MoLys2 is necessary for growth, conidiogenesis, lysine biosynthesis, and pathogenicity in Magnaporthe oryzae
MoLys2 is necessary for growth, conidiogenesis, lysine biosynthesis, and pathogenicity in Magnaporthe oryzae
复制标题
DOI：
10.1016/j.fgb.2014.04.001
复制
发表时间：
2014-06-01
影响因子：
3
通讯作者：
Zhang, Zhengguang
中科院分区：
文献类型：
--
作者：
Chen, Yue;Zuo, Rongfang;Zhang, Zhengguang
氨基酸生物合成是真核细胞生长和分化过程中复杂而重要的过程。在出芽酵母酿酒酵母（Saccharomyces cerevisiae）中，赖氨酸通过α -氨基己二酸（AA）途径生物合成包括几个步骤，包括AA还原酶ScLys2将AA还原为AA 6-半醛。在丝状真菌青霉菌中，LYS2基因的破坏阻断了赖氨酸的生物合成，但促进了次级代谢物青霉素的产生。相比之下，人们对AA还原酶Lys2在植物病原真菌中的作用知之甚少。本研究鉴定了稻瘟病菌Magnaporthe oryzae中与ScLys2同源物MoLys2的功能。结果表明，Delta Molys2突变体对赖氨酸缺乏营养。Delta Molys2突变体对水稻的致病性也显著降低，引起小的病损。显微镜检查显示，Delta Molys2突变体的侵袭性菌丝主要局限于原代感染的叶鞘细胞。此外，外源赖氨酸恢复了分生孢子的产生和接近野生型的附着胞分化，挽救了离体裸和水稻叶鞘分生孢子侵染的致病性缺陷。我们的研究结果表明，MoLys2是赖氨酸生物合成所必需的，影响真菌的生长、分生和致病性。该研究提示以赖氨酸为靶点的生物合成有可能用于开发针对米曲菌的新型杀菌剂。(C) 2014爱思唯尔公司版权所有。
Amino acid biosyntheses are complex but essential processes in growth and differentiation of eukaryotic cells. In the budding yeast Saccharomyces cerevisiae, the lysine biosynthesis via the alpha-aminoadipate (AA) pathway involves several steps, including reduction of AA to AA 6-semialdehyde by AA reductase ScLys2. In filamentous fungus Penicillium chrysogenum, disruption of the LYS2 gene blocked the lysine biosynthesis but promoted the production of the secondary metabolite penicillin. In comparison, little is known about the function of AA reductase Lys2 in phytopathogenic fungi. We here characterized the functions of MoLys2, a homolog of ScLys2, from the rice blast fungus Magnaporthe oryzae. Our results showed that the Delta Molys2 mutants were auxotrophic for lysine. The Delta Molys2 mutants also exhibited drastic reduction in pathogenicity on rice, inducing small disease lesions. Microscopic examination of the lesions revealed that the invasive hyphae of Delta Molys2 mutants were mostly restricted to the primary infected leaf sheath cells. In addition, exogenous lysine restored the production of conidia and near wild-type appressoria differentiation, and rescued the defect of pathogenicity in conidia infection of detached barely and rice leaf sheath. Our results indicated that MoLys2 is necessary for lysine biosynthesis that affects growth, conidiogenesis, and pathogenicity of the fungus. This study does implicate the potential for targeting lysine biosynthesis for the development of novel fungicides against M. oryzae. (C) 2014 Elsevier Inc. All rights reserved.