The study of photosynthesis in higher plants will benefit significantly from the sequencing of the entire genome of Arabidopsis thaliana and from the recent development of new genomic technologies. For large sets of genes, it is now possible to identify their functions and levels of expression, and the post-translational modifications and interactions of their products. This functional genomic approach to photosynthesis is summarised here by considering the application of knock-out mutant screens (forward genetics), the identification of mutant alleles of genes whose sequence is known (reverse genetics), the use of microarrays to detect gene expression at genome level, the separation of proteins by two-dimensional electrophoresis, and their identification by mass spectrometry and bioinformatics. This emerging, integrated approach to the elucidation of gene function is presented and its potential is discussed. (C) 2001 Editions scientifiques et medicales Elsevier SAS.