Dynamics of leaf water relations components in co-occurring iso- and anisohydric conifer species
Dynamics of leaf water relations components in co-occurring iso- and anisohydric conifer species
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DOI：
10.1111/pce.12327
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发表时间：
2014-11-01
影响因子：
7.3
通讯作者：
Sevanto, Sanna
中科院分区：
文献类型：
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作者：
Meinzer, Frederick C.;Woodruff, David R.;Sevanto, Sanna
由于等水和不等水物种在气孔调节芽水势波动速率和幅度方面存在差异，因此预计它们的芽水关系成分的可塑性可能会表现出差异，但很少对这种性质进行明确的比较。我们进行了切下的芽共同发生的anohydroxyJuniperus monosperma和isohydroxyPinus edulis的压力-体积分析，并没有事先人工复水。在J.monosperma中，在膨压损失时的枝水势（Psi（TLP））范围从人工复水的枝的-3.4MPa到初始的枝的-6.6MPa。的-5.5 MPa，而在P. edulis中，在初始Psi从-0.1到-2.3 MPa的范围内，平均Psi（TLP）保持在类似于-3.0 MPa。在充分膨压和体积弹性模量的地上部渗透势也急剧下降。而在紫背天蛾中不存在。J. monosperma和P. edulis的对比行为反映了它们对膨压的稳态调节能力的差异，这可能是一般异水和等水物种的代表，也可能与J. monosperma更强的耐受严重干旱的能力有关。
Because iso- and anisohydric species differ in stomatal regulation of the rate and magnitude of fluctuations in shoot water potential, they may be expected to show differences in the plasticity of their shoot water relations components, but explicit comparisons of this nature have rarely been made. We subjected excised shoots of co-occurring anisohydric Juniperus monosperma and isohydric Pinus edulis to pressure-volume analysis with and without prior artificial rehydration. In J. monosperma, the shoot water potential at turgor loss (Psi(TLP)) ranged from -3.4 MPa in artificially rehydrated shoots to -6.6 MPa in shoots with an initial. of -5.5 MPa, whereas in P. edulis mean Psi(TLP) remained at similar to -3.0 MPa over a range of initial Psi from -0.1 to -2.3 MPa. The shoot osmotic potential at full turgor and the bulk modulus of elasticity also declined sharply with shoot. in J. monosperma, but not in P. edulis. The contrasting behaviour of J. monosperma and P. edulis reflects differences in their capacity for homeostatic regulation of turgor that may be representative of aniso- and isohydric species in general, and may also be associated with the greater capacity of J. monosperma to withstand severe drought.