Study identifies genes that control heat response in crops

Rising temperatures are signalling crops to flower too early and become less productive. Global warming is expected to reduce crop yields by as much as one third in the next three decades. 

But now, experts at UC Riverside have identified two genes that help plants sense heat. The research may ultimately enable scientists to engineer heat-resistant crops that are able to thrive despite global warming.

“We need plants that can endure warmer temperatures, have a longer time to flower and a longer growth period,” said Professor Meng Chen. “But, to be able to modify plants’ temperature responses, you first have to understand how they work. So, that’s why identifying this gene that enables heat response is so important.”

The experts report that a shift in ambient growth temperature of only a few degrees can significantly alter the expression of hundreds of temperature-responsive genes, resulting in dramatic adaptive responses in plant development, growth, metabolism, and immunity.

“Because increases in global temperature are expected to drastically reduce crop productivity, understanding the mechanism of temperature signaling has become imminent to create a knowledge base for devising strategies to sustain crop production in a changing climate,” wrote the study authors. 

Professor Chen and his colleagues identified the heat-sensing gene HEMERA two years ago. They used an experiment to search for other genes that may be involved in heat response.

The team engineered a mutant Arabidopsis plant so that it was completely insensitive to temperature, and then modified it once again to become reactive.

While examining the genes of this twice-mutated plant, the team discovered a second gene, RCB, which works closely with HEMERA to stabilize the heat-sensing function. “If you knock out either gene, your plant is no longer sensitive to temperature,” said Professor Chen.

The two genes, HEMERA and RCB, are needed to control the abundance of a group of master regulatory genes that perform multiple functions, such as turning plants green and responding to light and temperature.

Going forward, Professor Chen says his laboratory will focus on understanding how these two parts of the cell communicate and work together to achieve growth, greening, flowering, and other functions.

“When you change light or temperature, genes in both the nucleus and chloroplasts change their expression. We think HEMERA and RCB are involved in coordinating gene expression between these two cell compartments,” explained Professor Chen.

The ultimate goal is to achieve the ability to modify temperature response to secure the future of the global food supply.

“We were excited to find this second gene,” said Professor Chen. “It’s a new piece of the puzzle. Once we understand how it all works, we can modify it, and help crops cope better with climate change.”

The study is published in the journal Nature Communications.

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By Chrissy Sexton, Earth.com Staff Writer