Chinese scientists have discovered a small molecule in plant cells that can trigger immunity.

The molecule, which has been patented, can potentially be developed into a broad-spectrum biopesticide, helping plants such as crops resist diseases.

"Once this biopesticide is put into use, it can function when it's sprayed on a plant's surface and is absorbed by the plant. Based on existing scientific knowledge, it potentially can be applied to different plants and combat many diseases," said Wan Li, a researcher at the Center for Excellence in Molecular Science of the Chinese Academy of Sciences.

"This small molecule originates from the plant itself, hence it's safe. It can inhibit the invasion of pathogens without causing harm to plants, humans or the ecosystem when properly used," he added.

His team's research findings, titled "Activation of a helper NLR by plant and bacterial TIR immune signaling", were published in the journal Science on Friday.

Wan's team conducted their research using the laboratory model plant Arabidopsis thaliana, which has nearly 150 such immune sensors in its cells. Different sensors react to corresponding pathogens and produce the same small molecule, 2'cADPR, which triggers the plant's disease resistance.

"Since specific sensors can only defend plants against specific pathogens, achieving effective broad-spectrum disease resistance against multiple pathogens has become a crucial topic in plant immunity research," Wan said.

"Sensors are specific, but they all produce 2'cADPR upon activation. By producing this small molecule, we bypass the specificity of the sensors, achieving broad-spectrum disease resistance," he added.

Wan noted that the small molecule discovered by his team has already been patented and put into production. The next step is to continue proving its actual broad-spectrum disease resistance in the field and hopefully put it to use soon.

Another study published concurrently in the same journal, titled "A canonical protein complex controls immune homeostasis and multipathogen resistance", verified the broad-spectrum effectiveness of the same immune pathway in rice.

Wan said that in the past, crops' resistance to pests and diseases mainly relied on chemical pesticides, which not only harm the environment but also pose certain risks to human health.

Two teams of Chinese scientists have made breakthroughs in plant broad-spectrum disease resistance from the perspectives of enhanced immune response and biopesticides. Both solutions address the problem of pesticides causing harm to the environment and human health simultaneously.