In recent years, contamination of salad vegetables by E. coli and salmonella bacteria—the most common causes of food poisoning—have led to large-scale recalls. Although most salmonella outbreaks are linked to contamination from post-harvest handling and transportation, this infectious bacterium can also enter the plant earlier, from contaminated soil.
But how exactly does it enter from the soil? A new study from the Indian Institute of Science (IISc) and the University of Agricultural Sciences (UAS), Bengaluru, has found the answer. Unlike other disease-causing bacteria that enter the root, fruit or leaf by producing enzymes to break down the plant’s cell wall, salmonella sneaks in through a tiny gap created when a lateral root branches out from the plant’s primary root, the study shows.