Emergence of Plastidial Intergenic Spacers as Suitable DNA Barcodes for Arid Medicinal Plant <i>Rhazya stricta</i>

Abstract

The desert plant Rhazya stricta has anticancer and antimicrobial properties, and is widely used in indigenous medicines of Saudi Arabia. However, the therapeutic benefits rely on an accurate identification of this species. The authenticity of R. stricta and other medicinal plants and herbs procured from local markets can be questionable due to a lack of clear phenotypic traits. DNA barcoding is an emerging technology for rapid and accurate species identification. In this study, six candidate chloroplastid barcodes were investigated for the authentication of R. stricta. We compared the DNA sequences from fifty locally collected and five market samples of R. stricta with database sequences of R. stricta and seven closely related species. We found that the coding regions matK, rbcL, rpoB, and rpoC1 were highly similar among the taxa. By contrast, the intergenic spacers psbK-psbI and atpF-atpH were variable loci distinct for the medicinal plant R. stricta. psbK-psbI clearly discriminated R. stricta samples as an efficient single locus marker, whereas a two-locus marker combination comprising psbK-psbI + atpF-atpH was also promising according to results from the Basic Local Alignment Search Tool and a maximum likelihood gene tree generated using PHyML. Two-dimensional DNA barcodes (i.e., QR codes) for the psbK-psbI and psbK-psbI + atpF-atpH regions were created for the validation of fresh or dried R. stricta samples.

Effective Antiplasmodial and Cytotoxic Activities of Synthesized Zinc Oxide Nanoparticles Using Rhazya stricta Leaf Extract

“…Rhazya stricta is an important medicinal plant, widely used for treatment of different diseases in Pakistan [ 12 ]. The leaf extract of Rhazya stricta has been used as anticancer, antifungal, analgesic, chemopreventive, rheumatism, and sedative agent [ 13 ]. Furthermore, it has many beneficial phytochemicals such as tannins, saponins, amino acids, gallic acid, and various flavonoids such as quercetin, hesperidin, kaempferol, quercetrin-3-rhamnaside, isoquercitrin, rutin, apigenin, and luteolin [ 14 – 16 ], which might act as reducing and stabilizing agents in synthesis of nanoparticles (NPs).…”

Research Article Evaluation of the capacity of the DNA barcode ITS2 for identifying and discriminating dryland plants

“…The ITS2 barcode was successfully used to identify 58 herbal medicinal plants, including samples of M. tenacissima and its adulterants (Yu et al, 2018). As well as a way to reveal commercial fraud in the herbal industry, especially if products are falsely sold as powdered plant material in traditional shops (Michel et al, 2016), it can also be used as a reliable means to verify the identity of herbs used in the pharmaceutical industry, in addition to traditional morphological and chemical methods, DNA barcoding with ITS2 has recently been used as a standard quality control procedure in several studies (Khan et al, 2017;Yu et al, 2017) In some cases, ITS2 failed in species identification in our study. A possible explanation for this might be that the sequences stored in GeneBank were misidentified.…”

“…Ali et al (2015) used ITS1 and ITS4 primers in DNA barcodes to study the system of the genus Echinops (Asteraceae). Khan et al (2017) used six DNA barcodes -matK, rbcL, rpoB, rpoC1, atpF-atpH and psbK -to identify the dryland medicinal plant Rhazya stricta (Apocynaceae).…”

Identification of dragon fruit (Selenicereus) species in Mekong Delta based on DNA barcode sequences

“…According to these findings, the combination of five loci, matK + rbcL + trnL-F + trnH-psbA + ITS showed the greatest species resolution while the single rbcL was the least. Khan et al (2017) reported that four coding regions matK, rbcL, rpoB, and rpoC1 were highly conservative among the taxa. On the other hand, the sequences of two intergenic spacers psbK-psbI and atpF-atpH were variable, specifically identifying the medicinal plant Rhazya stricta (Khan et al 2017).…”

“…Khan et al (2017) reported that four coding regions matK, rbcL, rpoB, and rpoC1 were highly conservative among the taxa. On the other hand, the sequences of two intergenic spacers psbK-psbI and atpF-atpH were variable, specifically identifying the medicinal plant Rhazya stricta (Khan et al 2017). Gogoi and Bhau (2018) indicated that single-locus ITS or combined with plastid matK expressed the better species authentication of the genus Nepenthes based on barcoding gaps.…”