Survival strategies of wetland plants in flooding environments
洪水条件下湿地植物的生存策略

Flooding is a common phenomenon in the nature.Wetland plants,due to their special habitats,are usually stressed by periodical or permanent flooding.In the process of long-time adaptive evolution,wetland plants adopted a series of special survival strategies to fit the wide range changes of hydrological conditions,and the main strategies are:1)adjusting their life history,e.g.,changing growth time to escape direct damage and taking use of the movability of flooding to diffuse their seeds into new regions;2)adjusting their root morphology and distribution depth of root into the top soil with relatively abundant oxygen content or grow adventitious roots to enhance the capacity of oxygen transportation;3)changing their anatomical characteristics,e.g.,the enhanced porosity and the formation of aerenchyma to ameliorate the "gas channels" from air to root system;and 4)changing their physiological and biochemical characteristics via enhancing the carbohydrate content to prolong survival time or releasing hormone(ethylene etc.)to regulate physiological activity or morphological and anatomical variations.In the further,the researches on the formation mechanisms of adventitious roots,the roles of ethylene in the formation of aerenchyma,the mechanisms of radial oxygen loss(ROL),and the regulation of ROL release should be strengthened.