Proteomics and metabolomics analyses reveal the cucurbit sieve tube system as a complex metabolic space
Proteomics and metabolomics analyses reveal the cucurbit sieve tube system as a complex metabolic space
复制标题
DOI：
10.1111/tpj.13209
复制
发表时间：
2016-09-01
期刊：
影响因子：
7.2
通讯作者：
Lucas, William J.
中科院分区：
文献类型：
--
作者：
Hu, Chaoyang;Ham, Byung-Kook;Lucas, William J.
植物维管系统，特别是韧皮部，在向发育中的汇器官分配固定碳方面起着关键作用。虽然糖和氨基酸的装载和卸载过程已经被很好地描述，但关于筛管系统（STS）中沿着该途径特定位点的其他代谢物的性质的信息很少。在这里，我们阐明了韧皮部酶沿着葫芦STS绘制的代谢物组成的空间特征。从黄瓜、西瓜和南瓜的加载区（源区）、卸载区（顶汇区）和茎根交界区采集韧皮部汁液（PS）。我们的PS分析显示，这三种葫芦的源库途径和STSs之间的代谢和蛋白质组学特征存在显著差异。此外，在PS和维管组织中建立的代谢物谱表明存在不同的成分，这与STS作为一个独特的辛质域的运作一致。在这方面，在STS的不同位置，我们可以将代谢物及其相关酶映射到特定的代谢途径。这些发现讨论了STS作为植物维管系统中一个独特和高度复杂的代谢空间的功能。
The plant vascular system, and specifically the phloem, plays a pivotal role in allocation of fixed carbon to developing sink organs. Although the processes involved in loading and unloading of sugars and amino acids are well characterized, little information is available regarding the nature of other metabolites in the sieve tube system (STS) at specific sites along the pathway. Here, we elucidate spatial features of metabolite composition mapped with phloem enzymes along the cucurbit STS. Phloem sap (PS) was collected from the loading (source), unloading (apical sink region) and shoot-root junction regions of cucumber, watermelon and pumpkin. Our PS analyses revealed significant differences in the metabolic and proteomic profiles both along the source-sink pathway and between the STSs of these three cucurbits. In addition, metabolite profiles established for PS and vascular tissue indicated the presence of distinct compositions, consistent with the operation of the STS as a unique symplasmic domain. In this regard, at various locations along the STS we could map metabolites and their related enzymes to specific metabolic pathways. These findings are discussed with regard to the function of the STS as a unique and highly complex metabolic space within the plant vascular system.