Cruz Jeffrey A, Avenson Thomas J, Kanazawa Atsuko, Takizawa Kenji, Edwards Gerald E, Kramer David M
Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USA.
J Exp Bot. 2005 Jan;56(411):395-406. doi: 10.1093/jxb/eri022. Epub 2004 Nov 8.
Plant photosynthesis channels some of the most highly reactive intermediates in biology, in a way that captures a large fraction of their energy to power the plant. A viable photosynthetic apparatus must not only be efficient and robust machinery, but also well integrated into the plant's biochemical and physiological networks. This requires flexibility in its responses to the dramatically changing environmental conditions and biochemical demands. First, the output of the energy-storing light reactions must match the demands of plant metabolism. Second, regulation of the antenna must be flexible to allow responses to diverse challenges that could result in excess light capture and subsequent photoinhibition. Evidence is presented for the interplay of two types of mechanistic flexibility, one that modulates the relative sensitivity of antenna down-regulation to electron flow, and the other, which primarily modulates the output ratio of ATP/NADPH, but also contributes to down-regulation.
植物光合作用以一种捕获大部分能量为植物供能的方式，引导生物学中一些反应活性最高的中间体。一个可行的光合装置不仅必须是高效且强大的机器，还必须很好地整合到植物的生化和生理网络中。这就要求它在应对急剧变化的环境条件和生化需求时具有灵活性。首先，储能光反应的输出必须与植物代谢的需求相匹配。其次，天线的调节必须灵活，以应对可能导致过多光捕获和随后光抑制的各种挑战。本文提供了两种机制灵活性相互作用的证据，一种调节天线下调对电子流的相对敏感性，另一种主要调节ATP/NADPH的输出比例，但也有助于下调。
