Vogler Frank, Sprunck Stefanie
a Cell Biology and Plant Biochemistry; Biochemie-Zentrum Regensburg; University of Regensburg ; Regensburg , Germany.
Plant Signal Behav. 2015;10(10):e1075684. doi: 10.1080/15592324.2015.1075684.
The flowering plant pollen tube is the fastest elongating plant cell and transports the sperm cells for double fertilization. The highly dynamic formation and reorganization of the actin cytoskeleton is essential for pollen germination and pollen tube growth. To drive pollen-specific expression of fluorescent marker proteins, commonly the strong Lat52 promoter is used. Here we show by quantitative fluorescent analysis that the gametophyte-specific ARO1 promoter from Arabidopsis drives an about 3.5 times weaker transgene expression than the Lat52 promoter. In one third of the pollen of F-actin-labeled ARO1p:tagRFP-T-Lifeact transgenic lines we observed mobile ring-shaped actin structures in pollen grains and pollen tubes. Pollen tube growth, transgene transmission and seed production were not affected by tagRFP-T-Lifeact expression. F-actin rings were able to integrate into emerging actin filaments and they may reflect a particular physiological state of the pollen or a readily available storage form provided for rapid actin network remodeling.
开花植物的花粉管是伸长速度最快的植物细胞，负责运输精细胞以进行双受精。肌动蛋白细胞骨架的高度动态形成和重组对于花粉萌发和花粉管生长至关重要。为了驱动荧光标记蛋白在花粉中的特异性表达，通常使用强Lat52启动子。在这里，我们通过定量荧光分析表明，来自拟南芥的配子体特异性ARO1启动子驱动的转基因表达比Lat52启动子弱约3.5倍。在F-肌动蛋白标记的ARO1p:tagRFP-T-Lifeact转基因系的三分之一花粉中，我们在花粉粒和花粉管中观察到了可移动的环形肌动蛋白结构。花粉管生长、转基因传递和种子生产不受tagRFP-T-Lifeact表达的影响。F-肌动蛋白环能够整合到新出现的肌动蛋白丝中，它们可能反映了花粉的一种特殊生理状态或为快速肌动蛋白网络重塑提供的一种现成的储存形式。
