GE rice’s adjustable immune system may protect against multiple diseases
In an effort to reduce the amount of pesticides sprayed on crops, scientists have been working to genetically engineer (GE) plants that are resistant.
In an effort to reduce the amount of pesticides sprayed on crops, scientists have been working to genetically engineer (GE) plants that are resistant. So far, attempts have offered protection against a single disease, but now researchers have developed a rice plant that fights multiple pathogens at once, according to an article published in Science. They have done this by engineering the rice plant to have an adjustable immune system. The researchers have detailed the discovery and application of such a mechanism in two studies published in Nature.
Using receptors on the outsides of their cells, plants can identify molecules that signal a microbial invasion and respond by releasing antimicrobial compounds. The theory is that by identifying the genes that signal the immune system into action and modifying the intensity of their response, researchers can create more resilient plants.
Researchers have been testing this hypothesis by intensifying the reaction of the gene NPR1 in the thale cress plant (Arabidopsis thaliana). However, they soon discovered that keeping the NPR1 gene turned on all the time stunts plant growth so severely there is no harvest for the farmers. To make NPR1 useful, researchers needed to figure out how to turn on the plant’s immune response only when it was under attack, but still enable the plant to grow.
While investigating an immune system-activating protein called TBF1 in Arabidopsis, researchers discovered an intricate system that speedily instigates an immune response. It works by taking ready-to-go messenger RNA molecules that encode TBF1, and quickly translating these molecules into TBF1 proteins, which then kick-start an array of immune defenses. The researchers were able to identify a segment of DNA that acts as the control switch for this plant’s immune response, which they then put in front of the NPR1 gene in rice plants. The result is a strain of rice that can rapidly ramp up its immune system to fend off pathogens but then subside to avoid stunted growth.
So far, the researchers have been to show that the GE rice is better able than regular plants to fight pathogens that cause rice blight and leaf streak diseases, as well as the fungus responsible for blast disease. While this technique is still in the very early stages and has yet to be tested in large trials, scientists are hopeful that someday it could eventually lead to the end of pesticides.