Osuna Daniel, Usadel Bjorn, Morcuende Rosa, Gibon Yves, Bläsing Oliver E, Höhne Melanie, Günter Manuela, Kamlage Beate, Trethewey Richard, Scheible Wolf-Rüdiger, Stitt Mark
Max-Planck-Institute for Molecular Plant Physiology, Am Mühlenberg 1, 14476 Golm, Germany.
Plant J. 2007 Feb;49(3):463-91. doi: 10.1111/j.1365-313X.2006.02979.x. Epub 2007 Jan 1.
Arabidopsis seedlings were subjected to 2 days of carbon starvation, and then resupplied with 15 mm sucrose. The transcriptional and metabolic response was analyzed using ATH1 arrays, real-time quantitative (q)RT-PCR analysis of >2000 transcription regulators, robotized assays of enzymes from central metabolism and metabolite profiling. Sucrose led within 30 min to greater than threefold changes of the transcript levels for >100 genes, including 20 transcription regulators, 15 ubiquitin-targeting proteins, four trehalose phosphate synthases, autophagy protein 8e, several glutaredoxins and many genes of unknown function. Most of these genes respond to changes of endogenous sugars in Arabidopsis rosettes, making them excellent candidates for upstream components of sugar signaling pathways. Some respond during diurnal cycles, consistent with them acting in signaling pathways that balance the supply and utilization of carbon in normal growth conditions. By 3 h, transcript levels change for >1700 genes. This includes a coordinated induction of genes involved in carbohydrate synthesis, glycolysis, respiration, amino acid and nucleotide synthesis, DNA, RNA and protein synthesis and protein folding, and repression of genes involved in amino acid and lipid catabolism, photosynthesis and chloroplast protein synthesis and folding. The changes of transcripts are followed by a delayed activation of central metabolic pathways and growth processes, which use intermediates from these pathways. Sucrose and reducing sugars accumulate during the first 3-8 h, and starch for 24 h, showing that there is a delay until carbon utilization for growth recommences. Gradual changes of enzyme activities and metabolites are found for many metabolic pathways, including glycolysis, nitrate assimilation, the shikimate pathway and myoinositol, proline and fatty acid metabolism. After 3-8 h, there is a decrease of amino acids, followed by a gradual increase of protein.
拟南芥幼苗先经历2天的碳饥饿处理，然后再供应15 mM的蔗糖。使用ATH1芯片、对2000多个转录调节因子进行实时定量(q)RT-PCR分析、对中心代谢酶进行自动化检测以及代谢物谱分析来研究转录和代谢反应。蔗糖在30分钟内导致100多个基因的转录水平发生三倍以上的变化，其中包括20个转录调节因子、15个泛素靶向蛋白、4个海藻糖磷酸合酶、自噬蛋白8e、几个谷氧还蛋白以及许多功能未知的基因。这些基因中的大多数对拟南芥莲座叶中内源糖的变化有反应，使其成为糖信号通路上游成分的极佳候选者。有些基因在昼夜周期中会有反应，这与它们在正常生长条件下平衡碳供应和利用的信号通路中发挥作用一致。到3小时时，超过1700个基因的转录水平发生变化。这包括参与碳水化合物合成、糖酵解、呼吸作用、氨基酸和核苷酸合成、DNA、RNA和蛋白质合成以及蛋白质折叠的基因的协同诱导，以及参与氨基酸和脂质分解代谢、光合作用以及叶绿体蛋白质合成和折叠的基因的抑制。转录本变化之后，中心代谢途径和生长过程会延迟激活，这些过程利用这些途径的中间产物。蔗糖和还原糖在最初3 - 8小时内积累，淀粉在24小时内积累，这表明直到重新开始用于生长的碳利用之前存在延迟。许多代谢途径，包括糖酵解、硝酸盐同化、莽草酸途径以及肌醇、脯氨酸和脂肪酸代谢，其酶活性和代谢物都有逐渐变化。3 - 8小时后，氨基酸减少，随后蛋白质逐渐增加。
