Soybean plants are sensitive to the effects of abiotic stress and belong to the group of crops that are less drought and salt tolerant. The identification of genes involved in mechanisms targeted to cope with water shortage is an essential and indispensable task for improving the drought and salt tolerance of soybean. One of the approaches for obtaining lines with increased tolerance is genetic modification. The dehydration-responsive element binding proteins (DREBs), belonging to the AP2 family, are trans-active transcription factors that bind to the cis-sequences of the promoter for activating the expression of the target genes that mediate drought and salt tolerant responses. In this study, the GmDREB6 transgene was introduced into DT84 cultivar soybean plants, using Agrobacterium-mediated transformation. The efficacy of GmDREB6 overexpression in enhancing the transcriptional level of GmP5CS and proline accumulation in genetically modified (GM) soybean plants was also assayed. The results demonstrated that ten GM soybean plants (T0 generation) were successfully generated from the transformed explants after selecting with kanamycin. Among these plantlets, the presence of the GmDREB6 transgene was confirmed in nine plants by Polymerase Chain Reaction (PCR), and eight plants showed positive results in Southern blot. In the T1 generation, four GM lines, labelled T1-2, T1-4, T1-7, and T1-10, expressed the recombinant GmDREB6 protein. In the T2 generation, the transcriptional levels of the GmP5CS gene were higher in the GM lines than in the non-transgenic plants, under normal conditions and also under conditions of salt stress and drought, ranging from 1.36 to 2.01 folds and 1.58 to 3.16 folds that of the non-transgenic plants, respectively. The proline content was higher in the four GM soybean lines, T2-2, T2-4, T2-7, and T2-10 than in the non-transgenic plants, ranging from 0.82 μmol/g to 4.03 μmol/g. The proline content was the highest in the GM T2-7 line (7.77 μmol/g). In GM soybean lines, T2-2, T2-4, T2-7, and T2-10 proline content increased after plants were subjected to salt stress for seven days, in comparison to that under normal conditions, and ranged from 247.83% to 300%, while that of the non-GM plants was 238.22%. These results suggested that GmDREB6 could act as a potential candidate for genetic engineering for improving tolerance to salt stresses.

Adrinandra megaphylla Hu is a medicinal plant belonging to the Adrinandra genus, which is well-known for its potential health benefits due to its bioactive compounds. This study aimed to assemble and annotate the chloroplast genome of A. megaphylla as well as compare it with previously published cp genomes within the Adrinandra genus. The chloroplast genome was reconstructed using de novo and reference-based assembly of paired-end reads generated by long-read sequencing of total genomic DNA. The size of the chloroplast genome was 156,298 bp, comprised a large single-copy (LSC) region of 85,688 bp, a small single-copy (SSC) region of 18,424 bp, and a pair of inverted repeats (IRa and IRb) of 26,093 bp each; and a total of 51 SSRs and 48 repeat structures were detected. The chloroplast genome includes a total of 131 functional genes, containing 86 protein-coding genes, 37 transfer RNA genes, and 8 ribosomal RNA genes. The A. megaphylla chloroplast genome indicated that gene content and structure are highly conserved. The phylogenetic reconstruction using complete cp sequences, matK and trnL genes from Pentaphylacaceae species exhibited a genetic relationship. Among them, matK sequence is a better candidate for phylogenetic resolution. This study is the first report for the chloroplast genome of the A. megaphylla.

The dehydration responsive element binding (DREB) is a plant protein subfamily expressed when soybean plants face abiotic stresses. These DREB proteins are also considered to activate the transcription of drought-resistant genes. In this study, we present the determined results of relationships between overexpression of Glycine max DREB2 (GmDREB2) with the transcription level of Glycine max pyrroline-5-carboxylate synthetase (GmP5CS) gene, proline accumulation and drought tolerant ability transgenic soybean plants as the basis for selection of transgenic lines with high drought tolerance. GmDREB2 was inserted into a plant transgenic vector and the 35S-GmDREB2-cmyc construct was transferred into the soybean plants by Agrobacterium-mediated transformation. Recombinant GmDREB2 protein with a molecular weight of approximately 20 kDa was expressed in four transgenic soybean lines in the T1 generation. The GmP5CS gene was shown to have significantly (P<0.05) increased expression in the T2 transgenic soybean lines and higher than compared to non-transgenic plants with considering both in well watered condition and stressed conditions were from 1.06 to 1.31-fold and 1.37 to 1.95-fold, respectively. The proline content of four transgenic soybean lines increased 155.81% to 187.42 % after five days in drought-stress conditions and increased from 180.52 % to 233.74 % after nine days under drought-stress conditions (P<0.05). Therefore, the overexpression of GmDREB2 resulted in increasing transcription level of P5CS gene, proline accumulation and drought-stress tolerance of the transgenic soybean plants. The GmDREB2 transformation into soybean plants was confirmed by the results of genetically modified lines in the T2 generation (T2-1, T2-6, T2-7, and T2-8) with higher drought tolerant ability than those of non-transgenic plants.

