University of Bayreuth, Soil Physics, Bayreuth Center of Ecology and Environmental Research (BayCEER), Universitätstrasse 30, D-95447 Bayreuth, Germany.
Université Catholique de Louvain, Earth and Life Institute, Croix du Sud L7.05.02, B-1348 Louvain-la-Neuve, Belgium; Agrosphere, Forschungszentrum Juelich GmbH, D-52425, Juelich, Germany.
Trends Plant Sci. 2020 Sep;25(9):868-880. doi: 10.1016/j.tplants.2020.04.003. Epub 2020 May 3.
The current trend towards linking stomata regulation to plant hydraulics emphasizes the role of xylem vulnerability. Using a soil-plant hydraulic model, we show that xylem vulnerability does not trigger stomatal closure in medium-wet to dry soils and we propose that soil hydraulic conductivity loss is the primary driver of stomatal closure. This finding has two key implications: transpiration response to drought cannot be derived from plant traits only and is related to soil-root hydraulics in a predictable way; roots and their interface with the soil, the rhizosphere, are key hydraulic regions that plants can alter to efficiently adapt to water limitations. We conclude that connecting below- and aboveground hydraulics is necessary to fully comprehend plant responses to drought.
当前将气孔调节与植物水力联系起来的趋势强调了木质部脆弱性的作用。我们使用土壤-植物水力模型表明，木质部脆弱性不会在中湿到干燥的土壤中引发气孔关闭，我们提出木质部导水率丧失是气孔关闭的主要驱动因素。这一发现有两个关键含义：干旱条件下的蒸腾响应不能仅从植物特性推导得出，而是与土壤-根系水力以可预测的方式相关；根系及其与土壤的界面，即根际，是植物可以改变以有效适应水分限制的关键水力区域。我们得出结论，连接地上和地下水力对于全面理解植物对干旱的响应是必要的。
