Arabidopsis and primary photosynthetic metabolism - more than the icing on the cake.

Historically speaking, Arabidopsis was not the plant of choice for investigating photosynthesis, with physiologists and biochemists favouring other species such as Chlorella, spinach and pea. However, its inherent advantages for forward genetics rapidly led to its adoption for photosynthesis research. In the last ten years, the availability of the Arabidopsis genome sequence - still the gold-standard for plant genomes - and the rapid expansion of genetic and genomic resources have further increased its importance. Research in Arabidopsis has not only provided comprehensive information about the enzymes and other proteins involved in photosynthesis, but has also allowed transcriptional responses, protein levels and compartmentation to be analysed at a global level for the first time. Emerging technical and theoretical advances offer another leap forward in our understanding of post-translational regulation and the control of metabolism. To illustrate the impact of Arabidopsis, we provide a historical review of research in primary photosynthetic metabolism, highlighting the role of Arabidopsis in elucidation of the pathway of photorespiration and the regulation of RubisCO, as well as elucidation of the pathways of starch turnover and studies of the significance of starch for plant growth.