While increased levels of atmospheric carbon dioxide encourage plant growth, it also reduces their nutritional value, which could have a greater impact on nutrition and food safety around the world. Michigan State University researchers have discovered a new way for plants to adapt to a changing climate - this information can be used to help plants grow strong while maintaining their nutritional value. Phys.org portal.
Phosphorus is used as a fertilizer and is essential for plant growth, but world reserves of phosphorus are limited.
“We can't synthesize [phosphorus] like nitrogen fertilizers,” said Hatem Ruashed, an assistant professor at the College of Agriculture and Natural Resources. “We need to better understand how plants consume phosphorus in order to survive.”
Ruashed and his team observed that when the plants were exposed to elevated levels of carbon dioxide, phosphorus levels in the shoots and leaves of the plants decreased.
“We wanted to know why plants don't take up more phosphorus,” Ruashed said. — And see if the decline is phosphorus level defect or adaptive response, and is there a way to change that so that plants grow and provide us with nutritious food.”
Ruashed and his team took a deep look at the subcellular level and found that plants avoid overloading their chloroplasts with phosphorus as an adaptive response to elevated carbon dioxide levels. Chloroplasts are where photosynthesis takes place, where chlorophyll, in the presence of sunlight, produces food for plant growth. Phosphorus is also an important part of photosynthesis and the creation of energy for cells.
"What's really important about our discovery is that when we try to get a plant to add a lot phosphorus into a chloroplast, the plant doesn’t grow,” Ruashed said. “We have found that the increase in phytic acid levels in plants must be tightly controlled so that plants can grow in conditions of high carbon dioxide.”
Researchers have found that once phytic acid levels exceed a certain threshold, plants do not grow.
“This article is the first to show that there is a need for a discussion on how we can protect plants from malnutrition caused by increasing carbon dioxide worldwide,” Ruashed said.
The study was published in the journal Current Biology.