Synthetic chemical fluorescent dyes promise to be useful for many applications in biology. Covalent, targeted labeling, such as with a SNAP-tag, uses synthetic dyes to label specific proteins in vivo for studying processes such as endocytosis or for imaging via super-resolution microscopy. Despite its potential, such chemical tagging has not been used effectively in plants. A major drawback has been the limited knowledge regarding cell wall and membrane permeability of the available synthetic dyes. Of 31 synthetic dyes tested here, 23 were taken up into BY-2 cells, while eight were not. This creates sets of dyes that can serve to measure endocytosis. Three of the dyes that were able to enter the cells, SNAP-tag ligands of diethylaminocoumarin, tetramethylrhodamine, and silicon-rhodamine 647, were used to SNAP-tag α-tubulin. Successful tagging was verified by live cell imaging and visualization of microtubule arrays in interphase and during mitosis in Arabidopsis (Arabidopsis thaliana) seedlings. Fluorescence activation-coupled protein labeling with DRBG-488 was used to observe PIN-FORMED2 (PIN2) endocytosis and delivery to the vacuole as well as preferential delivery of newly synthesized PIN2 to the actively forming cell plate during mitosis. Together, the data demonstrate that specific self-labeling of proteins can be used effectively in plants to study a wide variety of cellular and biological processes.

合成化学荧光染料有望在生物学的许多应用中发挥作用。共价靶向标记（例如 SNAP 标签）使用合成染料标记体内特定蛋白质，用于研究内吞作用等过程或通过超分辨率显微镜成像。尽管具有潜力，但这种化学标记尚未在植物中有效使用。一个主要缺点是对可用合成染料的细胞壁和膜渗透性的了解有限。这里测试的 31 种合成染料中，23 种被 BY-2 细胞吸收，而 8 种则没有。这产生了可用于测量内吞作用的染料组。能够进入细胞的三种染料，即二乙氨基香豆素、四甲基罗丹明和硅罗丹明 647 的 SNAP 标签配体，用于 SNAP 标签 α-微管蛋白。拟南芥）幼苗。使用 DRBG-488 荧光激活偶联蛋白标记来观察 PIN-FORMED2 (PIN2) 内吞作用和向液泡的递送，以及在有丝分裂过程中新合成的 PIN2 优先递送到活跃形成的细胞板。总之，这些数据表明，蛋白质的特定自标记可以有效地用于植物中，以研究各种细胞和生物过程。