Desiccation Tolerance in Immature Embryos of Maize: Sucrose, Raffinose and the ABA—Sucrose Relation

Abstract

Our previous experiments on desiccation tolerance in immature embryos of maize cast doubt on a crucial role of high concentrations of sucrose and high raffinose to sucrose mass ratio. In the present work we report experiments aimed at gaining a further insight into the above mentioned subject and to ascertain whether endogenous ABA may stimulate the accumulation of sucrose. Immature and desiccation sensitive embryos of maize were isolated and exposed to different drying conditions either leading or not leading to desiccation tolerance acquisition and allowing for different ABA and sugar responses. ABA concentrations as well as sugar concentrations were compared in embryos undergoing such different dehydration treatments. We conclude that in maize embryos: 1) sucrose, even at high concentrations, is not the sole factor responsible for desiccation tolerance; 2) high sucrose concentrations do not appear to be an absolute requirement of desiccation tolerance; 3) a high (>0.05) raffinose to sucrose mass ratio is not a prerequisite of desiccation tolerance; 4) ABA doesn’t seem to stimulate sucrose accumulation. We suggest that desiccation tolerance can occur even in the absence of raffinose.KeywordsSucrose ConcentrationImmature EmbryoDesiccation ToleranceSucrose AccumulationHigh Sucrose ConcentrationThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.