Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan.
Physiol Plant. 2013 Jan;147(1):46-54. doi: 10.1111/j.1399-3054.2012.01663.x. Epub 2012 Jul 11.
The timing of cambial reactivation plays an important role in determination of the amount and quality of wood and the environmental adaptivity of trees. Environmental factors, such as temperature, influence the growth and development of trees. Temperatures from late winter to early spring affect the physiological processes that are involved in the initiation of cambial cell division and xylem differentiation in trees. Cumulative elevated temperatures from late winter to early spring result in earlier initiation of cambial reactivation and xylem differentiation in tree stems and an extended growth period. However, earlier cambial reactivation increases the risk for frost damage because the cold tolerance of cambium decreases after cambial reactivation. The present review focuses on temperature regulation on the timing of cambial reactivation and xylem differentiation in trees, and also highlights recent advances in our understanding of seasonal changes in the cold stability of microtubules in trees. The review also summarizes the present understanding of the relationships between the timing of cambial reactivation, the start of xylem differentiation and changes in levels of storage materials in trees, as well as an attempt to identify the source of energy for cell division and differentiation. A better understanding of the mechanisms that regulate wood formation in trees and the influence of environmental conditions on such mechanisms should help in efforts to improve and enhance the exploitation of wood for commercial applications and to prepare for climatic change.
形成层活动时间的确定在树木木材的数量和质量以及树木的环境适应性方面起着重要作用。环境因素，如温度，影响树木的生长和发育。从冬末到早春的温度影响与形成层细胞分裂和木质部分化起始有关的生理过程。冬末到早春的累积高温导致树木茎干中形成层活动的更早启动和更长的生长周期，以及木质部分化。然而，较早的形成层活动会增加遭受霜害的风险，因为形成层活动后，形成层的耐寒性降低。本综述重点介绍了温度对树木形成层活动和木质部分化时间的调控，并强调了我们对树木中微管冷稳定性季节性变化的理解的最新进展。综述还总结了目前对形成层活动时间、木质部分化开始和树木中储存物质水平变化之间关系的理解，以及试图确定细胞分裂和分化的能量来源。更好地了解调节树木木材形成的机制以及环境条件对这些机制的影响，应有助于努力改进和增强木材在商业应用中的利用，并为气候变化做好准备。
