Oxygen radicals and cytoplasm zoning in growing lily pollen tubes
Oxygen radicals and cytoplasm zoning in growing lily pollen tubes
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百合花粉管生长过程中氧自由基与细胞质分区
DOI：
10.1007/s00497-021-00403-6
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发表时间：
2021-01-25
影响因子：
3.4
通讯作者：
Breygina, Maria
中科院分区：
文献类型：
--
作者：
Podolyan, Alexandra;Luneva, Oksana;Breygina, Maria
微环境（O over bar /MnTMPP/OH中心点）中ROS含量的差异调节影响百合花粉管的生长速度和形态。氧自由基影响离子分区：膜电位和pH gradients.Recently，氧化还原调节的尖端生长已被广泛研究，但不同的敏感性生长的细胞，特别是ROS和他们的亚细胞定位仍然不清楚。在这里，我们使用特定的染料，以提供映射的H2 O2和O-2（中心点）在酒吧在短和长的花粉管。我们发现H2 O2和产生H2 O2的细胞器在胫部的顶端积累，这些细胞器不与产生棒的线粒体上的O-2（中心点）共定位。萌发培养基中活性氧含量的差异调节影响生长速度和花粉管形态。氧自由基影响离子分区：膜电位和pH梯度。OH中心点引起整个沿着小管的去极化，而O-2（中心点）则引起超极化和细胞质碱化。棒上的O-2（中心点）加速了花粉管的生长并减小了花粉管直径，表明该ROS可以被认为是花粉管生长的刺激物。OH中心点和活性氧猝灭剂MnTMPP处理后，花粉管结构发生严重紊乱，花粉管生长速度减慢，顶端形成气球状突起，但OH中心点也影响了花粉管的膜运输和细胞器的分布。OH中心点是花粉管生长的负调节因子。花粉管，反过来，能够降低OH中心点的浓度，这是由电子顺磁共振光谱（EPR）评估。
Key message Differential modulation of ROS content of the microenvironment (O over bar /MnTMPP/OH center dot) affects growth speed and morphology in lily pollen tubes. Oxygen radicals influence ionic zoning: membrane potential and pH gradients.Recently, redox-regulation of tip growth has been extensively studied, but differential sensitivity of growing cells to particular ROS and their subcellular localization is still unclear. Here, we used specific dyes to provide mapping of H2O2 and O-2(center dot) over bar in short and long pollen tubes. We found apical accumulation of H2O2 and H2O2-producing organelles in the shank that were not colocalized with O-2(center dot) over bar -producing mitochondria. Differential modulation of ROS content of the germination medium affected both growth speed and pollen tube morphology. Oxygen radicals affected ionic zoning: membrane potential and pH gradients. OH center dot caused depolarization all along the tube while O-2(center dot) over bar provoked hyperpolarization and cytoplasm alkalinization. O-2(center dot) over bar accelerated growth and reduced tube diameter, indicating that this ROS can be considered as pollen tube growth stimulator. Serious structural disturbances were observed upon exposure to OH center dot and ROS quencher MnTMPP: pollen tube growth slowed down and ballooned tips formed in both cases, but OH center dot affected membrane transport and organelle distribution as well. OH center dot, thus, can be considered as a negative regulator of pollen tube growth. Pollen tubes, in turn, are able to reduce OH center dot concentration, which was assessed by electron paramagnetic resonance spectroscopy (EPR).