Skip to main content
Log in

Phenylalanine affects betalain biosynthesis and promotes ascorbic acid, α-tocopherol, and retinol accumulation in Amaranthus tricolor seedlings

  • Original Article
  • Published:
Acta Physiologiae Plantarum Aims and scope Submit manuscript

Abstract

Betalains are health-promoting plant pigments accumulated in non-anthocyanic plants. Owing to its limited distribution in nature, metabolic trade-offs of inhibiting them are poorly understood. The aim of this study was to investigate the effects of inhibition of betalains in Amaranthus tricolor seedlings to gain insights into the relationship of betalain biosynthesis with other biosynthetic pathways in betalain-accumulating plants. Phenylalanine (Phe; 12.5, 25, and 50 mmol L−1) and 3-methyl-2-benzothiazolinone hydrazone (MBTH) (25 mmol L−1) were treated to inhibit betalain biosynthesis in ten-day-old A. tricolor (red) seedlings. After two and six days of treatment, target (betalain-related metabolites) and non-target metabolites were analyzed. In two days, Phe content increased by 2.6, 8.5, and 17.4-fold in Phe (12.5, 25, and 50 mmol L−1)-treated seedlings, respectively, compared to control, indicating the uptake of Phe by the seedlings. Phe treatment led to a 10.1–18% decrease in betacyanins, while MBTH caused an 18.3% decrease in two days. In both treatments, cyclo-DOPA formation, which is essential for betacyanin biosynthesis, seems to be inhibited, albeit through different mechanisms. Betalain biosynthetic precursors and intermediates, viz., tyrosine, L-DOPA, and dopamine decreased differentially. Ascorbic acid, α-tocopherol, and retinol contents increased in both treatments concomitant with the reduction in betalains, total phenols, and antioxidant enzymes. Therefore, Phe treatment is beneficial in enhancing antioxidant metabolites in betalain-accumulating plants. However, the mechanism of increasing ascorbic acid on inhibiting betalains needs further investigation in other betalain-producing plants also to understand if ascorbic acid is involved in regulating betalain biosynthesis.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others

Data availability

All the data generated during this study have been presented in this paper and its accompanying supplementary information.

Abbreviations

MBTH:

3-Methyl-2-benzothiazolinone hydrazone

L-DOPA:

L-3,4-dihydroxyphenylalanine

DOD:

DOPA-4,5-dioxygenase

Phe:

Phenylalanine

PAL:

Phenylalanine ammonia-lyase

AsA:

Ascorbic acid

BSA:

Bovine serum albumin

PITC:

Phenyl isothiocyanate

HPLC:

High performance liquid chromatography

PPO:

Polyphenol oxidase

DO:

DOPA oxidase

CAT:

Catalase

AAO:

Ascorbic acid oxidase

SOD:

Superoxide dismutase

APx:

Ascorbate peroxidase

H2O2 :

Hydrogen peroxide

TEMED:

Tetramethylethylenediamine

EDTA:

Ethylenediamine tetraacetic acid

PDA:

Photo-diode array

TFA:

Trifluoroacetic acid

ACN:

Acetonitrile

EtOH:

Ethanol

DTT:

Dithiothreitol

SEM:

Standard error of mean

Chl:

Chlorophyll

Tyr:

Tyrosine

Ser:

Serine

Arg:

Arginine

PCA:

Principal component analysis PC Principal component

References

Download references

Acknowledgements

MIK thanks the University Grants Commission, Department of Biotechnology (DBT), and Science and Engineering Research Board (SERB), Govt of India for financial support through F.30-122/2015(BSR), BT/PR16902/NER/95/422/2015, and ECR/2016/000952, respectively. We thank the Head of the Department of Biotechnology, Gauhati University, for his encouragement, and for allowing access to analytical facilities in the department and the Institutional Biotech Hub. We also thank the Director of the National Institute of Pharmaceutical Education and Research (NIPER), Guwahati, Assam, India for providing access to the Central Analytical Instrument Facility.

Author information

Authors and Affiliations

Authors

Contributions

MK: data curation; formal analysis; original draft. HBS: data curation. MIK: conceptualization; funding acquisition; methodology; resources; project administration; supervision; original draft; review and editing.

Corresponding author

Correspondence to Mohammad Imtiyaj Khan.

Ethics declarations

Conflict of interest

The authors declare that there are no competing interests associated with this paper.

Additional information

Communicated by C.L. Cespedes.

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary file1 (DOC 518 KB)

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Kumari, M., Singh, H.B. & Khan, M.I. Phenylalanine affects betalain biosynthesis and promotes ascorbic acid, α-tocopherol, and retinol accumulation in Amaranthus tricolor seedlings. Acta Physiol Plant 46, 17 (2024). https://doi.org/10.1007/s11738-023-03629-1

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s11738-023-03629-1

Keywords

Navigation