University of Adelaide could breed climate-smart barley plants

The University of Adelaide has partnered with an international research team to identify a new mechanism in barley plants, which could aid crop growers in achieving high yields at higher temperatures. 

The study published by Nature Plants explored increasing seed production through the reproductive systems in plants that respond to high temperatures. The research was led by University of Adelaide Waite Research Institute’s Professor Dabing Zhang, and Shanghai Jiao Tong University’s Joint Lab for Plant Science and Breeding. 

“By having a better understanding of the genes underpinning desirable plant traits in response to temperature, scientists can offer insights into breeding climate-smart plants to sustain productivity,” University of Adelaide Waite Research Institute deputy director and study co-author, Associate Professor Matthew Tucker said. 

Traditional grains are highly sensitive to changing environmental conditions, with rising temperatures known to reduce seed numbers on each plant. The researchers’ solution is to increase the number of flowers or branches on each “spike,” the reproductive structure which produces grains. 

“Cereal crops such as wheat and barley are worth over $12 billion to the Australian economy,” University of Adelaide’s Waite Research Institute lead author Dr Gang Li said. 

“Genes that control the amount of grain produced per plant under higher temperatures are really attractive targets for breeders and researchers, particularly in the face of changing environmental conditions. 

“It has long been presumed that environmental cues such as temperature are responsible for the diversity of the biological structures between cereals. However, the mechanisms behind the structural changes have been largely unknown, which is why this study is important.” 

The research team discovered a barley protein known as HvMADS1 can regulate the number of flowers generated on each spike, in response to high temperatures. It was demonstrated that HvMADS1 is critical in maintaining an unbranched barley spike under high ambient temperatures. 

Using a genome editing technique, the researchers have generated new plants that lack the HvMADS1 function, converting an unbranched barley spike into a branched structure. 

“This could ultimately result in the production of more grain per plant,” Li said. 

“This study reveals a new role of this protein family in responding to thermal change and directing the composition of flowers on a stem,” Tucker said. 

“With short to medium temperature rises predicted globally, plant scientists and breeders have an enormous challenge ahead of them to generate crop yields needed to feed growing populations in higher temperatures.” 

This work provides new avenues for crop breeding, with the potential to overcome traditional compromises between heat tolerance and high yield. 

“This collaborative research demonstrates the importance of international partnerships in delivering fundamental scientific breakthroughs, and the value of gene editing strategies in crops, which are routinely used at the Waite Research Institute at the University of Adelaide,” Tucker said.