Stress-related Proteins Keep Plants from Getting Sunburn

Fair skinned humans know all too well the consequences of too much time under the Sun, but plants, even though outside and under the Sun their entire lives, never experience any sunburn in intense light. And now researchers from Dartmouth University-led team have pinpointed a set of stress-related proteins which enable plants to avoid burning under intense sunlight.

The find could one day lead to the development of biotechnologies that may help plants and crops cope better with hotter, drier conditions brought about by climate change.

Plants have sophisticated control systems to utilize the Sun's energy for photosynthesis while also protecting themselves from sunburn from intense sunlight.

When exposed to too little, too much or rapidly fluctuating light conditions, plants experience stress, the researchers report.

Scientists have identified the cellular systems that enable the plants to optimally regulate sunlight, but underlying processes of how that is done is not well understood.

Dartmouth researcher Hou-Sung Jung and his colleagues found that a group of cellular mechanisms which are being called "Heat Shock Transcription Factors" are responsible for plants being able to respond quickly to changes in light intensity. These transcription factors, which are proteins that regulate the flow of genetic information, respond to light conditions that are optimal for photosynthesis as well as bright light that causes sunburn.

Under intense light harmful, toxic molecules accumulate in the plant, and the transcription factors generate an enzyme responsible for detoxifying harmful molecules

Jung now working on characterizing factors involved in plants' responses to prolonged bright light. He believes that by studying these short-term and long-term response factors, it may become possible to generate plants with increased protection from bright light with enhanced photosynthesis rates.

Jung and his colleagues at Salk Institute for Biological Studies and Australian National University published their research in the journal Proceedings of the National Academy of Sciences.