Thursday, November 16, 2006 - 8:30 AM

Molecular and Physiological Characterization of Transgenic Bahiagrass with Constitutive Expression of Stress Inducible Transcription Factors.

Xi Xiong1, Fredy Altpeter1, Victoria James1, and A. Blount2. (1) Univ. of Florida - IFAS, PO Box 110300, PO Box 110300, Gainesville, FL 32611-0300, United States of America, (2) University of Florida, Gainesville, FL 32607

Bahiagrass (Paspalum notatum Flugge) is an important turf and forage grass in the south-eastern US and in subtropical regions around the world. The productivity and persistence of bahiagrass is limited by environmental stresses like drought, freezing and in salt affected areas. We isolated several transcription activators of genes involved in abiotic stress response and will present data on over-expression of the HvWRKY38 and OsMYB4 transcription activator in bahiagrass.

Transcription factors, like MYB4 are capable of activating the expression of multiple genes involved in protection against environmental stresses. The HvWRKY38 or OsMYB4 expression cassettes were introduced into bahiagrass cv. Argentine via biolistic gene transfer and transgenic plants over-expressing these transcription factors have been identified by RT-PCR. Transgenic bahiagrass plants over-expressing HvWRKY38 or OsMYB4  are currently being evaluated under field conditions in Northern Florida to determine productivity and persistence during seasonal environmental stress conditions. In addition we will present physiological data on dehydration and freezing tolerance of bahiagrass plants over-expressing  HvWRKY38 or OsMYB4  under controlled environment conditions.