|Kamo, Kathryn - Kathy|
Submitted to: In Vitro Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/21/2005
Publication Date: 6/18/2005
Citation: Kamo K, Jones B, Bolar J, Smith F (2005) Regeneration from long-term embryogenic callus of the Rosa hybrida cultivar Kardinal. In Vitro Cell Dev Biol-Plant 41:32-36. Interpretive Summary: Genetic engineering of roses for disease resistance can be used to lower the amount of pesticide used in the environment. Roses are ideal for genetic engineering because roses suffer from numerous pests, and they are one of the most important floral crops world-wide. A first step towards genetic engineering of roses is developing a cell system capable of regenerating plants. The foreign gene of interest for disease resistance can be put into the cells of rose that are then manipulated in culture to form a plant that consequently contains the disease resistance genes. In this manuscript the factors in the medium used to culture the rose cells and plants were studied for their affect on plant regeneration from the rose cells. Abscisic acid, a plant hormone, was shown to stimulate growth of regenerated rose plants.
Technical Abstract: Media components affecting regeneration of plants from embryogenic callus of the commercially important red rose cultivar Kardinal were determined. Embryogenic callus was maintained for five years on either Schenk and Hildebrandt's basal salts medium supplemented with 13.6 mM 2,4-D or Murashige and Skoog's basal salts medium supplemented with 18.1 mM dicamba and 0.46 mM kinetin. Three times as many embryos matured from callus maintained on the Schenk and Hildebrandt's basal salts medium supplemented with 2,4-D as compared to embryos from callus maintained on Murashige and Skoog's basal salts medium supplemented with dicamba and kinetin. Conversion of cotyledonary-stage embryos to plants was significantly higher (10X) when the embryos developed from callus that had been maintained on Murashige and Skoog's basal salts medium with dicamba and kinetin instead of the Schenk and Hildebrandt's basal salts medium with 2,4-D. Embryo maturation medium consisting of Murashige and Skoog's basal salts lacking hormones stimulated higher levels (5X) of embryo conversion as compared to Schenk and Hildebrandt's basal salts without hormones. Plants that developed from cotyledonary-stage embryos cultured on Murashige and Skoog's basal salts medium supplemented with abscisic acid (5-20 mM) survived at a significantly higher rate (2X) in the greenhouse than when embryos were cultured without abscisic acid. These results show that the highest rate of plant regeneration occurred when embryogenic callus of 'Kardinal' was maintained on MS basal salts medium supplemented with dicamba and kinetin and when the cotyledonary-stage embryos were cultured on MS basal salts medium supplemented with abscisic acid.