IN-VITRO TRANSLATION PRODUCTS OF MESSENGER-RNA FROM PERICARP TISSUE OF TOMATO CULTIVARS DIFFERING IN CHILLING TOLERANCE

In vitro translation products from two tomato cultivars, Lycopersicon esculentum cv. 'Early Cherry' ('EC') and L. esculentum x L. pimpinelli folium cv. 'New York 280' ('NY'), differing in chilling tolerance, wer e compared before and after 16 days of chilling at 4 degrees C, and af ter return of the fruit to 20 degrees C for one and five days. Ripenin g parameters, color and texture, were monitored during the experiments . Color development showed normal ripening of chill-tolerant 'NY' afte r the fruit were returned to 20 degrees C, but failure of chill-sensit ive 'EC' to ripen. Before chilling, slight differences in the patterns of translation products resolved by 2D-PAGE were observed between the two cvs. probably reflecting their different genetic background. Chil ling induced changes in gene expression that were for a large part sim ilar in fruit of both cvs. However, among responses that differed in t he two cvs., changes in the levels of two low-molecular-weight basic t ranslation products identified as 'A' (ca. 18 kDa, pH 8.0) and 'B' (ca . 14 kDa, pH 8.2) were most noticeable. Translation product 'A', faint ly visible in 'NY' before chilling, was strongly expressed after 16 da ys of chilling and 24 h after transfer to 20 degrees C, but had disapp eared five days after transfer to 20 degrees C. Translation product 'A ' also increased in abundance in 'EC' at low temperature and was retai ned at appreciable levels five days after the fruit were returned to 2 0 degrees C. Translation product 'B' highly expressed in chilling-tole rant 'NY' before chilling, was sharply reduced in ge was readily rever sible upon transfer to 20 degrees C, By contrast, the level of polypep tide 'B' remained low in 'EC' under all treatments.