Phytotoxin-like proteins produced by Fusarium oxysporum f. sp. cepae

尖孢镰刀菌（Fusarium oxysporum f. sp. cepae， FOC）分泌的蛋白质（NIP8和NIP8- s）可以诱导悬浮培养的寄主细胞在受到寄主根部抗真菌化合物的作用时坏死。本研究旨在阐明这些蛋白在FOC致病性中的作用。NIP8被证明是疏水蛋白的降解蛋白片段，与FOC的致病性无关。NIP8-S是一个功能未知的碱性蛋白（pI=9.4），有三个推断的二硫桥。大肠杆菌产生的重组NIP8-S诱导寄主植物萎蔫，提示NIP8-S在引起枯萎病症状中起作用。

Fusarium oxysporum f. sp. cepae (FOC) secretes proteins (NIP8 and NIP8-S) that can induce necrosis of the suspension-cultured host cells when the fungus is treated with antifungal compounds from the host roots. The present study was performed to clarify the roles of these proteins in the pathogenicity of FOC. NIP8 was proved to be a degraded protein fragment of hydrophobin and unrelated to the pathogenicity of FOC. NIP8-S was a basic protein (pI=9.4) of unknown function with three deduced disulfide bridges. Recombinant NIP8-S produced by Escherichia coli induced wilting on the host plants, suggesting that NIP8-S plays a role for causing the symptoms of Fusarium wilt.