Geitmann Anja
Institut de recherche en biologie végétale, Département de sciences biologiques, Université de Montréal, 4101 rue Sherbrooke est, Montréal, QC, H1X 2B2, Canada.
Sex Plant Reprod. 2010 Mar;23(1):63-71. doi: 10.1007/s00497-009-0121-4. Epub 2009 Nov 18.
Expansive growth in plant cells is a formidable problem for biophysical studies, and the mechanical principles governing the generation of complex cellular geometries are still poorly understood. Pollen, the male gametophyte stage of the flowering plants, is an excellent model system for the investigation of the mechanics of complex growth processes. The initiation of pollen tube growth requires first of all, the spatially confined formation of a protuberance. This process must be controlled by the mechanical properties of the cell wall, since turgor is a non-vectorial force. In the elongating tube, cell wall expansion is confined to the apex of the cell, requiring the tubular region to be stabilized against turgor-induced tensile stress. Tip focused surface expansion must be coordinated with the supply of cell wall material to this region requiring the precise, logistical control of intracellular transport processes. The advantage of such a demanding mechanism is the high efficiency it confers on the pollen tube in leading an invasive way of life.
植物细胞的扩展性生长对生物物理研究来说是一个棘手的问题，而支配复杂细胞几何形状形成的力学原理仍未得到充分理解。花粉作为开花植物的雄配子体阶段，是研究复杂生长过程力学的理想模型系统。花粉管生长的起始首先需要在空间上受限地形成一个突起。由于膨压是一种无矢量方向的力，这个过程必定受细胞壁力学特性的控制。在伸长的花粉管中，细胞壁的扩张局限于细胞顶端，这就要求管状区域能抵抗膨压引起的拉应力而保持稳定。顶端集中的表面扩张必须与细胞壁物质向该区域的供应相协调，这需要对细胞内运输过程进行精确的后勤控制。这种严格机制的优势在于它赋予花粉管以高效的侵入性生活方式。
