Proteomics in plant biotechnology and secondary metabolism research

Proteomics, the systematic analysis of (differentially) expressed proteins, is a tool for the identification of proteins involved in cellular processes. Proteomics has already been used for many different applications in plant sciences, including the study of proteins of biosynthetic pathways leading to secondary metabolites. In secondary metabolism, many enzymes are involved, often working in close collaboration to catalyse cascades of reactions. Besides the enzymes, transport and regulatory proteins are also involved, which makes the proteome an essential topic for studying metabolic pathways, Proteomics technology is based on high-throughput techniques for the separation and identification of proteins, allowing an integral study of many proteins at the same time. For the separation of protein mixtures the most powerful technique available is two-dimensional polyacrylamide gel electrophoresis: after separation, proteins can be subsequently identified by mass spectrometry (MS). The increasing amount of genome sequence data has to be followed by deciphering the function of the genes and proteins. Studying differential expression by proteomics is a complementary tool for functional analysis. In this review practical aspects and applications of proteomics in plant sciences, with particular emphasis on secondary metabolism, are discussed. Copyright (C) 2000 John Wiley & Sons, Ltd.