Liang Chao, Cheng Shifeng, Zhang Youjun, Sun Yuzhe, Fernie Alisdair R, Kang Kang, Panagiotou Gianni, Lo Clive, Lim Boon Leong
School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China.
Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany.
BMC Plant Biol. 2016 Feb 11;16:43. doi: 10.1186/s12870-016-0726-3.
Light plays an important role in plant growth and development. In this study, the impact of light on physiology of 20-d-old Arabidopsis leaves was examined through transcriptomic, proteomic and metabolomic analysis. Since the energy-generating electron transport chains in chloroplasts and mitochondria are encoded by both nuclear and organellar genomes, sequencing total RNA after removal of ribosomal RNAs provides essential information on transcription of organellar genomes. The changes in the levels of ADP, ATP, NADP(+), NADPH and 41 metabolites upon illumination were also quantified.
Upon illumination, while the transcription of the genes encoded by the plastid genome did not change significantly, the transcription of nuclear genes encoding different functional complexes in the photosystem are differentially regulated whereas members of the same complex are co-regulated with each other. The abundance of mRNAs and proteins encoded by all three genomes are, however, not always positively correlated. One such example is the negative correlation between mRNA and protein abundances of the photosystem components, which reflects the importance of post-transcriptional regulation in plant physiology.
This study provides systems-wide datasets which allow plant researchers to examine the changes in leaf transcriptomes, proteomes and key metabolites upon illumination and to determine whether there are any correlations between changes in transcript and protein abundances of a particular gene or pathway upon illumination. The integration of data of the organelles and the photosystems, Calvin-Benson cycle, carbohydrate metabolism, glycolysis, the tricarboxylic acid cycle and respiratory chain, thereby provides a more complete picture to the changes in plant physiology upon illumination than has been attained to date.
光在植物生长发育中起着重要作用。在本研究中，通过转录组学、蛋白质组学和代谢组学分析，研究了光对20日龄拟南芥叶片生理的影响。由于叶绿体和线粒体中产生能量的电子传递链由核基因组和细胞器基因组共同编码，去除核糖体RNA后对总RNA进行测序可提供有关细胞器基因组转录的重要信息。同时还对光照后ADP、ATP、NADP(+)、NADPH和41种代谢物水平的变化进行了定量分析。
光照后，虽然质体基因组编码的基因转录没有显著变化，但编码光系统中不同功能复合物的核基因转录受到差异调节，而同一复合物的成员之间相互协同调节。然而，由所有三个基因组编码的mRNA和蛋白质丰度并不总是呈正相关。一个例子是光系统组分的mRNA和蛋白质丰度之间呈负相关，这反映了转录后调控在植物生理学中的重要性。
本研究提供了全系统的数据集，使植物研究人员能够研究光照后叶片转录组、蛋白质组和关键代谢物的变化，并确定光照后特定基因或途径的转录和蛋白质丰度变化之间是否存在任何相关性。细胞器与光系统、卡尔文-本森循环、碳水化合物代谢、糖酵解、三羧酸循环和呼吸链的数据整合，从而比迄今为止所获得的信息更完整地呈现了光照后植物生理学的变化情况。
