| 692 | |
| Entry URI | http://metadb.riken.jp/db/SciNetS_ria224i/cria224u4ria224u18024556i |
| Entry name | Boccalandro Hernán E et al. 2008 Jan. Plant Physiol. 146(1):108-15. |
| Title | PHYTOCHROME KINASE SUBSTRATE1 regulates root phototropism and gravitropism. |
| Authors | Bergmann-Honsberger Ariane|Boccalandro Hernán E|Casal Jorge J|De Simone Silvia N|Fankhauser Christian|Schepens Isabelle |
| Abstract | Light promotes the expression of PHYTOCHROME KINASE SUBSTRATE1 (PKS1) in the root of Arabidopsis thaliana, but the function of PKS1 in this organ is unknown. Unilateral blue light induced a negative root phototropic response mediated by phototropin 1 in wild-type seedlings. This response was absent in pks1 mutants. In the wild type, unilateral blue light enhanced PKS1 expression in the subapical region of the root several hours before bending was detectable. The negative phototropism and the enhanced PKS1 expression in response to blue light required phytochrome A (phyA). In addition, the pks1 mutation enhanced the root gravitropic response when vertically oriented seedlings were placed horizontally. The negative regulation of gravitropism by PKS1 occurred even in dark-grown seedlings and did not require phyA. Blue light also failed to induce negative phototropism in pks1 under reduced gravitational stimulation, indicating that the effect of pks1 on phototropism is not simply the consequence of the counteracting effect of enhanced gravitropism. We propose a model where the background level of PKS1 reduces gravitropism. After a phyA-dependent increase in its expression, PKS1 positively affects root phototropism and both effects contribute to negative curvature in response to unilateral blue light. |
| Pubmed ID | 18024556 |
| Journal | Plant physiology |
| Volume | 146 |
| Issue | 1 |
| Pages | 108-15 |
| Publication date | 2008 Jan |
| Num of phenotype gene | 1 |