Plasticity of Morpho-Physiological and Oxidative Metabolism Patterns of Sium Species (Apiaceae) at Different Soil Moisture
Predicting the response of plants to global climate changes, including not only warming but also changes in rainfall and subsequent water availability, is one of the most significant scientific problems this centure. We performed a comparative study of certain micromorpological, physiological and molecular traits of widespread, closely related but ecologically different Sium species − aerial-aquatic S. latifolium and terrestrial S. sisaroideum to check a hypothesis about the important role of phenotypic plasticity in plant adaptation to different soil moisture in biotopes.
Plant samples were analyzed by using the methods of cell and molecular biology, in particular methods of light and confocal microscopy, Western-blot, RT-PCR, chemiluminescence, and spectrophotometry.
We show the differences in the levels of free-radical oxidation, PIP aquaporin gene expression, and HSPs, which were higher in S. sisaroideum, especially at an air temperature of 40°C, as well as the distinctions in the phytohormone content, micromorphological and histochemical traits of generative organs in plants grown in the river and on the river bank.
The increased levels of free-radical oxidation during ontogenesis is supposed to play an important role in S. sisaroideum droughtresistance. Being well-adjusted to the moisture of dry aerated soil, terrestrial plants retain their ability to adaptive respond on flooding. The studied species can serve as a convenient and adequate model for finding out the mechanisms of plant survival under stress.