BioTechnologia最新文献

Cacao swollen shoot virus (CSSV) is an endemic pathogen causing significant economic losses to cacao (Theobroma cacao L.) production in West Africa. There is limited updated report on the occurrence, spread, genetic diversity and species of CSSV and its mealybug vectors, especially in Nigeria. Nigeria is presently lagging behind in the search for resistance to CSSV and its vectors in T. cacao L. The present study aimed to map and screen for the presence of CSSV and its natural vectors - female mealybugs (Pseudococcidae: Hemiptera) in cacao plantations in Nigeria. Symptomatic and asymptomatic cacao leaves and whole female mealybug samples were collected from major cacao-growing areas in Nigeria - Abia, Akwa Ibom, Cross River, Edo, Ondo and Oyo States. A total of 2568 cacao leaves from 1052 cacao trees were screened with polymerase chain reaction (PCR) using an open reading frame 1 (ORF 1) CSSV-specific primer pair. PCR screening of the mealybug species was performed using the cytochrome c oxidase subunit I (COI) gene. A combination of scanning electron microscopy (SEM) and histology for morphological identification and DNA barcoding enabled to characterise the female mealybug species. The results revealed that CSSV and its mealybug vectors are present in the major cacaogrowing areas in Nigeria. Although CSSV and its vectors have been previously reported in Cross River, Ondo and Oyo States, our results present the first documented evidence of CSSV emergence and its mealybug vectors in Abia, Akwa Ibom and Edo States. We also present the first report of Pseudococcus jackbeardsleyi (Gimpel and Miller) mealybug species on cacao in Nigeria. In conclusion, it is pertinent to re-establish coordinated routine survey and monitoring of CSSV and its mealybug vector presence in T. cacao L. in Nigeria.

Gymnema sylvestre and Combretum micranthum are well known for their ethno-medicinal uses in the northwest of Nigeria. In our recent study, we demonstrated the antidiabetic and antioxidant activities of the aqueous-methanol extracts of the two plants and identified some potentially active compounds. The present study aimed to conduct molecular docking and ADME/drug-likeness screening of the identified potentially active candidate compounds from aqueous-methanol extracts of G. sylvestre and C. micranthum leaves by using in silico techniques. Molecular docking of compounds on target proteins (α-amylase, α-glucosidase, and phosphorylated insulin receptor tyrosine kinase) was performed using Molsoft ICM-pro 3.8-3. The physicochemical, ADME, and drug-likeness parameters were computed using the SwissADME online program. The result corroborated the antidiabetic activities of the plants with significant binding interactions between compounds A (2,2-dimethyl-3-[4-(acetyloxy)phenyl]-4-ethy-l2H-1-benzopyran-7-ol acetate), D (9,13-di-cis-retinoic acid), E (4-hydroxycinnamic acid), F ((-)-11-hydroxy-9,10-dihydrojasmonic acid), G (colnelenic acid), H (glyinflanin A), I (6,8a-seco-6,8a-deoxy-5-oxoavermectin "2a" aglycone), and J (3-deshydroxysappanol trimethyl ether) and at least one of the three target proteins. Four compounds, namely A (2,2-dimethyl-3-[4-(acetyloxy)phenyl]-4-ethyl-2H-1-benzopyran-7-ol acetate), E (4-hydroxycinnamic acid), H (glyinflanin A), and J (3-deshydroxysappanol trimethyl ether), yielded the best docking scores with respect to the target proteins, of which three (E (4-hydroxycinnamic acid), H (glyinflanin A), and J (3-deshydroxysappanol trimethyl ether)) were identified to have relatively optimal drug-likeness and medicinal chemistry characteristics. Thus, the present study concluded that these compounds may have contributed to the observed antidiabetic properties of these plants and can be investigated further as drugs or drug-like compound candidates.

In this study, the proteomic, morphometric, and photosynthetic pigment data of purslane (Portulaca oleracea) accessions were combined together to show their impact on genetic variation in order to establish a relationship between protein patterns and phenotypic behavior of the plant. Seeds of 18 collected purslane accessions were cultivated based on a completely randomized design with three replicates. Before the flowering stage, the data on morphology, photosynthetic pigment content, and seed proteins were obtained. The results showed a significant difference among purslane accessions in terms of the most studied agronomic characteristics and the content of photosynthetic pigments and proteins. The cluster analysis of the 18 purslane accessions based on agronomic data, and photosynthetic pigment content, and protein pattern data produced three main clusters. Moreover, the seed protein analysis revealed that the two polymorphic protein bands of size 40 kDa (protein "a") and 30 kDa (protein "b") effectively diversified the agronomic, photosynthetic pigment, and phylogenetic relationships among the purslane accessions. Interestingly, protein "a" was produced in plants growing in low altitude areas and played a suppressive role for TDW, while protein "b" was produced in plants growing in high altitude areas and functioned as an activator agent for this trait. Overall, the outcomes of the present study indicated the presence of high genetic variability (77.6%) among the purslane accessions. These findings suggest that these proteins should be sequenced for further proteomic analyses and can be used for hybridization to generate useful recombinants in segregating generations and improve breeding varieties of P. oleracea.

