In vitro translation products of mRNA 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. pimpinellifolium cv. 'New York 280' ('NY'), differing in chilling tolerance, were compared before and after 16 days of chilling at 4 degrees C, and after return of the fruit to 20 degrees C for one and five days. Ripening parameters, color and texture, were monitored during the experiments. Color development showed normal ripening of chill-tolerant 'NY' after the fruit were returned to 20 degrees C, but failure of chill-sensitive '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. Chilling induced changes in gene expression that were for a large part similar in fruit of both cvs. However, among responses that differed in the two cvs., changes in the levels of two low-molecular-weight basic translation products identified as 'A' (ca. 18 kDa, pH 8.0) and 'B' (ca. 14 kDa, pH 8.2) were most noticeable. Translation product 'A', faintly visible in 'NY' before chilling, was strongly expressed after 16 days of chilling and 24 h after transfer to 20 degrees C, but had disappeared five days after transfer to 20 degrees C. Translation product 'A' also increased in abundance in 'EC' at low temperature and was retained at appreciable levels five days after the fruit were returned to 20 degrees C. Translation product 'B' highly expressed in chilling-tolerant 'NY' before chilling, was sharply reduced in ge was readily reversible upon transfer to 20 degrees C, By contrast, the level of polypeptide 'B' remained low in 'EC' under all treatments.