桑树雌花不同组织蛋白质表达谱的差异分析

Protein Profile Characterization of Different Tissues from Mulberry Pistillate Flower

通过差异蛋白质组学分析探讨桑树雌花组织与发育、抗性相关的分子机制。以果桑品种大10为材料,采用二维凝胶电泳技术获得盛花期雌花花柱(带柱头)与子房2个组织的蛋白质双向电泳图谱,分别检测到382和348个蛋白质斑点,在26个表达差异显著的蛋白质斑点中,有20个为花柱特异表达蛋白质斑点。采用质谱分析、数据库检索及生物信息学分析方法,鉴定了20种花柱特异表达蛋白质组分,主要涉及乙烯的生物合成、植物应答防御、氧化还原反应以及光合作用。与子房相比,花柱中的葡聚糖内-1,3-β-葡糖苷酶呈上调表达,而脂氧合酶呈下调表达,二者分别涉及细胞壁代谢和脂质氧化反应。推测在桑雌花不同组织中这些差异表达的蛋白质可能与花粉萌发、花粉管生长或抵御异源物质的入侵有关。

This experiment was conducted to explore molecular mechanisms about mulberry pistillate flower tissues in relation with development and resistance of mulberry tree by differential proteomic analysis. With fruit mulberry variety Da 10 as material, two-dimensional electrophoresis （2-DE） patterns of style （with stigma） and ovary proteins were obtained from mulberry pistillate flowers at full-bloom stage. 382 and 348 protein spots were detected from the style and ovary tis- sues, respectively. 26 significant differential protein spots were detected based on 2-DE image analysis, among which 20 protein spots were specially expressed in the style. By mass spectrometry analysis, database search and bioinformat- ics analysis, 20 specifically protein components expressed in the style were identified. They were mainly involved in the biosynthetic metabolism of ethylene, plant defenses, photosynthetic reaction and oxidation-reduction reaction. Compared to ovary, style had an up-regulated expression of glucan endo-1,3-beta-glucosidase that is involved in cell wall metabolism and a down-regulated expression of lipoxygenase that participates in membrane lipid oxidation reaction. It could be speculated that these differentially expressed proteins in different tissues of mulberry pistillate flower are related to pollen germination, pollen tube growth or defense against xenobiotics intrusion.