Calcium and methyl jasmonate cross-talk in the secondary metabolism of grape cells

In grape cell cultures cv. Gamay Fréaux var. Teinturier, Ca was shown to decrease cell pigmentation through the inhibition of anthocyanin biosynthesis, while stimulating stilbenoids accumulation. Because methyl jasmonate (MeJA) is a well-known inducer of secondary metabolism in grape cells, and Ca antagonizes its stimulatory effect over several enzymes of core metabolic branches, in the present study we hypothesized that Ca and MeJA signaling pathways interact to regulate specific secondary metabolism routes. Grape cultured cells were elicited with MeJA or with MeJA + Ca and an UPLC-MS-based targeted metabolomic method was implemented to characterize their polyphenolic profiles. Results were compared with the profile of cells elicited with Ca only, previously reported. Data was complemented with gene expression analysis, allowing the assembly of a metabolic map that unraveled routes specifically regulated by both elicitors. MeJA + Ca specifically boosted E-resveratrol and E--viniferin levels by 180% and 140%, respectively, in comparison to cells treated with MeJA only, while the stimulatory effect of MeJA over flavonoid synthesis was inhibited by Ca. In parallel, Ca downregulated most flavonoid pathway genes, including LAR1, ANS, BAN and ANR. Ca was able to mimic or potentiate the effect of MeJA on the expression of JA signaling genes, including JAR1, PIN and PR10. Transcript/metabolite correlation networks exposed the central influence of FLS1, STS, CDPK17 and COI1 in polyphenolic biosynthetic routes. This study highlights the potential of the MeJA-Ca combination for diverting polyphenolic metabolism towards the production of specific metabolites of interest, highly relevant in a biotechnological perspective.This work was supported by the “Contrato-Programa” UIDB/04050/2020 funded by portuguese national funds through the FCT I.P. The work was also supported by FCT, CCDR-N (Norte Portugal Regional Coordination and Development Commission) and European Funds (FEDER/POCI/COMPETE2020) through the project AgriFood XXI (NORTE-01-0145-FEDER-000041) and the research projects BerryPlas tid (PTDC/BIA-FBT/28165/2017 and POCI-01-0145-FEDER-028165) and MitiVineDrought (PTDC/BIA-FBT/30341/2017 and POCI-01-0145- FEDER-030341). A.T. was supported by a postdoctoral researcher con tract/position within the project “BerryPlastid”. This article/publication is based upon work from COST Action CA 17111 INTEGRAPE, supported by COST (European Cooperation in Science and Technology) – in the context of a STSM to V.M. The R´egion-Centre Val de Loire (France) supported this work under the grant agreement to Projects CEPATLAS and VINODRONE to A.L.