Phase-specific transcriptional patterns of the oomycete pathogen Phytophthora sojae unravel genes essential for asexual development and pathogenic processes

Abstract

Oomycetes are filamentous microorganisms easily mistaken as fungi but vastly differ in physiology, biochemistry, and genetics. This commonly-held misconception lead to a reduced effectiveness by using conventional fungicides to control oomycetes, thus it demands the identification of novel functional genes as target for precisely design oomycetes-specific microbicide. The present study initially analyzed the available transcriptome data of the model oomycete pathogen, Phytophthora sojae, and constructed an expression matrix of 10,953 genes across the stages of asexual development and host infection. Hierarchical clustering, specificity, and diversity analyses revealed a more pronounced transcriptional plasticity during the stages of asexual development than that in host infection, which drew our attention by particularly focusing on transcripts in asexual development stage to eventually clustered them into 6 phase-specific expression modules. Three of which respectively possessing a serine/threonine phosphatase (PP2C) expressed during the mycelial and sporangium stages, a histidine kinase (HK) expressed during the zoospore and cyst stages, and a bZIP transcription factor (bZIP32) exclusive to the cyst germination stage were selected for down-stream functional validation. In this way, we demonstrated that PP2C, HK, and bZIP32 play significant roles in P. sojae asexual development and virulence. Thus, these findings provide a foundation for further gene functional annotation in oomycetes and crop disease management.

Mining oomycete proteomes for phosphatome leads to the identification of specific expanded phosphatases in oomycetes

“…In our study, we observed that oomycete species have a significantly higher number of phosphatases in the PPP, PPM and DSP families compared with fungi (Figure 2 ), all of which are related to serine/threonine phosphatase activity. This finding is particularly significant, and it aligns with previous research in oomycetes that has underscored the importance of serine/threonine phosphatase activity (Qiu et al., 2023 ). When comparing these two studies, it becomes evident that we have demonstrated the importance of serine/threonine phosphatase activity through two different strategies.…”

A novel method for extraction of high purity and high production Phytophthora sojae oospores

“…Notably, these zoospores exhibit a strong attraction to isoflavonoids soy glycosides released by soybean roots [ 1 , 19 ]. Upon detecting their host, they employ germ tubes to infiltrate the roots and commence infection [ 20 ]. In the sexual reproduction phase, P. sojae forms oospores [ 21 ].…”

A novel and ubiquitous miRNA-involved regulatory module ensures precise phosphorylation of RNA polymerase II and proper transcription

“…Phytophthora is a genus of oomycetes that resemble true fungi in morphology and pathogenesis, yet is phylogenetically distinct from fungi and could form some specific apparatus like sporangium [ 22 ]. This commonly-held misconception lead to a reduced effectiveness by using conventional fungicides to prevent Phytophthora , thus it demands the identification of novel and primary targets to precisely control these pathogens [ 23 ]. Over a hundred species of Phytophthora have been reported, including the notorious plant pathogen Phytophthora capsici , which is a destructive plant pathogen that causes root, fruit, and foliar diseases on more than 100 important crops [ 24 ].…”