Genome size as a predictor of guard cell length in Arabidopsis thaliana is independent of environmental conditions

Abstract

• 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. © The Authors (2008).