Biologists Found How Plants Interact with Beneficial Microbes in the Soil

For years, scientists wondered how legumes recognize nitrogen-fixing bacteria as both friendly and distinct from their own cells, and how the host plant's specialized proteins find the bacteria. A team of molecular biologists from the University of Massachusetts Amherst led by Dong Wang has found how a gene in the host plant encodes a protein that recognizes the cell membrane surrounding the symbiotic bacteria, then directs other proteins to harvest the nutrients.

The team looked at the gene SYNTAXIN 132, which encodes receptors (SYP132) that identify cell membranes, and interact with secretory vesicles. They found that the gene usually makes a transcript that always seeks out the plant cell's surface membrane. But if rhizobia are present in the host, that same gene will make a second type of protein that is able to find the membrane surrounding the bacteria. Surprisingly, symbiosis with arbuscular mycorrhizal fungi shares the same SYP132 receptor. Scientists now understand that the host membrane – both in legumes and beyond – around the fungal arbuscule has a lot in common with the membrane around the nitrogen-fixing bacteria.

For more details, read the news article at the UMassAmherts News and Media Relations.