Identification of brassinosteroid responsive genes inArabidopsis by cDNA array

Abstract
We have systematically monitored brassinosteroid (BR) responsive genes in a BR-deficient mutantdet2 suspension culture ofArabidopsis by using a cDNA array approach. Among 13000 cDNA clones arrayed on filters, 53 BR responsive clones were identified and designatedBRR1–BRR53. Sequence analysis of 43 clones showed that 19 clones are novel genes, 3 clones are genes involved in the control of cell division, 4 clones are genes related to plant stress responses, 4 clones are transcriptional factor or signal transduction component genes, and 3 clones are genes involved in RNA splicing or structure forming. In addition, we also found that BR regulated the transcription of genes related to many physiological processes, such as photoreaction, ion transportation and some metabolic processes. These findings present molecular evidence that BR plays an essential role in plant growth and development.