LONG-TERM CHILLING OF YOUNG TOMATO PLANTS UNDER LOW-LIGHT .6. DIFFERENTIAL CHILLING SENSITIVITY OF RIBULOSE-1,5-BISPHOSPHATE CARBOXYLASE OXYGENASE IS LINKED TO THE OXIDATION OF CYSTEINE RESIDUES

During long-term chilling under non-photoinhibitory conditions, ribulo se-1,5-bisphosphate carboxylase/oxygenase of the chilling-sensitive, c ultivated tomato (Lycopersicon esculentum Mill.) lost a substantial am ount of titrable sulfhydryl groups, both in the native and in the diss ociated state, while the content of disulfide bonds increased. In cont rast, accessible cysteine residues of the enzyme isolated from chillin g-tolerant, high-altitude lines of L. peruvianum (Mill.) were only inf eriorly affected during chilling stress.