STRUCTURAL RESPONSES OF Platanus orientalis L. LEAVES TO ELEVATED CO2 CONCENTRATION AND HIGH TEMPERATURE

Anatomical structure of the leaves and the leaf surface of two-year-old Platanus orientalis L. plants after treatment with elevated CO2 (800 ppm) and high temperature (38 degrees C for 4 h) were studied. Light microscopy analysis (LM) revealed that the examined stress factors have the strongest effect on the photosynthesising parenchyma of the leaves. They cause changes of the shape and structure of the photosynthetic cells and increase the apoplast volume in the spongy tissue. The most prominent effect on the tissue structure of expanding leaves has the combined treatment with stress factors. Scanning electron microscopy (SEM) analysis showed that elevated CO2 stimulates wax formation in expanding leaves as epidermal reaction in stress conditions.