What's happening at IRRI
Thursday, April 21, 2016, 01:15pm - 02:15pm
A pathway from basic science to a GM rice product and edited (non GM?) rice for a healthier rural community
Inez Hortense Slamet-Loedin
Genetics and Biotechnology
Collaborative research between IRRI rice transformation specialists, molecular biologists and breeders have successfully identified candidate genes for tolerance to drought, phosphorus-deficiency, anaerobic germination condition and higher yield under low fertilizer regime. Knowledge on these has been used to develop gene-based markers for breeding purposes. A challenging question for IRRI now is whether we will aim for another genetically modified (GM) product aside from Golden Rice and C4 rice.
Over two billion people are deficient in iron (Fe) and zinc (Zn). Polished grains of popular rice varieties have low micronutrient concentration. Improving iron and zinc content in rice is a potential approach to alleviate Fe and Zn deficiency, complementing other approaches. The HarvestPlus breeding programs for biofortified rice are targeting 13 µg g-1 Fe and 28 µg g-1 Zn in milled rice to reach approximately 30% of the estimated average requirement (EAR).
In response to this, IRRI and CIAT have investigated more than 16,000 rice accessions and found a limited variation for Fe in milled rice. Therefore, Fe biofortification was selected as the next GM trait to be developed. There have been a number of reports on different approaches in engineering Fe content in rice since the first pioneer work of Goto et al (1999), but the lack of translational science studies hindered the product development of Fe biofortified rice.
Here, in IRRI, we have successfully developed transgenic events, field evaluated in two countries, that show 15 μg g-1 Fe and 45.7 μg g-1 Zn in polished grain. The in-vitro cell assay indicated that Fe is bioavailable. Our findings proved that Fe and Zn biofortification targets could be achieved under field conditions without yield penalty. We have also developed back-up events through random integration, cisgenesis, and genome editing.
Havener Auditorium, International Rice Research Institute, Los Baños, 4030 Laguna, Philippines