Chen Guoqing, Liu Xiaohong, Zhang Lilin, Cao Huijuan, Lu Jianping, Lin Fucheng
State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou, China.
PLoS One. 2013 Jun 27;8(6):e67804. doi: 10.1371/journal.pone.0067804. Print 2013.
Many functions of vacuole depend on the activity of vacuolar ATPase which is essential to maintain an acidic lumen and create the driving forces for massive fluxes of ions and metabolites through vacuolar membrane. In filamentous fungus Magnaportheoryzae, subcellular colocalization and quinacrine staining suggested that the V1V0 domains of V-ATPase were fully assembled and the vacuoles were kept acidic during infection-related developments. Targeted gene disruption of MoVMA11 gene, encoding the putative c' subunit of V-ATPase, impaired vacuolar acidification and mimicked the phenotypes of yeast V-ATPase mutants in the poor colony morphology, abolished asexual and sexual reproductions, selective carbon source utilization, and increased calcium and heavy metals sensitivities, however, not in the typical pH conditional lethality. Strikingly, aerial hyphae of the MoVMA11 null mutant intertwined with each other to form extremely thick filamentous structures. The results also implicated that MoVMA11 was involved in cell wall integrity and appressorium formation. Abundant non-melanized swollen structures and rare, small appressoria without penetration ability were produced at the hyphal tips of the ΔMovma11 mutant on onion epidermal cells. Finally, the MoVMA11 null mutant lost pathogenicity on both intact and wounded host leaves. Overall, our data indicated that MoVMA11, like other fungal VMA genes, is associated with numerous cellular functions and highlighted that V-ATPase is essential for infection-related morphogenesis and pathogenesis in M. oryzae.
液泡的许多功能依赖于液泡ATP酶的活性，该酶对于维持酸性内腔以及为离子和代谢物通过液泡膜的大量流动创造驱动力至关重要。在丝状真菌稻瘟病菌中，亚细胞共定位和喹吖因染色表明，V-ATP酶的V1V0结构域已完全组装，并且在与感染相关的发育过程中液泡保持酸性。编码V-ATP酶假定c'亚基的MoVMA11基因的靶向基因破坏损害了液泡酸化，并在菌落形态不佳方面模拟了酵母V-ATP酶突变体的表型，消除了无性和有性繁殖、选择性碳源利用，并增加了对钙和重金属的敏感性，然而，并未出现典型pH条件致死性。令人惊讶的是，MoVMA11缺失突变体的气生菌丝相互缠绕形成极其粗大的丝状结构。结果还表明，MoVMA11参与细胞壁完整性和附着胞形成。在洋葱表皮细胞上，ΔMovma11突变体的菌丝尖端产生了大量未黑化的肿胀结构以及罕见的、没有穿透能力的小附着胞。最后，MoVMA11缺失突变体在完整和受伤的寄主叶片上均丧失了致病性。总体而言，我们的数据表明，MoVMA11与其他真菌VMA基因一样，与众多细胞功能相关，并突出表明V-ATP酶对于稻瘟病菌中与感染相关的形态发生和致病性至关重要。
