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International Journal of Environmental Science and Technology
https://doi.org/10.1007/s13762-018-1762-3
ORIGINAL PAPER
Molecular dissection of novel anthocyanin transcripts HsCHS
and HsF3H from the calyx tissue of Hibiscus sabdariffa L.
M. Roshani
1
· R. Nulit
1
· C. S. Y. Yong
1
Received: 14 July 2017 / Revised: 4 October 2017 / Accepted: 11 May 2018
© Islamic Azad University (IAU) 2018
Abstract
Flavonoids are polyphenolic compounds commonly found in vegetables as well as fruits and contribute significantly in the
human diet. The calyx of roselle (Hibiscus sabdariffa L.) is rich in polyphenolic compounds and anthocyanins. Chalcone
synthase (CHS) and flavanone 3-hydroxylase (F3H) are two important genes involved in the biosynthesis of flavonoids includ-
ing anthocyanins in plants. The two transcripts designated as HsCHS (KR709156) and HsF3H (KR709157) were isolated
from the calyx tissue of roselle using the Rapid Amplification of cDNA Ends PCR and PCR walking approaches, which
encoded the polypeptides of 389 and 368 amino acids, respectively. Several important domains were revealed in the HsCHS
amino acid sequence, including CHS-like, fabH, BcsA, Chal-sti-synt-N and Chal-sti-synt-C, which indicates that the isolated
gene is probably a CHS belonging to the polyketide synthase family. On the other hand, identification of 2OG-FeII_oxy,
Isopenicillin N synthase-like, DIOXN and PLN02515 domains in HsF3H protein sequence supports the idea that the isolated
gene is an F3H related to the large gene family of 2-oxoglutarate-dependent dioxygenases. This study predicted the putative
functions of the two central genes governing the flavonoid pathway in H. sabdariffa, which leads to anthocyanin production.
Keywords Transcriptomics · Anthocyanin pathway · Roselle
Introduction
The genus Hibiscus belongs to the family of Malvaceae,
which includes over 300 species, distributed in tropical and
sub-tropical regions. Hibiscus sabdariffa L., commonly
known as roselle, is an annual erect shrub with medici-
nal properties. The plant is widely cultivated in Malaysia,
China, Taiwan, India and Africa. The fleshy red calyx of
roselle is commercially important (Abdel-Moniem and Abd
El-Wahab 2006). The roselle calyx extract contains consid-
erable quantities of anthocyanins, phenolic compound and
vitamin C, is commonly used in pharmaceutical, food and
the cosmetic industry (Abdel-Moniem and Abd El-Wahab
2006). Molecular imprinting techniques and voltammetric
sensors have been developed for detecting these compounds,
recently (Gupta et al. 2014; Yola and Atar 2014; Yola et al.
2013). The calyx’s extract of roselle demonstrates a wide
range of beneficial properties, including antioxidant, anti-
cancer, antihypertensive, hypolipidemic, hepatoprotective,
anti-stress, antispasmodic, diuretic and antidiarrheal activi-
ties (Salem et al. 2014). Roselle is also used as a healthy and
cheap source of food colorant for the industrially-produced
wines (Bolade et al. 2009). In line with increasing claims
on the industrial features of this plant, the crude oil from
the seed of roselle was also introduced as a potential source
for biofuel production (Nakpong and Wootthikanokkhan
2010). Furthermore, it can also be used as an alternative
fiber source commercially (Chauhan and Kaith 2011).
Flavonoids are bioactive polyphenolic molecules, widely
distributed in the plants kingdom for the vital role they play
in different aspects (Sandhar et al. 2011). These molecules
are essential in the interaction happens between the envi-
ronment and plants. Flavonoids function differently as pig-
ments, phytoalexins, UV protectants, as well as signaling
molecules in plant–microbe interactions, antioxidants, and
pollinator attractants or feeding deterrents in different plant
species (Dao et al. 2011). To date, more than 4000 different
flavonoids have been identified and characterized. Poten-
tially, flavonoids are great source of natural antioxidants.
Editorial responsibiility: Xu Han.
* C. S. Y. Yong
chrisyong@upm.edu.my
1
Department of Biology, Faculty of Science, Universiti Putra
Malaysia, 43400 Serdang, Selangor DE, Malaysia
@Phil_Robichaud
@deepthiw
@JoseServera