SUGAR-BEET GUARD-CELL PROTOPLASTS DEMONSTRATE A REMARKABLE CAPACITY FOR CELL-DIVISION ENABLING APPLICATIONS IN STOMATAL PHYSIOLOGY AND MOLECULAR BREEDING
Rd. Hall et al., SUGAR-BEET GUARD-CELL PROTOPLASTS DEMONSTRATE A REMARKABLE CAPACITY FOR CELL-DIVISION ENABLING APPLICATIONS IN STOMATAL PHYSIOLOGY AND MOLECULAR BREEDING, Journal of Experimental Botany, 48(307), 1997, pp. 255-263
A highly-efficient protocol for the large-scale isolation of guard cel
l protoplasts from sugar beet (Beta vulgaris L.) has been developed, O
ptimization of conditions for culturing these protoplasts resulted in
extensive cell division and colony formation, at frequencies exceeding
50%. Plants can subsequently be regenerated from these guard cell-der
ived colonies, This provides definitive confirmation that, in sugar be
et leaf protoplast populations, only guard cells are the source of tot
ipotent protoplasts. These findings are the outcome of a directed, non
-empirical approach to overcoming plant cell recalcitrance which was i
nitiated by exploiting computer-assisted microscopy to couple in vitro
response to cell origin, The results reaffirm the conclusion that, in
plants, extreme degrees of cytodifferentiation need not entail termin
al specialization, The responsive nature of this system can be ascribe
d to the unique use of cultures essentially comprising a single in viv
o cell type. A uniform model system has thus been created with potenti
al for widespread application, Their distinct morphological (and mecha
nical) features make guard cells a valuable choice for studying Variou
s fundamental aspects, not only of stomatal physiology, but also of pl
ant cell (de)differentiation, differential gene expression etc. Furthe
rmore, an applied value for such a system can also be envisaged. Resul
ts indicate that these cells are highly amenable to genetic manipulati
on techniques, The importance of these observations to our understandi
ng of plant cell function and behaviour is discussed.