Washington, May 9 : A team of researchers has discovered a photosynthetic "dimmer switch" in light harvesting proteins in green plants, which could hold important implications for the future design of artificial photosynthesis systems, providing the world with a sustainable and secure source of energy.

The researchers were from the US Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) at Berkeley.

They made their discovery after studying the molecular mechanisms by which plants protect themselves from oxidation damage should they absorb too much sunlight during photosynthesis.

What they found was a molecular "dimmer switch" that helps control the flow of solar energy moving through the system of light harvesting proteins.

They identified the pigment-binding protein CP29, one of the "minor" light-harvesting proteins in green plants, as a valve that permits or blocks the critical release of excess solar energy during photosynthesis.

Furthermore, it has been proposed that raising or lowering ambient pH levels can control the opening and closing of this valve.

According to Graham Fleming, one of the leaders of the study, "This is really the first detailed picture ever obtained of the molecular mechanism behind the regulation of light harvesting energy."

"We believe we will soon be in position to build a complete model of the flow of energy through the photosynthetic light harvesting system that will include how the flow is controlled. This model could then be applied to the engineering of artificial versions of photosynthesis," he added.

Through photosynthesis, green plants are able to harvest energy from sunlight and convert it to chemical energy at an energy transfer efficiency rate of approximately 97 percent.

If scientists can create artificial versions of photosynthesis, the dream of solar power as the ultimate green and renewable source of electrical energy could be realized.