Submitted to: American Society of Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 1, 1995
Publication Date: N/A
Technical Abstract: The concept of Thermal Kinetic Windows (TKW), an indicator of enzyme performance, has provided a novel perspective for evaluating plant responses to thermal environments. To determine the usefulness of this concept in improving crop performance in diverse environments, we have utilized genetic engineering to evaluate the prediction that interspecific gene transfer could broaden the temperature characteristics of an enzyme pool. We introduced a 35S promoter - cucumber NADH-hydroxypyruvate reductase (HPR) gene into the genome of tobacco. The root system of the transgenic plants expresses only the cucumber enzyme (the native tobacco HPR gene is shoot specific). This enzyme exhibits a TKW centered at 32.5 degrees C, characteristic of cucumber. The pool of HPR in the shoots, containing both tobacco and cucumber enzymes, exhibits a broad TKW consistent with an equal mix of the two forms. These data strengthen the TKW concept and open the possibility for the alteration of the thermal properties of specific metabolic pathways.