Insights on the mechanics of hyphal growth

This article reviews recent progress in understanding the mechanics of hyphal growth. The pressurization of hyphae by osmosis is often considered an important feature of the tip growth process. But although the hydrostatic pressure within the cytoplasm smooths the expanding surface of these cells, there is little evidence that high levels of turgor are necessary for growth until the hypha encounters friction from its surroundings. Research on movement and growth processes in other kinds of cells, including amoebae and pollen tubes, has done a great deal to inform recent studies on hyphae. Experiments on pressure waves and rhythmic or pulsatile growth are particularly significant and are discussed in relation to the erratic extension rate of hyphae. Significant findings have also come from research on the hyphal cytoskeleton and on the biomechanics of invasive growth. It has been clear for some time that turgor powers the propulsion of hyphae through solid materials and experiments using new techniques have quantified the relevant forces.