New gene found in crops could help avoid drought stress

A NEW gene in barley and wheat that controls the angle of root growth in soil was recently discovered by researchers.

The discovery opens the door to new cereal varieties with deeper roots that are less susceptible to drought and nutrient stress, mitigating the effects of climate change.

“The angle at which barley roots grow down into the soil enables them to capture water and nutrients from different soil layers,” said joint first author on the study Dr Haoyu (Mia) Lou, from the University of Adelaide’s School of Agriculture, Food and Wine.

“Shallow roots enable plants to capture phosphate and surface water, while deeper, straighter roots can stabilise yield by accessing deeper water and nitrate; they can also bury carbon deeper in the soil.”

Researchers at the University of Adelaide worked alongside scientists from the UK, Italy, Germany and the USA to identify the new gene called Enhanced Gravitropism 1 (EGT1) in barley.

“Remarkably, the roots behave as if they are overly sensitive to gravity – they are unable to grow outwards from the plant, and instead grow straight down,” Dr Haoyu said.

Australian farmers face a wide range of risks, but the particular exposure to variability in climate has a flow-on effect to commodity prices.

Severe droughts are frequent and prolonged, particularly in the eastern and south-eastern parts of the country.

Coupled with the rising fertiliser costs and increased pressure to achieve sustainability across the country, there is a pressing need to develop new crop varieties able to capture nutrients, carbon and water better.

“These findings were made possible through exciting technologies such as X-ray CT, enabling root growth to be traced in soil,” said co-author and deputy director of the Waite Research Institute, Associate Professor Matthew Tucker.

“They could immediately help cereal breeders to select varieties with straighter roots from their genetic stocks, or aid in the development and deployment of new EGT1 alleles in the near future.”

Dr Lou undertook the research as part of a joint PhD program with the University of Nottingham, UK. The team’s findings have been published in the journal Proceedings of the National Academy of Sciences (PNAS).