Proteomic analysis of broccoli sprouts by iTRAQ in response to jasmonic acid.

Jasmonic acid (JA) is well known as a linolenic acid-derived signal molecule related to the plant response to biotic and abiotic stresses. JA can regulate various plant metabolisms, such as glucosinolate metabolism. In this study, the proteome profiles of broccoli sprouts under JA treatment were analyzed using the iTRAQ-based quantitative proteome approach. A total of 122 differentially expressed proteins participating in a wide range of physiological processes were confidently identified in broccoli sprouts treated with JA. Functional classification analysis showed that photosynthesis and protein synthesis were inhibited by JA treatment, thereby inhibiting sprout growth, while proteins related to carbohydrate catabolism and amino acid metabolism showed an increased expression. Additionally, proteins involved in defense and secondary metabolism were also up-regulated. Proteins related to glucosinolate biosynthesis and degradation were mediated by JA, leading to the accumulation of glucosinolates and sulforaphane. These results indicate that JA stimulated a defense response at the proteome level by redirecting metabolism of growth and physiology in broccoli sprouts.