Submitted to: International Conference on Plant Growth Substances Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 4/1/2007
Publication Date: 7/1/2007
Citation: Ariizumi, T., Steber, C.M. 2007. A comparative study of two f-box proteins, sleepy1 and sneezy in ga signaling. International Conference on Plant Growth Substances Proceedings, July 21-25, Puerta Vallerta, Mexico, PS1128. Interpretive Summary:
Technical Abstract: SNEEZY (SNE) is a homolog of SLEEPY1 (SLY1), encoding an F-box protein subunit of an SCF E3 ubiquitin ligase complex in Arabidopsis. SLY1 plays a central role in destruction of DELLA negative family proteins via 26S proteasome pathway in GA signaling pathway. DELLA proteins consist of five members including RGA, GAI, RGL1, RGL2 and RGL3. It is known that SCFSLY1 recognizes these DELLA proteins in response to GA, and trigger DELLA protein destruction, which releases DELLA inhibitory effects on GA responses. The sly1 mutant shows severe dwarfism, reduced fertility and seed dormancy apparently due to high accumulation of DELLA proteins. In this study, the effect of SLY1 and SNE over-accumulation on DELLA protein accumulation was determined. We found that all sly1 mutant phenotypes were rescued by SLY1 over-expression (SLY1-OE), while these phenotypes were partly restored by over expression of SNE (SNE-OE). The level of protein accumulation in RGA was decreased in the SNE-OE lines compared to sly1 mutant, suggesting that SNE could partially compensate GA signaling instead of SLY1. On the other hand, the level of RGL2 protein accumulation was not altered in the SNE-OE lines, suggesting that SNE was not able to recognize RGL2 as well as SLY1. sly1 sne double mutants were also constructed in this study. Characterization of sne single and the double mutants are reported in this study.