Scottish scientists say they have discovered a new way to protect crops from a devastating bacterial disease – without using environmentally damaging chemical sprays.
The Glasgow University team said the method could protect crops such as tomatoes and peppers against the bacteria Pseudomonas Syringae (PS), which causes huge economic losses.
The hope is that it could prove to be a viable alternative following the withdrawal of key active ingredients in agrochemicals.
Bacteria such as PS are responsible for about one-third of the plant diseases responsible for destroying an estimated 15% of world crops worth some £114bn annually.
The PS species complex consists of more than 50 known variants, responsible for diseases such as blight, spot and bacterial speck.
Once the bacteria infect part of a crop, the disease can spread rapidly because of the lack of genetic diversity in commercial crop varieties.
Using genetic modification, the Glasgow team was able to make plants express a targeted protein antibiotic, enabling the plants to successfully fight off the bacterial infection.
The team genetically modified plants to produce the bacteriocin throughout their life – the first time this modification has been trialled in plants.
Joel Milner of the Plant Science Group said: “Our results provide proof-of-principle that the expression of a bacteriocin in plants can provide effective resistance against bacterial disease.
“Unlike conventional antibiotics, bacteriocins are highly targeted. In this case, they act only against the PS strains that infect plants.”
Dr Milner said bacteriocins avoided the risks associated with conventional antibiotics that resistance would spread indiscriminately to other bacteria.
“In fact, by replacing conventional antibiotics, we take away an important driver of resistance that could even spread to human bacterial pathogens.”
“Now we know that expression of bacteriocins in crops can offer an effective strategy for managing bacterial disease, we are undertaking research to fully realise the potential of this novel method.”