Field: Agricultural and Biological Sciences › Plant ScienceType: No effect foundArea: plant physiologyTarget: Red to far-red light ratio in grapevineStage: full study
Hypothesis
Grapevines exposed to side light with a low red to far-red ratio, which signals nearby plants, would show the classic shade-avoidance response: longer stems and petioles and changed water transport.
What failed
Neither Syrah nor Torrontés Riojano vines showed any shade-avoidance changes in shape, dry matter, stomata, wood anatomy or water transport, even though growth hormone levels in the leaves rose.
Broken assumption
Grapevines respond to neighbour-shade light signals the way other plants do.
Why
The authors discuss the result in the context of the grapevine's natural environment. The hormone signal was present, but the plants did not respond to it.
From the published paper: González et al. PLoS ONE, 2016. ↗CC BY