Proteomics insight into phosphate limitation response in Burkholderia phytopathogens

Abstract

Inorganic phosphate (Pi) limitation is a pervasive environmental constraint that shapes microbial behaviour in soil and plant-associated niches. To determine how Pi scarcity influences the pathogenic potential of rice-infecting Burkholderia species, we performed comparative proteomic and lipidomic analyses of Burkholderia glumae and Burkholderia plantarii grown under Pi-replete and Pi-deplete conditions. Pi starvation triggered strong activation of the Pho regulon in both organisms, including induction of alkaline phosphatases, phosphonate transporters and the high-affinity PstSABC uptake system. Beyond classical phosphate-stress responses, Pi limitation markedly enriched proteins associated with virulence, secretion systems, toxins, chemotaxis and cell envelope modification. Both species also activated PlcP/Agt-mediated lipid remodelling pathways and synthesized phosphorus-free glycolipids exclusively during Pi depletion, indicating substantial membrane lipid restructuring. These results demonstrate that Pi limitation acts as a major environmental cue coordinating nutrient acquisition with multiple virulence-related functions. Our findings provide new insight into how phosphate scarcity shapes the environmental fitness and pathogenic capacity of Burkholderia phytopathogens and highlight nutrient limitation as an important driver of plant disease emergence.