Liu Zhanji, Yang Xiaohong, Fu Yang, Zhang Yirong, Yan Jianbin, Song Tongming, Rocheford T, Li Jiansheng
National Maize Improvement Center of China, China Agricultural University, Beijing 100094, China.
Mol Biol Rep. 2009 Apr;36(4):813-21. doi: 10.1007/s11033-008-9250-3. Epub 2008 Jun 4.
High-oil maize as a product of long-term selection provides a unique resource for functional genomics. In this study, the abundant soluble proteins of early developing germs from high-oil and normal lines of maize were compared using two-dimensional gel electrophoresis (2-DGE) in combination with mass spectrometry (MS). More than 1100 protein spots were detected on electrophoresis maps of both high-oil and normal lines by using silver staining method. A total of 83 protein spots showed significant differential expression (>two-fold change; t-test: P < 0.05) between high-oil and normal inbred lines. Twenty-seven protein spots including 25 non-redundant proteins were identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS). Functional categorization of these proteins was carbohydrate metabolism, cytoskeleton, protein metabolism, stress response, and lipid metabolism. Three such proteins involved in lipid metabolism, namely putative enoyl-ACP reductase (ENR), putative stearoyl-ACP desaturase (SAD) and putative acetyl-CoA C-acyltransferase (ACA), had more abundant expressions in high-oil lines than in normal. At the mRNA expression level, SAD, ENR and ACA were expressed at significantly higher levels in high-oil lines than in normal. The results demonstrated that high expressions of SAD, ENR and ACA might be associated to increasing oil concentration in high-oil maize. This study represents the first proteomic analysis of high-oil maize and contributes to a better understanding of the molecular basis of oil accumulation in high-oil maize.
高油玉米作为长期选育的产物，为功能基因组学提供了独特的资源。在本研究中，利用二维凝胶电泳（2-DGE）结合质谱（MS）对高油玉米和普通玉米自交系早期发育胚中的丰富可溶性蛋白质进行了比较。采用银染法在高油玉米和普通玉米自交系的电泳图谱上检测到1100多个蛋白点。共有83个蛋白点在高油自交系和普通自交系之间表现出显著差异表达（变化倍数>2倍；t检验：P<0.05）。通过基质辅助激光解吸电离飞行时间质谱（MALDI-TOF-MS）鉴定了27个蛋白点，包括25个非冗余蛋白。这些蛋白质的功能分类为碳水化合物代谢、细胞骨架、蛋白质代谢、应激反应和脂质代谢。其中3个参与脂质代谢的蛋白质，即假定的烯酰-ACP还原酶（ENR）、假定的硬脂酰-ACP去饱和酶（SAD）和假定的乙酰辅酶A C-酰基转移酶（ACA），在高油玉米自交系中的表达比普通玉米自交系中更丰富。在mRNA表达水平上，SAD、ENR和ACA在高油玉米自交系中的表达水平显著高于普通玉米自交系。结果表明，SAD、ENR和ACA的高表达可能与高油玉米中油含量的增加有关。本研究是对高油玉米的首次蛋白质组学分析，有助于更好地理解高油玉米中油脂积累的分子基础。
