PacC in the nematophagous fungus Clonostachys rosea controls virulence to nematodes

Abstract

Nematophagous fungi are commonly used as biological control agents of plant and animal parasitic nematodes. However, relatively little is known of the environmental attributes conferring pathogenicity in these fungi. In this report, we investigated the role of PacC-mediated pH response in the pathogenesis of the nematophagous fungus Clonostachys rosea. We identified a pacC orthologue from this fungus and found that its transcript was elevated in C. rosea during the early stage of its infection of nematode. Disruption of pacC resulted in slowed growth at alkaline pH, altered filamentation, reduced conidiation and attenuated virulence to nematodes. The expression of an extracellular serine protease PrC, a putative virulence factor, was downregulated in the pacC mutants. The PrC transcript levels were significantly higher under alkaline growth conditions than under acidic growth conditions. Promoter activity analysis and electrophoretic mobility shift assay indicated that the regulation of PrC by pH via the PacC pathway occurred at the transcriptional level. In conclusion, PacC functions as a positive regulator of virulence to nematodes in C. rosea.

Adaptation to pH and Role of PacC in the Rice Blast Fungus Magnaporthe oryzae

“…S1). Consistent with what has been shown in other fungi [29], [37]–[40], and consistent with the presence of three PacC consensus binding sites in its promoter sequence, MoPACC expression is activated when the fungus is placed under alkaline conditions. A 24-fold increase in expression was monitored after only 15 minutes of transfer from an acidic to an alkaline environment, and this demonstrates a very fast reaction of the fungal cell to pH that resembles what has been observed in S. sclerotiorum [40].…”

“…The role of the pH-signaling pathway in the virulence of various pathogenic fungi has been evaluated through the study of PACC deletion strains [23]–[29]. Interestingly, such deletion has mostly negative effects on the fungus capacity at secreting metabolites or lytic enzymes, undergoing developmental switches, penetrating the host or invading the host tissues.…”

The Pochonia chlamydosporia Serine Protease Gene vcp1 Is Subject to Regulation by Carbon, Nitrogen and pH: Implications for Nematode Biocontrol

“…In the nematophagous fungus Clonostachys rosea the PacC-mediated pH response has been shown to play an important role in pathogenesis [47]. Expression of the subtilisin-like extracellular protease PrC of C. rosea was upregulated in the presence of nematode cuticles but this only occurred under alkaline growth conditions [38].…”

From the ancient times of the agriculture to the biological control in plants: a little of the history

“…Nowadays in Brazil it can be mentioned studies in nematode controlling in guava tree by weevils (Conotrachelus psidii); pre immunization against citrus sadness by weak origins of the virus (BOECHAD & BETTIOL, 2009); the control of grey mold in multiple cultures by the fungi Clonostachys rosea (ZOU et al, 2010), besides e fungi known as pathogenic which can be opposed to other pathogens which produces metabolites and inhibits enzymes, and/or tissues destruction like the mycotoxins of Penicilium sp and Aspergillus sp (ESPOSITO & AZEVEDO, 2004) and glucanases and eniatinas of Fusarium sp. (POHANKA, 2004).…”