Effect of heat stress on tomato fruit protein expression.

We delayed the ripening of tomato fruit for several days (average 5 days) by a 1-day heat treatment at 37-42 degrees C. We analyzed the tomato fruit pericarp proteins, which were altered by the heat stress, using two-dimensional electrophoresis. Heat stress caused about 23.7% of the proteins in the pericarp to disappear and about 1.1% of new proteins to appear. We determined their apparent molecular mass, isoelectric point, and N-terminal amino acid sequence. Identified proteins included antioxidant enzymes, heat shock proteins, cell-wall-related proteins, etc.