00960naa a2200145 a 450000100080000000500110000800800410001910000200006024501020008026000090018252005350019170000210072670000180074777300490076516490272000-06-26       1977    bl ---       0--  u    #d1 aMUHLBACH, H. P.  aIsolation and properties of protoplasts from leaves of healthy and viroid-infected tomato plants.  c1977  aViable protoplasts were isolated from leaves of healthy and viroid-infected tomatoes by a two-step enzyme treatment. Cultured protoplasts regenerated cell walls and incorporated radioactive uridine into all cellular RNA species. In protoplasts from tomato leaves systemically infected with the viroid of the exocortis disease of citrus an extra band of radioactive viroid RNA could be detected 30 h after adding the [3H] uridine. Its incorporation into viroid RNA varied between. 0.01 and 0.3% of the label incorporated into tRNA.1 aHENRIQUEZ, A. C.1 aSANGER, H. L.  tPlant Science Lettersgv.8, p.183-189, 1977.