Mechanisms of heat shock-induced germination in Suaeda glauca (Bunge) bunge: insights from endogenous hormonal regulation.

backgroundFire cues, such as heat and smoke, play crucial roles in seed germination, particularly in fire-prone ecosystems. A key challenge in understanding how fire cues affect the germination process is characterizing the complex and varied relationships between fire cues and seed dormancy types. The mechanisms by which fire cues affect seed germination have long been a major focus of research. This study investigates the effects of heat shock, aerosol smoke, and their combination on the germination of Suaeda glauca, focusing on endogenous hormonal regulation.

resultsWe found that heat shock significantly reduced ABA levels and the ABA/GAs ratio, promoting the release of physiological dormancy. However, no significant synergistic effect between heat and smoke on seed germination was observed. Our findings highlight that cue intensity plays a more critical role than cue interaction in the dormancy release of S. glauca.

conclusionsThis work advances the current understanding of how fire cues release seed dormancy and introduces a new mechanism whereby heat shock releases physiological dormancy in S. glauca seeds by regulating the levels of endogenous hormones. Experiments targeting more species, especially those in which heat shock can release physiological dormancy, are essential to conclusively determine whether the mechanism we identified is broadly applicable.