|Fuchigami, L - OREGON STATE UNIVERSITY|
|Wang, Y - OREGON STATE UNIVERSITY|
|Norelli, John (jay)|
Submitted to: International Meeting on Plant and Microbe Adaptations to Cold
Publication Type: Abstract Only
Publication Acceptance Date: April 16, 2003
Publication Date: June 1, 2003
Citation: WISNIEWSKI, M.E., FUCHIGAMI, L., WANG, Y., SRINIVASAN, C., NORELLI, J.L. OVEREXPRESSION OF A CYTOSOLIC ASCORBATE PEROXIDASE GENE IN APPLE IMPROVES RESISTANCE TO TEMPERATURE STRESSES. INTERNATIONAL MEETING ON PLANT AND MICROBE ADAPTATIONS TO COLD. JUNE 2003. Technical Abstract: During exposure to both biotic and abiotic stress, molecular oxygen can undergo reactions that result in the formation of reactive oxygen intermediates (ROIs) and hydrogen peroxide. These elements are highly destructive to cellular components. Collectively, the resulting injury is called oxidative stress. In fruit crops, oxidative stress plays a role in low temperature injury, sunscald, and physiological scald. Plants have evolved antioxidant enzymes and other compounds to scavenge and detoxify ROIs and hydrogen peroxide. The objective of the present research was to produce transgenic apple plants (cv. Royal Gala) with enhanced production of a cytosolic ascorbate peroxidase (APX) and evaluate them for resistance to a variety of environmental stresses including low and high temperature, and exposure to UV-B. At least twelve transgenic lines of apple have been established and presence of the APX transgene has been confirmed with PCR. Preliminary evaluation of the lines for improved resistance to environmental stress indicates a range of improved tolerance. Several degrees of improved tolerance, as characterized by an LT50 in in vitro tests on apple leaves, have been observed for both acute low and high temperature stress. The greatest improvement in tolerance was in response to long term exposure to sub-lethal heat stress. Significant resistance to exposure to UV-B was also documented. Further analysis and field testing of the transgenic lines is in progress.