Pietruszka Mariusz, Haduch-Sendecka Aleksandra
University of Silesia, Faculty of Biology and Environment Protection, Laboratory of Plant Physiology, Katowice, Poland.
Gen Physiol Biophys. 2015 Apr;34(2):145-56. doi: 10.4149/gpb_2014035. Epub 2015 Feb 12.
The augmented growth equation introduced by Ortega is solved for the apical portion of the pollen tube as an oscillating volume, which we approach in the framework of a two-fluid model in which the two fluids represent the constant pressure and the fluctuating features of the system. Based on routine Fourier analysis, we calculate the energy spectrum of the oscillating pollen tube, and discuss the resonant frequency problem of growth rate oscillations. We also outline a descriptive model for cell wall thickness fluctuations associated with small, yet regular variations (~ 0.01 MPa) observed in turgor pressure. We propose that pressure changes must lead to the sliding of wall layers, indirectly resulting in a wave of polarization of interlayer bonds. We conclude that pollen tube wall thickness may oscillate due to local variations in cell wall properties and relaxation processes. These oscillations become evident because of low amplitude/high frequency pressure fluctuations δP being superimposed on turgor pressure P. We also show that experimentally determined turgor pressure oscillates in a strict periodical manner. A solitary frequency f0 ≈ 0.066 Hz of these (~ 0.01 MPa in magnitude) oscillations for lily pollen tubes was established by the discrete Fourier transform and Lorentz fit.
由奥尔特加引入的增长方程针对花粉管的顶端部分作为一个振荡体积来求解，我们在双流体模型的框架下进行研究，其中两种流体分别代表系统的恒定压力和波动特征。基于常规傅里叶分析，我们计算了振荡花粉管的能谱，并讨论了生长速率振荡的共振频率问题。我们还概述了一个描述性模型，用于解释与在膨压中观察到的微小但有规律的变化（约0.01兆帕）相关的细胞壁厚度波动。我们提出压力变化必然导致壁层滑动，间接导致层间键极化波。我们得出结论，花粉管壁厚度可能由于细胞壁性质的局部变化和松弛过程而振荡。由于低振幅/高频压力波动δP叠加在膨压P上，这些振荡变得明显。我们还表明，实验测定的膨压以严格的周期性方式振荡。通过离散傅里叶变换和洛伦兹拟合确定了百合花粉管这些（大小约为0.01兆帕）振荡的单一频率f0≈0.066赫兹。
