Isolation of an ent-kaurene oxidase cDNA from Cucurbita maxima

Four distinct cDNAs isolated from developing Cucurbita maxima Duchesne seed s included CYP701A1, a member of the same subfamily of cytochrome P450 enzy me as the Arabidopsis ent-kaurene oxidase GA3 which catalyses an early step in gibberellin (GA) biosynthesis. We have shown by complementation of the Arabidopsis ga3-2 mutant that the CYP701A1 cDNA encodes an ent-kaurene oxid ase activity. Another cDNA, CYP88A2, encodes a protein which is in the same subfamily as the maize Dwarf3 protein and is likely to encode another GA b iosynthetic enzyme catalysing a reaction between ent-kaurenoic acid and GA( 12).