Bhalerao Rishikesh P, Fischer Urs
Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences, Umeå, SE-90183, Sweden.
Physiol Plant. 2014 May;151(1):43-51. doi: 10.1111/ppl.12134. Epub 2013 Dec 27.
Various aspects of wood formation have been linked to the action of auxin, e.g. cambial activity, dormancy, secondary cell wall deposition and tension wood formation. The presence of a radial auxin concentration gradient across wood-forming tissue has been suggested to regulate cambial activity and differentiation of cambial derivatives by providing positional information to cells within the tissue. Similar patterning mechanisms that depend on the interpretation of auxin thresholds have subsequently been proposed for shoot and root apical meristems. However, direct evidence for the existence of auxin gradients has only been obtained for the cambium of various tree species. While the auxin gradient theory is based on a plethora of descriptive and pharmacological experiments, in recent years, auxin function on wood formation has been underpinned by molecular and functional data. Here, we review the latest progress in understanding the role of auxin in wood formation and discuss how auxin concentration gradients could be established and interpreted in wood-forming tissues.
木材形成的各个方面都与生长素的作用有关，例如形成层活动、休眠、次生细胞壁沉积和张力木形成。有人提出，在木材形成组织中存在一个径向生长素浓度梯度，通过向组织内的细胞提供位置信息来调节形成层活动和形成层衍生物的分化。随后，有人针对茎尖和根尖分生组织提出了类似的依赖于生长素阈值解读的模式形成机制。然而，仅在各种树木的形成层中获得了生长素梯度存在的直接证据。虽然生长素梯度理论基于大量的描述性和药理学实验，但近年来，生长素在木材形成中的作用已得到分子和功能数据的支持。在这里，我们回顾了在理解生长素在木材形成中的作用方面的最新进展，并讨论了生长素浓度梯度如何在木材形成组织中建立和解读。
