Abstract: Isolation and characterization of a novel plant fatty acid desaturase cDNA that encodes a .DELTA..sup.9 14:0-ACP desaturase. Expression of the .DELTA..sup.9 14:0-ACP desaturase is a critical factor for pest resistance in plants of the genus Pelargonium and other plants generally; the desaturase gene is also useful in other contexts and for other purposes such as increasing the percentage of unsaturated fatty acids in oil-producing crops such as soybeans, rapeseed, maize, sunflower, safflower, cotton, cuphea, peanut, coconut and oil-palm, as well as increasing the percentage of unsaturated fatty acids in other plants generally.

Abstract: The regeneration of plants from cotton callus (Gossypium hirsutum L. cv Coker 310) is described. Somatic proembryoids developed spontaneously after two years in culture on a modified Linsmaier and Skoog medium. The percentage of calli forming proembryoids was increased to about 30% by prolonged culture without NAA and kinetin. Development of proembryoids was enhanced by transferring proembryoids to media lacking NH.sub.4 NO.sub.3 but containing double the standard KNO.sub.3 concentration and gibberellic acid. Root initiation and growth was promoted by lowering the glucose concentration to 5 g/l.