An intracellular transporter OsNRAMP7 is required for distribution and accumulation of iron into rice grains

Jingjun Li; Yuanyuan Liu; Linghui Kong; Ending Xu; Yu Zou; Peijiang Zhang; Wei Zhang; Xi Chen

doi:10.1016/j.plantsci.2023.111831

An intracellular transporter OsNRAMP7 is required for distribution and accumulation of iron into rice grains

Plant Sci. 2023 Nov:336:111831. doi: 10.1016/j.plantsci.2023.111831. Epub 2023 Aug 19.

Authors

Jingjun Li¹, Yuanyuan Liu¹, Linghui Kong¹, Ending Xu¹, Yu Zou², Peijiang Zhang², Wei Zhang¹, Xi Chen³

Affiliations

¹ Department of Biochemistry & Molecular Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China.
² Rice Research Institute, Anhui Academy of Agricultural Sciences, Hefei, Anhui 230031, China.
³ Department of Biochemistry & Molecular Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China. Electronic address: xi.chen@njau.edu.cn.

PMID: 37598889
DOI: 10.1016/j.plantsci.2023.111831

Abstract

Iron (Fe) is an essential micronutrient for plant growth and human health. Plants have evolved an efficient transport system for absorbing and redistributing Fe from the soil to other organs; however, the molecular mechanisms underlying Fe loading into grains are poorly understood. Our study shows that OsNRAMP7, a member of the natural resistance-associated macrophage protein (NRAMP) family, is a rice Fe transporter that localizes to the Golgi and trans-Golgi network (TGN). OsNRAMP7 was highly expressed in leaf blade, node I, pollen, and vascular tissues of almost tissues at the rice flowering stage. OsNRAMP7 knockdown by RNA interference (RNAi) increased Fe accumulation in the flag leaf blade, but decreased the Fe concentration in node I and rice grains. In addition, the knockdown of OsNRAMP7 also reduced grain fertility, pollen viability, and grain Fe concentration in the paddy fields; OsNRAMP7 overexpression significantly promoted Fe accumulation in the grains. Thus, our results suggest that OsNRAMP7 is required for the distribution and accumulation of Fe in rice grains and its overexpression could be a novel strategy for Fe biofortification in staple food crops.

Keywords: Fe biofortification; Golgi; Grain; Natural resistance-associated macrophage protein; Rice.