The process of leaf elongation in grasses is characterized by the creation and transformation of distinct cell zones. The prevailing turgor pressure within these cells is one of the key drivers for the rate at which these cells divide, expand and differentiate, processes that are heavily impacted by drought stress. In this article, a turgor‐driven growth model for grass leaf elongation is presented, which combines mechanistic growth from the basis of turgor pressure with the ontogeny of the leaf. Drought‐induced reductions in leaf turgor pressure result in a simultaneous inhibition of both cell expansion and differentiation, lowering elongation rate but increasing elongation duration due to the slower transitioning of cells from the dividing and elongating zone to mature cells. Leaf elongation is, therefore, governed by the magnitude of, and time spent under, growth‐enabling turgor pressure, a metric which we introduce as turgor‐time. Turgor‐time is able to normalize growth patterns in terms of varying water availability, similar to how thermal time is used to do so under varying temperatures. Moreover, additional inclusion of temperature dependencies within our model pioneers a novel concept enabling the general expression of growth regardless of water availability or temperature.

中文翻译：

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Turgor-time 控制干旱胁迫下草叶伸长率和持续时间

草叶伸长过程的特点是不同细胞区的产生和转化。这些细胞内的普遍膨胀压力是这些细胞分裂、扩张和分化速度的关键驱动因素之一，这些过程受到干旱压力的严重影响。在本文中，提出了一种用于草叶伸长的膨胀驱动生长模型，该模型将基于膨胀压力的机械生长与叶子的个体发育相结合。干旱引起的叶膨压降低同时抑制细胞扩张和分化，降低伸长率，但由于细胞从分裂和伸长区向成熟细胞的转变较慢，伸长持续时间增加。因此，叶片伸长率受以下因素的影响：以及在促进增长的膨胀压力下花费的时间，我们将其引入为膨胀时间的指标。Turgor-time 能够根据不同的可用水量使生长模式正常化，类似于在不同温度下如何使用热时间来做到这一点。此外，在我们的模型中额外包含温度依赖性开创了一个新概念，无论水的可用性或温度如何，都可以实现生长的一般表达。