Identification and stress-induced expression of three 3β-hydroxysteroid dehydrogenases from Erysimum crepidifolium Rchb. and their putative role in cardenolide biosynthesis

Three individual cDNAs (EcHSD1, EcHSD2, EcHSD3) encoding functional 3β-hydroxysteroid dehydrogenases (3βHSD) were isolated from Erysimum crepidifolium leaves. Various forms of stress enhanced transcription of EcHSD2, EcHSD3 but not EcHSD1.