Gene may help feed world's growing populations

Human numbers are likely to bloat to 9.5 billion by 2050, with the same amount of water, fertilizers and arable land available today. Scientists now say a new gene could quell the ever growing challenge of feeding more humans.

The gene called Scarecrow, isolated by Cornell University researchers could lead to new varieties of staple crops with 50 percent higher yields and feed growing populations. Scarecrow is the first gene discovered to control a special leaf structure, known as Kranz anatomy, which leads to more efficient photosynthesis, the journal Plant and Cell Physiology reports.

Plants photosynthesize using one of two methods: C3, a less efficient, ancient method found in most plants, including wheat and rice; and C4, a more efficient adaptation employed by grasses, maize, sorghum and sugarcane that is better suited to drought, intense sunlight, heat and low nitrogen, according to a Cornell statement. 'Researchers have been trying to find the underlying genetics of Kranz anatomy so we can engineer it into C3 crops,' said Thomas Slewinski, who co-authored the study with Robert Turgeon, professor of plant physiology, as postdoctoral researcher in Turgeon's lab. Both are at Cornell. The finding 'provides a clue as to how this whole anatomical key is regulated', said Turgeon. 'There's still a lot to be learned, but now the barn door is open and you are going to see people working on this Scarecrow pathway.' The promise of transferring C4 mechanisms into C3 plants has been fervently pursued and funded on a global scale for decades, he added.

If C4 photosynthesis is successfully transferred to C3 plants through genetic engineering, farmers could grow wheat and rice in hotter, dryer environments with less fertilizer, while possibly increasing yields by half. C3 photosynthesis originated at a time in Earth's history when the atmosphere had a high proportion of carbon dioxide. C4 plants have independently evolved from C3 plants some 60 times at different times and places.

Source: IANS