Responses of temperate plants to drought conditions

 

Introduction
Background

Effects on:

     photosynthesis
     growth and allocation
Mitigating factors
References

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  

Response

Water Stress

ABA

Correlation
Short term      

   Stomatal conductance

 Decrease Decrease  + + +

   Photosynthesis

 Decrease Decrease  + + +

   Membrane permeability

 Increase/decrease Increase/decrease  +
   Ion transport Increase/decrease Increase/decrease  +
       
Long term: biochemical and       physiological      
   Specific mRNA and  protein    synthesis Increase Increase  + +
   Proline and betaine accumulation Increase Increase  + +
   Osmotic adaption Yes Yes  +
   Photosynthetic enzyme activity Decrease Decrease  +
   Desiccation tolerance Increase Increase  +
   Salinity and cold tolerance Induces Induces  + +
   Wax production Increase Increase  +
       
Long term: growth      
   General growth inhibition Yes Yes  + + +
   Cell division Decrease Decrease  + + +
   Cell expansion Decrease Decrease  + + +
   Germination Inhibits Inhibits  + +
   Root growth Increase/decrease Increase/decrease  + +
   Root/shoot ratio Increase Increase  + +
       
Long term: morphology      
   Production of trichomes Increase Increase  + +
   Stomatal index Decrease Decrease  + +
   Tillering in grasses Decrease Decrease  +
   Conversion from aquatic to aerial    leaf type Yes Yes  + +
   Induction of dormancy, terminal    buds or perennation of organs Yes Yes  + +
       
Long term: reproductive      
   Flowering in annuals Often advanced Often advanced  +
   Flower induction in perennials Inhibited Inhibited  +
   Flower abscission Increased Increased  +
   Pollen viability Decreased Decreased  +
   Seed set Decreased Decreased  +

Table 2. Evidence for the involvement of abscisic acid (ABA) in plant responses to water stress based on the similarity of responses to water stress and to exogenous ABA application (redone from Jones 1992). Strength of correlation is indicated by +.