RESUMEN
Iron and zinc deficiencies are the most prevalent cause of global hidden hunger. Rice, being one of the most consumed crops worldwide, is suitable to target for Fe and Zn biofortification. In present study, we generated rice transgenic lines to meet the recommended dietary requirement of iron and zinc through endosperm specific expression of dicot (kidney bean) and monocot (pearl millet) Ferritins along with constitutive expression of rice nicotianamine synthase 2 (OsNAS2) gene. Visualization through perls' prussian staining and quantification by ICP-MS showed significant improvement in grain iron content in all the transgenic lines. The transgenic lines expressing any of the three selected gene combinations (PvFerrtin-OsNAS2, feedPgFerrtin-OsNAS2 and foodPgFerritin-OsNAS2), showed the potential to surpass the 30% of the estimated average requirement (13 µg/g Fe and 28 µg/g Zn) proposed for rice in HarvestPlus breeding program. Though the expression of PvFerritin along with OsNAS2 gene in IET10364 (indica) variety showed the best result, providing up to 4.2- and 3.5-fold increase in iron (30.56 µg/g) and zinc (60.1 µg/g) content, respectively; in polished grains compared to non-transgenic control. Thus, the lines developed in our study can be used for further breeding purpose to enhance the iron and zinc content in commercial rice varieties.
Asunto(s)
Oryza , Pennisetum , Phaseolus , Hierro/metabolismo , Ferritinas/genética , Ferritinas/metabolismo , Zinc/metabolismo , Phaseolus/genética , Phaseolus/metabolismo , Pennisetum/genética , Pennisetum/metabolismo , Oryza/genética , Oryza/metabolismo , Biofortificación , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , FitomejoramientoRESUMEN
ABC transporters constitute the largest family of transporter proteins in living organisms and divided into eight subfamilies, from A-H. ABCG members, specific to plants and fungi, belong to subfamily G. In this study, we provide updated inventory, detailed account of phylogeny, gene structure characteristics, and expression profiling during reproductive development, abiotic and biotic stresses of members of ABCG gene family in rice along with reannotation and cloning of FL-cDNA of OsABCG50/PDR23. We observed that of the 22 ABCGs/PDRs, four genes evolved as a result of gene duplication events and their expression pattern changed after duplication. Analysis of expression revealed seed and developmental stage preferential expression of five ABCG/PDR members. Transcript levels of eight ABCGs/PDRs were affected by abiotic and biotic stresses. Expression of seven ABCG/PDR genes was also altered by hormonal elicitors. The modulated expression is nicely correlated with the presence of tissue/stress specific cis-acting elements present in putative promoter region.