Effects of Salinity on key Enzymes Activities and gene expression of Sucrose Metabolism during Tomato Fruit Development

The objective of this study was to investigate the effects of salt stress on activity of sucrose-metabolizing enzyme in tomato fruit and to provide a new evidence for tolerating salt stress of cultivated tomato. The related enzymes activities of sucrose metabolism including invertase, sucrose synthase and sucrose phosphate synthase and the expression of soluble acid invertase mRNAs were determined. The results indicated that the salinity can maintain or enhance the invertase activities of tomato fruit in a long period of time (45-60 days after anthesis), and elevate the expression of soluble acid invertase mRNA. But the effects of salinity treatment on sucrose synthase and sucrose phosphate synthase activities were weak under the condition of salt stress. It showed that hypersalinity could regulate the activity of sucrose-metabolizing enzymes by controlling its gene expression under salt stress.