Plant genomics and the reiselust gene

In 1995 Agriculture Victoria (now Primary Industries Research Victoria - the R&D division of the Victorian Department of Primary Industries) head-hunted a bright young plant molecular geneticist from the Swiss Federal Institute of Technology (ETH) to establish the state's first dedicated plant biotechnology research institute.

German Spangenberg completed his PhD at the University of Heidelberg and the Max Planck Institute of Cell Biology in Germany. Heidelberg was then the Mecca for molecular biologists in Europe.

He then became the youngest researcher ever to be awarded a DSc and hold an associate professorship at the Institute of Plant Sciences at ETH in Zurich.

Then came a call from Australia. Spangenberg seemed destined for a stellar research career in Europe and Down Under was far way. The job was to establish and develop a new plant biotechnology research centre in Melbourne, from scratch, on a modest annual budget of approximately half a million dollars.

But the reiselust (wanderlust) gene runs in the Spangenberg family. German Spangenberg's great, great grandfather migrated to Uruguay after the Napoleonic Wars in Europe two centuries ago, and settled in the capital, Montevideo.

Spangenberg's parents, both professors in physical chemistry at the University of the Republic in Montevideo, encouraged their children's interest in science. His grandfather and grand-uncle, also professors at the university in Uruguay, pursued academic and research careers in plant genetics, plant breeding and agronomy.

As an undergraduate at the University of Uruguay, Spangenberg studied agronomy, but became fascinated with plant cell biology and plant somatic cell genetics. The university did not offer PhD studies so he headed to Germany, to the Max Planck Institute in Heidelberg to do his PhD in plant cell and molecular biology.

After earning his PhD in record time, Spangenberg spent two more highly productive years honing his research skills at the Max Planck Institute, before accepting an assistant professorship at the Institute of Plant Sciences with Professor Ingo Potrykus, (the father of the 'Golden Rice') to earn his DSc in agricultural biotechnology.

"It was the exciting beginning of plant gene technology, and I was in the right place, at the right time - with great mentors," he says.

But the challenge - and opportunity - involved in setting up a plant biotechnology R&D centre from its beginnings in Australia intrigued him, so, with two of his Zurich co-workers, he moved to Melbourne late in 1995. There, he set up research laboratories with only six other staff in plant biotechnology at Melbourne's La Trobe University.

"I like challenges, and I was attracted by the challenges and opportunities involved in establishing a plant biotechnology centre from its inception, in a stimulating academic environment, and shape it into a path of growth for a successful future," he says.

As founding director of DPI's Plant Biotechnology Centre at La Trobe and DPI's research director for plant genetics and genomics, Spangenberg now provides science leadership to around 160 staff and PhD students, and administers an annual research budget in of $20 million-plus from competitive research grants, government and industry funding sources.

He is also research director and chief scientist for the Molecular Plant Breeding Cooperative Research Centre, headquartered at La Trobe's R&D Park; chairman of the Victorian AgriBiosciences Centre; managing director (R&D) of AgGenomics Pty Ltd, Australia's first agricultural genomics company; and chief scientific officer and executive director of Phytogene Pty Ltd, DPI's first agricultural biotechnology company.

From the outset, Spangenberg wanted to work on projects that would benefit plant-based industries in his adopted state and lead to significant outcomes for the community.

Proprietary technology

Victoria is the hub of Australia's dairy industry and exports of dairy products are worth more than $2 billion annually to the state's economy.

Spangenberg saw opportunities to convert novel plant genomic discoveries into genetic solutions by establishing a portfolio of proprietary technologies that would have a dominant effect in the world's temperate pastoral agriculture over years to come.

He undertook Australia's largest plant gene discovery program - fully in-house - for key temperate pasture plants. He also established a dedicated infrastructure in plant genome and transcriptome analyses, with capabilities in plant transgenesis for pasture species and wheat that is unmatched in the southern hemisphere.

The Plant Biotechnology Centre's research has given rise to an impressive portfolio of technologies that extends across over 30 patent families.

Spangenberg says the technologies have a wide range of applications in molecular breeding of forage plants, as well as potential applications beyond the pastoral industries, such as producing highly fermentable lignocellulosic feedstocks for biofuels in dedicated bioenergy crops, or use of cereal straw for bioenergy.

