Interactions between sucrose and jasmonate signalling in the response to cold stress

Astrid Wingler*
University College Cork

Veronica Tijero
Universitat de Barcelona

Sergi Munne-Bosch
Universitat de Barcelona

*Presenting Author

Jasmonic acid (JA) is involved in stress and defence responses in plants and interacts synergistically with sucrose in inducing anthocyanin accumulation. Here we explore the role of signalling interactions between sucrose and JA in the response of Arabidopsis to low temperature. To analyse the importance of JA signalling for cold tolerance and cold-induced anthocyanin synthesis, Arabidopsis JA response mutants (jar1-1 and coi1-16) and their respective wild types were grown at cold (4C) and warm (20C) temperatures. While both mutants were able to cold acclimate, the jar-1-1 mutant showed increased signs of stress, including a larger drop in photosystem II efficiency upon transfer to low temperature. In the absence of external sucrose supply, cold treatment resulted in sugar accumulation and increased anthocyanin contents in all genotypes. Addition of sucrose further increased anthocyanin accumulation, suggesting synergistic interactions between sucrose and low temperature. A comprehensive analysis of phytohormone contents by UHPLC/ESI-MS/MS showed reduced contents of JA conjugates, such as the active JA-Ile, in the jar1-1 mutant. In addition, the formation of JA conjugates was affected by cold temperature treatment in the other Arabidopsis lines. Contents of the stress hormones abscisic acid and salicylic acid were increased in response to sucrose and cold treatments, but altered patterns in the contents of these hormones were found in the coi1-16 mutant, indicating interactions between different groups of phytohormones in stress signalling.