Antioxidant activity of pitcher extracts from three Nepenthes species

Nepenthes, locally known as ‘periuk kera’ in Malaysia, is a fascinating species due to uniqueness in their morphology in having pitcher organ for carnivorous diet. The pitcher plant has been used for cooking traditional delicacies and as traditional remedies to treat illness. Hence, this species might possess beneficial health properties. This study aimed to compare the antioxidant activity of the pitcher extracts from Nepenthes ampullaria, Nepenthes rafflesiana and their hybrid, Nepenthes × hookeriana. The samples were extracted using methanol:chloroform:water (3:1:1) via sonication assisted extraction and the extracts were subjected to three different antioxidant assays, namely 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing power (FRAP) and total phenolic content (TPC). Extract from N. ampullaria exhibited the strongest radical scavenging activity (0.148 ± 0.04 mg/mL) with the highest ferric reducing power (0.009 ± 0.003 mg GA/mg dry weight) among the three species, whereas that of N. rafflesiana possessed the highest phenolic content (0.057 ± 0.017 mg GA/mg dry weight). However, the antioxidant capacities of the pitcher extracts were not significantly different (p>0.05) between the three species and were much lower than the gallic acid as a standard reference

Production of transgenic rice (indica cv. MR219) overexpressing Abp57 Gene through Agrobacterium-mediated transformation

Agrobacterium-mediated transformation of indica rice is undoubtedly a challenging task due to the rice recalcitrant nature to transformation process. Therefore, optimization of the transformation protocol is important for specific indica rice cultivar to ensure effectiveness of the transformation. In this study, crucial parameters affecting Agrobacterium-mediated transformation were optimized to obtain transgenic rice of local rice cultivar (indica MR219). Embryogenic calli were chosen for inoculation with Agrobacterium tumefaciens strain LBA4404 harbouring a binary vector pH2GW7-ABP57 containing gene of interest, Auxin binding protein 57 (Abp57). The parameters that have been optimized were the immersion time, co-cultivation period, acetosyringone concentration and co-cultivation temperature. A total of four days co-cultivation period and 30 min immersion of embryogenic callus are optimum for the transformation of MR219 with transformation efficiency of 26.4% and 16.0%, respectively. Acetosyringone at 200 μM and co-cultivation at 28°C also gave the highest transformation efficiency (14.4 and 18.4%, respectively). Meanwhile, inclusion of 20 g/L maltose+20 g/L sorbitol into the regeneration media has significantly improve the transformed somatic embryos growth and increase the regeneration efficiency up to 40.0%. The results of polymerase chain reaction (PCR) and reverse transcription-polymerase chain reaction (RT-PCR) indicated that the transgene was successfully integrated and overexpressed in transgenic rice of MR219. In conclusion, significant improvement in transformation efficiency for rice cv. MR219 has been obtained by using the optimised protocol for transformation and regeneration developed in this study

SMRT sequencing data for Garcinia mangostana L. variety Mesta

The “Queen of Fruits” mangosteen (Garcinia mangostana L.) produces commercially important fruits with desirable taste of flesh and pericarp rich in xanthones with medicinal properties. To date, only limited knowledge is available on the cytogenetics and genome sequences of a common variety of mangosteen (Abu Bakar et al., 2016 [1]). Here, we report the first single-molecule real-time (SMRT) sequencing data from whole genome sequencing of mangosteen of Mesta variety. Raw reads of the SMRT sequencing project can be obtained from SRA database with the accession numbers SRX2718652 until SRX2718659

Determination of the chromosome number and genome size of Garcinia mangostana L. via cytogenetics, flow cytometry and k-mer analyses