Endophytes are an important constituent of sustainable agriculture because of their ability to produce a large number of agriculturally important metabolites. A salt-tolerant fluorescent green pigment-producing endophytic bacterium was isolated on 2.5% NaCl-supplemented nutrient agar from the leaf samples of Zanthoxylum alatum Roxb. The isolate Z1B4 was identified as Pseudomonas fluorescens based on morphological features, fatty acid methyl ester analysis, biochemical tests, and 16S rRNA gene sequencing. P. fluorescens Z1B4 showed positive results for tricalcium phosphate solubilization; 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity; and production of auxins, siderophores, hydrogen cyanide, and ammonia. P. fluorescens Z1B4 also showed strong antagonistic activity against Curvularia lunata (MTCC 283), Fusarium verticillioides (MTCC 3322), and Alternaria alternata (MTCC 1362) and exhibited stress tolerance to a wide range of temperature and pH and concentrations of NaCl and calcium salts. Under natural conditions, following inoculation with the isolate Z1B4, a significant increase in the growth of pea and maize test plants in pots was observed compared to that of uninoculated control plants. The rifampicin-resistant mutant Z1B4^Rif was recovered from the roots, shoots, and leaves of the test plants, indicating that the isolated endophytic bacterium can grow well within different plant tissues. The present study indicated that the endophytic bacterium P. fluorescens Z1B4 can be used as a bacterial inoculant in stressed environments for sustainable agriculture.

Ericales is an ancient eudicot order encompassing numerous species of economic and ornamental values. Despite several phylogenomic studies, the evolutionary relationship among certain families of this group remains uncertain. The present study assessed a multilocus species tree of Ericales based on 107 chloroplast genomes. The plastome derived microsatellite motifs were also simultaneously explored to check their dynamicity in corroboration of species phylogeny and systematics. In addition to resolving the usual hierarchy, the present phylogenetic analysis enabled to resolve the persisting lineage disparity with valid statistical support. Accordingly, divergence incongruences of Primulaceae, Ebenaceae, and Sapotaceae from earlier reports were reinstated in presently inferred phylogeny, which further supported the latest transcriptome-based relationship of the corresponding group. Various SSR motif characteristics emerged following the recognition of the evolutionary pathway. Numerical variation in tetranucleotide repeats showed even intraspecific or varietal differences in Camellia sinensis. Validation of plastome microsatellite-based polymorphism among the related taxa might pave the way for future phylogenetic and population studies of this economically important group.

One major reason for the lack of clinical success of Staphylococcus aureus vaccine candidates is the inability of the antigens to develop a CD4⁺ T cell-mediated immune response. Hence, it is important to identify CD4⁺ T cell antigens from S. aureus. CD4⁺ T cells are activated following the presentation of epitopes derived from exogenous proteins on HLA class II molecules. Fifty-nine secretory proteins of S. aureus were analyzed computationally for the presence of HLA class II binding peptides. Fifteen-mer peptides were generated, and their binding to 26 HLA class II alleles was predicted. The structural feasibility of the peptides binding to HLA-II was studied using molecular docking. Of the 16,724 peptides generated, 6991 (41.8%) were predicted to bind to any one of the alleles with an IC₅₀ value below 50 nM. Comparative sequence analysis revealed that only 545 of the strong binding peptides are non-self in the human system. Approximately 50% of the binding peptides were monoallele-specific. Moreover, approximately 95% of the predicted strong binding non-self peptides interacted with the binding groove of at least one HLA class II molecule with a glide score better than -10 kcal/mol. On the basis of the analysis of the strength of binding, non-self presentation in the human host, propensity to bind to a higher number of alleles, and energetically favorable interactions with HLA molecules, a set of 11 CD4⁺ T cell epitopes that can be used as vaccine candidates was identified.

Chloroplast genetic engineering is a convenient method for the production of recombinant proteins by increasing the expression level of transgenes. Interferon-beta (IFN-β) is a member of type I interferons that possess some pharmaceutical properties. The present study aimed to investigate the overexpression and production of the recombinant human IFN-β gene (rhIFN-β) in the tobacco chloroplast genome. For this purpose, a codon-optimized rhIFN-β was transferred to the pVSR326 plastid vector containing the aadA gene as a selectable marker. The rhIFN-β gene was then successfully introduced into the tobacco chloroplast genome by using a gene gun. The integration of the rhIFN-β gene into the chloroplast genome and the homoplasmy of the T1 progeny were confirmed by PCR and Southern blot analysis, respectively. RT-PCR and western blot analyses confirmed the transcription and translation of the rhIFN-β gene, respectively. An enzyme-linked immunosorbent assay (ELISA) showed that the rhIFN-β protein in transplastomic plants comprised approximately 2.4% of total soluble protein (TSPs). The bioassay confirmed that the rhIFN-β protein expressed in the tobacco chloroplast had a relatively high biological activity (2.9 × 10⁴ IU/ml) and protected human amnionic cells against the vesicular stomatitis virus (VSV). On the basis of these findings, it can be concluded that plastid transformation can serve as an operative method for the production of pharmaceutical recombinant proteins.

Hyssopus officinalis L. is a medicinal plant containing valuable phytochemicals and is used extensively in the pharmaceutical industry. As this plant naturally contains low levels of these metabolites, plant cell and tissue culture technologies are used to produce them in large volumes. The present study aimed first to evaluate the effects of different types of cytokinins, including benzyl adenine (BA), kinetin (KIN), and thidiazuron (TDZ), at 1 ppm concentration in the culture medium on growth parameters and production of secondary metabolites and photosynthetic pigments in organ culture of H. officinalis; in the second step, the study investigated the effect of different concentrations (0, 0.2, 1, 1.5, and 2 ppm) of the most effective type of cytokinin. The results showed that TDZ was the optimal type of growth regulator compared to BA and KIN as it showed a positive influence on the studied traits; furthermore, its highest concentration of 2 ppm in culture medium was determined to be the best one that enabled the highest production of secondary metabolites and photosynthetic pigments. We conclude that the presence of growth regulators can strongly influence the growth and development of plants in tissue culture conditions.