Bekalu Zelalem Eshetu, Dionisio Giuseppe, Madsen Claus Krogh, Etzerodt Thomas, Fomsgaard Inge S, Brinch-Pedersen Henrik
Department of Agroecology, Aarhus University, Slagelse, Denmark.
Front Plant Sci. 2021 Jul 29;12:702557. doi: 10.3389/fpls.2021.702557. eCollection 2021.
Nepenthesins are categorized under the subfamily of the nepenthesin-like plant aspartic proteases (PAPs) that form a distinct group of atypical PAPs. This study describes the effect of nepenthesin 1 () protease from barley ( L.) on fungal histidine acid phosphatase (HAP) phytase activity. Signal peptide lacking HvNEP-1 was expressed in and biochemically characterized. Recombinant HvNEP-1 (rHvNEP-1) strongly inhibited the activity of and phytases, which are enzymes that release inorganic phosphorous from phytic acid. Moreover, rHvNEP-1 suppressed fungal growth and strongly reduced the production of mycotoxin, 15-acetyldeoxynivalenol (15-ADON), from . The quantitative PCR analysis of trichothecene biosynthesis genes () confirmed that rHvNEP-1 strongly repressed the expression of , , , and in . . The co-incubation of rHvNEP-1 with recombinant (rFgPHY1) and (FcPHY1) phytases induced substantial degradation of both phytases, indicating that HvNEP-1-mediated proteolysis of the fungal phytases contributes to the HvNEP-1-based suppression of .
猪笼草蛋白酶被归类于猪笼草蛋白酶样植物天冬氨酸蛋白酶（PAPs）亚科，它们构成了一组独特的非典型PAPs。本研究描述了来自大麦（Hordeum vulgare L.）的猪笼草蛋白酶1（HvNEP-1）对真菌组氨酸酸性磷酸酶（HAP）植酸酶活性的影响。在毕赤酵母中表达了缺乏信号肽的HvNEP-1，并对其进行了生化特性分析。重组HvNEP-1（rHvNEP-1）强烈抑制了禾谷镰刀菌和黄色镰刀菌植酸酶的活性，这两种酶可从植酸中释放无机磷。此外，rHvNEP-1抑制了禾谷镰刀菌的生长，并显著降低了禾谷镰刀菌中霉菌毒素15-乙酰脱氧雪腐镰刀菌烯醇（15-ADON）的产生。对单端孢霉烯生物合成基因（TRI genes）的定量PCR分析证实，rHvNEP-1强烈抑制了禾谷镰刀菌中TRI5、TRI3、TRI4和TRI101的表达。rHvNEP-1与重组禾谷镰刀菌（rFgPHY1）和黄色镰刀菌（FcPHY1）植酸酶的共孵育诱导了两种植酸酶的大量降解，这表明HvNEP-1介导的真菌植酸酶蛋白水解作用有助于基于HvNEP-1的对禾谷镰刀菌的抑制作用。
