Leaf Blade Micromorphology and the Silicon Content in Phragmites Australis (Poaceae) are Correlated with Water Balance in the Environment

Leaf Blade Micromorphology and the Silicon Content in Phragmites Australis (Poaceae) are Correlated with Water Balance in the Environment

The role of leaf blade micromorphology and the silicon (Si) content in the tolerance of Phragmites australis to changes in the soil water balance in natural conditions was examined. The features of leaf micromorphology and silicon distribution in leaf epidermis of Ph. australis emergent and terrestrial plants, which grew in the zone of Kiev (Ukraine), were studied by scanning electron microscopy, X-ray analysis, and laser confocal microscopy. Emergent (air-water) plants grew in riverside, along the shore of Venetian Strait of Dnipro River, Kiev, Ukraine. Terrestrial plants grew near 12-15 m far from the strain in a sandy soil. Rooted are emersed in the substrate of emergent plants, whereas leaves fully exposed to air (on-shore emergent). As far as terrestrial plants of the reed, the roots were in sandy soil, and the stems with leaves–are exposed over the land. It is established that change of soil humidity effect to leaf blade micromorphology, particularly the density of stomata and prickles. The investigation has shown that terrestrial environment leads to decrease of the density of stomata and prickles and increase of wax incrustation in the leaf epidermis. The comparison analysis of the presence of silicon ions, its content, and Si-bodies appearance in leaf blade of Ph. australis two ecotypes showed the images of the quantitative distribution of silicon bodies and silicon amorphous formations in the prickles, stomata and strands, and revealed the depending Si content on the cell type and environmental conditions of plant growth. The obtained results are documented in Ph. australis the plasticity for leaf micromorphology and silicon content in leaf epidermis depending on the water balance of the nature external environments. We discuss the important role of leaf micromorphology and silicon inclusions, the indicator of which depends on the water balance of the plant and light absorption.