Molecular breeding of Osfer2 gene to increase iron nutrition in rice grain

Abstract

Rice being a staple food, contains little iron in the edible grain. To increase the iron nutrition in rice grains, our present study highlights the first time development of high iron rice grain by exploring the endosperm specific overexpression of endogenous ferritin gene. The gene has been cloned from rice and overexpressed under the control of endosperm specific GlutelinA2 (OsGluA2) promoter. After genetic transformation of aromatic indica rice cultivar, Pusa-sugandhi II, the milled seeds of resulting T₃ transgenics exhibited 7.8-fold of ferritin overexpression, which contributed to 2.09- and 1.37-fold of iron and zinc accumulation respectively. T₃ seeds demonstrated endosperm specific localization of iron that confirms the tissue specific activity of GluA2 promoter. Transgenic and non-transgenic plants showed no difference in their agronomic traits. Our study suggested that overexpression of rice endogenous ferritin gene is a step ahead toward cisgenic approach and can act as an effective tool for iron biofortification.