Genetics of proteome variation for QTL characterization: application to drought-stress responses in maize

Abstract

The proteome is emerging as an important concept of the post-genome era.Powerful nucleic acid approaches (EST, DNA chips, etc.) are stilllimited because DNA sequences and mRNA levels are not sufficient topredict the structure, function, amount, and activity of the proteins inthe cell, The proteome can now be subjected tb large-scale analysis,owing to spectacular progress in the techniques of identification ofproteins excised from two-dimensional (2-D) gels. in addition,computer-based analysis of 2-D gels makes it possible to quantify theprotein spot intensities, which are commonly genetically variable. Theloci controlling these variations may be mapped on the genome (PQLs,Protein Quantity Loci), Beyond the interest for regulatory genetics andmolecular biology, the PQL methodology can provide an additional toolfor the difficult task of identifying QTLs (Quantitative Trait Loci), inthe context of the candidate gene approach. The PQL methodology ispresented with the example of the phosphoglycerate mutase Variations inmaize, and the candidate gene/protein approach is illustrated for traitsresponsive to drought stress.