Dr. Magdy Mahfouz, a Postdoctoral researcher in the Plant Stress Genomics Research Center (PSGRC) at KAUST has developed a technology for targeted genome modification in crop plants. The results of his original thinking and novel approach have been published in recent issue of the prestigious journal, 'Proceedings of the National Academy of Sciences of the United States of America.' (Jan 24, 2011).

In 2009, while assisting the set up and awaiting the completion of the PSGRC, which is directed by Professor Jian-Kang Zhu, Dr. Mahfouz decided to conduct a broad and comprehensive literature search on genome engineering. He discovered extensive materials.

As the world population increases and resources become more limited, this technology holds significant potential for improving the quality and yield of current crop varieties. An initial basic conclusion was that genetic engineering in plants has suffered from two major drawbacks, which are:

• novel genes are inserted at random locations in the genome;
• other forms of modification have relied on chemical or radiation induced mutations that are also random and laborious to exploit.

Therefore, inserting a new gene in the wrong place could make it ineffective or could disrupt an endogenous functional gene. In recent years, a bio-engineering technology based on enzymes called 'zinc finger nucleases' has been used to manipulate the genomes of many organisms, but the process is labor-intensive and has had limited efficiency and success.

Dr. Mahfouz assimilated all of this material prior to the completion of PSGRC. So, when the Reseach Center's molecular biology laboratory was fully operational in March 2010, he knew exactly what his first experiments would involve.

He devised a molecular "repair tool" in the form of an engineered protein that makes a complete cut in the DNA double helix of an organism's genome. The molecular scissors module of the protein is combined with an address seeking module (like a ZIP code) that, with pinpoint accuracy, takes the whole protein to the region or address of the genome. The address-seeking module can be engineered to recognize any sequence in the DNA. For specificity reasons this address has to be at least 12 base pairs and can be as long as 34 base pairs. The genome break created by the bi-modular protein can permit the addition, deletion or editing of genes with extreme specificity and precision.

To demonstrate the activity of the protein and the generation of the DNA break, Dr. Mahfouz analyzed the sequencing data of many reactions performed in the KAUST genomics core labs by Dr. Kumaresan Rathinam and Mr. Dinesh Reddy. Early tests of the engineered protein employed a special type of tobacco plant, nicotiana benthamiana, because this species is exceptionally easy to grow and genetically modify. Transient gene expression assays in tobacco leaves confirmed that Dr. Mahfouz's protein has achieved its intended function of genome engineering. Using this new technology, novel genes can be identified, crop trait development can be accelerated, and the range of possible traits can be expanded.

The implications for agricultural science are profound. The novel DNA-modifying protein will greatly facilitate "trait-stacking", which is the placement of more than one beneficial gene into a genome. In this case, multiple genes can be placed at one or more precise genomic addresses.

Historically, the process of genetically engineering plants has randomly introduced molecular artifacts into the genome including antibiotic resistant genes arising from the DNA of bacteria that are used as vectors to insert the genes of interest.

Although evidence is overwhelming that these extraneous DNA fragments are completely benign to humans and the environment, this foreign DNA is a major basis for opposition to genetically engineered (or, more popularly, genetically modified GM) plants by some environmental groups. Political pressure in many countries has imposed strict regulatory hurdles for commercialization of GM crops, based on the method of their development rather than the scientific assessment of actual risk from a particular modification. Such regulations add greatly to the expense and the years required for deploying GM crops in the field.

Dr. Mahfouz's novel approach can bypass concerns about foreign DNA and random integration and, potentially, disrupt the current paradigm of GM crop regulation. This is significant in Saudi Arabia and many other countries where laws do not yet allow GM crop production. Regions where water quantity and quality are limiting, such as the Middle East, could benefit by growing crops engineered for stress tolerance, which could feed burgeoning local populations and be exported to GM-restrictive markets.

While Dr. Mahfouz's work is aimed at agricultural improvement, it may have potential for much broader applications including human health. Gene therapy has long held the promise of freedom from diseases that devastate the lives of the afflicted and those who care for them. Human genetic disorders arise from mutated or deleterious genes that are non- functional or that encode defective proteins. Gene therapy involves molecular surgery on the "instruc- tion manual of life" by substituting "good" genes for bad, or by simply excising or silencing the defective genes that cause the disease. Dr. Mahfouz's new tech- nology could enhance this approach significantly.

Commenting on the research, KAUST Provost Stefan Catsicas saw the technology as a scientific breakthrough and, if a patent is eventually successful, having potentially promising revenues.

Distinguished Visiting Professor Dr. Nina Fedoroff, Professor of the Life Sciences at Penn State University, said;

"The Mahfouz paper shows the practicability of creating DNA-cutting enzymes tailored to cut a desired target sequence with very high specificity. This is an excellent step forward toward creating very specific genetic improvements in crop plants, while avoiding the potential risks many are concerned about with more conventional genetic modification strategies. Moreover, the paper gives the first evidence that this particular strategy will work in plants."

Professor Federoff further added that she is "delighted to see such cutting-edge contributions emerging from a university as young as KAUST."

Dr. Bengt Nordén, Professor of Physical Chemistry at Chalmers University of Technology in Sweden, former Chair of the Nobel Committee for Chemistry and the opening keynote lecturer at the recent Winter Enrichment Program at KAUST commented:

"It is very pleasing to see that KAUST has now produced a breakthrough contribution in the field of life science. The work by Mahfouz has great impact and connects with early discoveries by Nobel Laureate Sir Aaron Klug that DNA recognizing zinc finger proteins con- nected with a nuclease function may be exploited to create, highly selectively, double-strand breaks in DNA which initiate recombination-catalyzed insertion of an oligonucleotide sequence with surprisingly high efficiency. The possibility to take this DNA manipulation into clinic for gene correction therapy is thus no longer science fiction."