Genetic instability of plant tissue cultures: breakdown of normal controls.
Plants regenerated from relatively undifferentiated callus cultures possess a vast array of genetic changes. Such variations can result in useful agricultural and horticultural products. For other purposes, however, variations in traits other than those of interest may be undesirable--for example, using cultured cells for genetic engineering. Any steps made toward understanding the basis of tissue culture-induced genetic variation should be helpful in developing a more stable and manipulatable somatic cell system. This review provides a glimpse at the specific kinds of genetic changes encountered among regenerated plants and their progeny. Included among these variations are cytosine methylation alterations of the genome. The repeat-induced point mutation (RIP) phenomenon, reported for filamentous fungi, is invoked to provide a framework to consider the origin of variation in plant tissue cultures.
Phillips
R L
RL
Department of Agronomy, University of Minnesota, St. Paul 55108.
Kaeppler
S M
SM
Olhoft
P
P
D044503:5-Methylcytosine; D046508:Culture Techniques; D003596:Cytosine / Q000031:analogs & derivatives / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D008745:Methylation; D059828:Plant Cells; D010944:Plants / Q000235:genetics*; D017354:Point Mutation; D012091:Repetitive Sequences, Nucleic Acid
D044503:5-Methylcytosine; D003596:Cytosine; D004247:DNA