|Grennan, Aleel - PLANT BIOLOGY UOFI URBANA|
Submitted to: Plant Physiology Supplement
Publication Type: Abstract Only
Publication Acceptance Date: July 25, 2001
Publication Date: N/A
Technical Abstract: Environmental stress are routinely faced by plants in the field, a commonly encountered stress being the combination of high light and low temperature. This combination is especially deleterious in plants in semi-tropical and topical evolutionary origins. Tomato are among the long list of agriculturally important plants that fall into this category. Previous studies in tomato have shown a decrease in phosynthetic performance primarily due to impairment of photosynthetic metabolism rather than temperature stress induced stomatal closure. The de novo translation of chloroplast-encoded proteins are preferentially inhibited by high light, low temperature conditions. A most dramatic decrease of de novo synthesis is of D1, a photosynthetic II reaction center protein. No change is observed in steady state RNA levels indicating that it is at the post-transcriptional level. 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. Primer extension inhibition (toe-printing) analysis will reveal if the pausing occurs at specific or random locations along the D1 message.