Intersystem photosynthetic redox signals in retrograde chloroplast-to-nucleus communication of higher plant cells

植物光照的环境波动影响光合作用电子传递的效率，并诱导叶绿体醌和硫氧还蛋白氧化还原状态的特征变化。这些氧化还原变化启动了分子反应，使光合作用过程适应生存条件，并帮助植物在不断变化的环境中生存。众所周知，这种功能反馈机制涉及一个复杂的信号网络，它控制着叶绿体和核基因，但这个网络如何发挥作用在很大程度上是未知的。尤其是核基因的控制是复杂的，因为它需要(A)离开细胞器的信号级联(S)。因此，氧化还原信号代表了一类新的逆行信号。在芯片中，我们确定了目标基因和信号的速度，表明氧化还原信号整合了光合作用、呼吸作用、碳水化合物代谢以及四吡咯和脂肪的生物合成。我们的目标是：1)证明这种转录调控在各自的细胞过程中产生功能结果；2)通过新的突变筛选和启动子-蛋白质相互作用分析确定相关的信号成分。

Environmental fluctuations in plant illumination affect the efficiency of the photosynthetic electron transport and induce characteristic changes in the redox state of plastoquinone and thioredoxin. These redox changes initiate molecular responses which acclimate the photosynthetic process to the residing conditions and help the plant to survive in an everchanging environment. It is known that this functional feed-back mechanism involves a complex signalling network which controls plastid and nuclear genes, but how this network functions is largely unknown. Especially the control of nuclear genes is complex since it requires (a) signalling cascade(s) which leave(s) the organelle. Redox signals, therefore, represent a novel class of retrograde signals. In microarrays we identified the target genes and the velocity of the signals indicating that redox signals integrate photosynthesis, respiration, carbohydrate metabolism and tetrapyrrole and lipid biosynthesis. We aim i) to demonstrate that this transcriptional regulation produce functional outcomes in the respective cellular processes and ii) to identify the involved signalling components by novel mutant screens and promoter-protein interaction assays.