GPI7‐mediated glycosylphosphatidylinositol anchoring regulates appressorial penetration and immune evasion during infection of Magnaporthe oryzae

Abstract

Summary Glycosylphosphatidylinositol (GPI) anchoring plays key roles in many biological processes by targeting proteins to the cell wall; however, its roles are largely unknown in plant pathogenic fungi. Here, we reveal the roles of the GPI anchoring in Magnaporthe oryzae during plant infection. The GPI‐anchored proteins were found to highly accumulate in appressoria and invasive hyphae. Disruption of GPI7, a GPI anchor‐pathway gene, led to a significant reduction in virulence. The Δgpi7 mutant showed significant defects in penetration and invasive growth. This mutant also displayed defects of the cell wall architecture, suggesting GPI7 is required for cell wall biogenesis. Removal of GPI‐anchored proteins in the wild‐type strain by hydrofluoric acid (HF) pyridine treatment exposed both the chitin and β‐1,3‐glucans to the host immune system. Exposure of the chitin and β‐1,3‐glucans was also observed in the Δgpi7 mutant, indicating GPI‐anchored proteins are required for immune evasion. The GPI anchoring can regulate subcellular localization of the Gel proteins in the cell wall for appressorial penetration and abundance of which for invasive growth. Our results indicate the GPI anchoring facilitates the penetration of M. oryzae into host cells by affecting the cell wall integrity and the evasion of host immune recognition.

Comprehensive identification of lysine 2‐hydroxyisobutyrylated proteins in Ustilaginoidea virens reveals the involvement of lysine 2‐hydroxyisobutyrylation in fungal virulence

“…Precursor proteins are typically inactive and are converted into mature functional proteins through a series of PTMs, which modulate diverse protein properties and functions (Deribe et al, 2010). In phytopathogens, some protein modifications play important roles in development and pathogenesis, including sumoylation, N‐glycosylation, glycosylphosphatidylinositol (GPI), and acetylation (Liang et al, 2018a; Liu et al, 2020; Chen et al, 2020a).…”

Protein glycosylation during infection by plant pathogenic fungi

“…Therefore, mutants in glycosylation pathway genes often induce a strong host immune response. For example, mutants affecting N‐ glycosylation and GPI anchoring pathway genes induce host cell ROS accumulation (Chen et al ., 2014; Liu et al ., 2020), suggesting that cell wall modifications dependent on glycosylation may be important in preventing PAMP‐triggered immunity. This also suggests that secreted effector proteins involved in immunity suppression, particularly in the apoplastic compartment, may require glycosylation for their activity.…”

“…Several studies have also addressed the roles of GPI anchoring during infection by plant pathogenic fungi (Rittenour & Harris, 2013; Oliveira‐Garcia & Deising, 2016; Liu et al ., 2020). To date, only a few GPI anchoring pathway‐related genes have been successfully deleted in fungi (Table 1).…”

“…A similar mechanism was also reported in the human fungal pathogen Candida albicans (Shen et al ., 2015), suggesting that GPI anchoring‐mediated immune evasion may be widespread among pathogens of both plants and animals. Chitin deacetylases, which catalyse the conversion of chitin to chitosan and help shield chitin from host perception, are also predicted to be GPI‐anchored proteins (Liu et al , 2020), but it is not yet known whether the GPI anchor is important for their function.…”

Association Mapping of Verticillium Wilt Disease in a Worldwide Collection of Cotton (Gossypium hirsutum L.)

“…It has been reported that the IRK-interacting protein is involved in the maintenance and differentiation of the root and shoot meristem [38,39]. In the meantime, marker A4657 has been determined to be located on the glycosylphosphatidylinositol anchor attachment 1 protein gene, and glycosylphosphatidylinositol anchor genes play a key role in many biological processes by targeting proteins to the cell wall; however, its role in plant pathogenic fungi is largely unknown [40]. With this study, it was determined that the glycosylphosphatidylinositol anchor gene is associated with Verticillium wilt.…”