A HOPS Protein, MoVps41, Is Crucially Important for Vacuolar Morphogenesis, Vegetative Growth, Reproduction and Virulence in Magnaporthe oryzae

Abstract

The homotypic fusion and protein sorting protein complex (HOPS) is the first known tether complex identified in the endocytic system that plays a key role in promoting homotypic vacuolar fusion, vacuolar biogenesis and trafficking in a wide range of organisms, including plant and fungi. However, the exact influence of the HOPS complex on growth, reproduction and pathogenicity of the economically destructive rice blast fungus has not been investigated. In this study, we identified M. oryzae vacuolar protein sorting 41 (MoVps41) an accessory subunit of HOPS complex and used targeted gene deletion approach to evaluate its contribution to growth, reproduction and infectious life cycle of the rice blast fungus. Corresponding results obtained from this study showed that MoVps41 is required for optimum vegetative development of M. oryzae and observed that MoVps41 deletion mutant displayed defective vegetative growth. Our investigation further showed that MoVps41 deletion triggered vacuolar fragmentation, compromised membrane integrity and pathogenesis of the ΔMovps41 mutant. Our studies also showed for the first time that MoVps41 plays an essential role in the regulation of sexual and asexual reproduction of M. oryzae. In summary, our study provides insight into how MoVps41 mediated vacuolar fusion and biogenesis influences reproduction, pathogenesis, and vacuolar integrity in M. oryzae and also underscores the need to holistically investigate the HOPS complex in rice blast pathogen.

A subunit of the HOPS endocytic tethering complex, FgVps41, is important for fungal development and plant infection in Fusarium graminearum

“…Mutation of the endocytic pathway related components often showed defects in vacuole fusion and vesicle trafficking in different phytopathogens. These include the Rab GTPase FgRab7, the guanine nucleotide exchange factor FgMon1, the Vesicle trafficking in F. graminearum 1443 HOPS complex subunit FgVps39, the retromer complex subunit FgVps35 and the SNARE protein FgVam7 in F. graminearum (Li et al, 2015;Zheng et al, 2016;Li et al, 2017a), and the SNARE proteins MoVam7 and MoSec22, and MoVps41 in the rice blast fungus (Song et al, 2010;Dou et al, 2011;Zhang et al, 2017), the SNARE protein UmYup1 in Ustilago maydis (Fuchs et al, 2006). All of these gene deletion mutants showed fragmented vacuoles and was defective in fungal development and infection.…”

The casein kinase MoYck1 regulates development, autophagy, and virulence in the rice blast fungus

“…Vacuolar fusion is a complex process orchestrated by multiple factors, including the Rab GTPase Ypt7, soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE), SNARE complex disassembly chaperones, regulatory lipids, and the HOPS (homotypic fusion and vacuolar protein sorting) complex including Vps11, Vps16, Vps18, Vps33, Vps39 and Vps41 [30,31]. Functional analysis of several proteins involved in vacuolar membrane fusion in the plant pathogenic fungi M. oryzae and F. graminearum, including MoYpt7 [32], MoVam7 [33], MoMon1 [34], MoVps41 [35], FgYpt7 [36], FgVps41 [37], and FgMon1 [38], has established a link between vacuoles and fungal development and virulence. Functions of Vps41 homologs have been extensively explored in fungi, animals and plants and are implicated in vacuolar morphology, starvation response, intracellular survival, virulence, the endocytic pathway, antigen presentation and microbial killing [38][39][40][41].…”

A putative N-BAR-domain protein is crucially required for the development of hyphae tip appressorium-like structure and its plant infection in Magnaporthe oryzae

“…Membrane and vesicular trafficking processes such as endocytosis, vacuolar tethering and fusion, retrograde trafficking, and snaring, play crucial roles in morphological, reproductive and infectious development of the rice blast fungus (Zhang et al 2017). The understanding that BAR domain proteins play an indispensable role in driving clathrin-mediated endocytosis and regulating the biogenesis of transport carriers and the reorganization of the actin cytoskeleton through the induction of membrane curvature underscores the relevance of BAR domain in promoting fungal pathogenesis (Douglas et al 2009).…”

“…The rice blast fungus deploys asexual spores and hyphae as propagules for initiating blast infection on tissues of susceptible host plants (Giovannetti et al 1993;Kong et al 2013;Zhang et al 2017). Initiation and the subsequent development of asexual spore-and hyphaemediated blast infection involve the formation of a dome-shaped infectious structure called appressorium and appressorium-like structure in the germinating spore and hypha, respectively (Kong et al 2013).…”