A number of species within the Brassicaceae family have been identified as metal accumulators. To understand fully the genetics of metal accumulation, the vast genetic resources developed in A. thaliana must be extended to other metal accumulator species that display traits absent in this model species. A. thaliana microarray chips could be used to identify differentially expressed genes in metal accumulator plants in Brassicaceae. The integration of resources obtained from model and wild species of the Brassicaceae family will be of utmost importance, bringing most of the diverse fields of plant biology together such as functional genomics, population genetics, phylogenetics, and ecology. Further development of phytoremediation requires an integrated multidisciplinary research effort that combines plant biology, genetic engineering, soil chemistry, soil microbiology, as well as agricultural and environmental engineering.

Binding to Golgi membranes of ADP ribosylation factor 1 (ARF1) is the first event in the initiation of COPI coat assembly. Based on binding studies, a proteinaceous receptor has been proposed to be critical for this process. We now report that p23, a member of the p24 family of Golgi‐resident transmembrane proteins, is involved in ARF1 binding to membranes. Using a cross‐link approach based on a photolabile peptide corresponding to the cytoplasmic domain of p23, the GDP form of ARF1 (ARF1‐GDP) is shown to interact with p23 whereas ARF1‐GTP has no detectable affinity to p23. The p23 binding is shown to localize specifically to a 22 amino acid C‐terminal fragment of ARF1. While a monomeric form of a non‐photolabile p23 peptide does not significantly inhibit formation of the cross‐link product, the corresponding dimeric form does compete efficiently for this interaction. Consistently, the dimeric p23 peptide strongly inhibits ARF1 binding to native Golgi membranes suggesting that an oligomeric form of p23 acts as a receptor for ARF1 before nucleotide exchange takes place.