Differential proteome analysis of mature and germinated seeds of Magnolia sieboldii K. Koch.

摘要

Magnolia sieboldii K. Koch is an ornamental tree. The deep dormancy of its seeds hinders its cultivation for economic purposes. The biochemical basis of the regulation of seed germination remains poorly understood. The present study aimed to identify differentially expressed proteins in germinated seeds of M. sieboldii using polyethylene glycol fractionation. In total, 59 differentially expressed protein spots from two-dimensional gel maps were detected, 33 of which were identified by mass spectrometry. They were assigned to eight functional classes on the basis of their putative biological functions: photosynthesis (3%), chaperonin/heat shock protein (9%), protein and amino acid synthesis (9%), stress/defense (18%), cytoskeleton structure (3%), metabolism (18%), hormone and polyamine (9%) and storage proteins (31%). Among the other functions, the effects of plant hormones on seed germination may be one of the most important functions in plant growth. Gibberellins and ethylene positively regulate seed germination. The activities of several hormone-associated proteins possibly influencing seed germination were increased. The characterization of these proteins will be of great help in identifying the molecular mechanism underlying seed germination.