Claim · model-written summary
Internode growth in length and biomass was maximal under shade light with a reduced R/FR ratio (0.85) at low PAR of 157.
- Taxon
- Helianthus annuus
Helianthus annuuse0 - Organ / stage
- internodee1
- Treatment
- a shade light having a reduced R/FR ratio (0.85) under the low PAR of 157 micromol m(-2) s(-1)e1
- Outcome
- internode growth (length and biomass)e1
- Direction
- Maximale1
Not reportedMaterialGeneCompoundInteractorInteractor roleSecond interactorSecond interactor roleComparatorSettingValueQualifier
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“sunflower (Helianthus annuus) seedlings”
e1“Maximal internode growth (length and biomass) was induced by a shade light having a reduced R/FR ratio (0.85) under the low PAR of 157 micromol m(-2) s(-1)”
Title
L. V. Kurepin; R. J. N. Emery; R. P. Pharis; et al. Journal of Experimental Botany 2007. doi:10.1093/jxb/erm068
Other claims from this paper (15)
- Intervention effect Reducing the R/FR ratio under normal PAR gave similar internode growth trends, with a reduced magnitude of response.
- Intervention effect Leaf area growth was maximal at the higher (normal) PAR.
- Intervention effect Reducing the R/FR ratio by far-red enrichment significantly increased GA1 and IAA contents in internodes and leaves.
- Intervention effect Lower PAR had no significant effect on GA1 and IAA levels in internodes or leaves.
- Association Leaf and internode GAs and IAA content were positively and significantly correlated with internode growth.
- Association Leaf abscisic acid levels were positively and significantly correlated with internode growth.
- Association Changes in these three hormones bear little relationship to leaf growth.
- Mechanism The leaf may be the major source of GAs and IAA for the rapidly elongating internode.
- Intervention effect Leaf ethylene production was not influenced by changes in R/FR ratio.
- Intervention effect Leaf ethylene production was significantly reduced under the normal (higher) PAR.
- Intervention effect Growth-active free base and riboside cytokinins in leaves were significantly increased under a reduced R/FR ratio, but only at the higher (normal) PAR.
- Intervention effect Other light quality treatments caused no significant change in leaf cytokinins.
- Association Both components of shade light can influence the levels of a wide range of endogenous hormones in internodes and leaves.
- Association Light quality changes (FR enrichment) are most closely tied to increased hormone content, especially GA and IAA.
- Mechanism FR enrichment probably induces an overall increase in sunflower seedling GA biosynthesis.