A genetic hack to make photosynthesis more efficient could be a boon to agricultural production, at least for some plants.
This power of genetic engineering simplifies a complex, energy-intensive operation that many plants need to perform during photosynthesis photorespiration. In field trials, genetically modified tobacco increased plant growth by over 40 percent. If this leads to similar results in other crops, farmers could help meet the nutritional needs of a growing world population, researchers in Science report on January 4 .
Streamlining photorespiration is "a big step forward in improving photosynthesis," says Spencer Whitney, a plant biochemist at the Australian National University in Canberra who is not involved in the work.
Well, there While the agricultural industry has largely optimized the use of crop-raising agents such as pesticides, fertilizers and irrigation, researchers are seeking to improve and improve plant growth through micromanagement by finding ways to make photosynthesis more efficient ( SN: 24.1
Photorespiration is an important obstacle to achieving such efficiency, occurring in many crops such as soybeans, rice, and wheat, when an enzyme called Rubisco – whose main task is Converting carbon dioxide from the atmosphere to sugar that promotes plant growth – accidentally an oxygen molecule a us the atmosphere hijacked.
This rubisco-oxygen interaction, which occurs about 20 percent of the time, produces the toxic compound glycolate, which a plant must revert to useful molecules by photorespiration. This process involves a long chain of chemical reactions spanning four compartments in a plant cell. All in all, going through a cycle of photorespiration is like driving from Maine via Florida to Florida. This waste of energy can reduce crop yields by 20 to 50 percent depending on plant species and environmental conditions.
Using genetic engineering, researchers have now devised a more direct chemical pathway for photorespiration, confined to a single cell compartment – the cellular equivalent of a Maine-to-Florida cruise along the east coast.
Paul South, a molecular biologist at the US Department of Agriculture in Urbana, Illinois, and his colleagues embedded genetic directions for this acronym, written in pieces of algae and pumpkin DNA in tobacco plant cells. The researchers also genetically engineered the cells so as not to generate a chemical that allows glycolate to travel between cell compartments to prevent the glycolate from passing its normal path through the cell.
Contrary to previous experiments with man-made photorespiration pathways, the South team tested its photorespiration pathway in crops grown in fields under real agricultural conditions, producing 41 percent more GMO Biomass as a tobacco that has not been modified.
"It's very exciting" to see how well this genetic modification has worked in tobacco, says Veronica Maurino, a plant physiologist at Heinrich Heine University in Dusseldorf, Germany, who does not the research is involved, but "you" I can not say, "It works. Now it will work everywhere. "
Experiments with different plant types show whether this fix for photorespiration creates the same benefits for other crops as for tobacco The South team is currently conducting greenhouse experiments with potatoes with the new genetic modifications and is planning similar ones Tests with soybeans, peas with black eyes and rice.
The vetting process for such genetic modifications is to be approved for commercial use. Farms, including further field trials, will probably take at least another five to ten years, says Andreas Weber, a plant biochemist, also at Heinrich Heine University in Düsseldorf, who wrote a commentary on the study, in the same issue of Science .In the meantime, he expects researchers to continue trying to find even more efficient links for the phot orespiration, but the team from South "has now set a pretty high pace."