Ma Wendi, Yang Jun, Ding Junqiang, Zhao Wensheng, Peng You-Liang, Bhadauria Vijai
Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China.
Ministry of Agriculture and Rural Affairs, Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, China.
Front Plant Sci. 2022 Oct 26;13:1022819. doi: 10.3389/fpls.2022.1022819. eCollection 2022.
Didymella leaf blight (DLB) caused by is a new fungal disease of maize (), first detected in 2021 in Panjin, Liaoning province of China. Here we report the reference genome assembly of to unravel how the fungal pathogen controls its virulence on maize at the molecular level. A maize-infecting strain Pj-2 of the pathogen was sequenced on the Illumina NovaSeq 6000 and PacBio Sequel II platforms at a 575-fold genomic coverage. The 33.17 Mb gapless genome assembly comprises 32 scaffolds with L/N of 11/1.36 Mb, four of which represent full-length chromosomes. The Pj-2 genome is predicted to contain 10,334 protein-coding genes, of which 211, 12 and 134 encode effector candidates, secondary metabolite backbone-forming enzymes and CAZymes, respectively. Some of these genes are potentially implicated in niche adaptation and expansion, such as colonizing new hosts like maize. Phylogenomic analysis of eight strains of six spp., including three sequenced strains of , reveals that the maize (Pj-2)- and (CBS 528.66)-infecting strains of are genetically similar (sharing 92.37% genome with 98.89% identity), whereas Pj-2 shows truncated collinearity with extensive chromosomal rearrangements with the -infecting strain M27-16 of (sharing only 55.01% genome with 88.20% identity). Pj-2 and CBS 528.66 carry four major reciprocal translocations in their genomes, which may enable them to colonize the different hosts. Furthermore, germplasm screening against Pj-2 led to the identification of three sources of DLB resistance in maize, including a tropical inbred line CML496. DLB resistance in the line is attributed to the accumulation of ROS HO in the apoplastic space of the infected cells, which likely restricts the fungal growth and proliferation.
由[病原菌名称未给出]引起的玉米壳二孢叶斑病（DLB）是玉米的一种新真菌病害，2021年首次在中国辽宁省盘锦市被发现。在此，我们报告[病原菌名称未给出]的参考基因组组装情况，以从分子水平揭示这种真菌病原体如何控制其对玉米的毒力。该病原菌的一个感染玉米的菌株Pj - 2在Illumina NovaSeq 6000和PacBio Sequel II平台上进行了测序，基因组覆盖度达575倍。33.17 Mb的无间隙基因组组装包含32个支架，L/N为11/1.36 Mb，其中4个代表全长染色体。Pj - 2基因组预计包含10334个蛋白质编码基因，其中分别有211个、12个和134个基因编码效应子候选物、次生代谢物骨架形成酶和碳水化合物活性酶。这些基因中的一些可能与生态位适应和扩展有关，例如在像玉米这样的新宿主上定殖。对包括三个已测序菌株在内的六个[属名未给出]属的八个菌株进行系统基因组分析表明，感染玉米（Pj - 2）和[另一寄主名称未给出]（CBS 528.66）的[病原菌名称未给出]菌株在遗传上相似（与[另一寄主名称未给出]菌株共享92.37%的基因组，同一性为98.89%），而Pj - 2与感染[另一寄主名称未给出]的[病原菌名称未给出]菌株M27 - 16显示出截断的共线性以及广泛的染色体重排（仅共享55.01%的基因组，同一性为88.20%）。Pj - 2和CBS 528.66在其基因组中携带四个主要的相互易位，这可能使它们能够在不同宿主上定殖。此外，针对Pj - 2的种质筛选导致在玉米中鉴定出三个抗DLB的来源，包括一个热带自交系CML496。该品系对DLB的抗性归因于感染细胞质外体空间中ROS HO的积累，这可能限制了真菌的生长和增殖。
