Non-specific reactions in the leaves of pediculate oak (Quercus robur) after exposing to heat shock

Abstract

The experimental results of non-specific reactions in the leaves of pedunculate oak (Quercus robur) due to the action of thermal shock are presented. The leaves exposed to thermal shock was determined the relative quantum yield of photosystem II after 6 days of maintaining them in favourable conditions and estimated electrolyte leaks from the leaves. A high level of viability of the yellow leaves was highlighted in the control sample and a partial restoration in them of the relative quantum efficiency of photosystem II after the application of the thermal shock during 20 minutes. It was shown that the yellow leaves (yellowed due to the phenomenon of suffocation at the root level) compared to the green ones had a higher resistance to the action of heat shock. This fact suggests that the state of stress initiated by the asphyxiation phenomenon, determined the increase of the nonspecific resistance of the yellow leaves towards the stress factors.