Mangosteen (Garcinia mangostana L.) is one of the most popular tropical fruit of South-East Asia. It has considerable economic potential for local and export markets. This paper describes a research work to determine the number of chromosomes and genome size of G. mangostana through chromosome counting, flow cytometry and k-mer analyses. Chromosome count analysis revealed that the chromosome number of G. mangostana varied from 74 to 110. The high number observed could be due to the occurrence of mutation and aneuploidy in G. mangostana. Using flow cytometry with Glycine max cv. Polanka (2C = 2.5 pg) used as standard, G. mangostana genome size was found to be 2C = 6.00 ± 0.17 pg. Meanwhile, a genome survey of G. mangostana was performed using Illumina HiSeq 2000 DNA sequencing; k-mer analysis revealed that the genome size of G. mangostana was approximately 5.92 Gbp, or approximately 6.05 pg (1 pg DNA = 0.9780 × 109 bp). Based on the flow cytometry and genome survey, the study concludes that the genome size of G. mangostana is between 6.00 and 6.05 pg

RNA extractions of mangosteen (Garcinia mangostana L.) pericarps for sequencing

This study employed several RNA extraction methods for mangosteen pericarps prior to RNA sequencing. The sequencing platform heavily relies on a high quality RNA yield. However, pericarp tissues contain a lot of phenolic compounds that results in low RNA quality. Hence, we studied several RNA extraction methods to obtain the most suitable method for the best RNA quality from the pericarps of mangosteen. Five different methods including Lopez and Gomez, modified hexadecyltrimethyl ammonium bromide (CTAB) method, several commercial kits from TranszolUP, Favorgen and Qiagen RNeasy were compared. By optimising the CTAB method, it was found to be the best method to obtain pure RNA (high A260/A280 ratio) with the highest yields (up to approximately 600-800 ng/μL concentration). The QC control of these samples using bioanalyzer validated their suitability for the downstream RNA sequencing. This report details the method for extracting high quality and high yield RNA samples from fruit that are rich in polyphenolic compounds such as mangosteen

Uncaria gambir (W. Hunter) Roxb: From phytochemical composition to pharmacological importance

Purpose: To present an overview of the ethnopharmacology, phytochemistry, and pharmacological effects of the ‘wonder’ plant, Uncaria gambir (W. Hunter) Roxb.Methods: The literature search for information on phytochemical composition and pharmacological importance of U. gambir was undertaken using diverse electronic search engines, including Google, Scopus, Web of Science, scientific literature, and databases (Pubmed, Springer and Science Direct). Other relevant literature sources include books, book chapters, conference papers, theses, and other scientific publications.Results: Uncaria gambir Roxb possesses significant medicinal potentials as an antioxidant, anthelmintic, antibacterial, anti-diabetic, and for the management of osteoarthritis. Interest has increased among researchers for the utilization of this plant in complementary medicine, for example, to relieve sore throat, spongy gum, and dysentery, to treat atherosclerosis and obesity, and to prolong sexual intercourse.Conclusion: Uncaria gambir demonstrates significant pharmacological properties. This review will be useful for prospective research and development of this ethnomedicinal plant into potentially valuable health products. Keywords: Anthelmintic, Antibacterial,Anti-Diabetic, Osteoarthritis, Uncaria gambi

Transformasi Gen Proteolisis 6 (PRT6) berperantarakan Agrobacterium tumefaciens ke dalam kotiledon tomato kultivar Micro Tom

Gen Proteolisis 6 (PRT6) merupakan gen yang memainkan peranan penting dalam tapak jalan N-end rule dan berfungsi sebagai enzim E3 ligase. PRT6 berperanan dalam pengenalan protein sasaran bagi proses degradasi. Objektif utama kajian ini adalah untuk mentransformasi konstruk RNAi PRT6 ke dalam tomato berperantarakan Agrobacterium tumefaciens. Ini bertujuan untuk memahami peranan tapak jalan N-end rule semasa proses pemasakan buah. Beberapa faktor yang memberi kesan kepada transformasi seperti masa ko-penanaman dan juga kepekatan antibiotik yang digunakan telah dioptimumkan. Keputusan kajian menunjukkan pengeraman kotiledon selama 48 jam pada medium ko-penanaman dapat meningkatkan penghasilan kalus sebanyak 61% manakala penggunaan 500 mg/L antibiotik karbenisilin dalam medium regenerasi pucuk dapat mengurangkan kontaminasi A. tumefaciens sehingga 5.2%. Selain itu, strain A. tumefaciens C58 merupakan strain A. tumefaciens yang paling sesuai digunakan sebagai perantara dalam kajian ini. Tindak balas berantai polimerase (PCR) telah dijalankan pada pucuk yang terhasil untuk mengesahkan integrasi fragmen PRT6 ke dalam genom tomato. Berdasarkan analisis PCR, kesemua tujuh pucuk putatif transgenik adalah merupakan transforman positif

