Coffea arabica L. genes from isoprenoid metabolic pathways are more expressed in full sun cultivation systems than in agroforestry systems

Abstract

Coffee synthesizes two unique isoprenoid diterpenes, cafestol (C20H28O3) and kahweol (C20H26O3), ent-kaurene compounds produced through the mevalonate or mevalonate-independent pathway. These compounds are relevant to beverage quality, plant defense, human health and nutraceutical properties. We investigate the expression profile of genes in the early (CaHMGR, CaMVD, CaDXR and CaIDS) and final steps of isoprenoid diterpenes biosynthesis (Coffea arabica L. cytochrome P450s: CaCYP82C2, CaCYP71A25, CaCYP74A1 and CaCYP701A3) in two fruits development stages (90 and 210 days after flowering). We also observed total lipid, cafestol and kahweol accumulation in C. arabica grown using two crop systems (full sun and agroforestry) at IDR-Parana Londrina, PR, Brazil. Plants in full sun presented higher gene expression than plants grown in agroforestry systems, except for CaHMGR. Fruits showed higher levels of transcript activity 210 days after flowering, about 2.8 times more in the genes expressed during the first steps and 3.6 times in those in the later steps. Although lipid, cafestol and kahweol were higher in the full sun than the agroforestry system, only increased lipid content was statistically significant. Cultivation system plays an important role in the expression of the genes, particularly as regards light incidence.