Size-Dependent Changes in Biophysical Control of Tree Growth: The Role of Turgor
Size-Dependent Changes in Biophysical Control of Tree Growth: The Role of Turgor
复制标题
树木生长生物物理控制的尺寸依赖性变化：膨压的作用
DOI：
10.1007/978-94-007-1242-3_14
复制
发表时间：
2011
影响因子：
7.3
通讯作者：
F. Meinzer
中科院分区：
文献类型：
--
作者：
D. Woodruff;F. Meinzer
树木顶端的木质部压力随着树高的增加而降低，这是由于与水分通过木质部的运动有关的重力和摩擦的结果。顶端分生组织和维管分生组织的细胞膨胀率，除非通过渗透调节而改变，否则会随着木质部压力的增加而成比例下降。在地球上最高的针叶树种中，渗透调节不足以补偿木质部压力垂直梯度对发育和成熟组织膨大的负面影响。本章综合了在细胞、组织和整个树水平上解决与膨胀相关的生长限制的研究。我们研究了膨大在植物生长以及叶片和茎的结构和功能特征中的作用，因为它们受到与膨大高度相关的趋势的影响。我们还评估了与高度相关的膨胀度趋势，作为观察到的树高和树木生物量增长模式的原因，强调了膨胀度的减少如何影响高大树木光合作用的库/源关系。与高度相关的细胞膨大的减少对新梢的延伸和扩展产生了一系列直接和间接的影响。当树木接近树种和特定地点的高度限制时，膨胀限制生长的多种后果可能会以协同方式作用，进一步限制枝条的延伸。膨胀受限的组织扩张具有永久性的解剖学和形态学后果，这些后果支配着一系列与生长相关的生理过程中高度相关的变化。这些包括木质部导管尺寸减小对水分运输途径末端生长组织供水效率的影响，单位面积叶质量增加导致的生长效率降低，以及对CO2通过叶肉扩散到羧化部位的阻力增加。
Xylem pressure at the tops of trees decreases with increasing tree height as a result of gravitational force and friction associated with water movement through the xylem. Unless altered by osmotic adjustment, the turgor of cells in the apical and vascular meristems will decline proportionally with xylem pressure. In the tallest coniferous species on earth osmotic adjustment is insufficient to compensate for the negative impact of vertical gradients of xylem pressure on turgor of developing and mature tissue. This chapter synthesizes the research addressing turgor-related constraints on growth at the cellular, tissue, and whole tree levels. We examine the role of turgor in plant growth and foliar and stem structural and functional characteristics as they are influenced by height-related trends in turgor. We also evaluate height-related trends in turgor as a cause of observed patterns of tree height and tree biomass growth with an emphasis on how reductions in turgor can influence sink/source relationships for photosynthate in tall trees. Height-related reductions in cell turgor generate a cascade of direct and indirect effects on shoot extension and expansion. The multiple consequences of turgor-limited growth may act in a synergistic manner to further constrain shoot extension as trees approach species- and site-specific height limits. Turgor-limited tissue expansion has permanent anatomical and morphological consequences that govern height-dependent changes in an array of growth-related physiological processes. These include the impact of reduced xylem conduit dimensions on efficiency of water supply to growing tissues at the terminal portions of the water transport pathway, reduced growth efficiency associated with increased leaf mass per area, and increased resistance to CO2 diffusion through the mesophyll to the sites of carboxylation.
DOI：
10.1128/mr.54.4.381-431.1990
发表时间：
1990
期刊：
Microbiological reviews
影响因子：
--
作者：
Harold,FM
通讯作者：
Harold,FM