Many of these proprietary technologies relate to modifying genes encoding key enzymes involved in metabolic pathways in grasses, including those that synthesise lignins and fructans.

He says modified-lignin grasses are more digestible for ruminants, while fructans - energy-rich polyfructoses - make grasses sweeter and more palatable, encouraging higher feed intake, and improving the digestibility and available energy content of each kilogram of herbage.

Pasture quality and productivity strongly influence the production and quality of milk and dairy products - something that aficionados of the incomparable cheeses of Tasmania's King Island, in Bass Strait have known intuitively. Local lore attributes island's lush, highly palatable grasses to seeds from sailors' grass-stuffed mattresses that washed ashore after shipwrecks more than a century ago.

Where King Island's bountiful pastures flourish on rich volcanic soil, in the teeth of the reliable, rain-bearing gales of the Roaring 40s, Victorian dairy farmers must cope with highly variable climates and soils. The industry is based on two highly adaptable pasture species: perennial ryegrass (Lolium perenne) and white clover (Trifolium repens).

The centre's research focuses on computational biology, plant functional genomics, plant molecular genetics and molecular plant breeding applied to improving these key temperate forage species.

Hypoallergenic pollen

Perennial ryegrass pollen contains two potent respiratory allergens, Lol p 1 and Lol p 2, and brings misery to legions of allergy sufferers across southern Australia every spring. The species is largely responsible for Victoria having one of the highest rates of asthma and hayfever in the developed world.

Spangenberg and his research team have developed the world's first perennial ryegrass with hypoallergenic pollen by silencing the Lol p 1 and Lol p 2 genes, as well as the world's first perennial ryegrass with altered lignin, by silencing genes encoding key lignin biosynthetic enzymes, for enhanced herbage digestibility.

White clover is susceptible to aphid-borne alfalfa mosaic virus (AMV) infections - Spangenberg says the virus is estimated to cause annual productivity losses of $110 million across Australia's pastoral industries.

His research team has developed the world's first GM white clover with AMV field resistance. Spangenberg says the transgenic approach was the only way of developing AMV resistant white clover cultivars, in the absence of any natural source of effective resistance in the gene pool of white clover or its sexually compatible relatives.

Spangenberg's team has also developed a proprietary technology to delay leaf senescence in pasture and crop plants.

"If we can delay leaf senescence, and thus maintain the plant's photosynthetic capacity for longer, this opens up opportunities for enhancing biomass production and increasing seed yields," he says.

"It also creates new opportunities in molecular 'pharming' applications - by gene-tacking the delayed leaf senescence technology with technologies for the production of high value products in plant's leaves, such as vaccines, antibodies and industrial enzymes.

"We're working with overseas partners to further develop and commercialise the leaf anti-senescence technology, which we've called 'LXR' for 'elixir of life', since it extends the productive life of the plant's leaves.

"We have developed LXR white clover, and have demonstrated in first field trials a doubling of seed yields. We are now exploring the application of the LXR technology in wheat and canola, to improve grain and oil yields."

Spangenberg says the new AMV resistant GM white clover has been field-evaluated in Australia since 1997 and is expected to be ready for commercialisation upon regulatory approval within the next three to five years.

GM commercialisation

But commercialisation of GM crops is on hold pending the recommendations of the current review of Victoria's moratorium on commercialisation of GM canola by the recently announced review panel chaired by eminent Victorian medical scientist Sir Gustav Nossal.

Plant biotechnology researchers in Victoria have lived with the moratorium since March 2003; although it relates specifically to herbicide-tolerant GM canola, it amounts to a de facto ban on commercialisation of any other GM crop or pasture species.

Spangenberg experienced anti-GM activism in Switzerland and Germany before coming to Australia. .As a government officer, he is reluctant to comment on the impact of the moratorium on plant biotechnology research in Victoria, but said: "We live at a time of unprecedented new discoveries, some of which are expected to transform life sciences and technology development for years to come.

"They will present unique opportunities for people to improve their lives and the environment we live. We cannot ignore these.

"It's very important that society does not become technophobic, and that community and industry find the wisdom and appropriate balance to allow powerful new technologies to flourish to the benefit of humankind, because new technologies have always been at the heart of human progress and development.

"It is critical that we harness the benefits of technological advances - while at the same time safeguarding against the possible new risks that may accompany them. This is no different for plant gene technology."

