Promising results for developing drought-tolerant crops without sacrificing yield have been released. Two studies by researchers at the Center for Advanced Bioenergy and Bioproducts Innovation (CABBI) on C4 plants (such as maize, sugarcane and sorghum) in the US have been published in the Journal of Experimental Botany.

In the first study, researchers inserted a gene into sorghum. It altered the developmental pattern of the plant and reduced the number of stomata (pores) on the leaf surface.

With fewer stomata, the amount of water lost from the sorghum plants was reduced. This improved water use efficiency and did not impact the plants’ photosynthesis performance or biomass.

The second study demonstrated that reducing the number of stomata in sugarcane plants coincided with the pores opening wider, this reduced water use efficiency. However, the discovery is considered to represent a valuable new target for engineering an even more efficient plant, according to the research team.

CABBI director Andrew Leakey, team leader on the two studies, says the findings will help maximise production of bioenergy feedstock, aid crops in mitigating the effects of inadequate water supply, and open up new avenues of plant research.

Drought-tolerant wheat field trials

A drought-tolerant, genetically modified wheat variety known as HB4, developed by Argentinean company Bioceres Crop Solutions, is moving through research, development and regulatory pipelines around the world.

Most recently, field trials of the crop have been approved in Australia, while the wheat industry in the US has welcomed the variety’s commercial release.

Field trials were approved across sites in New South Wales, Victoria, South Australia and Western Australia over the coming five years by the Office of the Gene Technology Regulator (OGTR).

These trials will allow the variety to be assessed under Australian growing conditions. Its cultivation will be limited to the trial sites, and all material will be destroyed at the end of the trial. No trial material will be used in human food or animal feed.

The field trial licence has been granted to Trigall Australia, an Australian-based plant breeding company. The company, launched in 2022, is owned by Trigall Genetics, a joint venture of Bioceres Crop Solutions, Florimond Desprez and S&W Seed Company.

Meanwhile, the US Animal and Plant Health Inspection Service of the US Department of Agriculture has recently approved Bioceres’ HB4 wheat for commercial release in the country.

Although commercial release has been granted, the industry will conduct closed-system field trials to ensure careful stewardship for the cultivation, marketing and trade of the country’s inaugural GM wheat variety.

The industry’s long-held position will ensure that the variety receives regulatory approvals in major export markets before being commercially grown.

US Wheat Associates’ past chairman and Oklahoma wheat grower Michael Peters says an innovation such as HB4 holds a lot of interest for growers.

With global demand for wheat hitting new records almost every year, there is concern about variable production. A drought-tolerant trait offers more stable, sustainable production.

This GM wheat variety was first approved for commercial use in Argentina in 2020, where it has reportedly shown significant yield increases in field trials under drought conditions.

It has also received commercial release approval in Brazil, and food and feed use approvals in several countries, including Australia.

Resources

• Genetically-modified sorghum crops lose less water when they have fewer stomata
• DIR 204 – Limited and controlled release of wheat genetically modified for increased tolerance to environmental stress
• Trigall Australia gets go-ahead for trial of GM wheat
• OGTR approves trials of GM wheat
• U.S. wheat associates statement on USDA approval of HB4 drought-tolerant wheat trait

The Agricultural Biotechnology Council of Australia is an industry initiative established to increase public awareness of, and encourage informed debate and decision-making about, gene technology. The initiative is supported by a number of agricultural sectors and organisations all working to ensure the Australian farming sector can appropriately access and adopt this technology for the benefit of Australian agriculture.