Triacylglycerol biosynthesis in developing Ribes nigrum and Ribes rubrum seeds from gene expression to oil composition

•Triacylglycerol biosynthesis of Ribes sp. during berry development was described.•Gene expression and fatty acid composition in different growth stages.•Gene expression levels were very similar within each species.•Triacylglycerol composition had differences between species and cultivars. Oils with sufficient contents of fatty acids, which can be metabolized into precursors of anti-inflammatory eicosanoids, have potential health effects. Ribes sp. seed oil is rich in α-linolenic, γ-linolenic and stearidonic acids belonging to this fatty acid group. Only a few previous studies exist on Ribes sp. gene expression. We followed the seed oil biosynthesis of four Ribes nigrum and two Ribes rubrum cultivars at different developmental stages over 2 years in Southern and Northern Finland with a 686km latitudinal difference. The species and the developmental stage were the most important factors causing differences in gene expression levels and oil composition. Differences between cultivars were detected in some cases, but year and location had only small effects. However, expression of the gene encoding Δ9-desaturase in R. nigrum was affected by location. Triacylglycerol biosynthesis in Ribes sp. was distinctly buffered and typically followed a certain path, regardless of growth environment.