New Discoveries to Help Scientists Harness Power of Photosynthesis

A research team led by Donald A. Bryant, professor of biochemistry and molecular biology at Penn State University has identified the gene that converts chlorophyll a -- the most abundant light-absorbing pigment used by plants and other organisms that harness energy through photosynthesis -- into chlorophyll f -- a type of chlorophyll that absorbs light in the far-red range of the light spectrum.

The newly identified gene encodes an enzyme that is distantly related to one of the main components of the protein machinery used in oxygen-producing photosynthesis. The researchers showed that the conversion of chlorophyll a to chlorophyll f requires only this one enzyme in a simple system that could represent an early intermediate stage in the evolution of photosynthesis. The research showed that, without this enzyme, cyanobacteria could no longer synthesize chlorophyll f.

Another clue that the enzyme could represent an early stage in the evolution of photosynthesis is that the enzyme requires light to catalyze its reaction and may not require oxygen. Bryant said that it is possible the enzyme evolved before Photosystem II, the photosynthetic complex that produces oxygen.

For more details, read the news release at the Penn State University website.