GAS TRANSFER IN FLOATING-LEAVED PLANTS

Pressurized gas transport with flow rates of 1.1 to 1.81 gas h-1 plant-1 have been detected in the floating-leaved aquatic macrophyte Euryale ferox on sunny days. The younger leaves gave the highest pressurization, but the gas flow was initiated mainly by the middle-aged leaves of the plants. The gas through-flow was shown to be highly beneficial for floating-leaved plants. It improved the oxygen level in the acrenchyma of the submerged organs of Nymphaea alba and Nymphoides peltata, and doubled the ATP level in the root tissues. On the other hand, the sulphur dioxide fumigation experiments on Nymphae odorata indicated that the pressurized gas transport may adversely affect the floating-leaved plants, due to an increased contamination of the leaves leading to increased photo bleaching and impaired photosynthesis.