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内容記述 |
CorA-type ion channels, are known to function as major transporters mediating the membrane transport of magnesium ions (Mg2+). However, some transporters classified within this family, while exhibiting high affinity for Mg2+, are also capable of transporting other divalent cations such as nickel and zinc (Zn2+). In this study, we analyzed OsMRS2-8, a root-preferential member of CorA-type channel in rice, using genome-edited knockout lines. Elemental analysis revealed little change in Mg content but a significant increase in root Zn. Furthermore, OsMRS2-8 complemented the Zn requirement of an E. coli mutant, suggesting that this protein may participate in zinc transport in rice roots. PIXE analysis showed that the 1-week-old rice mutants had elevated Zn throughout the root, with a pronounced increase in the outer region. Meanwhile, changes in the expression of known zinc transporter genes suggested that OsMRS2-8 deficient roots sensed zinc shortage. Considering its preferential gene expression in the cortex and plasma membrane localization, it was inferred that OsMRS2-8 functions in cortical tissues to mediate the uptake of apoplastic Zn2+ into cells. |
