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电子传递的效率，并诱导质体醌和硫氧还蛋白的氧化还原状态的特征变化。这些氧化还原变化引发分子反应，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。已知这种功能反馈机制涉及控制质体和核基因的复杂信号网络，但该网络如何发挥作用在很大程度上是未知的。特别是核基因的控制是复杂的，因为它需要离开细胞器的信号级联。因此，氧化还原信号代表一类新的逆行信号。在微阵列中，我们确定了靶基因和信号的速度，表明氧化还原信号整合光合作用，呼吸，碳水化合物代谢和四吡咯和脂质生物合成。我们的目标是：i）证明这种转录调节在相应的细胞过程中产生功能结果; ii）通过新型突变体筛选和启动子-蛋白质相互作用测定来鉴定相关的信号传导成分。

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.