Figure 3.

Germination rates and seedling survival of FUS3 loss- and gain-of-function mutants during imbibition at supraoptimal temperature and recovery after heat stress. (A-G) Germination rates and% of seedlings survival of wild type (WT), FUS3 loss-of-function mutant (fus3-3) and ML1:FUS3-GFP (MFG) gain-of-function mutant during imbibition at control (21°C) and supraoptimal temperature (32°C). (A, B, E) Germination (radicle protrusion) rates of mature WT and MFG dry seeds imbibed on filter papers on MS plates in the absence or presence of 10 μM fluridone (+F) at 21°C (A) and 32°C (B). After six days of imbibition at 32°C, plates in B) were transferred to the control temperature (21°C) for six additional days and the% of seedlings survival (showing green cotyledon and green leaves) was calculated in (E). (C, D, F) Germination (radicle protrusion) rates of immature WT and fus3-3 green seeds imbibed on filter papers on MS media in the presence or absence of 10 μM fluridone (+F) at 21°C (C) and 32°C (D). After six days of imbibition at 32°C, plates in D) were transferred to the control temperature (21°C) for six additional days and the% of seedlings survival (showing green cotyledon and green leaves) was calculated in (F). (G) Appearance of representative WT and MFG seeds from the experiment shown in B). Averages from triplicates ± s.d. are shown (n ≥ 300 seeds). Experiments were repeated at least twice with similar results and one representative is shown. F, fluridone. Red bars, 32°C. Black bars, 21°C.