Llorente Briardo, D'Andrea Lucio, Rodríguez-Concepción Manuel
Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB Barcelona, Spain.
Front Plant Sci. 2016 Mar 7;7:263. doi: 10.3389/fpls.2016.00263. eCollection 2016.
Besides an essential source of energy, light provides environmental information to plants. Photosensory pathways are thought to have occurred early in plant evolution, probably at the time of the Archaeplastida ancestor, or perhaps even earlier. Manipulation of individual components of light perception and signaling networks in tomato (Solanum lycopersicum) affects the metabolism of ripening fruit at several levels. Most strikingly, recent experiments have shown that some of the molecular mechanisms originally devoted to sense and respond to environmental light cues have been re-adapted during evolution to provide plants with useful information on fruit ripening progression. In particular, the presence of chlorophylls in green fruit can strongly influence the spectral composition of the light filtered through the fruit pericarp. The concomitant changes in light quality can be perceived and transduced by phytochromes (PHYs) and PHY-interacting factors, respectively, to regulate gene expression and in turn modulate the production of carotenoids, a family of metabolites that are relevant for the final pigmentation of ripe fruits. We raise the hypothesis that the evolutionary recycling of light-signaling components to finely adjust pigmentation to the actual ripening stage of the fruit may have represented a selective advantage for primeval fleshy-fruited plants even before the extinction of dinosaurs.
除了作为一种重要的能量来源外，光还为植物提供环境信息。光感通路被认为在植物进化早期就已出现，可能是在古质体祖先时期，甚至可能更早。对番茄（Solanum lycopersicum）光感知和信号网络中各个组分的操控会在多个层面影响成熟果实的代谢。最引人注目的是，最近的实验表明，一些最初用于感知和响应环境光信号的分子机制在进化过程中被重新利用，为植物提供有关果实成熟进程的有用信息。特别是，绿色果实中叶绿素的存在会强烈影响透过果实果皮过滤的光的光谱组成。光质的相应变化可分别被光敏色素（PHYs）和与PHY相互作用的因子感知和转导，从而调节基因表达，进而调节类胡萝卜素的产生，类胡萝卜素是一类与成熟果实最终色素沉着相关的代谢产物。我们提出一个假说，即在恐龙灭绝之前，光信号组分的进化循环利用以根据果实的实际成熟阶段精细调节色素沉着，这可能对原始肉质果实植物具有选择性优势。
