1 Department of Molecular Biology, Department of Bioactive Material Sciences, Institute for Molecular Biology and Genetics, Chonbuk National University, Jeonju, Chonbuk 54896, Korea; and.
2 Department of Bio-Environmental Chemistry, Institute of Life Science and Natural Resources, Wonkwang University, Iksan, Chonbuk 54538, Korea.
Mol Plant Microbe Interact. 2019 Mar;32(3):286-295. doi: 10.1094/MPMI-07-18-0194-R. Epub 2019 Feb 7.
We identified a protein spot showing downregulation in the presence of Cryphonectria hypovirus 1 and tannic acid supplementation as a septin subunit with the highest homology to the Aspergillus nidulans aspA gene, an ortholog of the Saccharomyces cerevisiae Cdc11 gene. To analyze the functional role of this septin component (CpSep1), we constructed its null mutant and obtained a total of eight CpSep1-null mutants from 137 transformants. All CpSep1-null mutants showed retarded growth, with fewer aerial mycelia and intense pigmentation on plates of potato dextrose agar supplemented with L-methionine and biotin. When the marginal hyphae were examined, hyperbranching was observed in contrast to the wild type. The inhibition of colonial growth was partially recovered when the CpSep1-null mutants were cultured in the presence of the osmostabilizing sorbitol. Conidia production of the CpSep1-null mutants was significantly increased by at least 10-fold more. Interestingly, the conidial morphology of the CpSep1-null mutants changed to circular in contrast to the typical rod-shaped spores of the wild type, indicating a role of septin in the spore morphology of Cryphonectria parasitica. However, no differences in the germination process were observed. Virulence assays using excised chestnut bark, stromal pustule formation on chestnut stems, and apple inoculation indicated that the CpSep1 gene is important in pathogenicity.
我们发现了一个在 Cryphonectria hypovirus 1 和单宁酸补充存在下下调的蛋白质斑点，该斑点与 Aspergillus nidulans aspA 基因具有最高同源性，该基因是 Saccharomyces cerevisiae Cdc11 基因的同源物。为了分析这种隔膜成分（CpSep1）的功能作用，我们构建了其缺失突变体，并从 137 个转化体中总共获得了 8 个 CpSep1 缺失突变体。所有 CpSep1 缺失突变体的生长都明显迟缓，在添加 L-蛋氨酸和生物素的土豆葡萄糖琼脂平板上，气生菌丝较少，色素沉着强烈。当检查边缘菌丝时，与野生型相比，观察到过度分支。当 CpSep1 缺失突变体在含有渗透压稳定剂山梨醇的条件下培养时，菌落生长的抑制得到部分恢复。CpSep1 缺失突变体的分生孢子产量至少增加了 10 倍。有趣的是，CpSep1 缺失突变体的分生孢子形态发生了变化，从典型的野生型杆状孢子变成了圆形，表明隔膜在 Cryphonectria parasitica 的孢子形态中起作用。然而，在发芽过程中没有观察到差异。使用切除的栗树皮、栗茎上的基质脓疱形成和苹果接种进行的毒力测定表明，CpSep1 基因对致病性很重要。
