Powered by plants

The humid scent of hothouse plants surrounds you the moment you step inside the

transgenic glasshouses at the University of York's Centre for Novel Agricultural Products.

Green light filters down from the glass panels high overhead. Around you, the aroma of greenhouse tomatoes mingles with spicier and more exotic smells.

The plants do not look anything much. Rows and rows of scrubby little weeds; trays full of tiny seedlings, each carefully labelled; taller plants with woody stems and large, fleshy leaves.

But between them, they hold the potential to transform our lives for the better. A cure for malaria; an alternative to petrol; a natural way of cleaning up contamination left by explosives - they are all here.

The tall plants with the woody stems are called Jatropha, says Dr Joe Ross, the centre's head of development. Potentially, they offer a high-quality source of easily-harvested biodiesel fuel, a profitable cash crop that could be grown on marginal land in developing countries and help to reduce our reliance on fossil fuels.

The rows and rows of tiny seedlings - each growing in an individual tray - are Artemisia. They look uninspiring but they could hold the secret to the most effective anti-malaria drug yet, artemisinin.

The scrubby little weeds growing everywhere? Aribadopsis. They are completely useless, Dr Ross admits - except that, because they are so easy to grow and because scientists have decoded their entire genetic sequence, they are great for trying out new ways of genetically manipulating plants.

The 70-plus researchers at the Centre for Novel Agricultural Products (CNAP for short) are world leaders at exploiting the vast potential of plants for our benefit.

Plants are like mini factories, says CNAP director Prof Dianna Bowles. They use the power of the sun to manufacture chemicals - and many of those chemicals are potentially hugely useful.

We probably have the fact that plants can't move to thank for that, says Prof Bowles. Animals, having legs, can move. If they sense danger, they can run away. If they see something they want, they can chase after it.

Plants can't do that. So, over countless millions of years, they evolved their own ways of surviving. They make chemicals.

Poisons that plants evolved to repel predators are the basis for many powerful medicines.

Other scented chemicals plants evolved to attract bees and insects to pollinate them are the basis for many of our perfumes.

We have long understood that, Prof Bowles admits. But with recent breakthroughs in cracking the genetic codes of various plants and animals (including ourselves), our ability to exploit the power of plants to convert sunlight into substances useful to us has increased immensely.

CNAP was set up at the university six years ago, Prof Bowles says, to "build on the amazing capacity of plants to use solar energy to make useful things".

It is all about getting plants to manufacture things that we want. Researchers at the award-winning centre - it recently won a Queen's Anniversary Prize for its pioneering work - have developed a variety of techniques to do this.

They are now able both to get plants to 'grow' substances for us that they wouldn't normally grow - such as, astonishingly, fish oil - and also to stimulate plants to produce bigger quantities of chemicals that they produce naturally.

Some of the techniques involve genetic modification (GM) - the insertion of a gene from one plant or species into another.

Others, however, do not, involving instead a speeded-up version of traditional plant breeding and selection processes.

CNAP deputy-director Prof Ian Chapman makes no apologies for the occasional use of GM techniques. People are frightened of what they don't understand, he says. But there is no scientific evidence to suggest GM poses any risk to us or the environment. There is, however, overwhelming evidence for the benefits it can produce - new medicines, hardier and higher-yielding crops, new methods of combating pollution.

Scientists, in fact, have an ethical duty to use their knowledge to tackle some of the problems we face today, he says.

"We are now facing problems in society that are not going to go away - problems of rapidly diminishing natural resources," he says. "We have to think in the long term, not just the short term. A lot of the work we do is aimed at delivering solutions for the long term."

Prof Bowles agrees. "Scientists increasingly have a responsibility to use their creativity to help society," she says. "This centre is all about realising the potential of the natural world to benefit society."

Some of the work that researchers at CNAP are doing is truly extraordinary. Here are just a few examples:

NON GM

An alternative to petrol

Those tall, woody-stemmed jatropha plants in CNAP's transgenic glasshouse produce a crop of seeds that look a bit like grapes two or three times a year. These can be harvested to produce a high-grade biodiesel that makes a perfectly good substitute for fossil fuels such as petrol.

The plant is particularly exciting, says Dr Joe Ross, not only because it grows on marginal land in hot climates - making it ideal for growing as a cash crop on arid or semi-desert land in poor developing countries - but also because it can live for up to 50 years, and produce several crops a year.

CNAP researchers are trying to produce a variety of the plant with a higher yield - so that each plant produces more oil and delivers more biodiesel per acre.

They are not doing that by using GM techniques, but by a speeded-up variation of traditional breeding techniques.

The plant's pollen is treated with mutagenic chemicals which modify the plant's own DNA and therefore increase its genetic diversity.

The result is to quickly produce a range of new strains of the same plant, all slightly different from each other, some producing higher yields of oil than others.

It is a fairly random hit-and-miss process, but because hundreds of plants are treated at the same time, strains producing higher yields can be developed fairly quickly. These are then selected for breeding.

CNAP researchers' work on the plant doesn't stop there.

Jatropha naturally contains a poison which makes it inedible by animals. Researchers are hoping to create a strain that does not contain this poison - so that once the oil has been extracted, the remainder of the plant can be used for animal feed: potentially hugely valuable in developing countries.

A cure for malaria

The inoffensive little plant artemisia produces a chemical, artemisinin, which has the potential to be one of the most effective anti-malaria medicines ever. The trouble is, says Dr Ross, it only produces this chemical in very small quantities. Using similar non-GM techniques to those being used with jatropha to increase oil yields, CNAP researchers are trying to develop strains of the plant that produce much higher quantities of the chemical.

It could potentially have enormous benefits for the health of those living in poor malarial countries - especially children. An estimated 500 million doses of anti-malaria medicine are needed around the world every year, Prof Bowles points out.

GM

Growing 'fish oil'

The health benefits of the fatty acids found in fish oil are well documented - they can help reduce the risk of heart disease and type II diabetes for a start.

The trouble is, over-fishing is reducing fish stocks and causing enormous damage to the marine environment. At the same time diet-related diseases in the West are reaching near epidemic proportions.

The interesting thing about fish oil, says Prof Graham, is that it isn't produced by the fish themselves. They get it by eating marine algae - tiny aquatic plants - that do produce the oil.

CNAP researchers have identified the genes in marine algae which produce this oil and, with the help of European funding, have joined an international consortium of researchers looking at ways of introducing this gene into genetically-modified oil crops such as linseed or oilseed rape.

"The idea is that we could grow these naturally-beneficial fatty acids in oil crops," says Prof Graham. "This oil would then be as good for you as fish oil."

And we wouldn't have to wipe out fish populations to get it.

Pollution-busting plants

CNAP researchers have played a key role in developing strains of trees that act as natural pollution-busters.

A team led by CNAP's Prof Neil Bruce identified a tiny bacterium that thrives in land contaminated by explosives - such as military installations and training grounds. The bacterium breaks down the highly toxic explosive contaminant by feeding off the nitrogen in it: acting as a natural pollution-buster.

Now, using GM technology, the York team has been able to introduce the bacterium's pollution-busting ability into trees. These, Prof Bruce says, effectively act as big pollution pumps, sucking contaminated water out of the polluted land and breaking down the pollutant.

"It is a sustainable, low-maintenance and low-cost process which has the potential to clean up large areas of land in military training ranges or industrial sites," says Prof Bruce.

Updated: 09:18 Wednesday, March 01, 2006