Zheng Huakun, Chen Simiao, Chen Xiaofeng, Liu Shuyan, Dang Xie, Yang Chengdong, Giraldo Martha C, Oliveira-Garcia Ely, Zhou Jie, Wang Zonghua, Valent Barbara
State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry UniversityFuzhou, China; Department of Plant Pathology, Kansas State UniversityManhattan, KS, USA; Basic Forestry and Proteomics Research Center, Haixia Institute of Science and Technology (HIST), Fujian Agriculture and Forestry UniversityFuzhou, China.
State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University Fuzhou, China.
Front Plant Sci. 2016 Sep 27;7:1458. doi: 10.3389/fpls.2016.01458. eCollection 2016.
The Rab GTPase proteins play important roles in the membrane trafficking, and consequently protein secretion and development of eukaryotic organisms. However, little is known about the function of Rab GTPases in . To further explore the function of Rab GTPases, we deleted the ortholog of the yeast Sec4p protein in , namely . The Δ mutant is defective in polarized growth and conidiation, and it displays decreased appressorium turgor pressure and attenuated pathogenicity. Notably, the biotrophic invasive hyphae produced in rice cells are more bulbous and compressed in the Δ mutant. Further studies showed that deletion of the gene resulted in decreased secretion of extracellular enzymes and mislocalization of the cytoplasmic effector PWL2-mCherry-NLS. In accordance with a role in secretion, the GFP-MoSec4 fusion protein mainly accumulates at tips of growing vegetative hyphae. Our results suggest that the MoSec4 protein plays important roles in the secretion of extracellular proteins and consequently hyphal development and pathogenicity in the rice blast fungus.
Rab GTPase蛋白在膜运输中发挥重要作用，进而在真核生物的蛋白质分泌和发育过程中发挥作用。然而，关于Rab GTPases在……中的功能知之甚少。为了进一步探究Rab GTPases的功能，我们在……中敲除了酵母Sec4p蛋白的直系同源物，即……。Δ突变体在极性生长和产孢方面存在缺陷，其附着胞膨压降低且致病性减弱。值得注意的是，在水稻细胞中产生的活体营养型侵入菌丝在Δ突变体中更呈球茎状且受到挤压。进一步研究表明，基因的缺失导致细胞外酶分泌减少以及细胞质效应物PWL2-mCherry-NLS定位错误。与在分泌过程中的作用一致，GFP-MoSec4融合蛋白主要积累在生长中的营养菌丝尖端。我们的结果表明，MoSec4蛋白在水稻稻瘟病菌的细胞外蛋白分泌中发挥重要作用，进而在菌丝发育和致病性方面发挥重要作用。
