Original Research ARTICLE
Powdery mildews are characterized by contracted carbohydrate metabolism and diverse effectors to adapt to 3 obligate biotrophic lifestyle
- 1College of Plant Protection, Hainan University, China
- 2State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, China
Powdery mildew is a widespread plant disease caused by obligate biotrophic fungal pathogens involving species-specific interactions between host and parasite. To gain genomic insights into the underlying obligate biotrophic mechanisms, we analyzed 15 microbial genomes covering powdery and downy mildews and rust. We observed a genome-wide, massive contraction of multiple gene families in powdery mildews, such as enzymes in the carbohydrate metabolism pathway, when compared with ascomycete phytopathogens, while the fatty acid metabolism pathway maintained its integrity. We also observed significant differences in Candidate Secreted Effector Protein (CSEP) families between monocot-parasitic and dicot-parasitic powdery mildews, perhaps due to different selection forces. While CSEPs in monocot mildews are likely subject to positive selection causing rapid expansion, CSEP families in dicot mildews are shrinking under strong purifying selection. Our results not only illustrate obligate biotrophic mechanisms of powdery mildews driven by gene family evolution in nutrient metabolism, but also demonstrate how the divergence of CSEPs between monocot and dicot lineages might contribute to species-specific adaption.
Keywords: Erysiphales, Oidium heveae, Genome, Gene family contraction, Fatty Acids, CSEPs, positive selection, adaptive evolution
Received: 07 Sep 2018;
Accepted: 05 Dec 2018.
Edited by:Dirk A. Balmer, Syngenta, Switzerland
Reviewed by:Ralph Panstruga, RWTH Aachen Universität, Germany
Divya Chandran, Regional Centre for Biotechnology (RCB), India
Copyright: © 2018 Liang, Liu, Xu, Jiang, Yan, He, Liu, Lin, Wang and Miao. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. Weiguo Miao, Hainan University, College of Plant Protection, Haikou, China, firstname.lastname@example.org