Interplay between electrical signals and jasmonate coordinates systemic photosynthetic responses

Local stressors induce systemic inactivation of photosynthesis, yet the underlying mechanisms remain largely unknown. In Arabidopsis thaliana, local heating induced propagation of an electrical signal into systemic leaves, with its parameters dependent on vascular connections between leaves. The propagation of the electrical signal was followed by a rapid systemic increase in content of jasmonic acid and jasmonoyl-L-isoleucine, a systemic decrease in stomatal conductance, and a long-term systemic inactivation of photosynthesis. The spatial and temporal coherence of events, combined with analysis of the dynamics of jasmonate content, stomatal conductance, and photosynthesis activity in transgenic plants impaired in jasmonate biosynthesis, revealed that the systemic photosynthetic response is mediated by jasmonoyl-L-isoleucine-induced decrease in stomatal conductance. In turn, systemic jasmonate production is likely controlled by electrical signals, which also contributes to the decrease in photosynthesis activity. Collectively these findings highlight the complexity and fine-tuning of local stimulus-induced systemic photosynthetic responses that are mediated by interplay between electrical signals and jasmonates.