Guard cells control hypocotyl elongation through HXK1, HY5, and PIF4
| Autor: | Nitsan Lugassi, Hanita Zemach, Danja Brandsma, Aiman Egbaria, Nir Sade, Ofer Stein, Adi Doron-Faigenboim, David Granot, Eduard Belausov, Nir Carmi, Gilor Kelly, Felix Shaya |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
0106 biological sciences
0301 basic medicine Cell type Plant molecular biology Light QH301-705.5 Mutant Plant physiology Medicine (miscellaneous) 01 natural sciences General Biochemistry Genetics and Molecular Biology Article Hypocotyl 03 medical and health sciences chemistry.chemical_compound Guard cell Arabidopsis Hexokinase Light responses Basic Helix-Loop-Helix Transcription Factors Biology (General) Transcription factor Stomata biology Arabidopsis Proteins fungi Plant morphogenesis food and beverages biology.organism_classification Cell biology 030104 developmental biology Basic-Leucine Zipper Transcription Factors chemistry Elongation General Agricultural and Biological Sciences 010606 plant biology & botany |
| Zdroj: | Communications Biology, Vol 4, Iss 1, Pp 1-14 (2021) Communications Biology |
| ISSN: | 2399-3642 |
| Popis: | The hypocotyls of germinating seedlings elongate in a search for light to enable autotrophic sugar production. Upon exposure to light, photoreceptors that are activated by blue and red light halt elongation by preventing the degradation of the hypocotyl-elongation inhibitor HY5 and by inhibiting the activity of the elongation-promoting transcription factors PIFs. The question of how sugar affects hypocotyl elongation and which cell types stimulate and stop that elongation remains unresolved. We found that overexpression of a sugar sensor, Arabidopsis hexokinase 1 (HXK1), in guard cells promotes hypocotyl elongation under white and blue light through PIF4. Furthermore, expression of PIF4 in guard cells is sufficient to promote hypocotyl elongation in the light, while expression of HY5 in guard cells is sufficient to inhibit the elongation of the hy5 mutant and the elongation stimulated by HXK1. HY5 exits the guard cells and inhibits hypocotyl elongation, but is degraded in the dark. We also show that the inhibition of hypocotyl elongation by guard cells’ HY5 involves auto-activation of HY5 expression in other tissues. It appears that guard cells are capable of coordinating hypocotyl elongation and that sugar and HXK1 have the opposite effect of light on hypocotyl elongation, converging at PIF4. Kelly et al. show that Arabidopsis hexokinase1 (HXK1) expressed in guard-cells is sufficient to drive hypocotyl elongation through increasing the activity of PIF4 and auxin level, and competing with the effects of HY5. This study provides insights into how light and sucrose antagonistically coordinate the effort to achieve the height necessary for efficient photosynthetic, autotrophic sugar production. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|