Bacillus velezensis strain H166, isolated from the apple rhizosphere, exhibits strong biocontrol efficacy against apple replant disease (ARD), a complex soilborne disease in which Fusarium oxysporum can act as an important fungal pathogen. To elucidate the underlying biocontrol mechanisms, a high-quality genome assembly of strain H166 was generated using PacBio HiFi sequencing. The genome of strain H166 consists of a single circular chromosome of 3,929,791 bp with a GC content of 46.5%, and contains 4,035 protein-coding genes, 86 tRNA genes, 27 rRNA genes, and 16 sRNA genes. Twelve secondary metabolite biosynthetic gene clusters were identified, including those associated with fengycin, surfactin, and bacillaene biosynthesis. These gene clusters are presumed to be closely associated with the biocontrol functions of this strain against Apple Replant Disease. The genome sequence provides important foundational data for further elucidating the molecular mechanisms underlying the biocontrol activity of B. velezensis strain H166.
The SUN family protein MoSun4 in Magnaporthe oryzae has been previously implicated in mitophagy and has potential as a target for reducing rice blast, but its role as a secreted protein remains poorly understood. In this study, signal peptide prediction and yeast secretion assays confirmed MoSun4 signal peptide function, and co-localization revealed the localization of the extra-invasive hyphal membrane (EIHM)-associated apoplastic compartment or matrix, establishing MoSun4 as a secreted protein. In addition, deletion of the MoSUN4 gene reduced the hyphal growth, conidiation and virulence of M. oryzae. We further showed that MoSun4 is involved in regulating the expression of virulence-related genes, including multiple genes involved in cell wall degradation (eglC, eglD), secondary metabolism (gliK), and melanin biosynthesis (SDH1, BUF1, Cmr1, ALB1). Collectively, our study reveals that MoSun4 is a secreted protein that contributes to pathogenicity and is associated with altered expression of virulence-related genes, providing new insights into the functions of SUN family proteins.
Huimin Li, Zhenhe Su, Xiaomeng Liu et al.· Journal of Fungi· 0 citations