These authors contributed equally to this work.
Two Arabidopsis cytochrome P450 monooxygenases, CYP714A1 and CYP714A2, function redundantly in plant development through gibberellin deactivation
Article first published online: 11 MAY 2011
© 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd
The Plant Journal
Volume 67, Issue 2, pages 342–353, July 2011
How to Cite
Zhang, Y., Zhang, B., Yan, D., Dong, W., Yang, W., Li, Q., Zeng, L., Wang, J., Wang, L., Hicks, L. M. and He, Z. (2011), Two Arabidopsis cytochrome P450 monooxygenases, CYP714A1 and CYP714A2, function redundantly in plant development through gibberellin deactivation. The Plant Journal, 67: 342–353. doi: 10.1111/j.1365-313X.2011.04596.x
- Issue published online: 13 JUL 2011
- Article first published online: 11 MAY 2011
- Accepted manuscript online: 2 APR 2011 10:15AM EST
- Received 18 February 2011; revised 21 March 2011; accepted 31 March 2011; published online 11 May 2011.
- gibberellin deactivation;
- EUI P450 monooxygenase;
- expression pattern;
- gibberellin profile;
- rice traits
The rice gene ELONGATED UPPERMOST INTERNODE1 (EUI1) encodes a P450 monooxygenase that epoxidizes gibberellins (GAs) in a deactivation reaction. The Arabidopsis genome contains a tandemly duplicated gene pair ELA1 (CYP714A1) and ELA2 (CYP714A2) that encode EUI homologs. In this work, we dissected the functions of the two proteins. ELA1 and ELA2 exhibited overlapping yet distinct gene expression patterns. We showed that while single mutants of ELA1 or ELA2 exhibited no obvious morphological phenotype, simultaneous elimination of ELA1 and ELA2 expression in ELA1-RNAi/ela2 resulted in increased biomass and enlarged organs. By contrast, transgenic plants constitutively expressing either ELA1 or ELA2 were dwarfed, similar to those overexpressing the rice EUI gene. We also discovered that overexpression of ELA1 resulted in a severe dwarf phenotype, while overexpression of ELA2 gave rise to a breeding-favored semi-dwarf phenotype in rice. Consistent with the phenotypes, we found that the ELA1-RNAi/ela2 plants increased amounts of biologically active GAs that were decreased in the internodes of transgenic rice with ELA1 and ELA2 overexpression. In contrast, the precursor GA12 slightly accumulated in the transgenic rice, and GA19 highly accumulated in the ELA2 overexpression rice. Taken together, our study strongly suggests that the two Arabidopsis EUI homologs subtly regulate plant growth most likely through catalyzing deactivation of bioactive GAs similar to rice EUI. The two P450s may also function in early stages of the GA biosynthetic pathway. Our results also suggest that ELA2 could be an excellent tool for molecular breeding for high yield potential in cereal crops.