Strigolactone-Regulated Proteins Revealed by iTRAQ-Based Quantitative Proteomics in Arabidopsis

Strigolactones (SLs) are a new class of plant hormones. In addition to acting as a key inhibitor of shoot branching, SLs stimulate seed germination of root parasitic plants and promote hyphal branching and root colonization of symbiotic arbuscular mycorrhizal fungi. They also regulate many other aspects of plant growth and development. At the transcription level, SL-regulated genes have been reported. However, nothing is known about the proteome regulated by this new class of plant hormones. A quantitative proteomics approach using an isobaric chemical labeling reagent, iTRAQ, to identify the proteome regulated by SLs in Arabidopsis seedlings is presented. It was found that SLs regulate the expression of about three dozen proteins that have not been previously assigned to SL pathways. These findings provide a new tool to investigate the molecular mechanism of action of SLs.独脚金内酯（Strigolactones, SLs）是一类新型植物激素。除作为地上部分枝的关键抑制剂外，SLs还可诱导根寄生植物的种子萌发，促进共生丛枝菌根真菌的菌丝分枝与根系定殖，并调控植物生长发育的诸多其他环节。在转录水平上，已有研究报道了受SLs调控的基因，但目前尚未见此类新型植物激素调控蛋白质组的相关研究。本研究采用基于同重同位素化学标记试剂iTRAQ的定量蛋白质组学方法，对拟南芥幼苗中受SLs调控的蛋白质组进行了鉴定。研究发现，SLs可调控约三十余种此前未被归属于SL信号通路的蛋白质的表达。上述发现为探究独脚金内酯的分子作用机制提供了全新的研究工具。