大豆种子萌发过程中的差异蛋白质组研究

Differential Proteomic Analysis of Seed Germination in Soybean

运用蛋白质组学技术对大豆(Glycinemax)N2899种子萌发0h、8h、36h、60h4个时期蛋白质的差异表达情况进行了研究.结果发现,在考马斯亮蓝染色的双向电泳pH3～10胶上,PDQuest图像分析软件可识别的点约350个,其中表达量变化2.5倍以上的蛋白质点有24个,而绝大部分大豆种子贮藏蛋白在萌发期尚未降解.在萌发的第一阶段,24个差异表达蛋白中有10个蛋白质的丰度发生变化.第二阶段,差异表达蛋白的种类和量增加,其中15个蛋白质是动态变化的,14个蛋白质在胚根突破种皮时表达量达到峰值,表明吸胀后种子内的生命活动越来越强.对这24个蛋白质点进行胶内酶解,用基质辅助激光解析电离飞行时间质谱测定均获得肽质量指纹图谱.搜索大豆的UniGene库初步鉴定出6个蛋白质,分别是核苷二磷酸激酶、热激蛋白、硫氧还蛋白、35ku种子成熟蛋白及种子成熟蛋白PM36.对这些蛋白质在种子萌发过程中可能的作用进行了讨论.

A proteomic approach was used to analyze differential expression of proteins during soybean （Glycine max） N2899 seed germination at specific stages of 0 h, 8 h, 36 h and 60 h after imbibition. The results show that on the 2-DE gels stained by coomassie brilliant blue, PDQuest image software detected about 350 protein spots, of which 24 spots show more than 2.5-fold changes in abundance, and most of soybean seed storage proteins weren＇t mobilized during seed germination. At the first stage of germination, 10 proteins show changes in abundance. At the second stage, the quantities and categories of differentially expressed proteins increased and the abundance of 15 proteins dynamically changed. During radicle protrusion seed coat, the abundance of 14 proteins reached a peak. These suggested that the internal metabolisms of imbibition seeds became more active. These 24 proteins treated by tryptic in-gel digestion were characterized by matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry （MALDI-TOF-MS） and peptide mass fingerprintings of all were obtained. Soybean UniGene database was used to identify proteins, of which 6 proteins were identified. They were nucleotide diphosphate kinase, proglycinin A1aB1b subunit, thioredoxin fold, 35 ku seed maturation protein, heat shock protein and seed maturation protein PM36. The potential functions of these proteins during seed germination were discussed.