The iron-regulated transporter 1 plays an essential role in uptake, translocation and grain-loading of manganese, but not iron, in barley

TY - JOUR

T1 - The iron-regulated transporter 1 plays an essential role in uptake, translocation and grain-loading of manganese, but not iron, in barley

AU - Long, Lizhi

AU - Persson, Daniel Olof

AU - Duan, Fengying

AU - Jørgensen, Kirsten

AU - Yuan, Lixing

AU - Schjørring, Jan Kofod

AU - Pedas, Pai Rosager

N1 - © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

PY - 2018/3

Y1 - 2018/3

N2 - Transporters involved in manganese (Mn) uptake and intracellular Mn homeostasis in Arabidopsis and rice are well characterized, while much less is known for barley, which is particularly prone to Mn deficiency. In this study we have investigated the role of the iron-regulated transporter 1 (IRT1) for Mn uptake and translocation in barley plants. We employed an RNAi approach to reduce HvIRT1 expression to 5% of the wild-type level. This enabled characterization of the functional role of HvIRT1 by use of advanced imaging and phenotyping techniques applied to plants growing in hydroponics or soils with different Mn availability. Our results highlight the importance of HvIRT1 for the transport of Mn across the root endodermis into the stele. In the hvirt1-RNAi lines, a chlorotic phenotype with reduced shoot Mn concentration and impaired photosynthetic functionality was observed, especially under conditions with low Mn availability. We also document that HvIRT1 controlled the Mn distribution within the barley grain. Surprisingly, unlike other IRT1 orthologues, HvIRT1 played no significant role in iron uptake. We conclude that the barley IRT1 orthologue has a novel function with respect to ensuring sufficient shoot Mn concentrations. The preference of IRT1 for Mn instead of Fe is discussed in an evolutionary context.

AB - Transporters involved in manganese (Mn) uptake and intracellular Mn homeostasis in Arabidopsis and rice are well characterized, while much less is known for barley, which is particularly prone to Mn deficiency. In this study we have investigated the role of the iron-regulated transporter 1 (IRT1) for Mn uptake and translocation in barley plants. We employed an RNAi approach to reduce HvIRT1 expression to 5% of the wild-type level. This enabled characterization of the functional role of HvIRT1 by use of advanced imaging and phenotyping techniques applied to plants growing in hydroponics or soils with different Mn availability. Our results highlight the importance of HvIRT1 for the transport of Mn across the root endodermis into the stele. In the hvirt1-RNAi lines, a chlorotic phenotype with reduced shoot Mn concentration and impaired photosynthetic functionality was observed, especially under conditions with low Mn availability. We also document that HvIRT1 controlled the Mn distribution within the barley grain. Surprisingly, unlike other IRT1 orthologues, HvIRT1 played no significant role in iron uptake. We conclude that the barley IRT1 orthologue has a novel function with respect to ensuring sufficient shoot Mn concentrations. The preference of IRT1 for Mn instead of Fe is discussed in an evolutionary context.

U2 - 10.1111/nph.14930

DO - 10.1111/nph.14930

M3 - Journal article

C2 - 29206303

SN - 0028-646X

VL - 217

SP - 1640

EP - 1653

JO - New Phytologist

JF - New Phytologist

IS - 4

ER -