Professor John Bowman's genetic-level research with moss has reaped an unexpected harvest. Photo: Meredith O'Shea
By tinkering with the reproductive life of moss - and solving one of the fundamental questions about plant evolution - a Melbourne researcher has accidentally discovered a possible gateway to feeding an increasingly hungry world.
Monash University geneticist John Bowman - in collaboration with researchers in Japan - went in search of what the common ancestor of all land plants might look like, at a genetic level.
In solving part of that puzzle, Professor Bowman has taken a step closer to finding one of the holy grails of agriculture - a process called apomixis - in which high-yield, drought-resistant plants would clone themselves via their seeds.
''It would make new crop varieties both cheaper and more widely available,'' Professor Bowman said.
Seeds normally contain two sets of chromosomes - one from the female parent and the other from the male parent. Cloning would mean the seeds would contain chromosomes only from the mother plant - and so the resulting plant would be a genetic copy of the mother. It would be akin to producing a human baby with no sex.
If achievable, it would mean that complex hybrid agriculture, relying on buying new hybrid seeds every year, would be a thing of the past. The big winners would include Third World farmers.
''It's a breakthrough that would be highly beneficial in developing countries,'' Professor Bowman said.
He and his collaborator, Dr Keiko Sakakibara - formerly of the Monash School of Biological Sciences and now at Hiroshima University - were not setting out to save the world. In a study published in Science, they describe for the first time a particular gene that regulates the transition between stages of the life cycle in land plants.
Apart from the obvious, plants are different from animals.
In humans, each cell in the body has two sets of DNA. This is called a diploid state. The tiny single-cell sperm and eggs that we produce contain only the male or female DNA. This is called the haploid state.
''In contrast, plants have large complex bodies in both haploid and diploid generations,'' Professor Bowman said.
In the natural order, plants take on these different forms in alternating generations - in one generation they have a single set of genes (haploid), in the next they have two sets (diploid).
Professor Bowman and Dr Sakakibara upset the natural order by removing a gene, known as KNOX2, from moss.
They found this caused the diploid generation to develop as if it were a haploid. ''The equivalent mutations in humans would be if our entire bodies were transformed into either eggs or sperm,'' Professor Bowman said.
On the pure science front, the study provides insights into how land plants evolved these two complex generations, strongly supporting a theory that the original land plants had a complex body with a single set of genes - and that the diploid state later evolved.
The potential for feeding the world lies in genetic engineering - similar to that achieved in the lab by Professor Bowman - that would cause plants to skip a generation, produce seeds that are clones of the mother, and therefore keep the high-yielding traits intact.