Effects of cold acclimation and salicylic acid on changes in ACC and MACC contents in maize during chilling

The effect of 0.5 mM salicylic acid (SA) pretreatment and of growing at har dening temperatures on chilling-induced changes in 1-aminocyclopropane-1-ca rboxylic acid (ACC) and malonyl 1-aminocyclopropane-1-carboxylic acid (MACC ) was investigated in young maize (Zea mays L.) plants grown in hydroponic solution at 22/20 degreesC. Chilling at 5 degreesC caused an increase in AC C content; however, this increase was less pronounced in plants cold acclim ated at 13/11 degreesC 4 d before the chilling treatment, and in those whic h were pretreated with SA for 1 d before the cold stress. Changes in MACC a t low temperature showed no correlation with chilling tolerance in maize.