EXPRESSION OF THE LARGE PLASTID GENE, ORF2280, IN TOMATO FRUITS AND FLOWERS

The expression of ORF2280, a large plastid gene of unknown function, w as examined in tomato leaves, in a developmental series of tomato frui ts, and in tomato flowers. Western blots indicated that much more ORF2 280 protein is present in fruits and flowers than in leaves. The most abundant proteins detected, 68 and 59 kDa, are present in about equal amounts in fruits of all stages; they are even more abundant in flower s. A 170-kDa ORF2280 protein is also present in fruit of all stages; i t is most abundant in small green fruit. The presence of higher levels of ORF2280 proteins in tomato fruits and flowers indicates that it ma y have a specialized function in these nonphotosynthetic tissues.