%0 Journal Article
%T The compensatory effect in drought resistance of plants and its application in water-saving agriculture<br>植物抗旱性中的补偿效应及其在农业节水中的应用
%A HU Tian-Tian
%A <br>胡田田
%J 生态学报
%D 2005
%I 
%X In biology, compensation is a common phenomenon following environmental stresses such as drought, anoxia, salinity, and nutrient stresses. In some cases, stress is steady or unchanging. This may result in some adaptive responses by the plant. But in other cases, the plant may be exposed to fluctuating stress conditions. The compensatory effect may develop when there is an uneven supply of resources or when the plant's environment fluctuates between stressful and nonstressful conditions. We propose that the compensatory effect develops when plants are grown under conditions of fluctuating stress. As a result of the compensatory effect, plant morphology or function may equal or even surpass that of plants grown under nonstressed conditions. In contrast, plants grown under steady stress conditions exhibit other kinds of adaptive responses. These responses often offset each other. For example, under steady stress conditions, enzyme concentrations in a plant may go down, but the enzyme activity may go up. This should not be considered to be a compensatory effect. In this paper, we also distinguish among different types of compensatory effects based on the level and effect of compensation, as well as the number and fluctuation pattern of the environmental stresses. This review describes the compensatory effect on plant attributes such as biomass accumulation, water use efficiency, and the morphology and function of root systems. Compared to treatments that have sufficient and steady soil water contents, crop production and water use efficiency increase significantly when plants are exposed to drying and rewetting cycles. Roots tend to grow and proliferate in regions of high water availability. The hydraulic conductivity of roots increases noticeably under a locally restricted water supply. This also occurs after drying and rewetting cycles. The compensatory effect in these plants can be attributed to five physiological processes: (a) the maintenance of root growth during periods of mild water deficit; (b) the improvement of the morphology and function of the root system after the drying-wetting cycle; (c) the improvement of osmotic adjustment in the extension zone of both roots and leaves during the drying-wetting cycles; (d) the rapid recovery of photosynthesis during rewetting after a period of mild water deficit; and (e) changes in the allocation and reserve of assimilates during periods of water deficit. The plant hormone abscisic acid (ABA) plays an important role in the first three processes by regulating hydraulic conductivity, the extensibility of the cell wall, and osmotic adjustment for the maintenance of turgor pressure. The factors influencing the compensatory effect in the drought resistance of plants include the species, variety, plant development stage, and the intensity and duration of the water deficit. This paper also provides some examples for the application of the compensatory effect in water-saving agriculture. In the case of regu
%K compensatory effect
%K drought resistance of plants
%K extension growth
%K physiological mechanism
%K agricultural application<br>补偿效应
%K 抗旱性
%K 延伸生长
%K 生理学机制
%K 农业应用
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=90BA3D13E7F3BC869AC96FB3DA594E3FE34FBF7B8BC0E591&jid=FE163E5DB2274E5937319DE98913EC37&aid=8AE155450481833E&yid=2DD7160C83D0ACED&vid=C5154311167311FE&iid=E158A972A605785F&sid=745C7FAEA69986C7&eid=412FA1328E0CB9E9&journal_id=1000-0933&journal_name=生态学报&referenced_num=17&reference_num=48