One bad bout of weather at the wrong time can ruin a healthy crop of fruit, vegetables or grain. A cold snap when a rice crop is flowering for instance can cut the harvest by more than a quarter. If growers could control the cycle of the plant's growth and harvest time to match the environment, millions of dollars could be saved.

Dr. Liz Dennis of Australia's science agency CSIRO is hoping to do just that. With her colleagues, she has discovered a gene that controls the plant flowering, therefore delaying the harvest. After the cold of winter this gene naturally switches off to ensure that plants will flower in the spring. Dr. Dennis and her colleagues found a mutant in which this gene was naturally switched on permanently and flowering didn't occur at all. By varying the activity of this gene in a trial plant they found it was possible to control its flowering.

"The more of the gene activity there is the later a plant flowers. You can think of it as the knob on an amplifier. So you turn up the volume and the plant flowers later you turn down the volume and the plant flowers earlier."

The gene was next put into canola and again it worked, so it was decided to try and use the canola's own flowering gene. Once that worked it showed that the flowering gene was important in controlling flowering in different types of plants.

"We hope that this will extend to things like wheat which are more important to Australia and again where you might be able to match flowering time to the environment by having more or less of this gene activity."

While the technology will be used initially to match a certain climate, it's hoped that eventually a compound that switched this gene would be able to be sprayed onto plants if bad weather showed up unexpectedly.

The Flowering Switch technology could increase world crop production and be of great importance to subsistence farmers in developing countries, who are particularly at the mercy of the elements.

Jane Kahler
CSIRO Plant Industry
Black Mountain Laboratories
Clunies Ross St
Black Mountain ACT 2601
Jane.Kahler@csiro.au