Biochemistry and Physiology of Plants, Faculty of Biology, University of Bielefeld, 33501, Bielefeld, Germany.
Physiol Plant. 2018 Mar;162(3):262-273. doi: 10.1111/ppl.12644. Epub 2017 Nov 7.
Retrograde signals from the chloroplast control expression of nuclear genes. A large fraction of these genes is affected rapidly upon light intensity shifts. This study was designed to address the interdependence of signaling pathways involved in the rapid high light response and redox and reactive oxygen species signaling by exploiting the glutathione and ascorbate deficient mutants pad2 and vtc1. In the first set of experiments the transcriptional response of the two transcription factors ERF6 and ERF105 that had previously been shown to rapidly respond to light was shown to be deregulated in the pad2 mutant but not in the vtc1 background. The transcriptional response after combining the low-to-high light transfer with methylviologen pretreatment further demonstrated the significance of glutathione in strongly modulating the retrograde response. Transcripts encoding small heat shock proteins (HSP17.4, HSP176a, HSP20-like1 and HSP20-like2) and the lipid transfer protein LTP3 were taken as markers responding to the combinatorial treatment in wild type, and most strongly in pad2 in high light or upon methylviologen treatment. A correlation with H O accumulation was not observed. It is concluded that glutathione-dependent processes participate in light-triggered rapid gene regulation independent on cellular H O .
叶绿体逆行信号控制核基因的表达。这些基因中有很大一部分会在光强变化时迅速受到影响。本研究旨在通过利用谷胱甘肽和抗坏血酸缺陷突变体 pad2 和 vtc1，解决参与快速高光响应以及氧化还原和活性氧信号通路之间的相互依赖性。在第一组实验中，先前已经表明快速响应光的两个转录因子 ERF6 和 ERF105 的转录反应在 pad2 突变体中失调，但在 vtc1 背景中没有失调。将低光到高光转换与甲基紫精预处理相结合后的转录反应进一步证明了谷胱甘肽在强烈调节逆行反应中的重要性。编码小热休克蛋白 (HSP17.4、HSP176a、HSP20-like1 和 HSP20-like2) 和脂质转移蛋白 LTP3 的转录本被用作响应组合处理的标记物，在野生型中以及在高光或甲基紫精处理中，pad2 中最为强烈。未观察到与 H2O2 积累的相关性。因此可以得出结论，谷胱甘肽依赖性过程参与了独立于细胞 H2O2 的光触发的快速基因调控。
