Figure. The working model of erucamide exerting broad-spectrum antibacterial activity by inhibiting the assembly of the bacterial type III secretion system

Supported by the National Natural Science Foundation of China (Grant Nos. 22193073 and 92253305), the research team led by Dr. Xiaoguang Lei from Peking University, in collaboration with Jianmin Zhou's team from the Yazhou Bay National Laboratory, has made significant progress in the fields of chemical biology of plant natural products, molecular mechanisms of plant antimicrobial activity, and the development of novel biopesticides. Their findings, titled "A widespread plant defense compound disarms bacterial type III injectisome assembly," were published in Science on February 28, 2025.

Paper link: https://www.science.org/doi/10.1126/science.ads0377

Plant bacterial diseases pose a significant threat to agricultural production and ecological balance. These diseases, caused by pathogenic bacteria infections, can lead to a variety of symptoms such as leaf spots, wilting, and rot, and in severe cases, can result in widespread crop failure or even total loss of harvest. This not only directly threatens global food security but also triggers a cascade of repercussions, including economic losses and ecological environmental damage. Currently, the prevention and control of plant bacterial diseases face severe challenges: firstly, the rapid evolution of pathogen resistance has significantly reduced the effectiveness of traditional pesticides; secondly, the continuous mutation of pathogenic bacteria imposes higher technical requirements for the development of new pesticides, putting the effectiveness of existing control systems to an unprecedented test. In this context, in-depth research into the plant's own disease resistance mechanisms and its chemical defense strategies is of great theoretical and practical significance for the development of environmentally friendly new pesticides and the construction of a sustainable disease control system.

The research team has unveiled a class of naturally produced molecules endogenously existing in plants, known as erucamide, which possess a unique mechanism of action and broad-spectrum antimicrobial activity. Further studies have demonstrated that erucamide effectively inhibits the virulence of plant pathogenic bacteria by specifically disrupting the assembly of their type III secretion system (T3SS), thereby achieving a broad-spectrum inhibitory effect against various bacterial infections (as illustrated in the figure). This mechanism embodies an innovative antibacterial strategy of "disarming the enemy without fighting," which offers significant advantages over traditional antibiotic drugs: erucamide does not directly kill bacteria but selectively reduces the virulence of the pathogens. This unique mode of action not only ensures higher biosafety but also significantly reduces the risk of environmental pollution and effectively circumvents the development of bacterial resistance. This research not only breaks through the traditional understanding of the mechanisms of action of plant resistance metabolites but also provides an important theoretical foundation and technical support for the development of environmentally friendly biopesticides and the molecular breeding of disease-resistant crops, holding significant scientific and practical value for promoting the development of green agriculture.