|Grennan, K - LIFE SCIENCE UOFI URBANA|
Submitted to: Plant Physiology Supplement
Publication Type: Abstract Only
Publication Acceptance Date: July 15, 2000
Publication Date: N/A
Technical Abstract: High light and low temperature are among the environmental stresses that plants frequently encounter in the field. When combined, these stresses are especially deleterious in plants that have semi-tropical and tropical evolutionary origins. Tomato are among the long list of agriculturally important plants fall into this category in which photosynthetic performance is adversely effected by the combination of high light and low temperature. Previous studies in tomato showed that synthesis of chloroplast-encoded proteins are preferentially inhibited, relative to cytoplasmic synthesized polypeptides, by high light low temperature conditions. One plastid-encoded protein that displays a dramatic chill-induced decrease in de novo synthesis of the photosystem II reaction center protein D1. We have shown that this alteration in D1 synthesis is post-transcriptional since there is no change in steady state RNA levels during the course of the high light, low temperature exposure. Examination of the ribosome distribution on the message demonstrates that the observed decrease in D1 de novo synthesis is most likely due to pausing during the elongation phase of translation. We are currently conducting modified primer extension assays to We are currently conducting modified primer extension assays to determine if this pausing is random or occurs at specific sites on the message.