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Preharvest application of ethephon and postharvest UV-B radiation improve quality traits of beetroot (Beta vulgaris L. ssp. vulgaris) as source of colourant.
- Source :
-
BMC plant biology [BMC Plant Biol] 2018 Dec 03; Vol. 18 (1), pp. 316. Date of Electronic Publication: 2018 Dec 03. - Publication Year :
- 2018
-
Abstract
- Background: Betanins have become excellent replacers for artificial red-purple food colourants. Red beet (Beta vulgaris L. spp. vulgaris) known as beetroot, is a rich source of betalains, which major forms are betanin (red to purple) and vulgaxanthin (yellow). Betalains and phenolic compounds are secondary metabolites, accumulation of which is often triggered by elicitors during plant stress responses. In the present study, pre-harvest applications of ethephon (an ethylene-releasing compound) and postharvest UV-B radiation were tested as elicitors of betalains and phenolic compounds in two beetroot cultivars. Their effects on quality parameters were investigated, and the expression of biosynthetic betalain genes in response to ethephon was determined.<br />Results: Ethephon was applied as foliar spray during the growth of beetroot, resulting in increased betanin (22.5%) and decreased soluble solids contents (9.4%), without detrimental effects on beetroot yield. The most rapid accumulation rate for betanin and soluble solids was observed between 3 and 6 weeks after sowing in both untreated and ethephon-treated beetroots. Overall, the expression of the betalain biosynthetic genes (CYP76AD1, CYP76AD5, CYP76AD6 and DODA1), determining the formation of both betanin and vulgaxanthin, increased in response to ethephon treatment, as did the expression of the betalain pathway activator BvMYB1. In the postharvest environment, the use of short-term UV-B radiation (1.23 kJ m <superscript>- 2</superscript> ) followed by storages for 3 and 7 days at 15 °C resulted in increased betanin to vulgaxanthin ratio (51%) and phenolic content (15%).<br />Conclusions: The results of this study provide novel strategies to improve key profitability traits in betalain production. High betanin concentration and high betanin to vulgaxanthin ratio increase the commercial value of the colourant product. In addition, lowering soluble solids levels facilitates higher concentration of beetroot colour during processing. Moreover, we show that enhanced betanin content in ethephon-treated beetroots is linked to increased expression of betalain biosynthetic genes.
- Subjects :
- Beta vulgaris anatomy & histology
Beta vulgaris physiology
Betalains metabolism
Crop Production methods
Food Handling methods
Food Quality
Gene Expression drug effects
Organophosphorus Compounds administration & dosage
Phenols metabolism
Beta vulgaris drug effects
Organophosphorus Compounds pharmacology
Plant Growth Regulators pharmacology
Ultraviolet Rays
Subjects
Details
- Language :
- English
- ISSN :
- 1471-2229
- Volume :
- 18
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- BMC plant biology
- Publication Type :
- Academic Journal
- Accession number :
- 30509181
- Full Text :
- https://doi.org/10.1186/s12870-018-1556-2