Newly discovered protein in fungi bypasses plant defenses

Scientists from the USDA Agricultural Research Service and Washington State University have discovered a protein that allows the fungus that causes stem rot of white mold in more than 600 plants to overcome the plant's defenses

Knowledge of this protein, called SsPINE1, could help researchers develop a new, more precise system for controlling the sclerotiorum sclerotiorum, which attacks potatoes, soybeans, sunflowers, peas, lentils, canola and many other broadleaf crops

Sclerotium sclerotiorum destroys the cell walls of plants by secreting a chemical called polygalacturonase (PG), which causes plants to rot and die

"There is essentially an ongoing arms race between fungal pathogens and their plant hosts, a fierce battle of attack, counter-attack and counter-offensive, with each side continually developing and changing its chemical tactics to circumvent or overcome the other's defense

The key to identifying SsPINE1, Chen said, is to look beyond the fungal cell

"We discovered it by looking at what the fungus excreted," he said

Then, to show that the SsPINE1 protein allowed Sclerotium to bypass PGIP in plants, Chen and his colleagues deleted the protein in the fungus in the lab, which greatly reduced its effect

"When we found this protein, I got goosebumps," said Kiwamu Tanaka, an associate professor of plant pathology at Washington State University and one of the paper's co-authors

The discovery of SsPINE1 opens up new avenues for research into controlling the white mold stem rot pathogen, including potentially more efficient and targeted breeding to make plants naturally resistant to sclerotinia

The research is part of the National Sclerotinia Initiative, a multi-organization effort that ARS created to fight Sclerotium, a fungus that causes so much damage around the world

The research team also included scientists from the U.

The Agricultural Research Service is the primary scientific research agency within the USDA

article title

Fungal extracellular effector inactivating plant polygalacturonase inhibitory protein