Chloroplasts are specialized compartments in plant cells that convert sunlight, carbon dioxide and water into sugars and oxygen during photosynthesis. Michigan State University scientists said their newly identified protein, trigalactosyldiacylglycerol 4, or TGD4, offers insight into how the process works.

"Nobody knew how this mechanism worked before we described this protein," said Professor Christoph Benning, who led the study. "This protein directly affects photosynthesis and how plants create biomass (stems, leaves and stalks) and oils."

The researchers said their finding shows how TGD4 is essential for the plant to make chloroplasts. Plants that don't have the protein die before they can develop beyond the embryonic stage.

They said understanding how TGD4 works might allow scientists to create plants that could be used exclusively to produce biofuels, possibly making the process more cost-effective.

The study that included Assistant Research Professor Changcheng Xu, Jilian Fan and Adam Cornish is reported in the journal Plant Cell.