Nguyen Nhat Nam

Amomum cinnamomeum Škorničk., Luu & H.Ð.Trần was first identified as an endemic species of Vietnam in 2019. It has a cinnamon-like odor. Over the years, the phytochemical and phylogenetic relationships of A. cinnamomeum have been investigated; however, its genomic features remain uncharacterized. In this study, we employed the Illumina platform and bioinformatic tools to sequence the complete chloroplast genome of A. cinnamomeum, which is 163,763 bp in length and exhibits a circular quadripartite structure. This structure includes a large single-copy region of 88,612 bp, a small single-copy region of 15,519 bp, and two inverted repeat regions of 29,816 bp each. Comparative genomic analysis revealed a conserved pattern in this chloroplast genome as regards its gene content and order, comprising 79 protein-coding genes, 30 transfer RNA genes, and four ribosomal RNA genes. However, the following three hypervariable regions were identified in this chloroplast genome: atpF-atpI, rpoB-psbM, and ycf1. Additionally, phylogenetic analysis revealed a close relationship among A. cinnamomeum, Amomum maximum, and Amomum longipetiolatum. This study successfully sequenced and characterized the chloroplast genome of A. cinnamomeum. Its findings provide an initial comparative chloroplast genomic analysis of accepted Amomum species. This analysis will be useful for further research concerning the evolutionary history, development of molecular markers, and population genetics of Amomum and related Zingiberaceae species.

Homalomena perplexa K.Z.Hein, Vuong, Bao & V.S.Dang has been recently recognized and identified as a Vietnamese endemic species. Its chemical contents and bioactivities have been investigated, but its genomic information is still scarce. In the current study, we sequenced and characterized the complete chloroplast genome of H. perplexa using the next‐generation sequencing method. The circular genome was 169,893 bp in length and contained 79 protein‐coding genes, 30 transfer RNA genes, and four ribosomal RNA genes. Nucleotide diversity analysis revealed only two hypervariable regions between the two Homalomena chloroplast genomes. However, repeat analysis indicated that there were shared and unique repeats between H. perplexa and H. occulta chloroplast genomes. In Araceae chloroplast genomes, there was a high variation of the junctions among the large‐single copy, small‐single copy, and inverted repeat regions, especially 13 variations identified in Aroideae species. In addition, phylogenetic analysis revealed the monophyly of Araceae subfamilies and a close relationship between Homalomena and Furtadoa genera. The results of this study enlarge the genomic data of the Homalomena genus and provide useful information for further comparative genomic studies of H. perplexa and related species in Aroideae. In addition, updates on comparative chloroplast genomics and phylogenetic relationships add valuable information for further evolutionary studies of Araceae.

Silver nanoparticles (AgNPs) have been widely applied as antimicrobial materials. In this work, a new fabrication method of AgNPs has been proposed through a combination of tea seed saponin extraction as a non-ionic biological surfactant and cetyltrimethylammonium chloride (CTAC) as a co-surfactant. The morphology and optical properties of as-prepared AgNPs were analysed by SEM and UV-vis absorbance measurement, respectively. The results indicate that AgNPs obtained high homogeneous particle sizes with a mean diameter of 44.5 ± 3.8 nm. The optical property of AgNPs was exhibited through a UV-vis absorbance spectrum of ~420 nm. In addition, the antibacterial behaviour of E. coli (ATCC 25922) was increased according to the AgNPs concentration. The diameter of inhibition zones was 12 mm, 14 mm and 16 mm under AgNPs concentrations of 0.8 ppm, 8 ppm and 80 ppm, respectively. Our initial trial treatment of AgNPs in young broccoli (Brassica oleracea) exhibited promising potential for plant protection in agricultural applications.

Erythrina variegata L. 1754, a thorny deciduous tree of Fabaceae, contains various chemical compounds such as alkaloids, flavonoids, and triterpenoids and exhibits anti‐depressant, anti‐inflammatory, and antidiabetic activities. However, genomic data of E. variegata are limited. In this study, the complete chloroplast genome of E. variegata was sequenced and characterized using Illumina sequencing platform. The chloroplast genome of E. variegata was 152,351 bp in length and consisted of a large single copy (82,907 bp), a small single copy (26,309 bp), and two inverted repeat regions (16,826 bp). There were 79 protein‐coding genes, 30 transfer RNA genes, and four ribosomal RNA genes. Comparative analysis revealed high conservation of chloroplast genomes among Erythrina species regarding genome size, structure, and gene content. The phylogenetic study also indicated a close relationship between E. variagata and E. sanwicensis. This study provides initial plastome data for further genomic studies examining E. variegata and related species in Fabaceae.

