A gene that causes jellyfish to glow in the dark is lighting the way for scientists who are working to develop better sugar for consumers and export customers of Australia's $1.8 billion sugar industry.
While the jellyfish gene itself will not be used in any farm crops used to make sugar, it is proving an invaluable tool for researchers at CSIRO Tropical Agriculture who want to find out if desirable genes inserted into sugarcane plants are working properly - or if undesirable genes have been switched off.
"It's a marker gene, and a particularly good one because it can be easily switched on - and you can see it working at once. It can help us identify the best way to transfer a new gene into a particular plant, determine which are the best switches to turn it on, and whether it is working as it should," explains Dr Adrian Elliott, a member of a small team led by Dr. Christopher Grof that aims to understand sucrose metabolism.
The jellyfish gene has other advantages - it is extremely quick to use compared with other gene markers, and enables scientists to check more samples for the best results at a far lower cost. The jellyfish gene is also a trailblazer, opening the way for the use of genes that will add value and quality to Australia's sugar production or help reduce its environmental impact through genes that confer resistance to pests and diseases.
While the gene is being trialled as a marker for genetic improvement of sugarcane, it may also prove useful in research by CSIRO Tropical Agriculture to improve other crops such as sunflowers, barley and mung beans.
The glow-in-the-dark substance is called green fluorescent protein (GFP) and is made by a naturally-occurring gene in jellyfish called gfp, Dr Elliott explains. Why jellyfish glow in the dark is not certain - but some biologists believe they emit a flash of fluorescent light as a defensive measure to deter predators.
"The gene was discovered overseas and optimised by US and British researchers for use in higher cellular organisms. We've been able to adapt it for use in sugarcane and other crops," Dr Elliott says.
"It is a lot more versatile, quicker and cheaper to use than other kinds of marker genes, and is particularly effective where genes are being transferred using the microbe Agrobacterium. It is also non-toxic."
All the researchers have to do to see if the jellyfish gene is working is shine a blue or ultraviolet light on plant cells containing it and watch through a microscope equipped with a special filter to see if they glow. This takes about 10 seconds, compared with other methods that can take a couple of days and involve very expensive equipment.
"The gfp gene is strictly a scientific tool. You wouldn't include it in any crop for human consumption, simply because there is no need to. Even if it was, sugar is a pure refined product and we would not eat the protein or gene, which is disposed of with the sugarcane plant during refining. But it is a big help in ensuring the genes we do want in our crops are there and working as they should."
GFP is proving to be a very useful tool for sugarcane improvement in general. It is being applied to other aspects of sugarcane research aiming to improve sucrose yield and quality.
Aspects of this research are being supported by the Sugar Research and Development Corporation.
CSIRO Tropical Agriculture has a large number of scientists working to improve tropical crops. Within the sugarcane improvement group led by Dr John Manners, a broad spectrum of disciplines are covered from plant physiology and biochemistry to field crop technologies.