Ruttink Tom, Arend Matthias, Morreel Kris, Storme Véronique, Rombauts Stephane, Fromm Jörg, Bhalerao Rishikesh P, Boerjan Wout, Rohde Antje
Department of Plant Systems Biology, Flanders Institute for Biotechnology, 9052 Gent, Belgium.
Plant Cell. 2007 Aug;19(8):2370-90. doi: 10.1105/tpc.107.052811. Epub 2007 Aug 10.
The growth of perennial plants in the temperate zone alternates with periods of dormancy that are typically initiated during bud development in autumn. In a systems biology approach to unravel the underlying molecular program of apical bud development in poplar (Populus tremula x Populus alba), combined transcript and metabolite profiling were applied to a high-resolution time course from short-day induction to complete dormancy. Metabolite and gene expression dynamics were used to reconstruct the temporal sequence of events during bud development. Importantly, bud development could be dissected into bud formation, acclimation to dehydration and cold, and dormancy. To each of these processes, specific sets of regulatory and marker genes and metabolites are associated and provide a reference frame for future functional studies. Light, ethylene, and abscisic acid signal transduction pathways consecutively control bud development by setting, modifying, or terminating these processes. Ethylene signal transduction is positioned temporally between light and abscisic acid signals and is putatively activated by transiently low hexose pools. The timing and place of cell proliferation arrest (related to dormancy) and of the accumulation of storage compounds (related to acclimation processes) were established within the bud by electron microscopy. Finally, the identification of a large set of genes commonly expressed during the growth-to-dormancy transitions in poplar apical buds, cambium, or Arabidopsis thaliana seeds suggests parallels in the underlying molecular mechanisms in different plant organs.
温带多年生植物的生长与休眠期交替出现，休眠期通常在秋季芽发育期间开始。在一种系统生物学方法中，为了解析杨树（欧洲山杨×银白杨）顶芽发育的潜在分子程序，将转录组和代谢物谱分析应用于从短日照诱导到完全休眠的高分辨率时间进程。代谢物和基因表达动态用于重建芽发育过程中事件的时间顺序。重要的是，芽发育可分为芽形成、对脱水和寒冷的适应以及休眠。对于这些过程中的每一个，都有特定的调控基因、标记基因和代谢物与之相关联，并为未来的功能研究提供了一个参考框架。光、乙烯和脱落酸信号转导途径通过启动、调节或终止这些过程来连续控制芽发育。乙烯信号转导在时间上位于光信号和脱落酸信号之间，可能由短暂的低己糖池激活。通过电子显微镜确定了芽内细胞增殖停滞（与休眠相关）和储存化合物积累（与适应过程相关）的时间和位置。最后，在杨树顶芽、形成层或拟南芥种子从生长到休眠转变过程中共同表达的大量基因的鉴定表明，不同植物器官的潜在分子机制存在相似之处。
