Citrus, olives and bananas are under threat in many areas due to diseases that affect plants’ circulatory systems and that cannot be treated by applying pesticides. Huanglongbing (HLB) is the disease inflicting heavy damage on citrus in Florida and many other parts of the world.
These diseases are difficult to detect early and to treat, given the lack of precision tools to access plant vasculature to treat pathogens and to sample biomarkers.
A new method developed by engineers at Massachusetts Institute of Technology (MIT) may offer a starting point for delivering life-saving treatments to plants ravaged by such diseases. The MIT team decided to take some of the principles involved in precision medicine for humans and adapt them to develop plant-specific biomaterials and drug-delivery devices.
The method uses an array of microneedles made of a silk-based biomaterial to deliver nutrients, drugs or other molecules to specific parts of the plant. The findings are described in the journal Advanced Science, in a paper by MIT professors Benedetto Marelli and Jing-Ke-Weng, graduate student Yunteng Cao, postdoc Eugene Lim at MIT, and postdoc Menglong Xu at the Whitehead Institute for Biomedical Research.
The microneedles, which the researchers call phytoinjectors, can be made in a variety of sizes and shapes, and can deliver material specifically to a plant’s roots, stems or leaves, or into its xylem (the vascular tissue involved in water transportation from roots to canopy) or phloem (the vascular tissue that circulates metabolites throughout the plant). In lab tests, the team used tomato and tobacco plants, but the system could be adapted to almost any crop, they say. The microneedles can not only deliver targeted payloads of molecules into the plant, but they can also be used to take samples from the plants for lab analysis.
The work started in response to a request from the U.S. Department of Agriculture for ideas on how to address the HLB crisis, which is threatening the collapse of a $9 billion industry, Marelli says. HLB is spread by an insect called the Asian citrus psyllid that carries a bacterium into the plant. There is as yet no cure for it, and many U.S. citrus groves have already been devastated. In response, Marelli’s lab swung into gear to develop the novel microneedle technology, led by Cao as his thesis project.
Learn more about the technique here.
Source: Massachusetts Institute of Technology