Aconitum carmichaelii Debx. is a herbal species that contains many precious bioactive substances, which are alkaloids, flavonoids, steroids, and glycosides. Flavonoids, which are major secondary compounds, play an important role in maintaining redox balance in the cells of the plant body. Many flavonoids have antibacterial, antioxidant, and anticancer properties. However, studies have mainly focused on aconitine, which is a highly toxic group A poison belonging to the alkaloid group, but with little mention of flavonoids. The flavonoids in A. carmichaelii are a group of substances with high content, concentrated in leaves and flowers, including quercetin and kaempferol. F3′5′H (Flavonoid 3′5′-hydroxylase) has been identified as the key enzyme involved in the final steps of flavonoid biosynthesis in plants in general and in A. carmichaelii specifically. This study offers the first report, and demonstrates that the overexpression of the F3′5′H gene from a herbal plant, A. carmichaelii, increases flavonoid content in genetically modified tobacco plants. The A. carmichaelii gene was transformed into tobacco leaf tissue to create transgenic tobacco plants. The AcF3′5′H gene was incorporated into the tobacco genome and was expressed in four transgenic tobacco lines (T₀1, T₀3, T₀5, and T₀14). The F3′5′H content increased from 20.33% to 32.00% compared with that in non-transformed plants (P < 0.001). Therefore, the flavonoid content of four transgenic tobacco lines increased compared to the WT, from 69.23% to 122.23% (P < 0.001). The results of the successful expression of the AcF3′5′H gene in model tobacco plants are the basis for using the AcF3′5′H gene for improving flavonoid content in other medicinal plants. Thus, the AcF3′5′H gene considered in this work could be a candidate for gene technology to enhance flavonoid accumulation in plants.

Catharanthus roseus contains vincristine and vinblastine, which are outstanding drugs for cancer. In the biosynthetic pathways of terpenoid indole alkaloids (TIAs) in C. roseus, deacetylvindoline 4-O-acetyltransferase (DAT) is a key enzyme that catalyses the last reaction of vindoline biosynthesis to form vinblastine and vincristine. In this study, the CrDAT transgene was transferred into the periwinkle by Agrobacterium-mediated transformation and generated transgenic periwinkle lines with an increase in vincristine accumulation. The C. roseus DAT gene was introduced into C. roseus plants and it was confirmed that CrDAT was successfully transferred into the genome of periwinkle plants and efficiently translated to synthesise recombinant DAT protein. Four transgenic periwinkle lines in T1 generation, T1-1, T1-3, T1-6, and T1-7, expressed recombinant DAT protein with the total protein content in the range of 2.86 μg.mg⁻¹ to 5.12 μg.mg⁻¹. Moreover, the vincristine contents of four transgenic lines increased by 1.63−2.48-fold compared to non-transgenic plants, ranging from 6.91 µg.g⁻¹ (fresh weight) to 10.53 µg.g⁻¹ (fresh weight). The T1-1 line had the highest vincristine content. Hence, the overexpression of the recombinant DAT protein can improve the vincristine accumulation of transgenic C. roseus plants. Abbreviation: CrDAT - Catharanthus roseus Deacetylvindoline-4-O-Acetyl Transferase; D4H - Deacetoxyvindoline 4-hydroxylase; ELISA - Enzyme-Linked Immunosorbent Assay Monoterpene indole alkaloid; T0, T1 - Generations of transgenic plants; TIAs - Terpenoid indole alkaloids; WT- The wild-type tobacco plants (non transgenic plant); 35S - Cauliflower mosaic virus 35S promoter