Arabidopsis thaliana. Photo: US National Science Foundation.
Did you know? ... Gene for drought resistance found
An international group of plant scientists led by Dr Gonzalo Estavillo and Professor Barry Pogson at the Australian National University have discovered a natural genetic mutation in plants that may make it possible to breed drought-resistant crops. The mutation, in a gene called SAL1, enabled plants to survive 50% longer without water than plants with the normal version of SAL1. Plants carrying the mutation produced higher amounts of various substances that protect plants against stress.
The team found SAL1 in a plant called Arabidopsis, which is the “fruit fly” of plant science. Many genes first found in Arabidopsis have later been found in other plant species, and SAL1 occurs in other important plant species, including wheat and rice. Therefore it should have the same function there too. It is now a matter of screening plants to find mutations with the same effect.
The discovery has important implications for Australia. Current climate models predict that southern Australia will become much drier over the next 50 years, so any innovation that sustains food supply or makes the water go further is critical. The Grains Research Development Corporation is funding Dr Estavillo and Professor Pogson to identify variants of SAL1 in wheat.
The discovery of natural mutants in wheat or rice will simplify the breeding process, avoiding the need for genetic engineering, which is both costly and controversial. Simple crossing of plants with the mutation with elite cultivars will allow the mutation to be introduced in as little as 3 years.
Breeding hardier cultivars could mean the difference between some harvest and no harvest in years of moderate drought, and reduce the need to draw water from the nation’s drying rivers.
Further reading
Industry Search. 2009. Mutant gene offers hope of new drought resistant crops. Press release.
Drought tolerant plant gene discovered. 2 Nov 2009. Media Release, ANU College of Medicine Biology and Environment.
Wilson PB, Estavillo GM et al. 2009. The nucleotidase/phosphatase SAL1 is a negative regulator of drought tolerance in Arabidopsis. Plant J. 58(2): 299–317.