Park Sunchung, Keathley Daniel E, Han Kyung-Hwan
Department of Forestry, Michigan State University, East Lansing, MI 48824-1222, USA.
Tree Physiol. 2008 Mar;28(3):321-9. doi: 10.1093/treephys/28.3.321.
Cycling between vegetative growth and dormancy is an important adaptive mechanism in temperate woody plants. To gain insights into the underlying molecular mechanisms, we carried out global transcription analyses on stem samples from poplar (Populus deltoides Bartr. ex Marsh.) trees grown in the field and in controlled environments. Among seasonal changes in the transcriptome, up-regulation of defense-related genes predominated in early winter, whereas signaling-related genes were up-regulated during late winter. Cluster analysis of the differentially expressed genes showed that plants regulated seasonal growth by integrating environmental factors with development. Short day lengths induced some cold-associated genes without concomitant low temperature exposure, and enhanced the expression of some genes when combined with low temperature exposure. These mechanisms appear to maintain closer synchrony between cold hardiness and climate than would be achieved through responses to temperature alone.
营养生长和休眠之间的循环是温带木本植物的一种重要适应机制。为了深入了解其潜在的分子机制，我们对在田间和可控环境中生长的杨树（Populus deltoides Bartr. ex Marsh.）树干样本进行了全转录组分析。在转录组的季节性变化中，防御相关基因的上调在初冬占主导，而信号相关基因在冬末上调。对差异表达基因的聚类分析表明，植物通过整合环境因素和发育来调节季节性生长。短日照在没有伴随低温暴露的情况下诱导了一些与寒冷相关的基因，并在与低温暴露结合时增强了一些基因的表达。这些机制似乎比仅通过对温度的反应能在抗寒性和气候之间保持更紧密的同步。
