Ricinus

Abstract

Since castor bean (Ricinus communis L.) is a single-species genus in the Euphorbiaceae family, we will focus our discussion mainly on it. The USDA, ARS, Plant Genetic Resources Conservation Unit conserves more than 1,000 castor bean accessions from countries worldwide including the United States. Conservation efforts have been devoted to quality conservation of the genetic variation and diversity in castor bean. Castor bean seeds contain 35-55% of oil, which is proved to be safe and effective when used as a stimulant laxative. Castor bean could become one of the premier crops for health enhancing phytochemicals. An immunotoxin derived from castor bean constituents was successful in combination with chemotherapy in treating patients with AIDS-related non-Hodgkin's lymphoma. In addition, castor bean is currently undergoing intense research in its development as a biodiesel crop in the United States. Cloning functional genes for ricin coupled with an understanding of ricin synthesis will provide an opportunity to manipulate these genes for ricin reduction in castor bean seeds through genetic engineering. As castor bean is not a food crop and can be grown in many landscapes, it can provide healthy products and biodiesel. In addition, the establishment of stable genetic transformants of castor bean will lead to further development of transgenic castor bean seeds in the future. Tissue culture and genetic transformation will assist in the breeding of superior germplasm and cultivars for use in the United States and abroad as a phytopharmaceutical and biodiesel crop.