Adaptive changes to hypoxia in resistant species by flooding the root system

A comparative study of the activity of the enzymes responsible for adaptation to long-term flooding of the roots was conducted with two perennial species resistant to hypoxia, viz., Bromus inermis Leyss. and Festuca pratensis Huds. The increase in the activity of NAD alcohol dehydrogenase and NADP glucose 6-phosphate dehydrogenase in the leaves of both the species and the decrease in NADH malate dehydrogenase in roots were observed at 20-day of hypoxia. The root hypoxia did not affect on the activity of NADH alcohol dehydrogenase in green leaves of B. inermis and F. pratensis. Along with this, NAD and NADH malate dehydrogenases were activated in leaves of B. inermis and F. pratensis. Though levels of pigment in the leaves of both species decreased under waterlogging condition, but there was no change in the ratio of chlorophyll a to chlorophyll b, which indicates the stability of functioning of the photosynthetic apparatus. Analysis of the activity of the studied enzymes and the content of photosynthetic pigments in the two species suggests the existence of universal as well as individual adaptive responses in each species