Variation in leaf wax n-alkane characteristics with climate in the broad-leaved paperbark (Melaleuca quinquenervia)
Variation in leaf wax n-alkane characteristics with climate in the broad-leaved paperbark (Melaleuca quinquenervia)
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DOI：
10.1016/j.orggeochem.2019.02.004
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发表时间：
2019-04-01
影响因子：
3
通讯作者：
Greenway, Margaret
中科院分区：
文献类型：
--
作者：
Andrae, Jake W.;McInerney, Francesca A.;Greenway, Margaret
在高等植物中，叶蜡为非气孔水分损失提供了屏障，并且它们的组成在物种之间和物种内都不同。正构烷烃是这些蜡中普遍存在的一组化合物，其特征被认为受到植物生长环境中水的可用性和温度的影响。较长的正构烷烃的分布与较少的变化链长的假设，赋予更大的阻力，非气孔水分流失，因此预计在更高的丰度在干燥的环境。正构烷烃的分布与降水和温度之间的关系以前已经观察到。尽管如此，目前还不清楚正构烷烃链长分布是否随气候变化而发生塑性变化，或者它们是否在不同气候条件下固定在种群内。为了更好地理解这一点，我们研究了五脉白千层的正构烷烃特征与空间和时间气候变化之间的关系。在整个澳大利亚东部，我们发现，正构烷烃同系物的浓度和分布在M。quinquenervia不随气候而变化，即使气候显示出显着的变化。然而，正构烷烃同系物的浓度和分布在地理上分离的种群之间在非常不同的气候条件下确实存在很大差异。这些结果表明，正构烷烃的特征不是对气候变化的塑性反应，而是可能是固定的，可能是由种群之间的遗传差异驱动的。这对正构烷烃作为古环境代用指标具有重要意义。(C)2019爱思唯尔有限公司版权所有。
In higher plants, leaf waxes provide a barrier to non-stomatal water loss, and their composition varies both between and within species. Characteristics of n-alkanes, a suite of ubiquitous compounds in these waxes, are thought to be influenced by the availability of water and the temperature in a plant's growing environment. Longer n-alkane distributions with less variability in chain length are hypothesised to confer greater resistance to non-stomatal water loss and thus are expected in higher abundance in desiccating environments. Relationships between the distribution of n-alkanes and both precipitation and temperature have previously been observed. Despite this, it is unclear whether n-alkane chain length distributions vary plastically in response to climate, or whether they are fixed within populations in different climate settings. To better understand this, we examine the relationship between n-alkane characteristics of Melaleuca quinquenervia and both spatial and temporal climate variation. Across eastern Australia, we find that n-alkane homolog concentrations and distributions in leaves of M. quinquenervia do not vary with climate where samples are proximate, even when climate shows significant variability. However, the concentration and distribution of n-alkane homologs do differ considerably between geographically separated populations in very different climate regimes. These results suggest n-alkane characteristics are not a plastic response to climate variability, and instead are likely fixed and could be driven by genetic differences between populations. This has important implications for the use of n-alkane characteristics as palaeoenvironmental proxies. (C) 2019 Elsevier Ltd. All rights reserved.