Function of the TRY C-terminal region artificially fused with its homologous transcription factors inducing root hair differentiation in Arabidopsis.

TRIPTYCHON (TRY) is one of the R3-MYB transcription factors. Its extended C-terminal 19 amino-acid region (CTRY) is considered to affect the ability of root hair differentiation in Arabidopsis. Here, to further understand the function of CTRY, it, together with GFP, was artificially fused with TRY homologs, CPC and ETC1, which do not contain such extended regions and induce root hair differentiation. Arabidopsis transgenic plants carrying the fusion proteins, CPC-CTRY-GFP and ETC1-CTRY-GFP, induced root hair differentiation as observed in those carrying the original proteins without CTRY. The expression levels of the fusion proteins in the transgenic plants were essentially the same as those of the original proteins, although their subcellular localization to nuclei of root epidermal cells was slightly changed by CTRY. Therefore, CTRY does not affect the ability of CPC and ETC1 to induce root hair differentiation when artificially fused, and its function may be restricted in TRY.