Abstract
In previous study, we reported that expression of NIP5;1, one of NIP family, is strongly induced by boron (B) deficiency in roots and transports B (Takano et, al). NIP6;1 is the most similar gene to NIP5;1 in all nine members of the Arabidopsis NIP family. It is possible that NIP6;1 is also involved in B transport. To verify this hypothesis, we studied Arabidopsis NIP6;1. Transcript accumulation of NIP6;1 was induced by B deficiency, especially in rosette leaves. Expansion of rosette leaves was inhibited only under B deficiency in Arabidopsis T-DNA insertion lines, but not in the wild type. NIP6;1 localized to the plasma membrane and expressed in nodes and vascular bundles of immature young leaves. NIP6;1 facilitated boric acid transport in Xenopus laevis oocytes. Taken together, NIP6;1 is important for B transport in Arabidopsis under low B condition and has distinct roles from NIP5;1.
