AsianScientist (Mar. 26, 2012) – A team of Australian scientists has bred salt tolerance into a variety of durum wheat, resulting in improved grain yield by 25 percent on salty soils.
In the article, published recently in Nature Biotechnology, the team used non-genetically modified (GM) crop breeding techniques to introduce a salt-tolerant gene into commercial durum wheat.
“This work is significant as salinity already affects over 20 percent of the world’s agricultural soils, and salinity poses an increasing threat to food production due to climate change,” said lead author Dr. Rana Munns, a CSIRO Plant Industry scientist.
Domestication and breeding has narrowed the gene pool of modern wheat, leaving it susceptible to environmental stress. Durum wheat, used for making such food products as pasta and couscous, is particularly susceptible to soil salinity.
Drawing upon the wild relatives of modern-day wheat (Triticum monococcum), the researchers discovered the TmHKT1;5-A gene, which works by excluding sodium from the leaves.
They then used a ‘non-GM’ breeding process to introduce the salt-tolerance gene into the wheat plants, which means that the plants are not classified as transgenic, or ‘GM’, and can therefore be planted without restriction.
“Salty soils are a major problem because if sodium starts to build up in the leaves it will affect important processes such as photosynthesis, which is critical to the plant’s success,” said senior author Dr. Matthew Gilliham.
“The salt-tolerant gene (known as TmHKT1;5-A) works by excluding sodium from the leaves. It produces a protein that removes the sodium from the cells lining the xylem, which are the ‘pipes’ plants use to move water from their roots to their leaves,” he explained.
Field trials were conducted at a variety of sites across Australia, including a commercial farm in northern New South Wales. Not only was there no yield penalty with this gene, crop yields were increased by up to 25 percent.
The researchers have also crossed the salt-tolerance gene into bread wheat, and are currently testing it under field conditions.
The article can be found at: Munns R et al. (2012) Wheat grain yield on saline soils is improved by an ancestral Na+ transporter gene.
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Source: University of Adelaide.
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