Underground solution to starving rice plants

Scientists have pinpointed a gene that enables rice plants to produce around 20 percent more grain by increasing uptake of phosphorus, an important, but limited, plant nutrient.

The discovery unlocks the potential to improve the food security of rice farmers with the lowest value phosphorus-deficient land, allowing them to grow more rice to add to global production, and earn more.

The gene – called PSTOL1, which stands for phosphorus starvation tolerance – helps rice grow a larger, better root system and thereby access more phosphorus. Farmers can apply phosphorus fertilizers to increase productivity but, on problem soils, phosphorus is often locked in the soil and unavailable to plants.

Also, phosphorus fertilizer is often unaffordable to poor farmers. Adding to the problem is that phosphorus is a non-renewable natural resource and rock phosphate reserves – the source of most phosphorus fertilizers – are running out.

“For many years, we have searched for genes that improve phosphorus uptake,” said Dr. Sigrid Heuer, senior scientist at the International Rice Research Institute (IRRI) and leader of the team that published the discovery in Nature.

“We’ve known for a long time that the traditional rice variety Kasalath from India has a set of genes that helps rice grow well in soils low in phosphorus,” she added.

Kasalath’s superior performance under phosphorus deficiency was initially discovered by Dr. Matthias Wissuwa from the Japan International Research Center for Agricultural Sciences. He then started collaborating with IRRI and shared the DNA information of Kasalath. The current research was supported and facilitated by the CGIAR Generation Challenge Program.

“We have now hit the jackpot and found PSTOL1, the major gene responsible for improved phosphorus uptake and understand how it works,” Heuer said.

Source: International Rice Research Institute