The Use of Proteome and Transcriptome Profiling in the Understanding of Seed Germination and Identification of Intrinsic Markers Determining Seed Quality, Germination Efficiency and Early Seedling Vigour

摘要

In order to better understand seed germination and identify molecular markers of seed vigour, two global expression-profiling methods have been used (i.e. proteomics and tran-scriptomics) on the model plant Ambidopsis (Ambidopsis thaliana (L.) Heynh.). The requirements for germination, in terms of protein and RNA syntheses, were studied. Approximately 400 seed proteins were identified by mass spectrometry. In addition to the storage proteins, dry mature seeds contain a number of other proteins, including enzymes that are required for the resumption of metabolism during the early stages of germination. Moreover, the use of alpha-amanitin demonstrated that, even in the absence of transcription, radicle protrusion can still occur. This suggests that diy mature seeds possess all the stored mRNAs and proteins necessary and sufficient for germination. Transcriptomic experiments carried out using an oligo-based microarray, covering the entire genome of Arabidopsis, revealed that 6500 genes are differentially regulated during germination. Furthermore, a clustering analysis unravelled specific sets of genes that are expressed at different phases of the germination process. This combined approach allowed, for the first time, the comparison of proteomic andtranscrip-tomic data for such a complex developmental process and the discovery of novel features of seed germination.