Rice metal-nicotianamine transporter, OsYSL2, is required for the long-distance transport of iron and manganese

• Published in: The Plant journal : for cell and molecular biology Vol. 62; no. 3; pp. 379 - 390
• Main Authors: Ishimaru, Yasuhiro, Masuda, Hiroshi, Bashir, Khurram, Inoue, Haruhiko, Tsukamoto, Takashi, Takahashi, Michiko, Nakanishi, Hiromi, Aoki, Naohiro, Hirose, Tatsuro, Ohsugi, Ryu, Nishizawa, Naoko K
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.05.2010; Blackwell Publishing Ltd; Blackwell
• Subjects: Biological and medical sciences; Biological Transport; Cation Transport Proteins - genetics; Cation Transport Proteins - metabolism; endosperm; Endosperm - metabolism; Freshwater; Fundamental and applied biological sciences. Psychology; Iron; Iron - metabolism; manganese; Manganese - metabolism; Manganese compounds; nicotianamine; Oligonucleotide Array Sequence Analysis; Oryza - genetics; Oryza - metabolism; Oryza sativa; Plant physiology and development; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Shoots - metabolism; Promoter Regions, Genetic; Rice; RNA Interference; RNA, Plant - genetics; yellow stripe 1; Monocotyledones; Long distance; Biological transport; nicotianamine; Iron; rice; yellow stripe 1; Oryza sativa; Gramineae; Angiospermae; Spermatophyta; Endosperm; Manganese
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1111/j.1365-313x.2010.04158.x

Rice (Oryza sativa) is indispensable in the diet of most of the world's population. Thus, it is an important target in which to alter iron (Fe) uptake and homeostasis, so as to increase Fe accumulation in the grain. We previously isolated OsYSL2, a functional iron [Fe(II)]- and manganese [Mn(II)]-nicotianamine complex transporter that is expressed in phloem cells and developing seeds. We produced RNAi (OsYSL2i) and overexpression lines (OXOsYSL2) of OsYSL2. At the vegetative stage in an OsYSL2i line, the Fe and Mn concentrations were decreased in the shoots, and the Fe concentration was increased in the roots. At the reproductive stage, positron-emitting tracer imaging system analysis revealed that Fe translocation to the shoots and seeds was suppressed in OsYSL2i. The Fe and Mn concentrations were decreased in the seeds of OsYSL2i, especially in the endosperm. Moreover, the Fe concentration in OXOsYSL2 was lower in the seeds and shoots, but higher in the roots, compared with the wild type. Furthermore, when OsYSL2 expression was driven by the sucrose transporter promoter, the Fe concentration in the polished rice was up to 4.4-fold higher compared with the wild type. These results indicate that the altered expression of OsYSL2 changes the localization of Fe, and that OsYSL2 is a critical Fe-nicotianamine transporter important for Fe translocation, especially in the shoots and endosperm.