The bZIP transcription factor PsBZP32 is involved in cyst germination, oxidative stress response, and pathogenicity of Phytophthora sojae

Abstract

The basic leucine zipper (bZIP) transcription factor family, one of the largest and most diverse transcription factor families in eukaryotes, is associated with the development and stress responses of many eukaryotic organisms. However, their biological functions in oomycete plant pathogens are unclear. A genome-wide analysis of bZIP transcription factors in Phytophthora sojae showed that PsBZP32, which has a unique bZIP-PAS domain structure, exhibited a high transcription level during the early stages of P. sojae infection. We silenced PsBZP32 in P. sojae and found that the transformants showed defective cyst germination and pathogenicity. The transformants could not eliminate host-derived reactive oxygen species during infection and were more sensitive to oxidative stress. Their response to oxidative stress was independent of the PsBZP32 transcription level; however, subcellular localization and phosphorylation of PsBZP32 were affected by H2O2 stress. These results indicate that PsBZP32 is involved in regulation of P. sojae cyst germination, oxidative stress response, and pathogenicity.

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

“…Studies have associated this transcription factor with cyst germination in P . sojae and Peronophythora litchi [ 30 , 31 ].…”

“…To further investigate the role of Ps132948 (bZIP32) in GC stage, we used previously generated bZIP32 -silenced mutants (bZIP32-Line1 and bZIP32-Line2) with reduced bZIP32 transcript levels (>50%) ( S1G Fig ) [ 31 ]. In 50% (v/v) V8 liquid medium, 90% of the wild-type germ tubes maintained a tapering tip and a constant diameter ( Fig 5B ).…”

“…Ps132948 (bZIP32), a putative bZIP transcription factor with an additional PAS domain, was highly expressed during cyst germination and the infection stages (Fig 5A). Studies have associated this transcription factor with cyst germination in P. sojae and Peronophythora litchi [30,31].…”

The bZIP transcription factor UvbZIP6 mediates fungal growth, stress response, and false smut formation in Ustilaginoidea virens

“…Deletion of UvbZIP6 in U. virens leads to increased vegetative hyphal growth and biomass, which was also observed in UvBI-1 knockout mutants (Xie et al 2019). In Phytophthora sojae, silencing PsBZP32 leads to decreased cyst germination, but does not affect mycelial growth, sporangium formation, and oospore production (Sheng et al 2021). In M. oryzae, disrupting the bZIP gene MoAP1 results in abnormal conidial morphology and reduced conidiation (Guo et al 2011).…”

Identification of a C2H2 Transcription Factor (PsCZF3) Associated with RxLR Effectors and Carbohydrate-Active Enzymes in Phytophthora sojae Based on WGCNA

“…For instance, in both P. sojae and P. infestans , the MADS-box transcription factors played significant roles in sporulation [ 7 , 8 ], while the Myb transcription factors regulated both vegetative growth and sporulation [ 9 , 10 ]. Other transcription factors have been shown to be involved in the resistance of plant defense response [ 11 , 12 , 13 ]. Despite the association of transcription factors with pathogenesis that have been found, no transcription factor has been reported to directly regulate RxLR effectors.…”