Mitochondrial genome of Garcinia mangostana L. variety Mesta

Fruits of Garcinia mangostana L. (mangosteen) are rich in nutrients with xanthones found in the pericarp having great pharmaceutical potential. Mangosteen variety Mesta is only found in Malaysia, which tastes sweeter than the common Manggis variety in Southeast Asia. In this study, we report the complete mitogenome of G. mangostana L. variety Mesta with a total sequence length of 371,235 bp of which 1.7% could be of plastid origin. The overall GC content of the mitogenome is 43.8%, comprising 29 protein-coding genes, 3 rRNA genes, and 21 tRNA genes. Repeat and tandem repeat sequences accounted for 5.8% and 0.15% of the Mesta mitogenome, respectively. There are 333 predicted RNA-editing sites in Mesta mitogenome. These include the RNA-editing events that generated the start codon of nad1 gene and the stop codon of ccmFC gene. Phylogenomic analysis using both maximum likelihood and Bayesian analysis methods showed that the mitogenome of mangosteen variety Mesta was grouped under Malpighiales order. This is the first complete mitogenome from the Garcinia genus for future evolutionary studies

Recent advancement of engineering microbial hosts for the biotechnological production of flavonoids

Flavonoids are polyphenols that are important organic chemicals in plants. The health benefits of flavonoids that result in high commercial values make them attractive targets for large-scale production through bioengineering. Strategies such as engineering a flavonoid biosynthetic pathway in microbial hosts provide an alternative way to produce these beneficial compounds. Escherichia coli, Saccharomyces cerevisiae and Streptomyces sp. are among the expression systems used to produce recombinant products, as well as for the production of flavonoid compounds through various bioengineering approaches including clustered regularly interspaced short palindromic repeats (CRISPR)-based genome engineering and genetically encoded biosensors to detect flavonoid biosynthesis. In this study, we review the recent advances in engineering model microbial hosts as being the factory to produce targeted flavonoid compounds

Rapid Assembly of yeast expression cassettes for phenylpropanoid biosynthesis in Saccharomyces cerevisiae

Microbial production of natural products using metabolic engineering and synthetic biology approaches often involves the assembly of multiple gene fragments including regulatory elements, especially when using eukaryotes as hosts. Traditional cloning strategy using restriction enzyme digestion and ligation are laborious and inflexible owing to the high number of sequential cloning steps, limited cutting sites and generation of undesired ‘scar’ sequences. In this study, a homology-based isothermal DNA assembly method was carried out for one-step simultaneous assembly of multiple DNA fragments to engineer plant phenylpropanoid biosynthesis in Saccharomyces cerevisiae. Rapid construction of yeast plasmid harboring dual gene expression cassettes was achieved via isothermal assembly of four DNA fragments designed with 20 bp overlapping sequences. The rate-limiting enzyme of phenylpropanoid pathway, cinnamate 4-hydroxylase encoded by C4H gene from Polygonum minus was cloned in tandem with yeast promoter and terminator elements of S. cerevisiae for efficient construction of phenylpropanoid biosynthetic pathway in recombinant yeast. The assembled pAG-CAT (C4H-ADH1t-TEF1p) shuttle plasmid and transformation of S. cerevisiae with the plant C4H gene were confirmed via PCR analysis. Based on these findings, the yeast shuttle plasmid harboring P. minus phenylpropanoid biosynthesis gene was efficiently constructed to be the starting platform for the production of plant natural products in genetically-engineered S. cerevisiae