Experiment: | 638 |
Title: | DELLA-mediated regulation of seedling trascriptome |
Date: | 2012-06-15 |
Description: | Seedling growth in short days shows a rhythmic pattern occurring mostly at the end of the night. The increase in growth rate is related with changes in the expression of PIF4, PIF5 and several phytohormone genes as well as with an increment in auxin signaling in the seedling (Nozue, Covington et al. 2006; Covington and Harmer 2007; Michael, Breton et al. 2008). Gibberellins (GA) are main promoters of hypocotyl elongation, and the way in which they contribute to rhythmic growth is still unknown.We found that in short day grown seedlings, DELLA proteins accumulate during the day and show a minimum at the middle of the night, shortly before the period when hypocotyl growth increases. The circadian clock regulates the transcript level of two GA receptor genes; GID1A and GID1B. Changes in DELLA accumulation are associated with GID1s expression, indicating that DELLA proteins oscillation in the seedlings is regulated, at least in part, by the clock-mediated control of GID1s. The decrease in DELLA proteins at the end of the night is relevant for proper hypocotyl growth.In order to study the way in which DELLA oscillations contribute to rhythmic patterns of growth we performed transcriptome analysis of wild type and quintuple della mutant seedlings grown under SD. Samples were taken in two periods of the night: shortly after the dark period starts (ZT9), characterized by a strong DELLA accumulation and low growth rate, and near the end of the night (ZT21) where the opposite pattern is observed. Genes exhibiting a diurnal oscillation in circadian gene expression databases (e.g. Diurnal: http://diurnal.cgrb.oregonstate.edu/) and show a different pattern of regulation in della mutants compared with the wild type early in the night will be chosen for diurnal expression studies and functional analysis.ReferencesCovington, M. and S. Harmer (2007)."The Circadian Clock Regulates Auxin Signaling and Responses in Arabidopsis."PLOS Biology 8: 1773-1784.Michael, T., G. Breton, et al. (2008)."A morning-specific phytohormone gene expression program underlying rhythmic plant growth."PLOS Biology 6(9): e225. doi:10.1371/journal.pbio.0060225.Nozue, K., M. Covington, et al. (2006)."Rhythmic growth explained by coincidence between internal and external cues."Nature(448): 358-363. |
ftp Link: | ftp Link |
Slide ID | Slide Name | Genetic Background | Tissue | Stock Code | Cel File |
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Alabadi_638-10_Ler-ZT21_Rep3_ATH1 | 7780949 | whole plant | NW20 | Arana_1-6_Ler-21hrs_Rep3_ATH1.CEL | |
Alabadi_638-11_5x-della-ZT9_Rep3_ATH1 | 7780950 | Ler(Landsberg_erecta) | whole plant | N16298 | Arana_1-9_dellla-9hrs_Rep3_ATH1.CEL |
Alabadi_638-12_5x-della-ZT21_Rep3_ATH1 | 7780951 | Ler(Landsberg_erecta) | whole plant | N16298 | Arana_1-12_dellla-21hrs_Rep3_ATH1.CEL |
Alabadi_638-1_Ler-ZT9_Rep1_ATH1 | 7780940 | whole plant | NW20 | Arana_1-1_Ler-9hrs_Rep1_ATH1.CEL | |
Alabadi_638-2_Ler-ZT21_Rep1_ATH1 | 7780941 | whole plant | NW20 | Arana_1-4_Ler-21hrs_Rep1_ATH1.CEL | |
Alabadi_638-3_5x-della-ZT9_Rep1_ATH1 | 7780942 | Ler(Landsberg_erecta) | whole plant | N16298 | Arana_1-7_dellla-9hrs_Rep1_ATH1.CEL |
Alabadi_638-4_5x-della-ZT21_Rep1_ATH1 | 7780943 | Ler(Landsberg_erecta) | whole plant | N16298 | Arana_1-10_dellla-21hrs_Rep1_ATH1.CEL |
Alabadi_638-5_Ler-ZT9_Rep2_ATH1 | 7780944 | whole plant | NW20 | Arana_1-2_Ler-9hrs_Rep2_ATH1.CEL | |
Alabadi_638-6_Ler-ZT21_Rep2_ATH1 | 7780945 | whole plant | NW20 | Arana_1-5_Ler-21hrs_Rep2_ATH1.CEL | |
Alabadi_638-7_5x-della-ZT9_Rep2_ATH1 | 7780946 | Ler(Landsberg_erecta) | whole plant | N16298 | Arana_1-8_dellla-9hrs_Rep2_ATH1.CEL |
Alabadi_638-8_5x-della-ZT21_Rep2_ATH1 | 7780947 | Ler(Landsberg_erecta) | whole plant | N16298 | Arana_1-11_dellla-21hrs_Rep2_ATH1.CEL |
Alabadi_638-9_Ler-ZT9_Rep3_ATH1 | 7780948 | whole plant | NW20 | Arana_1-3_Ler-9hrs_Rep3_ATH1.CEL |