University of Melbourne researchers have isolated a genetic ‘switch’ that can be turned on or off to alter the development of sex cells in plants.

The discovery, which was published in the journal Science, brings understanding of fertilisation in plants to a new level, and is an important step towards growing greater amounts of food through increased fertilisation of crop plants.

Professors Mohan Singh and Prem Bhalla, who head the University’s Plant Molecular Biology and Biotechnology Laboratory in the Faculty of Land and Food Resources, analysed the genetic makeup of white lilies and other flowering plants to identify a germline-restrictive silencing factor (GRSF).

The GRSF is a protein which is present in all plants during growth and can be manipulated to effectively block the development of sex cells in plants, and can be turned on or off by the plant, depending on the stage of growth.

Plants that produce pollen causing hayfever may be able to have their sex cell development – and therefore pollen production – turned off.

“If this protein is manipulated, it can act like a brake applied to the parts of the plant turning into sperm cells, and stop fertilisation,” Professor Singh says.

Altering gene developments can also have a big impact on food production. Switching off male sex cells in some plant species will create male sterile lines, which when crossed to another species will produce hybrid plants. Hybrid plants produce 20 to 30 per cent more crop yield.

“All the plant food we eat, such as wheat or vegetables, is grown due to fertilisation, but we still know very little about how that process actually occurs,” says Professor Singh.

“This discovery is a step towards producing more food, which is important as food becomes scarcer as the population grows – soon we may need to make twice as much,” Professor Singh says.

The researchers say they tested many other flowering plants during their study, and the same GRSF protein, which can block sex cell development in male germlines, appears to exist in all plants, all the time.

Professor Singh says while the gene in a plant seed can be turned on or off completely, it can also be manipulated so plants grow faster or slower.

He says scientists should soon be able to introduce this practice widely, rather than wait for it to naturally occur.