Department of Wood Science, University of British Columbia, 2424 Main Mall, Vancouver, BC V6T 1Z4, Canada.
Tree Physiol. 2009 Jul;29(7):937-46. doi: 10.1093/treephys/tpp028. Epub 2009 May 8.
The objective of this study was to manipulate the intracellular pools of sucrose, and investigate its role in regulating plant growth, phenology (leaf senescence and bud break) and fibre development. This objective was achieved by differentially expressing an Arabidopsis (Arabidopsis thaliana L. Heynh.) sucrose phosphate synthase (SPS) gene in hybrid poplar (Populus alba L.xPopulus grandidentata Michx.), a model system for tree biology with substantial industrial relevance in the context of short rotation forestry and a target bioenergy crop. Phenotypic differences were evident in the transgenic trees, as both the timing of bud flush and leaf senescence were altered compared to wild-type (WT) trees. Tree height and stem diameter were similar in WT and in the AtSPS transgenic trees, however, there were differences in the length of xylem fibres. Elevated concentrations of intracellular sucrose in both leaf and stem tissue of the transgenic trees are associated with a prolonged onset of senescence and an advancement in bud flush in the following spring. The association among sucrose content, tree phenology and elevated SPS gene expression implicates both enzyme and product in regulating poplar developmental processes.
本研究的目的是操纵细胞内蔗糖库，研究其在调控植物生长、物候（叶片衰老和芽休眠）和纤维发育中的作用。这一目标通过在杂种白杨（Populus alba L.xPopulus grandidentata Michx.）中差异表达拟南芥（Arabidopsis thaliana L. Heynh.）蔗糖磷酸合成酶（SPS）基因来实现，杂种白杨是树木生物学的模式系统，在短轮伐林业和目标生物能源作物方面具有重要的工业相关性。转基因树木表现出明显的表型差异，因为与野生型（WT）树木相比，芽休眠和叶片衰老的时间都发生了改变。WT 树木和 AtSPS 转基因树木的树高和茎直径相似，但木质部纤维的长度存在差异。转基因树木叶片和茎组织中细胞内蔗糖浓度升高与衰老开始时间延长以及次年春季芽休眠提前有关。蔗糖含量、树木物候和 SPS 基因表达升高之间的联系表明，该酶及其产物都参与了调控杨树的发育过程。
