Xu Xihui, He Qin, Chen Chen, Zhang Chulong
College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay, 30095, Israel.
PLoS One. 2016 Sep 22;11(9):e0163368. doi: 10.1371/journal.pone.0163368. eCollection 2016.
During infection, both phytopathogenic and endophytic fungi form intimate contact with living plant cells, and need to resist or disable host defences and modify host metabolism to adapt to their host. Fungi can achieve these changes by secreting proteins and enzymes. A comprehensive comparison of the secretomes of both endophytic and pathogenic fungi can improve our understanding of the interactions between plants and fungi. Although Magnaporthe oryzae, Gaeumannomyces graminis, and M. poae are economically important fungal pathogens, and the related species Harpophora oryzae is an endophyte, they evolved from a common pathogenic ancestor. We used a pipeline analysis to predict the H. oryzae, M. oryzae, G. graminis, and M. poae secretomes and identified 1142, 1370, 1001, and 974 proteins, respectively. Orthologue gene analyses demonstrated that the M. oryzae secretome evolved more rapidly than those of the other three related species, resulting in many species-specific secreted protein-encoding genes, such as avirulence genes. Functional analyses highlighted the abundance of proteins involved in the breakdown of host plant cell walls and oxidation-reduction processes. We identified three novel motifs in the H. and M. oryzae secretomes, which may play key roles in the interaction between rice and H. oryzae. Furthermore, we found that expression of the H. oryzae secretome involved in plant cell wall degradation was downregulated, but the M. oryzae secretome was upregulated with many more upregulated genes involved in oxidation-reduction processes. The divergent in planta expression patterns of the H. and M. oryzae secretomes reveal differences that are associated with mutualistic and pathogenic interactions, respectively.
在感染过程中，植物病原真菌和内生真菌都会与活的植物细胞形成密切接触，并且需要抵抗或抑制宿主防御反应并改变宿主代谢以适应其宿主。真菌可以通过分泌蛋白质和酶来实现这些变化。对内生真菌和病原真菌的分泌组进行全面比较，有助于我们更好地理解植物与真菌之间的相互作用。虽然稻瘟病菌、禾顶囊壳菌和早熟禾叶斑病菌是具有重要经济意义的真菌病原体，而相关物种稻生哈普孢菌是一种内生菌，但它们都从一个共同的致病祖先进化而来。我们使用了一种流程分析方法来预测稻生哈普孢菌、稻瘟病菌、禾顶囊壳菌和早熟禾叶斑病菌的分泌组，分别鉴定出1142、1370、1001和974种蛋白质。直系同源基因分析表明，稻瘟病菌的分泌组比其他三个相关物种的分泌组进化得更快，产生了许多物种特异性的分泌蛋白编码基因，如无毒基因。功能分析突出了参与宿主植物细胞壁分解和氧化还原过程的蛋白质的丰富性。我们在稻生哈普孢菌和稻瘟病菌的分泌组中鉴定出三个新基序，它们可能在水稻与稻生哈普孢菌的相互作用中起关键作用。此外，我们发现参与植物细胞壁降解的稻生哈普孢菌分泌组的表达下调，但稻瘟病菌的分泌组上调，且有更多上调基因参与氧化还原过程。稻生哈普孢菌和稻瘟病菌分泌组在植物体内不同的表达模式分别揭示了与共生和致病相互作用相关的差异。
