmu1 的催化活性。ZmKWL1 通过涉及真菌 Cmu1 直向同源物特有的结构特征的密切相互作用阻止底物进入 Cmu1 的活性位点。系统发育分析表明，植物 kiwellins 具有多功能支架，可以专门对抗病原体效应物，如 Cmu1。我们揭示了 kiwellin 家族成员的生物学活性，这是一组广泛保守的蛋白质，以前仅被认为是重要的人类过敏原。 发现玉米中的 kiwellin 蛋白抑制玉米分泌酶分支酸变位酶的活性- 感染病原真菌，表明 kiwellins 在植物免疫中的作用。