GhAOS integrates circadian rhythm and jasmonic acid signaling to regulate high temperature stress responses in cotton and Arabidopsis.

Background: Cotton (Gossypium spp.) cultivation is significantly challenged by high temperatures (HT), especially during reproductive stages, leading to male abortion and yield losses.

Results: This study investigated the complex interplay between circadian rhythm (CR), HT, and jasmonic acid (JA) signaling in cotton and Arabidopsis. Disruption of CR led to reduced JA content, triggering bud yellowing and abscission at the tetrad stage (TS) in the HT-sensitive cotton line H05 and longer stigma in Arabidopsis. To elucidate the role of JA under continuous light (CL), targeting the JA biosynthesis gene GhAOS in cotton and using Arabidopsis mutants aos and aoc2 revealed accelerated drying, decreased JA content, and male sterility, alongside altered expression patterns of pivotal bioclock-associated genes (PRR1 and LHY). Additionally, mutant anthers manifested elevated ion leakage and H₂O₂ levels, coupled with reduced activities of antioxidant enzymes SOD and POD during CL + HT stress.

Conclusions: Current study investigated the complex interplay between CR, HT, and JA signaling pathways in cotton and Arabidopsis, focusing on their impact on male fertility under HT stress. These findings highlight the importance of JA and CR in plant fitness, crucial for future crop improvement and sustainable agriculture.