Table 1

Protoplast mortality and the incidence of the HII phase (tightly packed cylinders) and associated ultrastructural morphologies (well-ordered striations and loosely ordered swirls) in protoplasts isolated from leaves of nonacclimated RLD and T8 plants

RLDT8
−5.0°CProtoplast mortality (LOR-HII)65%44%
Incidence of HII morphologies63% (32/51)37% (33/89)
 loosely ordered swirls 33% (17/51) 26% (23/89)
 well-ordered striations 33% (17/51) 15% (13/89)
 tightly packed cylinders 22% (11/51)  7% (6/89)
−5.5°CProtoplast mortality (LOR-HII)83%56%
Incidence of HII morphologies76% (82/108)57% (100/176)
 loosely ordered swirls 15% (16/108) 45% (80/176)
 well-ordered striations 22% (24/108) 17% (30/176)
 tightly packed cylinders 44% (47/108)  9% (16/176)
−6.0°CProtoplast mortality (LOR-HII)87%74%
Incidence of HII morphologies91% (19/21)74% (84/113)
 loosely ordered swirls 62% (13/21) 44% (50/113)
 well-ordered striations 67% (14/21) 42% (48/113)
 tightly packed cylinders 52% (11/21) 21% (24/113)
  • Protoplast mortality (LOR-HII) was calculated from the survival data after a freeze/hypertonic thaw treatment shown in Fig. 1B. The number before the slash represents the number of protoplasts in which the particular morphology was observed; the number after the slash represents the total number of protoplasts observed.