Discovery of a gene that turns fungi into pathogens presents chemists with a target for fungicides that could bring relief to arable farmers and vegetable growers, according to scientists at Rothamsted.
A random mutation in a convenient host led to the discovery of a gene responsible for fungal disease that wrecks up to one fifth of the world’s cereal production, or hundreds of millions of tonnes of crops. Near identical genes are also present in the fungi that cause vegetables to rot, it said.
Rothamsted researchers were screening genes of the wheat pathogen, Zymoseptoria tritici, which causes septoria leaf blotch, when they noticed one specimen not developing hyphae, or filaments, that are essential to enable the fungus to invade its host and were able to identify the mutant gene responsible.
Subsequent analysis revealed that the same gene or near identical version is present in more than 800 genomes from diverse fungi, many of which infect plants and humans. However, it is not present in all pathogenic fungi, notably Puccinia rust fungi, which also infect wheat.
The next stage is to characterise the rogue protein, glycosyltransferase, coded for by the gene, said Jason Rudd, a molecular pathologist at Rothamsted Research. “We need to know what it is actually making and how it works, which would then allow us to know how to attack it.
“The aim would be to develop a fungicidal spray - because the gene is not present in plants or animals - to stun spores before they become pathogenic.”