Patent ID: 8030073

Claim:
A method of producing and maintaining a sustained totipotent embryogenic cell culture of a monocotyledonous plant comprising: (a) cultivating an explant of tissue from a monocotyledonous plant shoot tip to produce a sustained totipotent embryogenic cell culture, wherein the monocotyledonous plant is selected from the group consisting of Scirpus spp. and Thysanolaena spp.; (b) treating the sustained totipotent embryonic cell culture with a cold temperature, wherein the cold temperature treatment is for a duration from about 60 days to about 360 days and comprises a temperature in a range from about 4° C. to about 10° C.; (c) removing the sustained totipotent embryogenic cell culture from the cold temperature treatment; and (d) cultivating the sustained totipotent embryogenic cell culture, whereby the sustained totipotent embryogenic cell culture of the monocotyledonous plant has an increased growth rate as compared to a control.