Role of microstructure and silicon of leaf in adaptation of Quercus robur trees to different light intensity.

The purpose the experiment was to investigate the microstructure, localization, and content of silicon inclusions in the leaf epidermis of Quercus robur trees grown in forest-steppe zones of southern Ukraine with varying levels of solar radiation (sunlight intensities). The investigations utilized the electron microscopic method and laser confocal microscopy. It was determined that sunlight intensity influenced size and area of the leaves, leaf epidermis ultrastructure, and change in silicon content in epidermis of Q. robur leaves. The research indicated that trichomes, stomata, and ordinary epidermal cells of oak leaves were the primary accumulators of silicon. The results suggest that variations in the leaf size, microstructure and silicon content contribute to the optimal ability to absorb and reflect light on the leaf surface. These changes may be considered as indicators of plant phenotype plasticity and adaptive markers depending on light intensity conditions. The various compounds of these leaves, including of presence of wax structures and silicon, can be used for practical applications.