A secreted glycerophosphodiester phosphodiesterase (GDPD) domain–containing protein, FpGDPD, is involved in Fusarium pseudograminearum virulence

Microbial pathogens secrete a diverse array of proteins to manipulate plant defense mechanisms and facilitate infection. However, few secreted proteins were thoroughly characterized in Fusarium pseudograminearum. Here, we identify and characterize FpGDPD, a gene encoding a secretory glycerophosphodiester phosphodiesterase (GDPD) domain-containing protein in F. pseudograminearum. We found that FpGDPD expression was significantly upregulated during specific stages of fungal infection. Disruption of FpGDPD in F. pseudograminearum did not affect vegetative growth, stress responses, or conidiation but enhanced phosphate tolerance and reduced fungal virulence in wheat. Furthermore, we demonstrated the secretory nature of the N-terminal signal peptide of FpGDPD and that the signal peptide contributes to F. pseudograminearum pathogenicity. Interestingly, FpGDPD triggers immune responses in Nicotiana benthamiana, inducing reactive oxygen species (ROS) accumulation and upregulating defense-related genes. Collectively, our findings reveal that FpGDPD plays a dual role: it promotes fungal virulence while simultaneously eliciting plant immune responses.