If GM white clover makes it into the farmers' fields in 2012, a hypoallergenic, high-energy GM ryegrass is likely to follow in 2013. It will be ready for commercialisation after regulatory approval.

Benefits of GMOs

A common critique of the anti-GM movement is that GMOs offer no benefits to the community, only risks. Spangenberg says that, by stacking transgenes for altered-lignin or high-fructans with hypoallergenic pollen traits in single cultivars of pasture grasses such as perennial ryegrass and tall fescue, the research centre hopes to deliver productivity gains and higher profits for the grazing industries, while also helping to reduce serious environmental and public-health problems.

The research centre also has a significant R&D program in wheat transgenesis, particularly aimed at developing drought-tolerant GM wheats and GM wheats with durable disease resistance. It has already submitted an application to the Office of the Gene Technology Regulator and has just received corresponding regulatory approval to conduct the first field trial in Australia of GM wheat expressing candidate genes for drought tolerance as a proof-of-concept research.

"Many genes are involved in transcriptional regulation and modulation of biochemical and signal transduction pathways that mediate plant responses to abiotic stresses such as drought, and we need to test how plants respond to water stress in the more relevant context of field conditions," he says.

"In season 2006/2007 season, Australia is estimated to have lost more than 60 per cent of its wheat crop and Victoria up to 76 per cent, due to severe drought conditions. That represented a $300 million loss to Victoria.

"We are also exploring candidate genes to improve the frost tolerance of cereals, arising out of our gene discovery program in Antarctic hairgrass (Deschampsia Antarctica) - the only grass that has succeeded in colonising the Antarctic Peninsula.

"Antarctic hair grass expresses a family of genes encoding novel anti-freeze proteins that inhibit ice recrystallisation in the extra-cellular space of shoot and root tissues, as a likely mechanism for freezing tolerance.

"These proteins, called ice recrystallisation inhibition proteins (IRIPs), bind tightly to the surface of ice crystals and prevent them from growing and puncturing the cells.

"We have demonstrated recrystallisation inhibition activity in leaf extracts from test plants genetically modified to express the Antarctic hair grass IRIP genes. We are now interested in testing the Antarctic hair grass IRIP genes as candidates for enhancing frost tolerance in wheat."

On average, frost is estimated to cause production losses of just under $140 million a year in Victoria and South Australia's wheat and barley crops alone, Spangenberg says.

He believes plant gene technology will be essential for adapting crops and pastures to climate variability and changing environmental conditions caused by global warming and climate change.

"With predictions that climate change will result in more frequent and prolonged drought, it is critical that we examine ways to support our agricultural industries by developing novel plant genetics for these emerging environments of water scarcity and likely also higher temperatures.

"The agricultural industries account for approximately 67 per cent of the nation's total water use, with the key component of agricultural water consumption being pasture production. It is estimated that nearly half of Australia's irrigated water is used for this purpose."

Greenhouse gas emissions

Spangenberg also sees opportunities in the application of plant gene technology for abatement of greenhouse emissions and their impact on climate change. For example, through the development of GM forages that would suppress methanogens and thus reduce methane production in the rumen, the large microbial fermentation chamber in the foregut of ruminant livestock.

A dairy cow belches around 40 litres of methane into the atmosphere every day, and the world's millions of dairy and beef cattle, sheep and deer are the largest single source of anthropogenic emissions of the methane, a potent greenhouse gas.

The centre also makes use of RNA-interference (RNAi) technology as a tool for determining the function of newly discovered genes - the phenotypic effects of targeted RNAi gene knockouts provide clues to the function of those genes.

"We use two main approaches to investigate gene function," Spangenberg says. "We can over-express genes, or use RNAi to silence them. Over-expressing a gene in a transgenic plant, also ectopically in tissues where it is normally silent, provides some clues to its normal function."

RNAi transgenes are already being used to develop virus resistant plants, and Spangenberg says there are exciting prospects that RNAi transgenes could also be used to disrupt genes crucial to the intimate plant host-fungal relationships, such as those in pasture grass-fungal endophyte associations. The centre has a research project in this field.

"In principle, many of the mechanisms involved in host-parasite or host-symbiont relations are amenable to an RNAi solution - whether the target genes are in the plant host, or in the parasite and symbiont."