Scientists have pinpointed a gene that enables rice plants to produce around 20% 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.
Close-up of roots that can power increased grain production by taking up more phosphorus thanks to the PSTOL1 gene discovery.
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.
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.
"We have now hit the jackpot and found PSTOL1, the major gene responsible for improved phosphorus uptake and understand how it works..
Dr. Sigrid Heuer and the team of researchers involved in the PSTOL1 discovery.
According to Dr. Wricha Tyagi at the School of Crop Improvement at the Central Agricultural University in the Indian state of Meghalaya knowledge of the exact gene will be critical for future breeding programs suited to Eastern and North-Eastern – parts of India where rice productivity is less than 40% of the national average due to acidic soil and poor availability of phosphorus.
The discovery of the PSTOL1 gene means that rice breeders will be able to breed new rice varieties faster and more easily, and with 100% certainty their new rice will have the gene.
"In field tests in Indonesia and the Philippines, rice with the PSTOL1 gene produced about 20% more grain than rice without the gene.
The two rice plant rows on the left are bigger and growing much better – they have the PSTOL1 gene.
The group of rice (the aus-type) that Kasalath is part of is also the source of the submergence tolerance gene, which IRRI has used to breed submergence-tolerant (Sub1) rice varieties that are being widely adopted across Asia.
New rice varieties with the enhanced capacity to take up phosphorus may be available within a few years to farmers.