Peng Xiaoyan, Qin Zhongliang, Zhang Guopeng, Guo Yaomin, Huang Junli
Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University Chongqing, China.
Front Plant Sci. 2015 Jun 17;6:351. doi: 10.3389/fpls.2015.00351. eCollection 2015.
Leaf vascular system differentiation and venation patterns play a key role in transporting nutrients and maintaining the plant shape, which is an important agronomic trait for improving photosynthetic efficiency. However, there is little knowledge about the regulation of leaf vascular specification and development. Here we utilized the rice midribless mutant (dl2) to investigate the molecular changes in transcriptome and proteome profiles during leaf vascular specification and differentiation. Using isobaric tags for relative and absolute quantification (iTRAQ) with digital gene expression (DGE) techniques, a nearly complete catalog of expressed protein and mRNA was acquired. From the catalog, we reliably identified 3172 proteins and 9,865,230 tags mapped to genes, and subsets of 141 proteins and 98 mRNAs, which were differentially expressed between the dl2 mutant and wild type. The correlation analysis between the abundance of differentially expressed mRNA and DEPs (differentially expressed proteins) revealed numerous discordant changes in mRNA/protein pairs and only a modest correlation was observed, indicative of divergent regulation of transcription and translational processes. The DEPs were analyzed for their involvement in biological processes and metabolic pathways. Up- or down- regulation of some key proteins confirmed that the physiological process of vascular differentiation is an active process. These key proteins included those not previously reported to be associated with vascular differentiation processes, and included proteins that are involved in the spliceosome pathway. Together, our results show that the developmental and physiological process of the leaf vascular system is a thoroughly regulated and complicated process and this work has identified potential targets for genetic modification that could be used to regulate the development of the leaf vasculature.
叶片维管系统的分化和叶脉模式在营养物质运输和维持植物形态方面起着关键作用，而这是提高光合效率的一项重要农艺性状。然而，关于叶片维管特化和发育的调控机制，我们所知甚少。在此，我们利用水稻中脉缺失突变体（dl2）来研究叶片维管特化和分化过程中转录组和蛋白质组图谱的分子变化。采用等压标签相对和绝对定量（iTRAQ）技术结合数字基因表达（DGE）技术，获得了一份几乎完整的表达蛋白和mRNA目录。从该目录中，我们可靠地鉴定出3172种蛋白质以及9865230个映射到基因的标签，还有141种蛋白质和98种mRNA的子集，它们在dl2突变体和野生型之间存在差异表达。对差异表达mRNA丰度与差异表达蛋白（DEPs）之间的相关性分析显示，mRNA/蛋白质对存在大量不一致的变化，仅观察到适度的相关性，这表明转录和翻译过程存在不同的调控。对差异表达蛋白参与的生物学过程和代谢途径进行了分析。一些关键蛋白的上调或下调证实了维管分化的生理过程是一个活跃的过程。这些关键蛋白包括以前未报道与维管分化过程相关的蛋白，以及参与剪接体途径的蛋白。总之，我们的结果表明，叶片维管系统的发育和生理过程是一个受到全面调控且复杂的过程，这项工作已经确定了可用于调控叶片维管系统发育的潜在基因改造靶点。
