The cyclophilin ROC1 links phytochrome and cryptochrome to brassinosteroid sensitivity
Although multiple photoreceptors converge to control common aspects of seedling de-etiolation, we are relatively ignorant of the genes acting at or downstream of their signalling convergence. To address this issue we screened for mutants under a mixture of blue plus far-red light and identified roc1-1D. The roc1-1D mutant, showing elevated expression of the ROTAMASE CYCLOPHILIN 1 [ROC1/AtCYP18-3] gene, and partial loss-of function roc1 alleles, has defects in phytochrome A [phyA]-, cryptochrome 1 [cry1]- and phytochrome B [phyB]-mediated de-etiolation, including long hypocotyls under blue or far-red light. These mutants show elevated sensitivity to brassinosteroids in the light but not in the dark. Mutations at brassinosteroid signalling genes and the application of a brassinosteroid synthesis inhibitor eliminated the roc1 and roc1-D phenotypes. The roc1 and roc1-D mutants show altered patterns of phosphorylation of the transcription factor BES1, a known point of control of sensitivity to brassinosteroids, which correlate with the expression levels of genes directly targeted by BES1. We propose a model where perception of light by phyA, cry1 or phyB activates ROC1 [at least in part by enhancing its expression]. This in turn reduces the intensity of brassinosteroid signalling and fine-tunes seedling de-etiolation.
| Main Authors: | , , |
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| Format: | Texto biblioteca |
| Language: | eng |
| Subjects: | ARABIDOPSIS, BRASSINOSTEROID, CRYPTOCHROME, PHYTOCHROME, ROTAMASE CYCLOPHILIN 1, BRASSINOSTEROIDS, CRYPTOCHROMES, CYCLOPHILIN, PHOSPHORYLATION, PLANTS [BOTANY], TRANSCRIPTION FACTORS, GENES, ARABIDOPSIS PROTEIN, BES1 PROTEIN, ARABIDOPSIS, CRY1 PROTEIN, ARABIDOPSIS, NUCLEAR PROTEIN, PHYTOCHROME A, ROC1 PROTEIN, ARABIDOPSIS, GENETICS, LIGHT, METABOLISM, MUTATION, PHENOTYPE, ARABIDOPSIS PROTEINS, NUCLEAR PROTEINS, , |
| Online Access: | http://ceiba.agro.uba.ar/cgi-bin/koha/opac-detail.pl?biblionumber=46655 |
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