The role of root system architecture and root hairs in promoting anchorage against uprooting forces in Allium cepa and root mutants of Arabidopsis thaliana
The role of root system architecture and root hairs in promoting anchorage against uprooting forces in Allium cepa and root mutants of Arabidopsis thaliana
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DOI：
10.1093/jexbot/53.367.333
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发表时间：
2002-02-01
影响因子：
6.9
通讯作者：
Fitter, AH
中科院分区：
文献类型：
--
作者：
Bailey, PHJ;Currey, JD;Fitter, AH
侧根和根毛在促进植物锚固中所起的作用，特别是对垂直拔根力的抵抗已经通过实验确定。研究了两个物种，洋葱（洋葱），它有一个特别简单的根系和两个突变体的拟南芥，一个没有根毛（rhd 2-1），另一个减少侧根分枝（axr 4-2）。单个洋葱根的最大强度随植物年龄的增加而增加。在洋葱幼苗的根拔试验中，根拔抗性可以分解为一系列与单个根的断裂相关的事件。在回归模型中解释了峰值抗拔力的组合的措施，植物的大小和程度的连根拔起阻力的个人根加性。这种加性效应被称为根系合作。提出了一个简单的模型，以证明根的合作在拔除阻力所发挥的作用。在类似的拔根试验拟南芥，突变体axr 4-2，具有非常有限的横向发展，表现出14%的峰值拉阻力相比，野生型植物相似的芽干重。axr 4-2的拔出力轨迹与野生型不同，主轴对锚定的贡献比野生型更大。相比之下，根毛缺失突变体rhd 2-1与野生型相比在拔顶抗性方面没有表现出差异，这表明根毛在拔顶抗性中通常不起作用。结果表明，侧根在锚固中起着重要作用，而根与根之间的协同作用可能是最重要的因素。
The role played by lateral roots and root hairs in promoting plant anchorage, and specifically resistance to vertical uprooting forces has been determined experimentally. Two species were studied, Allium cepa (onion) which has a particularly simple root system and two mutants of Arabidopsis thaliana, one without root hairs (rhd 2-1) and another with reduced lateral root branching (axr 4-2). Maximum strength of individual onion roots within a plant increased with plant age. In uprooting tests on onion seedlings, resistance to uprooting could be resolved into a series of events associated with the breakage of individual roots. Peak pulling resistance was explained in a regression model by a combination of a measure of plant size and the extent to which the uprooting resistance of individual roots was additive. This additive effect is termed root co-operation. A simple model is presented to demonstrate the role played by root co-operation in uprooting resistance. In similar uprooting tests on Arabidopsis thaliana, the mutant axr 4-2, with very restricted lateral development, showed a 14% reduction in peak pulling resistance when compared with the wild-type plants of similar shoot dry weight. The uprooting force trace of axr 4-2 was different to that of the wild type, and the main axis was a more significant contributor to anchorage than in the wild type. By contrast, the root hair-deficient mutant rhd 2-1 showed no difference in peak pulling resistance compared with the wild type, suggesting that root hairs do not normally play a role in uprooting resistance. The results show that lateral roots play an important role in anchorage, and that co-operation between roots may be the most significant factor.