New research reveals an essential step in scientists' quest to create targeted, more eco-friendly fungicides that protect food crops.
While biological cells manufacture tiny, round structures called extracellular vesicles, their pivotal roles in communication between invading microorganisms and their hosts were recognized only recently.
Researchers have found plants use these vesicles to launch RNA molecules at fungal invaders, suppressing the genes that make the fungi dangerous.
Using extracellular vesicles and small RNAs has several advantages over conventional fungicides. They're more eco-friendly because they are similar to naturally occurring products. Eventually, they degrade and do not leave toxic residues in the soil. Also, Jin explained, this method of fighting fungi is less likely to breed drug-resistant pathogens.
A sticking point for scientists in creating these fungicides has been figuring out how to load their desired small RNAs into the vesicles.The researchers have identified several RNA-binding proteins in Arabidopsis that bind to specific small RNA molecules and load them into extracellular vesicles. This suggests the proteins play an important role in loading and stabilizing small RNAs in the vesicles. The finding can help increase the payload of gene-silencing RNAs that make it into vesicles and enhance the efficiency of disease control.
Some scientists have taken inspiration from the RNA communication in plant vesicles to design human therapies. For example, some are attempting to load anti-cancer RNAs and drugs into extracellular vesicles in fruits or vegetables, so people can eat or drink them. Jin is hopeful that her lab's discovery can aid these efforts.
Baoye He, Qiang Cai, Lulu Qiao, Chien-Yu Huang, Shumei Wang, Weili Miao, Tommy Ha, Yinsheng Wang, Hailing Jin. RNA-binding proteins contribute to small RNA loading in plant extracellular vesicles. Nature Plants, 2021; DOI: 10.1038/s41477-021-00863-8
Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)