Botrytis cinerea is a saprophytic plant pathogenic fungus that can infect a variety of crops and cause gray mold, which leads to huge losses worldwide. The role of exocyst in fungal pathogenicity is being revealed. In this study, homologous recombination technology was used to knock out the exocyst subunit BcSec3 of B. cinerea , and it was found that the BcSec3 subunit plays a crucial role in the growth and pathogenicity of B. cinerea . Compared with the wild-type strain B05.10, the mycelial growth ability of the BcSec3 deletion strain was reduced by up to 49.8%, the conidia production capacity of the deletion strain was severely lost, and no sclerotia was formed. The polygalacturonase, is one of plant cell wall hydrolases, whose activity in BcSec3 deletion strain was significantly reduced. In the tomato leaves infection assay in vitro , the lesion area caused by the BcSec3 deletion strain was only 20% of the wild type after 5 days of infection. Observation by light microscope showed that the morphology of BcSec3 deletion strain mycelium was significantly changed, the mycelium became thinner and deformed, and the polarity growth was not obvious. Further observation with laser confocal microscopy and transmission electron microscopy was conducted. It was found that compared with the wild type, the number of vesicles in BcSec3 deleted cells reduced and localization and distribution of vesicles changed. In mutant cell, vesicles relatively concentrated in the cytoplasm, while in wild-type cell mainly concentrated inside the cell membrane. These evidences indicate that the exocyst subunit BcSec3 plays an important role in the growth, development and pathogenicity of B. cinerea .

中文翻译：

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Exocyst 亚基 BcSec3 调节灰葡萄孢的生长、发育和致病性

Botrytis cinerea 是一种腐生植物病原真菌，可感染多种作物并引起灰霉病，在全球范围内造成巨大损失。外囊在真菌致病性中的作用正在被揭示。本研究采用同源重组技术敲除B. cinerea的胞外囊泡亚基BcSec3，发现BcSec3亚基在B. cinerea的生长和致病性中起关键作用。与野生型菌株B05.10相比，BcSec3缺失菌株的菌丝生长能力降低了49.8%，缺失菌株的分生孢子生产能力严重丧失，未形成菌核。多聚半乳糖醛酸酶是植物细胞壁水解酶之一，其在 BcSec3 缺失菌株中的活性显着降低。在体外番茄叶片感染试验中，感染5天后，BcSec3缺失株引起的病灶面积仅为野生型的20%。光镜观察发现BcSec3缺失株菌丝形态发生明显变化，菌丝变细变形，极性生长不明显。用激光共聚焦显微镜和透射电子显微镜进一步观察。发现与野生型相比，BcSec3缺失细胞中的囊泡数量减少，囊泡的定位和分布发生了变化。在突变细胞中，囊泡相对集中在细胞质中，而在野生型细胞中，囊泡主要集中在细胞膜内部。这些证据表明胞外亚基 BcSec3 在 B. cinerea 的生长、发育和致病性中起重要作用。