SUCROSE METABOLISM IN NACL-TREATED CALLI FROM LYCOPERSICON-ESCULENTUM, L-PENNELLII AND THEIR INTERSPECIFIC HYBRID

dThe enzyme activities of sucrose metabolism were determined in contro l and salt-(140 mM NaCl) treated calli from leaves, stems and roots of the cultivated tomato Lycopersicon esculentum cv. P-73, the wild spec ies L. pennellii and their interspecific hybrid. Taking into account t he apoplasmic contents, the NaCl-sensitive tissues (calli from L. escu lentum, calli from leaves of the hybrid) accumulated less Na+ and Cl- and more total soluble sugars than the NaCl-tolerant calli (calli from L. pennellii, calli from stems and roots of the hybrid). Sucrose hydr olysis, via acid invertase, and hexose phosphorylation, via glucokinas e, decreased more in the salinized sensitive tissues than in the toler ant ones. The interconversion between Glc-6P and Glc-1P, via phosphogl ucomutase, sucrose synthesis, via sucrose phosphate synthase and the e nzyme activities of glycolysis or the pentose phosphate pathway were n ot coupled with the NaCl-tolerance degree of the tissues. Under contro l and salt-conditions, the ADP-glucose-pyrophosphorylase capacities of the tolerant tissues were 20- to 50-fold higher than those of the sen sitive ones. Relations between the magnitudes of sucrose metabolism en zymes or the sugar levels and the salt tolerance of the heterotrophica lly grown calli are discussed.