Botany of this species is encoded by about 135 million base pairs of DNA, forming one of the smallest genomes among flowering plants. "Arabidopsis" was the first plant to have its genome sequenced, in 2000. The sequencing of some other relatively small genomes, of rice ("Oryza sativa") and "Brachypodium distachyon", has made them important model species for understanding the genetics, cellular and molecular biology of cereals, grasses and monocots generally. Model plants such as "Arabidopsis thaliana" are used for studying the molecular biology of plant cells and the chloroplast. Ideally, these organisms have small genomes that are well known or completely
12-oxophytodienoate reductase 12-oxophytodienoate reductase 12-oxophytodienoate reductase (OPRs) is an enzyme of the family of Old Yellow Enzymes (OYE). OPRs are grouped into two groups: OPRI and OPRII – the second group is the focus of this article, as the function of the first group is unknown, but is the subject of current research. The OPR enzyme utilizes the cofactor flavin mononucleotide (FMN) and catalyzes the following reaction in the jasmonic acid synthesis pathway: This reaction occurs in peroxisomes in plants. Several isozymes have been discovered, with varying substrate stereospecificity: three in "Lycopersicon esculentum", 13 in "Oryza sativa", and five in "Arabidopsis thaliana".