Study Reveals Plant Sugar Transporter Involved in Carbon Sequestration

Two research teams led by Wolf Frommer at the Carnegie Institution for Science have identified sugar transport proteins which play key roles in various plant processes.

The first research team, led by Liang Feng from Stanford University School of Medicine unravelled the molecular structure of a SWEET2 transporter from rice. Discovering the structure of SWEET2, and determining the key amino acids in the protein necessary for function, is the key to understanding how it works, and what happens when the transporter fails due to disease or pathogens. The other research team, on which Frommer worked with Woei-Jiun Guo and Dorothea Tholl of Virginia Tech, focused on SWEET2's role in protecting Arabidopsis from parasitic infection. They showed that SWEET2 helps stockpile sugars in the vacuole, thereby limiting the sugar supply to feed only the good microbes and prevent the growth of the bad ones.

The team showed that SWEET2 facilitates the retention of sugar in the roots, which could starve and resist pathogens living in the immediate root surroundings. They found that SWEET2 expression increased 10-fold during parasite infection and that specially created mutants lacking SWEET2 were more susceptible to the parasite. Frommer said, "Together, these two papers provide first insights not only into how plants control carbon sequestration into the soil, but also improve our understanding of the functioning of this unique class of SWEET transporters."

For more details, read the news release from Carnegie.