Turgor loss point (πₜₗₚ) has been suggested to be a key trait for drought resistance in woody species. In herbaceous grassland species, the role of πₜₗₚ for species drought survival has not yet been tested, although grasslands are projected to experience more frequent and intense droughts with climate change. To gain insights into the role of πₜₗₚ for drought resistance of temperate perennial grassland species, we assessed πₜₗₚ of 41 species common in Germany (20 forbs, 21 grasses). We directly related them to the species’ comparative whole‐plant drought survival and midday leaf water potentials under drought (ΨMD) assessed in a common garden drought experiment, and to species moisture association. Species drought survival increased with increasing πₜₗₚ across all species as well as within forbs or grasses separately. ΨMD was positively related to πₜₗₚ and drought survival. Our results imply that high πₜₗₚ promotes drought survival of common perennial European temperate mesic grassland species by enabling them to maintain high leaf water potentials under drought, that is, a desiccation avoidance strategy. However, πₜₗₚ was not related to species moisture association. The positive relationship between πₜₗₚ and drought survival in herbaceous grassland species was opposite to the negative relationship previously established in woody plants, implying that mechanisms of drought resistance differ between woody and herbaceous species. Our results highlight the necessity of directly testing the relationship of functional traits to whole‐plant drought survival in different plant life forms, before using trait assessments for predicting plant responses to drought. A free plain language summary can be found within the Supporting Information of this article.

中文翻译：

---

干旱生存与温带多年生草原物种的高膨胀损失点正相关

Turgor 损失点 (πₜₗₚ) 已被认为是木本物种抗旱性的关键性状。在草本草原物种中，πₜₗₚ 对物种干旱生存的作用尚未得到测试，尽管预计随着气候变化草原将经历更频繁和更强烈的干旱。为了深入了解 πₜₗₚ 在温带多年生草原物种抗旱性方面的作用，我们评估了德国常见的 41 个物种（20 种杂草，21 种草）的 πₜₗₚ。我们将它们与在普通花园干旱实验中评估的物种的比较全植物干旱存活率和中午叶片水势 (ΨMD) 以及物种水分关联直接相关。物种干旱存活率随着 πₜₗₚ 在所有物种以及杂草或禾本科植物中的增加而增加。ΨMD与πₜₗₚ和干旱存活率呈正相关。我们的结果表明，高 πₜₗₚ 通过使它们在干旱下保持高叶水势，即一种避免干燥的策略，促进了常见的多年生欧洲温带中等草原物种的干旱生存。然而，πₜₗₚ与物种水分关联无关。πₜₗₚ 与草本草原物种的干旱存活率之间的正相关与先前在木本植物中建立的负相关相反，这意味着木本和草本物种之间的抗旱机制不同。我们的结果强调了在使用性状评估预测植物对干旱的反应之前，有必要直接测试功能性状与不同植物生命形式中全株干旱存活率的关系。