Login

GPC Members Login
If you have any problems or have forgotten your login please contact [email protected]


Shedding light on the energy-efficiency of photosynthesis

Photosynthesis is one of the most crucial life processes on Earth. It's how plants get their food, using energy from sunlight to convert water and carbon dioxide from the air into sugars. It's long been thought that more than 30 percent of the energy produced during photosynthesis is wasted in a process called photorespiration.

A new study led by researchers at the University of California, Davis, suggests that photorespiration wastes little energy and instead enhances nitrate assimilation, the process that converts nitrate absorbed from the soil into protein.

"Understanding the regulation of these processes is critical for sustaining food quality under climate change," said lead author Arnold Bloom in the Department of Plant Sciences at the UC Davis College of Agricultural and Environmental Sciences. The study was published in the journal Nature Plants.

During photorespiration, the most prevalent protein on the planet, called Rubisco, combines sugars with oxygen in the atmosphere instead of carbon dioxide. This was thought to waste energy and decrease sugar synthesis. Rubisco, thus, seemed to act like the molecular equivalent of a good friend with a bad habit. Researchers speculate that photorespiration persists because most plants have reached an evolutionary dead-end.

Bloom proposes that something else is going on that shows plants aren't so stupid. Rubisco also associates with metals, either manganese or magnesium. When Rubisco associates with manganese, photorespiration proceeds along an alternative biochemical pathway, generates energy for nitrate assimilation, and promotes protein synthesis. Nearly every recent test tube study of Rubisco biochemistry, however, has been conducted in the presence of magnesium and absence of manganese, allowing for only the less energy efficient pathway for photorespiration.

"There's a lot we can learn from observing what plants are doing that can give us clear messages of how we should proceed to develop crops that are more successful under the conditions we anticipate in the next few decades," said Bloom.

Read the paper: Manganese binding to Rubisco could drive a photorespiratory pathway that increases the energy efficiency of photosynthesis.

Article source: University of California - Davis.

Image credit: Getty Images, via University of California - Davis

News

Hot temperatures can trigger an RNA response in plants

The stress of hotter temperatures may trigger a response in a plant's RNA, or ribonucleic acid — part of a cell's genetic messaging system — to help manage this change in its environment, according to a team of Penn State researchers.


Study provides whole-system view of plant cold stress

When temperatures drop, plants can’t bundle up. Stuck outside, exposed, plants instead undergo a series of biochemical changes that protect cells from damage. Scientists have described these changes and identified some of the genes controlling them, but it’s not clear how all the processes work together. Lacking this global view, plant breeders have struggled to engineer cold-tolerant crops.


Photosynthesis Like a Moss

Moss evolved after algae but before vascular land plants, such as ferns and trees, making them an interesting target for scientists studying photosynthesis, the process by which plants convert sunlight to fuel. Now researchers at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have made a discovery that could shed light on how plants evolved to move from the ocean to land.