Reduced phototropism in pks mutants may be due to altered auxin-regulated gene expression or reduced lateral auxin transport
| Autor: | Christian Fankhauser, Claus Schwechheimer, Melina Zourelidou, Laure Allenbach, Erika Isono, Kotaro T. Yamamoto, Chitose Kami, Masaaki K. Watahiki, Karin Ljung, Frédéric Schütz |
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| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
0106 biological sciences
Light Hypocotyl/genetics Mutant Arabidopsis Plant Science 01 natural sciences Hypocotyl Gene Expression Regulation Plant Genes Reporter Hypocotyl/physiology Phosphoproteins/genetics polycyclic compounds Cluster Analysis Phototropism chemistry.chemical_classification 0303 health sciences Phytochrome Intracellular Signaling Peptides and Proteins phototropism phytochrome kinase substrate phototropin 1 auxin Arabidopsis thaliana food and beverages Cell biology Phosphoproteins/metabolism Arabidopsis Proteins/genetics Phytochrome/metabolism Intracellular Signaling Peptides and Proteins/metabolism Hypocotyl/cytology Biochemistry Arabidopsis/radiation effects Phytochrome/analysis Signal Transduction Phototropin Seedlings/physiology Seedlings/genetics Biology Protein Serine-Threonine Kinases 03 medical and health sciences Auxin ddc:570 Genetics Arabidopsis/physiology Arabidopsis/genetics 030304 developmental biology Hypocotyl/radiation effects Indoleacetic Acids Arabidopsis Proteins Indoleacetic Acids/metabolism fungi Membrane Proteins Seedlings/radiation effects Biological Transport Cell Biology biology.organism_classification Phosphoproteins chemistry Seedlings Mutation Arabidopsis Proteins/metabolism Arabidopsis/cytology Seedlings/cytology Polar auxin transport Intracellular Signaling Peptides and Proteins/genetics Indoleacetic Acids/analysis 010606 plant biology & botany |
| Zdroj: | Plant Journal, vol. 77, no. 3, pp. 393-403 Plant Journal |
| Popis: | Phototropism allows plants to orient their photosynthetic organs towards the light. In Arabidopsis, phototropins 1 and 2 sense directional blue light such that phot1 triggers phototropism in response to low fluence rates, while both phot1 and phot2 mediate this response under higher light conditions. Phototropism results from asymmetric growth in the hypocotyl elongation zone that depends on an auxin gradient across the embryonic stem. How phototropin activation leads to this growth response is still poorly understood. Members of the phytochrome kinase substrate (PKS) family may act early in this pathway, because PKS1, PKS2 and PKS4 are needed for a normal phototropic response and they associate with phot1 in vivo. Here we show that PKS proteins are needed both for phot1- and phot2-mediated phototropism. The phototropic response is conditioned by the developmental asymmetry of dicotyledonous seedlings, such that there is a faster growth reorientation when cotyledons face away from the light compared with seedlings whose cotyledons face the light. The molecular basis for this developmental effect on phototropism is unknown; here we show that PKS proteins play a role at the interface between development and phototropism. Moreover, we present evidence for a role of PKS genes in hypocotyl gravi-reorientation that is independent of photoreceptors. pks mutants have normal levels of auxin and normal polar auxin transport, however they show altered expression patterns of auxin marker genes. This situation suggests that PKS proteins are involved in auxin signaling and/or lateral auxin redistribution. published |
| Databáze: | OpenAIRE |
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