Back to Search
Start Over
Reduced phototropism in pks mutants may be due to altered auxin-regulated gene expression or reduced lateral auxin transport.
- Source :
-
The Plant journal : for cell and molecular biology [Plant J] 2014 Feb; Vol. 77 (3), pp. 393-403. Date of Electronic Publication: 2013 Dec 17. - Publication Year :
- 2014
-
Abstract
- 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.<br /> (© 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.)
- Subjects :
- Arabidopsis cytology
Arabidopsis genetics
Arabidopsis radiation effects
Arabidopsis Proteins genetics
Biological Transport
Cluster Analysis
Genes, Reporter
Hypocotyl cytology
Hypocotyl genetics
Hypocotyl physiology
Hypocotyl radiation effects
Indoleacetic Acids analysis
Intracellular Signaling Peptides and Proteins genetics
Intracellular Signaling Peptides and Proteins metabolism
Light
Membrane Proteins
Mutation
Phosphoproteins genetics
Phosphoproteins metabolism
Phototropism
Phytochrome analysis
Protein Serine-Threonine Kinases
Seedlings cytology
Seedlings genetics
Seedlings physiology
Seedlings radiation effects
Signal Transduction
Arabidopsis physiology
Arabidopsis Proteins metabolism
Gene Expression Regulation, Plant
Indoleacetic Acids metabolism
Phytochrome metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1365-313X
- Volume :
- 77
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- The Plant journal : for cell and molecular biology
- Publication Type :
- Academic Journal
- Accession number :
- 24286493
- Full Text :
- https://doi.org/10.1111/tpj.12395