How do roots penetrate strong soil?
How do roots penetrate strong soil?
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DOI：
10.1023/a:1026140122848
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发表时间：
2003-08-01
期刊：
影响因子：
4.9
通讯作者：
Barraclough, PB
中科院分区：
文献类型：
--
作者：
Clark, LJ;Whalley, WR;Barraclough, PB
本文综述了高机械阻抗条件下根系生长的力学和生理基础。在完全受阻的豌豆根的最大轴向根生长压力（σ（最大））的最佳估计似乎是从0.5至0.6 MPa，这是由约0.8 MPa的膨压。当根系不完全受阻时，已报道了一系列反应。根不以简单的机械方式改变伸长速率以响应机械阻抗的变化。相反，乙烯可能在介导根直径的增加和伸长速率的降低中起关键作用。这些变化在移除阻抗后持续数小时或数天。物种之间的差异，在他们的能力，穿透强土层是不相关的smax的差异，但似乎是由于根直径的差异。在水稻中，品种之间根穿透强蜡层能力的差异与它们通过均匀强培养基的伸长率无关。种或品种之间穿透强土层能力的差异可能是由于根从弱环境向强环境生长时偏斜或弯曲的倾向不同。
The mechanical and physiological bases for root growth against high mechanical impedance are reviewed. The best estimates of maximum axial root growth pressure (sigma(max)) in completely impeded pea roots appear to be from 0.5 to 0.6 MPa, which results from a turgor pressure of about 0.8 MPa. When roots are incompletely impeded, a range of responses has been reported. Roots do not change elongation rate in a simple mechanical way in response to changes in mechanical impedance. Instead, ethylene might play a key role in mediating an increase in root diameter and a decrease in elongation rate. These changes persist for some hours or days after impedance is removed. Differences between species in their ability to penetrate strong soil layers are not related to differences in smax, but appear to be due to differences in root diameter. In rice, differences between cultivars in the ability of their roots to penetrate strong wax layers are not related to their elongation rates through uniformly strong media. Differences between species or cultivars in their ability to penetrate strong layers may be due to differences in the tendency of roots to deflect or buckle when they grow from a weak to a strong environment.