The increased demand for consuming seafood has made seafood production undergo a rapid period of growth. However, seafood has a high risk of contamination from harmful microorganisms and marine toxins which can cause health problems for humans consuming it. Concerning this issue, monitoring seafood safety has become a center of attention for researchers, and developing effective methods for detecting contamination in seafood has become a critical research field. In this context, biosensors have served as a promising approach to monitor seafood contamination. Compared to conventional methods, biosensors have some key benefits such as high sensitivity, selectivity, portability, and user-friendly operation. Along with significant advances in biosensors, processes of seafood monitoring can be simplified and performed outside the laboratory. In this review article, we describe the mechanisms of two main types of biosensors regarding electrochemical and optical biosensors. The current reports within the last five years on the application of these biosensors for seafood monitoring are also summarized.

The mitochondrial plastid DNAs (MTPTs) in seed plants were reported more than 40 years ago and exhibited a high diversity regarding gene content, quantity, and size. However, the mechanism that resulted in the current diversity of MTPTs in angiosperms has not been fully discovered. In this study, we sequenced and characterized the complete organelle genomes of Limonia acidissima L., a monotypic species of Rutaceae. The newly generated and previously published organelle genomes of 42 species were used to explore the diversity of MTPTs regarding quantity, gene content, size, and coverage of chloroplast genome (cpDNA) regions. The results showed that the number of MTPTs ranged from three to 74, of which the lengths were from 100 to 53,731 bp. The highest coverage of MTPTs was found in the inverted repeat region, whereas the small single repeat region had the lowest coverage. Based on the previous data and current results, we propose a scenario for the diversity of MTPTs in angiosperms. In the first stage, the whole cpDNA might migrate to the mitogenome. Then, different genomic events, such as duplication, deletion, substitution, and inversion, have occurred continuously and independently and resulted in extremely variable profiles of mitogenomes among angiosperms. Our hypothesis provides a new and possibly reliable scenario for explaining the present circumstances of MTPTs in angiosperms. However, more genomic data should be mined, and more studies should be conducted to clarify this natural phenomenon in plants.

A COMPLETE CHLOROPLAST GENOME OF POUZOLZIA SP. AND IMPLICATIONS FOR BIODIVERSITY AND CONSERVATION OF MEDICINAL PLANTS Tóm tắt: Sâm đất Côn Đảo (Pouzolzia sp.) còn được gọi là sâm rừng, sâm quy bầu và sâm nam, có giá trị dược liệu cao. Trong nghiên cứu này, hệ gen lục lạp của cây sâm đất Côn đảo được giải trình tự và phân tích. Hệ gen lục lạp có kích thước 153.176 cặp nucleotide được chia làm bốn vùng gồm: một vùng trình tự đơn lớn (kích thước 83.928 cặp nucleotide), một vùng trình tự đơn nhỏ (kích thước 18.648 cặp nucleotide), và hai vùng trình tự lặp đảo với kích thước mỗi vùng là 25.300 cặp nucleotide. Hệ gen lục lạp của cây sâm đất Côn Đảo bao gồm 79 gen liên quan mã hóa protein, 30 gen liên quan mã hóa tRNA và bốn gen liên quan mã hóa rRNA. Trong đó, tám gen liên quan mã hóa protein, bảy gen liên quan mã hóa tRNA và bốn gen liên quan mã hóa rRNA có thêm một bản sao do nằm trong vùng trình tự lặp đảo. Các gen có một intron cũng được ghi nhận. Trong đó, clpP1 và pafI gen có hai intron. Các dữ liệu cơ bản về hệ gen lục lạp của cây sâm đất Côn Đảo làm tiền đề cho các nội dung thực hiện tiếp theo về phát triển các chỉ thị phân tử, di truyền quần thể, bảo tồn giống và tiến hóa phân tử. Con Dao Pouzolzia (Pouzolzia sp.), also known as forest ginseng, sand ginseng, and southern ginseng, has high medicinal value. In this study, the chloroplast genome of Pouzolzia sp was sequenced and analyzed. Consequently, a quadripartite circular genome was completed and was 153,176 bp in length, including an LSC region of 83,928 bp, an SSC region of 18,648 bp, and two IR regions of 25,300 bp. This genome contained 79 protein-coding genes, 30 tRNA genes, and four rRNA genes. Among the genes, eight protein-coding genes, seven tRNA genes, and four rRNA genes were duplicated because of being located in the inverted repeat regions. Genes with a single intron were also noted. Notably, the clpP1 and pafI genes contain two introns. The results of this study provided fundamental information about the chloroplast genome of Pouzolzia sp. and initial data for further studies examining molecular markers, population genetics, conservation, and molecular evolution.