Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics and Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany.
Department of Genetics of Eukaryotic Microorganisms, Institute of Microbiology and Genetics and Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany.
Mol Plant Pathol. 2021 Aug;22(8):939-953. doi: 10.1111/mpp.13071. Epub 2021 May 5.
Amphidiploid fungal Verticillium longisporum strains Vl43 and Vl32 colonize the plant host Brassica napus but differ in their ability to cause disease symptoms. These strains represent two V. longisporum lineages derived from different hybridization events of haploid parental Verticillium strains. Vl32 and Vl43 carry same-sex mating-type genes derived from both parental lineages. Vl32 and Vl43 similarly colonize and penetrate plant roots, but asymptomatic Vl32 proliferation in planta is lower than virulent Vl43. The highly conserved Vl43 and Vl32 genomes include less than 1% unique genes, and the karyotypes of 15 or 16 chromosomes display changed genetic synteny due to substantial genomic reshuffling. A 20 kb Vl43 lineage-specific (LS) region apparently originating from the Verticillium dahliae-related ancestor is specific for symptomatic Vl43 and encodes seven genes, including two putative transcription factors. Either partial or complete deletion of this LS region in Vl43 did not reduce virulence but led to induction of even more severe disease symptoms in rapeseed. This suggests that the LS insertion in the genome of symptomatic V. longisporum Vl43 mediates virulence-reducing functions, limits damage on the host plant, and therefore tames Vl43 from being even more virulent.
双二倍体真菌Verticillium longisporum 菌株 Vl43 和 Vl32 可以定殖植物宿主油菜（Brassica napus），但它们引起病症的能力不同。这两个菌株代表了来自两个不同的单倍体亲本Verticillium 菌株杂交事件的 V. longisporum 谱系。Vl32 和 Vl43 携带来自双亲本谱系的相同性别交配型基因。Vl32 和 Vl43 同样可以定殖和穿透植物根部，但无症状的 Vl32 在植物体内的增殖率低于毒力较强的 Vl43。高度保守的 Vl43 和 Vl32 基因组包含不到 1%的独特基因，15 或 16 条染色体的核型由于大量基因组重排而显示出遗传同线性的改变。一个 20 kb 的 Vl43 谱系特异性（LS）区域显然源自与 Verticillium dahliae 相关的祖先，它是 Vl43 引起症状的特异性区域，编码七个基因，包括两个假定的转录因子。在 Vl43 中部分或完全缺失这个 LS 区域并没有降低毒力，但导致在油菜中诱导出更严重的病症。这表明，在 V. longisporum Vl43 的基因组中，LS 插入介导了毒力降低的功能，限制了对宿主植物的损害，因此使 Vl43 变得不那么毒力。
