Method of plant selection using glucosamine-6-phosphate deaminase

A selection method for selecting from a population of plant cells one or more genetically transformed plant cells is described. In the method, the population of plant cells includes selectable genetically transformed plant cells and possible non-transformed plant cells. Each of the selectable genetically transformed plant cells comprises a first expressible nucleotide sequence and optionally a second expressible nucleotide sequence. In the method, a component or a metabolic derivative thereof when present in a low concentration in a medium is a nutrient for both the selectable genetically transformed plant cells and the non-transformed plant cells. In the method, the component or the metabolic derivative thereof when present in a high concentration in a medium is toxic to the non-transformed plant cells. The first nucleotide sequence codes for a gene product having glucosamine-6-phosphate deaminase activity which is capable of converting the component or the metabolic derivative thereof when present in a high concentration in a medium to a nutrient for the selectable genetically transformed plant cells. The method includes the step of introducing the population of plant cells to a medium, wherein the medium includes a high concentration of the component or the metabolic derivative thereof. In the method, the component or the metabolic derivative thereof is a source of both carbohydrate and nitrogen for the selectable genetically transformed plant cells.