Hejazi Mahdi, Mahlow Sebastian, Fettke Joerg
a Plant Physiology; Institute of Biochemistry and Biology; University of Potsdam; Potsdam-Golm, Germany.
Plant Signal Behav. 2014;9(7):e28892. doi: 10.4161/psb.28892.
Starch phosphorylation mediated by the α-glucan, water dikinase (GWD) is crucial for transitory starch metabolism. The impact of the GWD action on transitory starch metabolism was analyzed in Arabidopsis mutants either lacking or revealing different reduced levels of GWD activity. In these mutants, glucose 6-phosphate (G6P) levels of the transitory leaf starch, the average leaf starch content, as well as alterations in the growth phenotype were determined under different light length conditions, including continuous light. Based on biochemical and growth phenotypical data, we found that the length of the light phase affects the phosphorylation state of the transitory starch and, by this, the average leaf starch content and the resulting growth of the plants. Additionally, we discuss data referring to an involvement of the GWD mediated glucan phosphorylation in starch synthesis, as, e.g., starch phosphorylation occurred even when a dark phase was omitted.
由α-葡聚糖水二激酶（GWD）介导的淀粉磷酸化对暂存淀粉代谢至关重要。在缺乏或具有不同程度降低的GWD活性的拟南芥突变体中，分析了GWD作用对暂存淀粉代谢的影响。在包括连续光照在内的不同光照时长条件下，测定了这些突变体中暂存叶淀粉的葡萄糖6-磷酸（G6P）水平、平均叶淀粉含量以及生长表型的变化。基于生化和生长表型数据，我们发现光期的长度会影响暂存淀粉的磷酸化状态，进而影响平均叶淀粉含量以及由此产生的植物生长。此外，我们还讨论了有关GWD介导的葡聚糖磷酸化参与淀粉合成的数据，例如，即使省略暗期，淀粉磷酸化仍会发生。
