The CSIR and Pioneer Hi-Bred Inc have jointly filed two patent applications for two novel technologies that promise to enhance the efficiency of genetic transformation of plants for scientific research and plant breeding.
Dr Luke Mehlo
Exploiting our knowledge of the cell cycle, a single embryo isolated from a single grain of sorghum can give rise to hundreds of progeny
According to Dr Luke Mehlo, a senior researcher in the plant biotechnology research group at CSIR Biosciences, genetic modification in plant biotechnology research is conventionally conducted using a variety of approaches that include agrobacterium or applying a gene gun to shoot desired traits into plant cells. The latter is considered a more random process and does not reliably produce desired results of simpler integration patterns and single trait copies.
"Agrobacterium is a bacterium that is known to naturally transfer a segment of its DNA into plants for the purpose of synthesising nutrients for its survival," explains Mehlo.
Scientists noticed the wonder of this plant pathogen and found a way to exploit the bacterium for the purpose of transforming and transferring valuable genetic traits into plants as expression systems. "Scientists realised that they can replace the T-DNA, a segment of agrobacterium that is transferred to plant cells and replace it with genes of interest so that when the bacterium comes into contact with the plant, it transfers genes of interest 'thinking' it is transferring its own DNA to create nutrients for its survival. Once these genes are integrated into the plant's genome, the plant then uses its own machinery to reproduce and express in its own cells the trait genes of interest to scientists. But in order to fulfil genetic modification you have to conduct transformation and use enabling technologies," he reveals.
While working on the Africa Biofortified Sorghum (ABS) project, which aims to enhance the nutrient quality and digestibility of grain sorghum through genetic modification, Mehlo and his research partner, Dr Zhao Zuo-Yhu of Pioneer, found new methods that will provide a deeper understanding of the cell cycle as well as modifications around the use of agrobacterium. The project is driven by an international consortium of scientists.
These scientists have essentially invented a manner of recruiting somatic cells, and abundant callus, converting them into cells that can grow and give rise to multiple organs of a plant and regenerate the entire plant itself – much like stem cells in an animal or human being. The second technology enables them to use agrobacterium to transfer improved sorghum genes back into the plant by activating genetic sequences in agrobacterium that are responsible for transferring the T-DNA.
"The combined inventions are aimed at enhancing transformation efficiency so that one achieves transformation events faster, reliably and efficiently. We envisage this technology to be useful for genetic engineers and plant breeders who will on a charitable basis produce the seed for poor farmers – the sector targeted by the ABS project," says Mehlo.
The ABS project is funded by the Grand Challenges for Global Health initiative, a programme linked to the Bill and Melinda Gates Foundation. This programme supports novel research that could provide solutions to some of the major problems affecting the developing world and embraces humanitarian values.
Dr Rachel Chikwamba, principal investigator on the ABS project on behalf of the CSIR, said any technologies generated under this programme will be protected through patenting. "In order to make them available to the poor in line with the global access strategy that is approved by the Bill and Melinda Gates Foundation for completeness, and to allay fears that patenting will deprive the poor of access."
Enquiries: CSIR Communication