Tomato and barley contain duplicated copies of cryptochrome 1

The cryptochrome family of blue-light photoreceptors is involved in the con trol of plant photomorphogenesis and photoperiodic responses. Two cryptochr omes have been described in Arabidopsis and tomato. To investigate the comp osition of the cryptochrome gene family in angiosperms, we used a 'garden P CR' approach, amplifying DNA from different plant species with the same pai r of degenerated oligonucleotides representing conserved sequences from the flavin-binding domain. Different numbers of Cry-homologous sequences were found in different species: two each in Arabidopsis (picots, Brassicaceae), melon (picots, Cucurbitaceae) and banana tree (Monocots, Musaceae); three each in tomato (picots, Solanaceae) and barley (Monocots, Graminaceae). The se sequences contain open reading frames (OFRs) with high homology to crypt ochromes, but not photolyases, and are transcribed into RNA. In each case, a Cry1- and a Cry2-like sequence was recognizable. The third gene of tomato and barley seems to have arisen from recent, independent duplications of C ry1, and was thus named Cry1b. The tomato Cry1b gene encodes a protein of 5 83 amino acids (the shortest of the three tomato cryptochromes), with a hig h similarity to Cry1. The C-terminus of Cry1b is truncated before the conse rved Ser-Thr-Ala-Glu-Ser-Ser-Ser (STAESSS) motif found in both Cry1a and Cr y2. The Cry1b mRNA is expressed throughout the tomato plant,, reaching maxi mal levels of expression in the flower (like Cry1a and Cry2). We conclude t hat tomato and barley contain at least one additional expressed member of t he Cry1 gene family.