Research has led to a breakthrough for a new generation of fungicides. Plants that are attacked by pathogens have an automatic immune response, and fungi get around the plant immunity by injecting proteins in the cells of the host plant. These proteins, effector proteins, allow the fungi to escape the plant’s immune system and enable the fungal cells to enter into the plant unrecognized.

Exeter scientists have indicated that signalling organelles, or early endosomes, become long distance messengers in the fungi. The organelles travel quickly along long tube-like cells inbetween the plant-invading fungal cell tip and the fungal cell nucleus. The quick communication between the point of invasion and the fungal cell nucleus allows the fungus to produce the effector proteins that assist in evading the plant’s immune response from the instant the fungus enters the host tissue.

Professor Gero Steinberg from the University of Exeter said in a statement, “Pathogenic fungi are a major threat to our food security – they can devastate crops and cost billions of pounds worth of damage. In fact, losses of wheat, rice, and maize to fungal pathogens, per year, are the same as the annual spend by US Department of Homeland Security – some 60 billion US dollars.” He continued, “As fast growing microbes, fungi adapt rapidly to anti-fungal treatments and so we need to develop new fungicides all the time. Our research has led to a better understanding of the mechanisms by which the intruder attacks and overcomes the plant defence. In order to efficiently protect crops, we must better understand molecular mechanisms like these that occur in the very earliest stages of infection.”

According to the American Phytopathological Society, a fungicide is a specific type of pesticide that controls fungal disease by specifically inhibiting or killing the fungus causing the disease.