The ‘pears and lemons’ protein UvPal1 regulates development and virulence of Ustilaginoidea virens

Abstract

Ustilaginoidea virens is an economically important fungus causing a devastating grain disease, rice false smut. An insertional mutagenesis screen was used to explore biological mechanisms underlying infection process of U. virens. T184, a new mutant was identified, with abnormal conidial morphology and deficient virulence. Analysis of the T-DNA inserted gene UvPal1 in the mutant confirmed it as a putative homologue of a cellular morphogenetic protein in yeast, Pal1, whose function has not been well characterized. Deletion of UvPal1 affected hyphal growth, cell morphology, stress adaptation and virulence. UvPal1 could interact with the endocytic proteins, UvEde1 and UvSla2, but was not required for receptor-mediated endocytosis. A yeast two-hybrid (Y2H) analysis was further carried out to screen the UvPal1-interacting proteins, resulting in the identification of 16 putative interacting proteins. Interestingly, UvPal1 interacted with a septin protein, UvCdc11 in vivo and in vitro, and also affected subcellular localization of UvCdc11 protein. Deletion of the four core septins impaired the growth, morphogenesis, stress response and virulence. Collectively, effects on cell morphology, oxidative stress response and virulence are similar to those of UvPal1, suggesting that UvPal1 physically interacts with UvCdc11 to mediate the septin complex to maintain the cellular morphology and virulence of U. virens.

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

“…Using a previously reported method (Chen et al, 2020c), approximately 1.5 kb of upstream and downstream flanking sequences of the target gene were ligated with pGKO to generate a gene deletion vector (Figure S3A). The vector was introduced into A. tumefaciens strain EHA105, and then transformed into conidia of the wild‐type strain using ATMT following the method of Chen et al (2020c).…”

“…We performed a Co-IP assay to further validate the protein interactions of UvSlt2 and UvRpd3 based on a previously described method (Chen et al, 2020b). The coding sequences of UvSlt2 and UvRpd3 were introduced into pNeo3300III-GFP and pGKO-Flag to generate the UvSlt2-GFP and UvRpd3-Flag vectors, respectively.…”

Ustilaginoidea virens modulates lysine 2‐hydroxyisobutyrylation in rice flowers during infection

“…The middle section of distal internodes of susceptible rice plants (cv. Wanxian-98) were injected with 2 mL of mycelial/conidial suspension (1 × 10 6 conidia/mL) with a syringe at the early booting stage (Chen et al, 2020c). Rice plants injected with water served as controls.…”

“…The middle section of distal internodes of rice plants at the early booting stage were injected with 2 mL of mycelial/conidial suspension (1 × 10 6 conidia/mL) of U. virens HWD-2 with a syringe at the early booting stage based on the method of Chen et al (2020c). At 21 dpi, the number of smut balls was calculated for each spikelet.…”

A novel transcription factor UvCGBP1 regulates development and virulence of rice false smut fungus Ustilaginoidea virens

“…Comparative genomics and transcriptomic analyses of U. virens infection of rice offer numerous important information for pathogenic mechanisms, of which many pathogenicity factors have been predicted [ 9 ]. To date, some pathogenicity genes of U. virens have been experimentally confirmed, including Uvt3277, UvAc1, UvPdeH, SCRE1, SCRE2 ( UV_1261 ), UvBI-1, UvPmk1, UvCDC2, UvCdc3, UvCdc10, UvCdc11, UvCdc12, UvPal1, UvHox2, UvRpd3, UvATG8, UvEC1, UvCom1 and UvPRO1 [ 10–23 ]. An understanding of the pathogenic mechanism of U. virens could provide new effective strategies to control RFS.…”