Effects of anion channel blockers NPPB and DIDS on tobacco pollen tube growth and its mitochondria state

• Published in: Cell and tissue biology 2010, Vol.4 (3), p.289-296
• Main Authors: Breygina, M. A., Smirnova, A. V., Maslennikov, M. V., Matveeva, N. P., Yermakov, I. P.
• Format: Article
• Language: English
• Subjects: Biomedical and Life Sciences; Cell Biology; Life Sciences
• ISSN: 1990-519X; 1990-5203
• DOI: 10.1134/S1990519X10030119

The 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 μM) blocked pollen tube growth completely, but didn’t change its diameter. DIDS (20–80 μM) 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 μM) wasn’t accompanied by changes in the tube growth rate. The mapping of plasma membrane potential of pollen tubes 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 DiOC 5 (3), i.e. caused hyperpolarization of mitochondrial membranes. At the same time DIDS influenced on intramitochondrial ROS content and ROS release from mitochondria. Thus, NPPB and DIDS in different ways influenced on plasma membrane potential distribution along pollen tube, 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.