Altering Flowing Times in Food Crops
PM's Science Prize - Liz Dennis and Jim Peacock
Rosemary Sutton
In the last issue of the WISENET Journal we noted that the inaugural Prime Minister's Prize for Science, for Australian scientists who promote human welfare through an outstanding achievement in science or technology, was awarded to Dr Liz Dennis and Dr Jim Peacock. Research by these two scientists from CSIRO Plant Industry has the potential to boost world grain harvests and enhance the nutritional value of grains eaten by many of the world's poorest people.
Dr Peacock and Dr Dennis were recognised for their work in plant molecular biology, primarily the discovery of the Flowering Switch Gene, a key gene in determining when plants end their vegetative growth phase and start flowering.
This discovery has direct implications for improving the performance of food crops. Adverse weather conditions when crops are in flower cost farmers in Australia and worldwide heavy losses each year. If Australia’s $700 million rice crop experiences a cold snap around the time it is flowering, the harvest can be cut by 25 per cent or more. Hot temperatures when wheat is flowering can reduce yield equally significantly. These are big losses for our growers, but when crops in the Third World are similarly affected, the impact can be devastating.
By manipulating the Flowering Switch Gene, it should be possible to produce
strains of canola, wheat and other crops that flower at the right time for the
climate in which they're grown, so reducing the risk of yield losses.
The Science
The discovery of the gene was the fruit of a 20 year collaboration between Dr Dennis and Dr Peacock. One of the great mysteries in plant biology had long been what causes plants to flower when they're subjected to a period of low temperature — a process called vernalisation. Their hypothesis that there was a gene that switched on flowering after a period of cold under epigenetic control was proved using the experimental plant, Arabidopsis. By reducing the level of chemical change (methylation) in the plant's DNA, they found they could minimise the need for cold before the plant would flower.
They explored the idea further with a strain of Arabidopsis that flowered very late. A normal Arabidopsis flowers after about thirty days. This strain hadn't flowered in 150 days. The team then isolated the gene that causes the late flowering mutation. In a normal plant the gene represses flowering until the plant undergoes a period of cold. Come the cold, the gene switches off and the plant flowers. By knocking out the flowering repression gene in the odd strain of Arabidopsis, they caused the plant to flower. Thus this gene is clearly critical in flowering control and the research provided a molecular understanding of the flowering process.
The next move was to show the same gene controlled flowering in canola, and current research aims isolate the same gene in wheat.
Application of this Science
Photo courtesy CSIRO Plant Industry.
If the team succeeds, wheat growers will eventually be able to select a wheat that heads at just the right time to suit their local climate. It will take about six years before wheat crops with modified Flowering Switch Genes are available to farmers. However that timeframe may be influenced by public acceptance, if the seed is genetically modified.
Liz Dennis estimates that if seed wheat developed using the Flowering Switch Gene was planted extensively, it could improve the value of Australia¹s $4 billion wheat harvest by up to ten per cent and if Flowering Switch technology, with other genes, were taken up world-wide, it would add billions of tonnes to world crop output.
Jim Peacock believes Flowering Switch technology can make an important difference to the lives of subsistence farmers in developing countries, who are even more at the mercy of the elements than western farmers. CSIRO owns the patents to their research, so that it can benefit Australia, and also be made it available to developing nations.
For further information:
Jane Kahler
Communication Manager
CSIRO Plant Industry
GPO Box 1600
Canberra ACT 2601
Phone: 02 6246 5077
Fax: 02 6246 5299
Email: Jane.Kahler@pi.csiro.au
This is an edited version of a CSIRO press release.