Developmental Regulation of the Expression of Amaryllidaceae Alkaloid Biosynthetic Genes in Narcissus papyraceus.

Tarun Hotchandani,Justine de Villers,Isabel Desgagné-Penix

doi:10.3390/genes10080594

Tarun Hotchandani, Justine de Villers + Show 1 more

Open Access

https://doi.org/10.3390/genes10080594

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Journal: Genes	Publication Date: Aug 7, 2019
Citations: 15	License type: CC BY 4.0

Affiliation: Université du Québec à Trois-Rivières

Abstract

Amaryllidaceae alkaloids (AAs) have multiple biological effects, which are of interest to the pharmaceutical industry. To unleash the potential of Amaryllidaceae plants as pharmaceutical crops and as sources of AAs, a thorough understanding of the AA biosynthetic pathway is needed. However, only few enzymes in the pathway are known. Here, we report the transcriptome of AA-producing paperwhites (Narcissus papyraceus Ker Gawl). We present a list of 21 genes putatively encoding enzymes involved in AA biosynthesis. Next, a cDNA library was created from 24 different samples of different parts at various developmental stages of N. papyraceus. The expression of AA biosynthetic genes was analyzed in each sample using RT-qPCR. In addition, the alkaloid content of each sample was analyzed by HPLC. Leaves and flowers were found to have the highest abundance of heterocyclic compounds, whereas the bulb, the lowest. Lycorine was also the predominant AA. The gene expression results were compared with the heterocyclic compound profiles for each sample. In some samples, a positive correlation was observed between the gene expression levels and the amount of compounds accumulated. However, due to a probable transport of enzymes and alkaloids in the plant, a negative correlation was also observed, particularly at stage 2.

Highlights

Plants produce specialized metabolites having a wide range of biological activities
Viladomat et al (1986) [34] found that the bulb of N. assoanus accumulated a large amount of alkaloids, while Kreh (2002) [32] reported that the concentration of galanthamine was relatively high in the bulb of N. pseudonarcissus (L.) cv
In a more recent study by Shawky et al (2015) [33], in which nine different samples of N. papyraceus were analyzed, alkaloids were found to be most abundant in the bulb

Summary

Introduction

Plants produce specialized metabolites having a wide range of biological activities. One class of specialized metabolites, the alkaloids, are mainly characterized by the occurrence of at least one nitrogen atom in a heterocyclic ring. The toxic properties (cytotoxic, cytostatic, anti-microbial, etc.) of alkaloids make them suitable for use, at low doses, as medical drugs. One family of plants known to produce a wide variety of alkaloids with promising medicinal potential is the Amaryllidaceae family [3]. It includes ornamental species such as daffodils, jonquils and snowdrops. Only one Amaryllidaceae alkaloid (AA), galanthamine, is currently available as a commercial drug, marketed under the names Reminyl and Razadyne [5]. Owing to its acetylcholinesterase inhibitory property, it is used to treat the symptoms of Alzheimer’s disease [6,7]

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