Liu Liping, Yan Yaqin, Huang Junbin, Hsiang Tom, Wei Yangdou, Li Yu, Gao Jie, Zheng Lu
Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, China.
Laboratory of Plant Pathology, Department of Agronomy, Jilin Agricultural University, Changchun, China.
Front Microbiol. 2017 Oct 10;8:1953. doi: 10.3389/fmicb.2017.01953. eCollection 2017.
is a widely distributed fungus attacking many cruciferous species. To investigate pathogenic mechanisms of the pathogen on the host , we screened and obtained a virulence-deficient mutant Ch-1-T513 in a T-DNA insertion mutant library of The mutant Ch-1-T513 produced yellow colony centers with distorted multi-branching hyphal tips as well as producing few conidia. Heavily swollen hyphae in the mutant could be observed, and intra-hyphal hyphae were found to be formed in the balloon-shaped hyphae. The mutant failed to produce lesions on 12-day-old seedlings, and invasive hyphae did not differentiate into large primary and thin secondary hyphae after appressorial formation on leaves, but formed abundant bulbous hyphae in epidermal cells. Southern blot analysis showed Ch-1-T513 had double-site T-DNA integrations. The mutant had insertions upstream of genes for a major facilitator superfamily (MFS) transporter, and an aldo/keto reductase, . Complementation experiments by transforming genomic sequences from a wild-type strain into the insertion mutant demonstrated that is involved in the Ch-1-T513 phenotype. The complementation strain C-ChMfs1-1 exhibited normal hyphal morphology, conidiation, and pathogenicity identical to the wild-type. The results demonstrate that is involved in intra-hyphal hyphae production, conidiation, and pathogenicity in To our knowledge, this is the first report of a MFS transporter gene in a phytopathogenic fungus associated with intra-hyphal hyphae formation, playing a key role in infection of its plant host.
是一种广泛分布的真菌，可侵染多种十字花科植物。为研究该病原菌对寄主的致病机制，我们在的T-DNA插入突变体文库中筛选并获得了一个毒力缺陷型突变体Ch-1-T513。突变体Ch-1-T513产生黄色菌落中心，菌丝顶端多分支扭曲，分生孢子极少。可观察到突变体中有严重肿胀的菌丝，在气球状菌丝中发现有菌丝内菌丝形成。该突变体在12日龄的幼苗上不产生病斑，在叶片上形成附着胞后，侵入菌丝不会分化为大型的初级菌丝和纤细的次级菌丝，而是在表皮细胞中形成大量的球状菌丝。Southern杂交分析表明Ch-1-T513有双位点T-DNA整合。该突变体在一个主要促进剂超家族（MFS）转运蛋白基因和一个醛糖/酮还原酶基因的上游有插入。通过将野生型菌株的基因组序列转化到插入突变体中进行互补实验，表明参与了Ch-1-T513的表型。互补菌株C-ChMfs1-1表现出与野生型相同的正常菌丝形态、分生孢子形成和致病性。结果表明参与了菌丝内菌丝的产生、分生孢子形成和致病性。据我们所知，这是首次报道植物病原真菌中一个与菌丝内菌丝形成相关的MFS转运蛋白基因，其在侵染植物寄主中起关键作用。
