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 hardening temperatures on chilling-induced changes in 1-aminocyclopropane-1-carboxylic 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 ACC content; however, this increase was less pronounced in plants cold acclimated at 13/11 degreesC 4 d before the chilling treatment, and in those which were pretreated with SA for 1 d before the cold stress. Changes in MACC at low temperature showed no correlation with chilling tolerance in maize.