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- Butenko, Melinka A., et al.
(författare)
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Inflorescence deficient in abscission controls floral organ abscission in Arabidopsis and identifies a novel family of putative Ligands in Plants
- 2003
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Ingår i: The Plant Cell. - : American Society of Plant Biologists. - 1040-4651 .- 1532-298X. ; 15:10, s. 2296-2307
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Tidskriftsartikel (refereegranskat)abstract
- Abscission is an active process that enables plants to shed unwanted organs. Because the purpose of the flower is to facilitate pollination, it often is abscised after fertilization. We have identified an Arabidopsis ethylene-sensitive mutant, inflorescence deficient in abscission (ida), in which floral organs remain attached to the plant body after the shedding of mature seeds, even though a floral abscission zone develops. The IDA gene, positioned in the genomic DNA flanking the single T-DNA present in the ida line, was identified by complementation. The gene encodes a small protein with an N-terminal signal peptide, suggesting that the IDA protein is the ligand of an unknown receptor involved in the developmental control of floral abscission. We have identified Arabidopsis genes, and cDNAs from a variety of plant species, that encode similar proteins, which are distinct from known ligands. IDA and the IDA-like proteins may represent a new class of ligands in plants
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| 2. |
- Stangeland, Biljana, et al.
(författare)
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AtMBD8 is involved in control of flowering time in the C24 ecotype of Arabidopsis thaliana
- 2009
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Ingår i: Physiologia Plantarum. - : Blackwell Publishing. - 0031-9317 .- 1399-3054. ; 136:1, s. 110-126
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Tidskriftsartikel (refereegranskat)abstract
- The Arabidopsis thaliana accession C24 is a vernalization-responsive, moderately late flowering ecotype. We report that a mutation in AtMBD8, which encodes a protein with a putative Methyl-CpG-Binding Domain (MBD), in C24 background, results in a delay in flowering time during both long and short days. The atmbd8-1 mutant responded to vernalization as wild type (wt) plants. Consistent with a role in modulation of flowering time, an AtMBD8::GUS-reporter construct was expressed in the shoot meristem region and developing leaves. Full-genome transcriptional profiling revealed very few changes in gene expression between atmbd8-1 and wt plants. The expression level of FLC, the major repressor of transition to flowering, was unchanged in atmbd8-1, and in accordance with that, genes upstream of FLC were unaffected by the mutation. The expression level of CONSTANS, involved in photoperiodic control of flowering, was very similar in atmbd8-1 and wt plants. In contrast, the major promoters of flowering, FT, and SOC1, were both downregulated. As FT is a regulator of SOC1, we conclude that AtMBD8 is a novel promotor of flowering that acts upstream of FT in the C24 accession. In contrast to atmbd8-1, the Colombia (Col) SALK T-DNA insertion line, atmbd8-2, did not display a delayed transition to flowering. Transcriptional profiling revealed that a substantial number of genes were differentially expressed between C24 and Col wt seedlings. Several of these genes are also differentially expressed in late flowering mutants. We suggest that these differences contribute to the contrasting effect of a mutation in AtMBD8 in the two ecotypes.
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