The tAPX-NDH interplay: Its control and signalling impact

类囊体结合的抗坏血酸过氧化物酶(TAPX)的表达在胁迫后的几天内缓慢增加，这导致转录和酶的积累随着时间的推移达到比胁迫前更高的水平。我们最近的工作表明，胁迫后的tAPX调节是植物胁迫记忆的一部分，对指定未来的胁迫信号具有因果重要性。我们认为，tAPX通过与叶绿体NDH(铁氧还蛋白依赖的质醌还原酶)竞争与光系统I的供体部位相互作用，动态地控制类囊体膜中叶绿体到细胞核信号的启动。在我们未来的项目中，我们将分析tAPX-NDH相互作用的控制和信号影响。我们将研究tAPX、光系统、捕光复合体和NDH在类囊体膜上的分布与tAPX丰度和tAPX昼夜调控的关系，并对tAPX的微环境进行质谱分析。为了研究调控tAPX-NDH相互作用的驱动力，我们将在一系列不同的遗传背景下研究tAPX和NDH的调控。我们将扩展最近一项关于tAPX特异性基因调控的RNA-Seq研究，以区分tAPX依赖的基因调控中的NDH活性和NDH结构成分。

Expression of thylakoid-bound ascorbate peroxidase (tAPX) slowly increases for several days in the poststress phase, which leads over time to accumulation of the transcripts and the enzyme to higher levels than the pre-stress ones. Our recent work demonstrated that post-stress tAPX regulation is part of the plant stress memory and of causal importance for specification of future stress signalling. We propose that tAPX dynamically controls initiation of chloroplast-to-nucleus signalling in the thylakoid membrane by competing with plastid NDH (ferredoxin-dependent plastoquinone reductase) for interaction with the donor site of photosystem I.In our future project, we will analyse the control and signalling impact of the tAPX-NDH interplay. We will investigate the distribution of tAPX, of the photosystems, light harvesting complexes and NDH in the thylakoid membrane with respect to tAPX abundance and diurnal tAPX regulation and analyse the micro-environment of tAPX mass-spectrometrically. To investigate the driving forces regulating the tAPX-NDH interplay, we will study tAPX and NDH regulation in a series of differentiating genetic backgrounds. We will extent a recent RNA-Seq study on tAPX-specific gene regulation to differentiate the NDH activity and NDH structural components in tAPX-dependent gene regulation.