M. Czako et al., SUSTAINED ROOT CULTURE FOR GENERATION AND VEGETATIVE PROPAGATION OF TRANSGENIC ARABIDOPSIS-THALIANA, Plant cell reports, 12(11), 1993, pp. 603-606
Excised roots of wild-type and nitrate-reductase deficient mutant Arab
idopsis thaliana (L.) HEYNH. can be propagated as sustained root cultu
res in liquid medium. Culture initiation from a single seedling requir
ed a two-day indoleacetic acid treatment at 0.05 mg/l concentration. I
ndoleacetic acid facilitated subculture but was not essential for sust
ained growth. This procedure has allowed the clonal propagation of roo
ts derived from individual wild-type and mutant seedlings for more tha
n 21 months. The cultured roots retained their shoot regeneration abil
ity; however, a controlled desiccation treatment was required to resto
re it to the level of freshly excised roots. The chromosome number rem
ained diploid and no evidence for the accumulation of recessive mutati
ons was observed. The cultured roots are competent for Agrobacterium-m
ediated transformation. The sustained root culture technology allowed
the maintenance of transgenic tissues in which expression of a dominan
t, seed-lethal gene (seed-specific pea vicilin promoter fused to dipht
heria toxin A chain gene) precluded generative propagation.