Fungal higginsianin B inhibits plant immune responses.
IPB scientists, in cooperation with international plant researchers, have identified a natural compound from the fungus and plant pathogen Colletotrichum higginsianum that inhibits plant immunity.
According to the study, the isolated terpene higginsianin B inhibits the activity of chymotrypsin- and caspase-like proteases and prevents the degradation of the JAZ repressor protein, presumably at the 26S proteasome. This blocks the Jasmonat-Isoleucin signaling pathway, which normally induces the expression of appropriate response genes against wounding or pathogens.
Overall, the study indicates that specific fungal secondary metabolites, such as higginsianin B, can act similarly to protein effectors to suppress jasmonate-induced plant defenses and subvert plant immune and developmental responses. Work is ongoing to genetically test the contribution of higginsianin B to fungal virulence and plant defense suppression.
Reference:
Dallery J.F., Zimmer M., Halder V., Suliman M., Pigné S., Le Goff G., Gianniou D.D., Trougakos I.P., Ouazzani J., Gasperini D. and O'Connell R.J. Inhibition of jasmonate-mediated plant defences by the fungal metabolite higginsianin B. Journal of Experimental Botany 2020. pii: eraa061. Epub ahead of print. doi: 10.1093/jxb/eraa061
