Monday, November 13, 2006

Overexpression of Tobacco Phytochrome B1 Gene Influences Performance of Transgenic Creeping Bentgrass under Various Light Conditions.

Jia Yan, The Ohio State Univ., "308 Howlett Hall, 2001 Fyffe Court", Columbus, OH 43210, United States of America, T. K. Danneberger, OSU-Dept. Hort./Crop Science, 2001 Fyffe Court, 2001 Fyffe Court, Columbus, OH 43210-1086, United States of America, and David Gardner, Ohio State University - Columbus, The Ohio State University, 344 Howlett Hall 2001 Fyffe Ct., Columbus, OH 43210.

Phytochromes are a family of photoreceptors that regulate plant photomorphogenesis.  Previous research has demonstrated that overexpression of phytochrome B gene induced dwarf phenotypes in transgenic plants. Creeping bentgrass (Agrostis palustris) plants were regenerated from embryogenic callus bombarded with a plasmid containing tobacco (Nicotiana tabacum L.)  phytochrome B (phyB) gene under the control of CaMV 35S promoter. Four transgenic creeping bentgrass lines were grown under full sun, neutral shade cloth, soybean canopy, and photoselective plastic film with a far-red absorbing property. As expected, overexpression of phyB caused dwarfism, dark green leaves, and horizontal growth habit under all light conditons. Both light intensity and quality (red: far-red light) reduction had less adverse impact on growth of transgenic creeping bentgrass plants than wild type. Furthermore, compactness and overall quality of transgenic creeping bentgrass plants increased more than wild type under far-red light absorbing filters. Collectively, these data demonstrated that genetic modification might be an effective approach to improve creeping bentgrass growth and lower maintenance cost under shade.