Content area
Full Text
Mol Biol Rep (2009) 36:813821 DOI 10.1007/s11033-008-9250-3
Proteomic analysis of early germs with high-oil and normal inbred lines in maize
Zhanji Liu Xiaohong Yang Yang Fu Yirong Zhang Jianbin Yan Tongming Song T. Rocheford Jiansheng Li
Received: 3 February 2008 / Accepted: 1 April 2008 / Published online: 4 June 2008 Springer Science+Business Media B.V. 2008
Abstract 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 signicant 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 identied by matrix-assisted laser desorption/ionization-time of ight 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 signicantly
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 rst proteomic analysis of high-oil maize and contributes to a better understanding of the molecular basis of oil accumulation in high-oil maize.
Keywords Germ High-oil maize Proteome
Real-time PCR
Introduction
As a special kind of maize with more than 6% oil concentration in the grain [1], high-oil maize has a larger germ (scutella and embryo) because 85% of the oil is stored in the germ [2]. Recently, it has received increased interest, especially in the developed world, because of its higher caloric content and better protein quality. High-oil maize was developed by human long-term selection. In 1896, scientists at the University of Illinois began the longest ongoing genetic selection experiment to change the kernel composition in terms of...