Postprint version. Published in New Phytologist, Volume 181, Issue 2, January 1, 2009, pages 311-314.
The definitive version is available at https://doi.org/10.1111/j.1469-8137.2008.02700.x.
• The recent discovery of a strong positive relationship between angiosperm genome size and stomatal guard cell length (GCL) opens the possibility of using plant fossil guard cell size as a proxy for changes in angiosperm genome size over periods of environmental change.
• The responses of GCL to environmental stimuli are currently unknown and may obscure this predictive relationship.
• Here, we investigated the effects of environmental variables (atmospheric CO2, drought, relative humidity, irradiance, ultraviolet radiation and pathogen attack) on GCL in the model plant Arabidopsis thaliana to quantify environmentally induced variation.
• GCL responded to all variables tested, but the changes incurred did not significantly impinge on the predictive capability of the relationship.
2009 Blackwell Publishing.