生长后期持续干旱下乙烯调控剂对甘蔗糖代谢的影响OA

Prolonged drought during the late growth stage severely disrupts normal sugarcane growth and metabolic homeostasis,ultimately reducing yield.To further investigate the physiological mechanisms by which ethylene regulators influence sugar accumulation and metabolic responses to sustained drought stress,this study investigated the effects and mechanisms of ethephon,an ethylene regulator,on sugar metabolism under prolonged drought stress during the late growth stage.The experimental material used in this study was Guitang42,a major cultivated sugarcane variety.Following drought stress,Guitang42 plants were sprayed with double-distilled water(ddH2O),400 mg/L ethephon(ETH),or 46 μmol/L aminoethoxyvinylglycine(AVG).Phenotypic changes in sugarcane plants were observed,while sucrose metabolism enzymes,endogenous hormones,and sugar content were measured in functional leaves,immature stems,and mature stems,followed by correlation analysis.Results indicated that ethephon treatment significantly reduced leaf length,width,and total area,yet increased relative chlorophyll content(SPAD)in leaves.Ethephon treatment elevated the activity of sucrose metabolism-related enzymes in sugarcane,whereas aminoethoxyvinylglycine treatment reduced their activity.Ethephon-treated sugarcane leaves exhibited increased levels of gibberellin(GA3),auxin(IAA),and cytokinin(ZT),while aminoethoxyvinylglycine treatment produced the opposite effect.ABA content increased in the aminoethoxyvinylglycine-treated group,while it decreased in the ethephon-treated group.Ethephon promoted sucrose accumulation in sugarcane,particularly evident in immature stems,where sucrose content increased by 109%.Whereas AVG treatment exhibited opposite effects.In immature stems,sucrose content showed significant correlations with sucrose metabolic enzyme activity and endogenous hormone levels.In functional leaves,sucrose content was significantly correlated with sucrose synthetase enzyme activity,sucrose phosphate synthase enzyme activity,and GA3 content.This study further demonstrates that ethephon serves as an effective regulator for drought resistance and sugar accumulation.The findings provide theoretical support for sugarcane cultivation in arid regions.