Changes in sizes of mesophyll cells underlies the adaptation of Betula platyphylla Sukacz. leaf to increased climate aridity

Climate changes in Central Asia attract increasing attention to studies successions, ecosystem transformations and plant adaptation. Functional mechanisms of adaptation are related the leaf structure, first all, architecture carbon-assimilating tissues. We studied mesophyll structure Betula platyphylla Sukacz. from geographical regions southern part East Siberia Mongolia with different climate aridity. Birch populations represented a latitudinal range middle taiga forest-steppe. According our results occurred along aridity gradient, which manifested significant decrease (by 38-40 %) cell sizes an increase surface area volume ratio mesophyll. Such rearrangement provides higher rate intraleaf diffusion CO2 maintenance high level photosynthesis under water deficiency. concluded that cells underlies restructuring three-dimensional organization regulation gas exchange, is key mechanism for photosynthetic function increased climate.