Abstract: Slow rate of water loss (RWL) in leaf surface is induced by removal of plants from soil, leading to drought stress to some extent. In the present paper, Catharanthus roseus with strong desiccation tolerance was conducted to investigate the dynamics of ABA and soluble sugar contents in leaves and roots. The ABA content in roots of seedlings was lower than that in leaves in control condition, while dehydration treatment promoted its accumulation in roots, arriving at the peak value at 6 h. The activity of acid invertase (AI) may be activated by elevated ABA and increased by 30% after 6 h treatment. Total soluble sugar content in control leaves was observed to be very stable, but when exerted in stress, they appeared to increase linear with prolong of stress time (r²=0.964). At the same time, sucrose and hexose also exhibited the trend of enhancement due to drought stress, to play a role of osmotic adjustment.

Key words: Catharanthus roseus, drought stress, ABA, soluble sugar, sucrose acid invertase