We have isolated some of the enzymes involved in production of gibberellins and demonstrated that their activities change in certain tissues throughout development. During the past year several of the genes which encode enzymes in the gibberellin biosynthetic pathway have been discovered and sequenced by others. We are currently working toward the isolation of the last few genes in this pathway. These genes encode oxidative enzymes known as cytochromes P450. We hope to discover how these genes and gibberellin production are regulated.
Current studies involve the combined use of biochemistry, genetics and plant molecular biology.
We are comparing the genes expressed in wild-type and mutant plants. The mutants don't make gibberellins. The enzyme was first purified from extracts of wheat seedlings. The amino acid sequence of one end of the protein was determined experimentally. From the amino acid sequence we determined the nucleic acid sequence of the mRNA which encodes the protein.