Dissecting the impact of environment, season and genotype on blackcurrant fruit quality traits.

This work aims to determine the effect of genotype x environment (GxE) interaction that influence blackcurrant (Ribes nigrum) fruit quality. We applied metabolomics-driven analysis on fruits from four cultivars grown in contrasting European-locations over two seasons. By integrating metabolomics and sensory analysis, we also defined specific metabolic signatures associated with consumer acceptance. Our results showed that rainfall is a crucial factor associated with accumulation of delphinidin- and cyanidin-3-O-glucoside, the two mayor blackcurrant pigments meanwhile temperature affects the main organic acid levels which can be decisive for fruit taste. Sensorial analysis showed that increases in terpenoid and acetate ester volatiles were strongly associated with higher appreciation score, while proacacipetalin, a cyanogenic-glycoside, was positively associated to bitter taste. Our results pave the way for the selection of high-quality cultivars and suitable production sites for blackcurrant cultivation.

Quantitative trait loci mapping of polyphenol metabolites in blackcurrant (Ribes nigrum L.).

INTRODUCTION: Commercially, blackcurrants (Ribes nigrum L.) are grown mainly for processing, especially for juice production. They are valued for their high levels of polyphenols, especially anthocyanins, which contribute to their characteristic deep colour, but also as a good source of vitamin C. Recently, evidence has accrued that polyphenols, such as anthocyanins, may have specific human health benefits. OBJECTIVE: The aims of this study were to investigate the genetic control of polyphenols and other key juice processing traits in blackcurrants. METHODS: The levels, over 2 years, of vitamin C, citrate, malate, succinate, total organic acids, total anthocyanins and total phenolics together with 46 mainly polyphenol metabolites were measured in a blackcurrant biparental mapping population. Quantitative trait loci (QTLs) for these traits were mapped onto a high-density SNP linkage map. RESULTS: At least one QTL was detected for each trait, with good consistency between the 2 years. Clusters of QTLs were found on each of the eight linkage groups (LG). For example, QTLs for the major anthocyanidin glucosides, delphinidin-3-O-glucoside and cyanidin-3-O-glucoside, co-localised with a QTL for total anthocyanin content on LG3 whereas the major anthocyanidin rutinosides, delphinidin-3-O-rutinoside and cyanidin-3-O-rutinoside, had QTLs on LG1 and LG2. Many of the QTLs explained a high proportion of the trait variation, with the most significant region, on LG3 at ~ 35 cM, explaining more than 60% of the variation in the coumaroylated metabolites, Cyanidin-coumaroyl-glucose, Delphinidin-coumaroyl-glucose, Kaempferol-coumaroyl-glucose and Myricetin-coumaroyl-glucose. CONCLUSION: The identification of robust QTLs for key polyphenol classes and individual polyphenols in blackcurrant provides great potential for marker-assisted breeding for improved levels of key components.

Chemical profile and antioxidative and antimicrobial activity of juices and extracts of 4 black currants varieties (Ribes nigrum L.).

UNLABELLED: The aim of this article was to determine the chemical composition (anthocyanin and ascorbic acid contents, total phenols, and tannins), and the antioxidative, and antimicrobial activities of the juices and methanol extracts of 4 varieties-Tenah, Triton, Ben Sarek, and Ometa. The juices were made during 2008, 2009, and 2010 from the berries grown on the same location. Statistically significant differences were found in all the tested parameters of each variety for every year. Ometa variety exhibited the best antioxidative activity. The highest ascorbic acid value had Tenah juice from 2010 (211 mg/100 g) and Ben Sarek methanol extract (656 mg/100 g). Delphinidin-3-ruthenoside was the dominant anthocyanin in Triton, Tenah, and Ben Sarek variety during all 3 y and Ometa in 2010 where Ometa in 2008 and 2009 had slightly higher content of cyanidin-3-ruthenoside. The minimum inhibitory and microbicidal concentrations ranged from MIC/MBC(MFC) = 62.5 to 500 mg/mL for juices and 0.4 to 500 mg/mL for extracts. There was no significant difference in the effect of the juices against Gram(+) and Gram(-) bacteria. All the extracts acted in lower concentrations than juices. PRACTICAL APPLICATION: Data contained in this article provide an insight into the effects the weather condition has on the content of the bioactive compounds in genetically different types of black currants, during the 3-y observation period. This article is relevant to the commercial application of black currants-based dietary supplements.

Identification and functional analysis of the genes encoding Delta6-desaturase from Ribes nigrum.

Gamma-linolenic acid (gamma-linolenic acid, GLA; C18:3 Delta(6, 9, 12)) belongs to the omega-6 family and exists primarily in several plant oils, such as evening primrose oil, blackcurrant oil, and borage oil. Delta(6)-desaturase is a key enzyme involved in the synthesis of GLA. There have been no previous reports on the genes encoding Delta(6)-desaturase in blackcurrant (Ribes nigrum L.). In this research, five nearly identical copies of Delta(6)-desaturase gene-like sequences, named RnD8A, RnD8B, RnD6C, RnD6D, and RnD6E, were isolated from blackcurrant. Heterologous expression in Saccharomyces cerevisiae and/or Arabidopsis thaliana confirmed that RnD6C/D/E were Delta(6)-desaturases that could use both alpha-linolenic acids (ALA; C18:3 Delta(9,12,15)) and linoleic acid (LA; C18:2 Delta(9,12)) precursors in vivo, whereas RnD8A/B were Delta(8)-sphingolipid desaturases. Expression of GFP tagged with RnD6C/D/E showed that blackcurrant Delta(6)-desaturases were located in the mitochondrion (MIT) in yeast and the endoplasmic reticulum (ER) in tobacco. GC-MS results showed that blackcurrant accumulated GLA and octadecatetraenoic acids (OTA; C18:4 Delta(6,9,12,15)) mainly in seeds and a little in other organs and tissues. RT-PCR results showed that RnD6C and RnD6E were expressed in all the tissues at a low level, whereas RnD6D was expressed at a high level only in seeds, leading to the accumulation of GLA and OTA in seeds. This research provides new insights to our understanding of GLA synthesis and accumulation in plants and the evolutionary relationship of this class of desaturases, and new clues as to the amino acid determinants which define precise enzyme activity.