Lignin composition is related to xylem embolism resistance and leaf life span in trees in a tropical semiarid climate
Lignin composition is related to xylem embolism resistance and leaf life span in trees in a tropical semiarid climate
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DOI：
10.1111/nph.15211
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发表时间：
2018-09-01
期刊：
影响因子：
9.4
通讯作者：
Araujo, Francisca S.
中科院分区：
文献类型：
--
作者：
Lima, Taysla R. A.;Carvalho, Ellen C. D.;Araujo, Francisca S.
木材性质影响树冠的叶寿命。由于木质素是木材和水运系统的重要组成部分，我们研究了它与季节性干燥热带生态系统中几种树种的抗栓塞性和LL的关系。我们测定了巴西最常见的半干旱树种（当地称为Caatinga）的总木质素和愈创木酰(G)和丁香酰(S)的单体含量，并将它们与木材性状和木质部易栓塞性（50）联系起来。叶寿命与（50）负相关，与S:G正相关，与（50）负相关。这意味着更大的S:G通过减少（50）来增加LL。木质素含量与各变量均无相关性。我们发现了两个明显不相关的抗旱性轴。一个轴与木质素单体组成有关，由于木质部栓塞易损性降低，在旱季增加了LL。另一种与木材密度和茎含水量有关，有助于无叶树木抵御干旱，并使它们在旱季结束时重新发芽。因此，木质素（S:G）的单体组成是影响半干旱气候下热带树种几个关键功能方面的重要功能木材属性。
Wood properties influence the leaf life span (LL) of tree crowns. As lignin is an important component of wood and the water transport system, we investigated its relationship with embolism resistance and the LL of several tree species in a seasonally dry tropical ecosystem. We determined total lignin and the monomer contents of guaiacyl (G) and syringyl (S) and related them to wood traits and xylem vulnerability to embolism ((50)) for the most common species of the Brazilian semiarid, locally known as Caatinga. Leaf life span was negatively related to (50) and positively related to S:G, which was negatively related to (50). This means that greater S:G increases LL by reducing (50). Lignin content was not correlated with any variable. We found two apparently unrelated axes of drought resistance. One axis, associated with lignin monomeric composition, increases LL in the dry season as a result of lower xylem embolism vulnerability. The other, associated with wood density and stem water content, helps leafless trees to withstand drought and allows them to resprout at the end of the dry season. The monomeric composition of lignin (S:G) is therefore an important functional wood attribute affecting several key functional aspects of tropical tree species in a semiarid climate.