Tradeoff between storage capacity and embolism resistance in the xylem of temperate broadleaf tree species
Tradeoff between storage capacity and embolism resistance in the xylem of temperate broadleaf tree species
复制标题
温带阔叶树种木质部储存能力和抗栓塞性之间的权衡
DOI：
10.1093/treephys/tpaa046
复制
发表时间：
2020-08-01
期刊：
影响因子：
4
通讯作者：
Liu, Shirong
中科院分区：
文献类型：
--
作者：
Chen, Zhicheng;Zhu, Shidan;Liu, Shirong
木质部性状是与水分运输、机械支持、碳水化合物和水分储存相关的重要植物功能性状。关于木质部水力效率-安全性权衡的研究很多，但很少考虑木质部薄壁组织的贮藏功能。研究了北方干旱石灰岩生境中19种温带阔叶树木质部性状对水分运输、抗栓塞性、机械支撑、贮藏能力和非结构性碳水化合物（NSC）含量的影响。19种阔叶树种的木质部水力效率与安全性之间不存在权衡关系。总薄壁组织分数与纤维分数呈负相关。抗栓塞性与导管壁强化度、导管壁厚度和纤维壁厚度等木质部机械强度指标呈正相关，与轴向薄壁组织分数呈负相关，尤其是与近轴薄壁组织分数呈负相关。血管壁薄壁组织分数与血管壁薄壁组织分数与血管壁薄壁组织分数的比值呈正相关。此外，木质部NSC浓度与总薄壁组织分数和轴向薄壁组织分数呈正相关。在干旱石灰岩生境中，19种阔叶树木质部存在贮水能力-抗栓塞能力的权衡。我们推测，温带阔叶树种可能表现出一系列的木质部水力策略，从栓塞阻力策略相关的一个更负的P-50（水的潜力，相当于50%的木质部电导率的损失）栓塞修复策略的基础上更paradherheal薄壁组织。
Xylem traits are critical plant functional traits associated with water transport, mechanical support, and carbohydrate and water storage. Studies on the xylem hydraulic efficiency-safety tradeoff are numerous; however, the storage function of xylem parenchyma is rarely considered. The effects of a substantial number of xylem traits on water transport, embolism resistance, mechanical support, storage capacity and nonstructural carbohydrate (NSC) content were investigated in 19 temperate broadleaf species planted in an arid limestone habitat in northern China. There was no xylem hydraulic efficiency-safety tradeoff in the 19 broadleaf species. The total parenchyma fraction was negatively correlated with the fiber fraction. Embolism resistance was positively correlated with indicators of xylem mechanical strength such as vessel wall reinforcement, vessel wall thickness and fiber wall thickness, and was negatively related to the axial parenchyma fraction, especially the paratracheal parenchyma fraction. The paratracheal parenchyma fraction was positively correlated with the ratio of the paratracheal parenchyma fraction to the vessel fraction. In addition, the xylem NSC concentration was positively related to the total parenchyma fraction and axial parenchyma fraction. There was a storage capacity-embolism resistance tradeoff in the xylem of 19 broadleaf species in arid limestone habitats. We speculate that the temperate broadleaf species may show a spectrum of xylem hydraulic strategies, from the embolism resistance strategy related to a more negative P-50 (the water potential corresponding to 50% loss of xylem conductivity) to the embolization repair strategy based on more paratracheal parenchyma.