Intraspecific Comparative Analysis Reveals Genomic Variation of Didymella arachidicola and Pathogenicity Factors Potentially Related to Lesion Phenotype
Author:
Li Shaojian1ORCID,
Wang Zhenyu1ORCID,
Gao Meng1,
Li Tong1ORCID,
Cui Xiaowei1,
Zu Junhuai1,
Sang Suling1,
Fan Wanwan1,
Zhang Haiyan1
Affiliation:
1. Institute of Plant Protection, Henan Key Laboratory of Crop Pest Control, International Joint Research Laboratory for Crop Protection of Henan, Key Laboratory of Integrated Pest Management on Crops in Southern Region of North China, Henan Academy of Agricultural Sciences, Zhengzhou 450000, China
Abstract
Didymella arachidicola is one of the most important fungal pathogens, causing foliar disease and leading to severe yield losses of peanuts (Arachis hypogaea L.) in China. Two main lesion phenotypes of peanut web blotch have been identified as reticulation type (R type) and blotch type (B type). As no satisfactory reference genome is available, the genomic variations and pathogenicity factors of D. arachidicola remain to be revealed. In the present study, we collected 41 D. arachidicola isolates from 26 geographic locations across China (33 for R type and 8 for B type). The chromosome-scale genome of the most virulent isolate (YY187) was assembled as a reference using PacBio and Hi-C technologies. In addition, we re-sequenced 40 isolates from different sampling sites. Genome-wide alignments showed high similarity among the genomic sequences from the 40 isolates, with an average mapping rate of 97.38%. An average of 3242 SNPs and 315 InDels were identified in the genomic variation analysis, which revealed an intraspecific polymorphism in D. arachidicola. The comparative analysis of the most and least virulent isolates generated an integrated gene set containing 512 differential genes. Moreover, 225 genes individually or simultaneously harbored hits in CAZy-base, PHI-base, DFVF, etc. Compared with the R type reference, the differential gene sets from all B type isolates identified 13 shared genes potentially related to lesion phenotype. Our results reveal the intraspecific genomic variation of D. arachidicola isolates and pathogenicity factors potentially related to different lesion phenotypes. This work sets a genomic foundation for understanding the mechanisms behind genomic diversity driving different pathogenic phenotypes of D. arachidicola.
Funder
Fund for Outstanding Young Scholars from Henan Academy of Agricultural Sciences
Innovation and Creativity Project of Henan Academy of Agricultural Sciences
Major Science and Technology Project of Henan Province
Subject
General Agricultural and Biological Sciences,General Immunology and Microbiology,General Biochemistry, Genetics and Molecular Biology
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