Molecular mechanism of differential light responses between adaxial and abaxial stomata

Jian Wei, Yin Wang
Institute of Ecology, College of Urban and Environmental Sciences, Key Laboratory for Earth Surface Processes of Ministry of Education, Peking University, Beijing, 100871 China

In most herbaceous plants, stomata distribute on both the adaxial (upper) and abaxial (lower) surfaces of leaf. However, because of the differences in micro-environments, adaxial and abaxial stomata exhibit distinct environmental responses, especially light responses. The distinct features of adaxial and abaxial stomata were reported in vitro and in vivo using species such as Vicia faba, Helianthus annuus, Xanthium strumarium, etc, Indicating that the light response of adaxial stomata was significantly weaker than abaxial stomata, and the differences between both stomata were probably inherent. In this study, across Inner Mongolia, we conducted a comprehensive survey of stomatal features on the adaxial and abaxial surfaces of leaves of wild herbaceous plants to elucidate general patterns of differential light responses of stomata on the two surfaces. Additionally, by labortary experiments, we examined the phenotype of stomata from adaxial and abaxial surfaces of leaves of the model plant Arabidopsis thaliana. The results suggest a possible underlying mechanism for the differential light responses of adaxial and abaxial stomata.