Rapid recovery of photosynthetic cell suspension cultures following heterotrophic bleaching

Summary Seven suspension-cultured lines of five different species (Amaranthus powellii Datura innoxia, Glycine max, Gossypium hirsutum, andNicotiana tabacum × Nicotiana glutinosa fusion hybrid), which had been grown under photomixotrophic conditions, were placed under heterotrophic conditions (darkness and media with 3% sucrose or starch) where the chlorophyll levels declined to near zero. After three transfers over a 70-d period, the cells were placed back into photomixotrophic or photoautotrophic conditions where regreening occurred rapidly and continued growth was observed. This rapid adaptation to photosynthetic conditions contrasts with the original initiation process for these cultures, which required many months and an apparent selection since many of the original cells died. Thus, these seven photosynthetic cell suspension cultures appear to be different from the original cultures due possible to genetic or adaptive changes.