THE DYNAMICS OF ENDEGENOUS HORMONES ACTIVITY IN PLANT LEAVES DEPENDING ON THE ALTITUDE OF THEIR GROWING

Abstract

The hormonal response of cultivated and wild plants to high intensity of UV-radiation and other stress factors of the highlands was studied. The activity of auxins and growth inhibitors substances in wheat (Triticum aеstivum L), barley (Hordium vulgare L), horse bean (Vicia faba L), and eurotia (Ceratoides papposa) leaves, that grew in a field condition were analyzed at different stages of development, using thin-layer chromatography and bioassay. The leaves of cultivated plants (2320 and 2700 m above the sea level) and wild plants (2320 and 4000 m above the sea level) were collected at two elevations in Pamir highland (Tajikistan). The level of auxin activity at the beginning of ontogenesis in plant leaves that grew at both elevations was relatively higher in comparison with the activity of growth inhibitors. However, at the end of the vegetation period an increase in growth inhibitor activity was observed in plant leaves at both elevations. Increasing of the total auxin activity in plants was observed at low altitude compared to higher. Conversely, the activity of growth inhibitors substances increased in plants that grow at higher elevations.