Are Sugar-sensing Pathways Involved in Desiccation Tolerance?

摘要

Sugars serve as substrates for respiration, synthesis of metabolic intermediates and starch and lipid reserves. Seeds have evolved mechanisms to monitor, respond and adapt their metabolism to intrinsic and external stimuli, including developmental programmes, abiotic stresses, light or nutrient deficiency. A well-known example of this is the sugar-induced repression of some alpha-amylase genes in germinating cereals (Loreti et al., 2000, 2001). More than 40 sugar-related genes have been identified inplants. In seeds, most of them are related to sucrose metabolism, storage reserves, cell division and fermentation. However, sugars can act, at the millimolar range, as signalling molecules that are sensed by sugar-binding enzymes, proteins and transporters (Gibson, 2000; Smeekens, 2000).