Stealthy diseases sometimes trick plants by hijacking their alarm system. Once the plant diverts resources for the “wrong attack,” the pathogen easily sneaks in.
Scientists are testing a new way to help plants counter these attacks by boosting their alert system. They’ve engineered the receptor for jasmonate, a plant hormone that plays a central role in plant defense, to fend off such stealthy attacks from highly evolved pathogens.
“This new strategy is different from conventional resistance gene-based crop breeding and is based on a deep understanding of a key component, the jasmonate receptor, of the plant immune system,” says Sheng Yang He, a professor in the Department of Energy Plant Research Laboratory at Michigan State University.
The findings may provide a general strategy for producing a new generation of disease-resistant crop plants against many plant diseases, which collectively cause crop losses of more than $200 billion annually worldwide, adds He.
Jasmonate regulates plant defenses against a wide variety of pathogens and insects. However, a group of highly evolved pathogens produce a jasmonate-mimicking toxin called coronatine.
The bacteria use this toxin to override the jasmonate receptor, which allows they to attack without tripping any alarms.
The solution: Researchers created an enhanced receptor, one that can still signal for insect defense but also has a greatly reduced sensitivity to coronatine toxin.
The team’s proof-of-concept demonstration shows that the coronatine-based takeover of the jasmonate receptor by bacterial pathogens can be stopped and that plants can be engineered to be resistant to both insects and pathogens, which has been one of the elusive goals of plant pathology/entomology research.
Researchers from Western Michigan University, Aligarh Muslim University (India), and the Max Planck Institute for Chemical Ecology (Germany) also contributed to this research, which appears in the Proceedings of the National Academy of Sciences.
Source: Michigan State University