Breĭgina M A, Smirnova A V, Maslennikov M V, Matveeva N P, Ermakov I P
Tsitologiia. 2010;52(4):334-41.
Influence of anion channel blockers NPPB and DIDS on pollen tube growth and its mitochondria functioning was studied by means of fluorescence microscopy and flow cytometry. NPPB (40 microM) blocked pollen tube growth completely, but did not change its diameter. DIDS (20-80 microM) caused pollen tube swelling and bursting, suggesting that DIDS-sensitive channels take part in the regulation of pollen tube osmotic balance. The osmotic effect of low DIDS concentration (20 (Mkappa)M) was not accompanied by changes in the tube growth rate. The mapping of membrane potential on the pollen tube plasmalemma using Di-4-ANEPPS revealed the involvement of NPPB-sensitive but not DIDS-sensitive anion channels in the maintenance of the longitudinal membrane potential gradient along the tube surface. The study of isolated pollen mitochondria showed that DIDS increased their capacity to take up potential-dependent dye DiOC5(3), i. e. caused hyperpolarization of mitochondrial membranes. At the same time DIDS influenced on intramitochondrial ROS content and excretion of ROS from mitochondria. Thus, NPPB and DIDS differently influenced on transmembrane potential distribution along pollen tube plasmalemma, on its osmotic balance, and on mitochondria functioning. This set of data suggests that pollen tube growth is dependent on activity of anion channels that differ in localization and functions.
通过荧光显微镜和流式细胞术研究了阴离子通道阻滞剂NPPB和DIDS对花粉管生长及其线粒体功能的影响。NPPB（40微摩尔）完全阻断了花粉管生长，但未改变其直径。DIDS（20 - 80微摩尔）导致花粉管肿胀和破裂，表明对DIDS敏感的通道参与了花粉管渗透平衡的调节。低浓度DIDS（20微摩尔）的渗透作用并未伴随着花粉管生长速率的变化。使用Di - 4 - ANEPPS对花粉管质膜上的膜电位进行映射显示，NPPB敏感而非DIDS敏感的阴离子通道参与了沿花粉管表面维持纵向膜电位梯度。对分离的花粉线粒体的研究表明，DIDS增加了它们摄取电位依赖性染料DiOC5(3)的能力，即导致线粒体膜超极化。同时，DIDS影响线粒体内活性氧含量以及线粒体活性氧的排泄。因此，NPPB和DIDS对沿花粉管质膜的跨膜电位分布、其渗透平衡以及线粒体功能有不同影响。这组数据表明，花粉管生长依赖于定位和功能不同的阴离子通道的活性。
