Metabolite profiling and expression analysis of flavonoid, vitamin C and tocopherol biosynthesis genes in the antioxidant-rich sea buckthorn (Hippophae rhamnoides L.)

Phytochemistry. 2015 Oct;118:181-91. doi: 10.1016/j.phytochem.2015.08.008. Epub 2015 Aug 25.

Abstract

In this study, phenolic compounds were analyzed in developing berries of four Canadian grown sea buckthorn (Hippophae rhamnoides L.) cultivars ('RC-4', 'E6590', 'Chuyskaya' and 'Golden Rain') and in leaves of two of these cultivars. Among phenolic acids, p-coumaric acid was the highest in berries, while gallic acid was predominant in leaves. In the flavonoid class of compounds, myricetin/rutin, kaempferol, quercetin and isorhamnetin were detected in berries and leaves. Berries of the 'RC-4' cultivar had approximately ⩾ 2-fold higher levels of myricetin and quercetin at 17.5mg and 17.2 mg/100 g FW, respectively, than the other cultivars. The flavonoid content in leaves was considerably more than in berries with rutin and quercetin levels up to 135 mg and 105 mg/100 g FW, respectively. Orthologs of 15 flavonoid biosynthesis pathway genes were identified within the transcriptome of sea buckthorn mature seeds. Semi-quantitative RT-PCR analysis of these genes in developing berries indicated relatively higher expression of genes such as CHS, F3'H, DFR and LDOX in the 'RC-4' cultivar than in the 'Chuyskaya' cultivar. Vitamin C levels in ripened berries of the Canadian cultivars were on the high end of the concentration range reported for most other sea buckthorn cultivars. Orthologs of genes involved in vitamins C and E biosynthesis were also identified, expanding the genomic resources for this nutritionally important plant.

Keywords: Elaeagnaceae; Flavonoids; Gene expression; Hippophae rhamnoides L.; Phenolic acids; Sea buckthorn; Tocopherol; Transcriptome; Vitamin C.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antioxidants / analysis*
  • Antioxidants / chemistry
  • Ascorbic Acid / analysis*
  • Chromatography, High Pressure Liquid
  • Coumaric Acids
  • Flavonoids / analysis
  • Flavonoids / metabolism
  • Fruit / chemistry
  • Fruit / growth & development
  • Hippophae / chemistry*
  • Hippophae / growth & development
  • Nuclear Magnetic Resonance, Biomolecular
  • Phenols / analysis
  • Plant Leaves / chemistry
  • Polymerase Chain Reaction
  • Propionates
  • Quercetin / analogs & derivatives
  • Tocopherols / analysis*

Substances

  • Antioxidants
  • Coumaric Acids
  • Flavonoids
  • Phenols
  • Propionates
  • 3-methylquercetin
  • myricetin
  • Quercetin
  • trans-3-(4'-hydroxyphenyl)-2-propenoic acid
  • Ascorbic Acid
  • Tocopherols