Scientists at the Uni-versity of California-Davis in America have identified a gene that makes lettuce susceptible to E.coli.
A team at the university’s Department of Plant Sciences is working on identifying strains of the vegetable that are better at resisting bacteria.
Led by Maeli Melotto, the boffins are searching for a type of lettuce that will avoid the cases of sickness that the poor bacteria can cause.
They also want to find a strain that will cut production costs to farmers.
Lettuce “sweats” substances onto the surface of leaves that E. coli and other bacteria can eat.
In addition, bacteria can live just below the surface of lettuce leaves.
Professor Melotto, who spec-ialises in the interactions between plants and microbes, is studying the genetic factors that determine how long bacteria can endure in the leaves.
She and her team looked at more than 300 samples of lettuce and how they react to the pathogens, identifying the gene responsible for letting them in.
Their next step is to test whether removing that gene could make lettuce more resistant to bacteria.
In a related study, Prof Melotto’s team is looking at the surface of lettuce leaves and the layer just below, which has tiny spaces where bacteria can live.
The researchers want to learn what natural chemicals are in these two areas, and what compounds lettuce releases onto the surface of leaves that bacteria can use as food.
Prof Melotto expects to find that some types of lettuce are genetically disposed toward “feeding” bacteria.
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