We report the effects of abrupt transitions of light intensity on the growth patterns and mechanical properties of young tobacco leaves. Changes in light intensity induce large variations in the leaf strain rate, which can be an order of magnitude larger than the average growth rates, and include both tissue expansion and shrinkage. These are accompanied by large changes in the tissue’s mechanical properties. Similar effects are observed in response to wind. We show evidence supporting the hypothesis that these effects originate from hydraulic mechanisms, i.e., variations in turgor pressure. In the context of growth patterns and growth regulation, we show giant fluctuations in strain rate to be a normal part of the growth process of leaves, which should be taken into account as a means for redistributing the stresses accumulated during the process of growth.

我们报告了光强度突然转变对年轻烟叶的生长模式和机械性能的影响。光强度的变化会引起叶片应变率的大变化，该变化可能比平均生长率大一个数量级，并且包括组织扩张和收缩。这些伴随着组织机械性能的巨大变化。响应风观察到类似的效果。我们显示了支持以下假设的证据：这些影响源自液压机制，即，膨胀压力的变化。在生长方式和生长调控的背景下，我们显示出应变率的巨大波动是叶片生长过程的正常部分，