Feature: Pushing the boundaries of crop science

Professor Marilyn Anderson’s work has led to a greatly improved understanding of how plants protect themselves from insects and disease, and in turn how various assailants circumvent these defence mechanisms.

An academic with the department of biochemistry at Melbourne’s La Trobe University, she discovered that the female sexual tissues of plants produce high concentrations of molecules which act to maintain reproductive capacity in the face of adversity in the field.

Currently, her research spans from elementary work on the structure and role of these molecules to the practical challenges of producing crops with enhanced resistance against insects and disease.

However, Anderson is perhaps best known for her work in discovering the so-called self-incompatibility gene, nucleosome assembly protein 1 (NaP1) in flora, and the subsequent mapping of its unique structure.

The protein folds in a rather unusual way, creating what looks like a bracelet with six beads, one for each of its individual proteinase inhibitors. Anderson explains that it was this understanding that led her and a handful of colleagues to form the now internationally renowned agri-biotech company Hexima, where she is currently Chief Science Officer.

NaP1 is at the core of the company’s two leading technologies: the proteinase inhibitor technology for insect control; and multiple gene expression vehicle MGEV). Anderson explains that, at the time scientists began working with proteinase inhibitors some 20 years ago, it wasn’t known that insects possess genes enabling them to get around them. “We are now trying to find different gene combinations that work with different proteinase inhibitors.”

Hexima’s MGEV essentially allows scientists to insert new proteinase inhibitor genes to replace those to which insects have developed resistance. It also allows for the delivery of anti-fungal molecules to combat disease. “The idea is to use this MGEV bracelet to deliver a whole range of different types of defences,” says Anderson.

Last year, Hexima signed a landmark deal with US agricultural giant, Du Pont, in which Hexima licensed control of its transgenic anti-fungal protein disease research to Du Pont’s Pioneer Hi-Bred International business. This saw Pioneer take a five per

cent stake in Hexima, which was granted exclusive commercialisation rights to Pioneer’s library of anti-fungal proteins.

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The companies have combined their respective libraries and Hexima is now responsible for identifying and developing anti-fungal resistance traits, while DuPont will take on later-product development and marketing of those traits in corn and soy.

They have also partnered to construct a major new glasshouse facility at Melbourne’s La Trobe University – complete with tissue culture facilities and robotics – for the purposes of growing transgenic crops and testing against fungal disease. Anderson says that she expects they will be producing around 10,000 transgenic corn plants a year ready to be shipped off to the US for pre-market testing.

Hexima also has partnerships with multinational giants Dow Chemicals and Monsanto and is looking for more. “We’re really into synergy now, as we look to find natural molecules that work naturally together,” says Anderson. “We are talking to other multinationals so as to establish a path to market.”

It is hoped that Hexima’s technology will be able to help affect significant improvements in crop efficiency, therefore reducing the amount of money and land required to produce food. In the US for instance, some 10 to 12 per cent of corn yields are lost every year with up to 25 per cent losses in the worst areas, amounting to costs of around US$8 billion a year. The implications for Hexima’s technology in the developing world are readily apparent.

Hexima has also enjoyed success working with cotton. Last year it reported that field trials yielded their third consecutive year of positive results, with the anti-fungal technology again demonstrating it reduces crop death and improves yields in the presence of a common fungal disease. Last year, the company received a Climate Ready grant from the Commonwealth Government of $1.38 million thanks to the potential of its technology to greatly increase land efficiency.

Anderson says that the company intends to soon expand its activities to include soy and other food crops provided that it gets the right results from the corn project. “We are looking to eventually apply this science to improving a range of different crops,” she said.