Tominaga-Wada Rumi, Wada Takuji
Graduate School of Biosphere Sciences, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, 739-8528, Japan.
Graduate School of Biosphere Sciences, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, 739-8528, Japan.
J Plant Physiol. 2016 Jul 20;199:111-115. doi: 10.1016/j.jplph.2016.05.014. Epub 2016 May 27.
Cell fate determination is a critical step of plant morphogenesis. Root hair and trichome formation is a good model for studying cell fate determination. The gene CAPRICE (CPC) encodes an R3 type MYB transcription factor, promotes root hair formation, and inhibits trichome formation in Arabidopsis thaliana. The CPC homologous gene CPC LIKE MYB3 (CPL3) encoded 66% similar amino acid sequence to CPC, and it also possessed a cell-to-cell movement WxM motif. CPC protein moves from non-hair cells to neighboring root hair forming cells and induces root hair formation in Arabidopsis root epidermal cells. In this study, to investigate the function and cell-to-cell movement ability of CPL3, we generated CPC:CPL3:GFP transgenic plants to compare against CPL3:CPL3:GFP transgenic plants. CPC:CPL3:GFP transgenic plants showed no-trichome and many root-hair phenotypes, confirming similar function of CPL3 to CPC in root hair and trichome cell fate determination. However, CPL3:GFP fusion protein localized exclusively in non-hair cells in CPC:CPL3:GFP transgenic plants. Collectively, our results suggest that the CPL3 protein does not have cell-to-cell movement ability. Our findings indicate that the CPC family includes a movement protein and a protein that does not move. We believe our results provide new insight into the regulatory mechanism that mediates epidermal cell fate determination.
细胞命运决定是植物形态发生的关键步骤。根毛和表皮毛的形成是研究细胞命运决定的良好模型。CAPRICE（CPC）基因编码一种R3型MYB转录因子，促进拟南芥根毛形成并抑制表皮毛形成。CPC同源基因CPC LIKE MYB3（CPL3）编码的氨基酸序列与CPC有66%的相似性，并且它还具有细胞间移动的WxM基序。CPC蛋白从非毛细胞移动到相邻的根毛形成细胞，并在拟南芥根表皮细胞中诱导根毛形成。在本研究中，为了研究CPL3的功能和细胞间移动能力，我们构建了CPC:CPL3:GFP转基因植物与CPL3:CPL3:GFP转基因植物进行比较。CPC:CPL3:GFP转基因植物表现出无表皮毛和多根毛的表型，证实了CPL3在根毛和表皮毛细胞命运决定中与CPC具有相似的功能。然而，在CPC:CPL3:GFP转基因植物中，CPL3:GFP融合蛋白仅定位于非毛细胞中。总的来说，我们的结果表明CPL3蛋白不具有细胞间移动能力。我们的研究结果表明，CPC家族包括一种可移动蛋白和一种不可移动蛋白。我们相信我们的结果为介导表皮细胞命运决定的调控机制提供了新的见解。
