Biofortified indica rice attains iron and zinc nutrition dietary targets in the field

Abstract

More than two billion people are micronutrient deficient. Polished grains of popular rice varieties have concentration of approximately 2 μg g−1 iron (Fe) and 16 μg g−1 zinc (Zn). The HarvestPlus breeding programs for biofortified rice target 13 μg g−1 Fe and 28 μg g−1 Zn to reach approximately 30% of the estimated average requirement (EAR). Reports on engineering Fe content in rice have shown an increase up to 18 μg g−1 in glasshouse settings; in contrast, under field conditions, 4 μg g−1 was the highest reported concentration. Here, we report on selected transgenic events, field evaluated in two countries, showing 15 μg g−1 Fe and 45.7 μg g−1 Zn in polished grain. Rigorous selection was applied to 1,689 IR64 transgenic events for insert cleanliness and, trait and agronomic performances. Event NASFer-274 containing rice nicotianamine synthase (OsNAS2) and soybean ferritin (SferH-1) genes showed a single locus insertion without a yield penalty or altered grain quality. Endosperm Fe and Zn enrichment was visualized by X-ray fluorescence imaging. The Caco-2 cell assay indicated that Fe is bioavailable. No harmful heavy metals were detected in the grain. The trait remained stable in different genotype backgrounds.

Yield and Zn content of biofortified rice genotypes in an Indonesian rice agro-ecosystem

“…Nevertheless, it has not been utilized maximally to improve grain Zn concentration in its bioavailability (Nakandalage et al 2016). On the other hand, molecular and transgenic approaches have been used to generate high grain Zn content rice varieties.The transgene used to increase Fe and Zn content is from the Os-NAS gene family and resulted in Fe content up to 15 ppm and Zn content of 45.7 ppm in polished rice grains (Trijatmiko et al 2016).…”

“…Harvest Plus is an international program which developed initiatives to address human micronutrient malnutrition through improving the micro nutrient concentration of staple foods. This program has targeted Zn level of brown and polished rice up to 30 ppm and 28 ppm respectively (JohnsonBeebout et al 2009, Trijatmiko et al 2016.…”

“…Breeding efforts to conduct Zn biofortification for rice has been initiated at IRRI either by using conventional breeding approaches (Graham et al 1999;Gregorio et al 2000;Slamet-Leodin et al 2015) or transgenic approaches (Trijatmiko et al 2016), and efforts continue on both.Promising breeding materials have been developed and shared with collaborating countries, including Indonesia. Bangladesh and Philippines had just released Zn rice varieties for the certain countries.…”

Isolation and In Silico Analysis of Iron Regulated Transporter 2 Gene from Indian Barnyard Millet (Echinochloa frumentacea L.)

“…These studies have led to development of rice lines with enhanced iron accumulation in endosperm (15 μg/g Fe in polished rice) by over-expressing genes viz., nicotianamine synthesis 2 (OsNAS2) and soybean ferritin (Trijatmiko et al, 2016). Based on results of several experiments, it is postulated that synergistic improvement of iron mobilization in soil, uptake of Fe by roots, transport of Fe from roots to shoots and finally accumulation in grains will help in developing crop varieties with enhanced iron in grains or edible parts.…”

Transgenic Pro-Vitamin A Biofortified Crops for Improving Vitamin A Deficiency and Their Challenges

“…Recently, reported Carolight TM was indistinguishable from its near isogenic line for agronomic performance including yield [57]. Rice has made similar ( [58]. Rice thus can combine enhanced iron, zinc and pVA to complement multimicronutrients interventions [58].…”