Abstract
The plant hormones brassinosteroids (BR) promote hypocotyl elongation of Arabidopsis thaliana (A. thaliana) seedlings both under light and dark (etiolated) conditions. A common assay to determine if a mutant or transgenic line is affected in BR biosynthesis or response is a sensitivity assay to brassinazole (BRZ), an inhibitor of P450 cytochromes specific to BR biosynthesis. Here we provide a protocol to compare BRZ sensitivity of different A. thaliana genotypes in terms of hypocotyl elongation (Bernardo-García et al., 2014).
Keywords: Brassinosteroid response, Hypocotyl elongation, Brassinazole
Materials and Reagents
Equipment
Software
Procedure
Figure 1. A flow chart of the steps described in our procedure
Representative data
Representative data showing hypocotyl measurements of type Col-0 and bes1D mutant are shown in Figures 4 and 5. BES1 is a transcription factor essential for BL response. bes1D mutation renders a constitutively active form of BES1. bes1D plants display constitutive response to BL and therefore are less sensitive to BRZ. Figure 4. 7-days old Col-0 and bes1D seedlings grown under light (A) and dark conditions (B) in the indicated BRZ concentrations Figure 5. BRZ sensitivity of Col-0 and bes1D estimated by determining hypocotyl length reduction by increasing BRZ concentrations under light (A) and dark conditions (B). Error bars represent standard deviation. Asterisks indicate significant differences between Col-0 and bes1-D for each BRZ concentration (n = 20, p<0.01).
Recipes
Acknowledgments
We gratefully acknowledge funding through grants BIO2008-04160 and BIO2011-30546 from the Spanish Ministry of Science and Innovation.
References
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