Kameoka Hiromu, Dun Elizabeth A, Lopez-Obando Mauricio, Brewer Philip B, de Saint Germain Alexandre, Rameau Catherine, Beveridge Christine A, Kyozuka Junko
Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan (H.K., J.K.).
School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia (E.A.D., P.B.B., C.A.B.).
Plant Physiol. 2016 Nov;172(3):1844-1852. doi: 10.1104/pp.16.01212. Epub 2016 Sep 26.
The cell-to-cell transport of signaling molecules is essential for multicellular organisms to coordinate the action of their cells. Recent studies identified DWARF14 (D14) as a receptor of strigolactones (SLs), molecules that act as plant hormones and inhibit shoot branching. Here, we demonstrate that RAMOSUS3, a pea ortholog of D14, works as a graft-transmissible signal to suppress shoot branching. In addition, we show that D14 protein is contained in phloem sap and transported through the phloem to axillary buds in rice. SLs are not required for the transport of D14 protein. Disruption of D14 transport weakens the suppression of axillary bud outgrowth of rice. Taken together, we conclude that the D14 protein works as an intercellular signaling molecule to fine-tune SL function. Our findings provide evidence that the intercellular transport of a receptor can regulate the action of plant hormones.
信号分子的细胞间运输对于多细胞生物协调其细胞的活动至关重要。最近的研究确定DWARF14（D14）为独脚金内酯（SLs）的受体，独脚金内酯作为植物激素发挥作用并抑制枝条分枝。在这里，我们证明了豌豆中D14的同源物RAMOSUS3作为一种可通过嫁接传递的信号来抑制枝条分枝。此外，我们表明D14蛋白存在于韧皮部汁液中，并通过韧皮部运输到水稻的腋芽。D14蛋白的运输不需要SLs。D14运输的破坏会削弱对水稻腋芽生长的抑制作用。综上所述，我们得出结论，D14蛋白作为一种细胞间信号分子来微调SL的功能。我们的研究结果提供了证据，表明受体的细胞间运输可以调节植物激素的作用。
