A review on biogenic green synthesis of ZnO nanoparticles by plant biomass and their applications

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGNanobiotechnology has recently gained prominence as a fundamental branch of modern science and a novel epoch in the field of material researches. Due to a wide range of applications it attracts attention of many scientists from all over the world. Bionanomaterials are prepared using a variety of physical, chemical, and biological techniques and methods. Many different metal and metal oxide nanoparticles are reported to be produced by biological systems, including bacteria, fungi, actinomycetes, yeasts, viruses, and plants. Among all of them, biocompatible zinc oxide nanoparticles (ZnO NPs), obtained through biosynthesis with the aid of plant-derived materials, appears to be a highly successful way to create a fast, clean, non-toxic, and environmentally friendly platform for the production and application of these bionanomaterials. This review focuses on the plant extractderived ZnO NPs synthesis, with a special emphasis on the recent advances and applications of these nanomaterials

Genetic diversity and relationships among wild and cultivated Ficus carica L.: Usefulness of RGA markers

Disease resistance and the maintenance of genetic diversity in wild and cultivated populations are very important challenges to implement breeding program and markers assisted selection of Ficus carica L. facing climate change and its consequences. Resistance gene analogs (RGA) markers were used for variety discrimination and assessment of genetic structure and diversity of wild and cultivated Ficus carica L. species in Tunisia. The RGA markers were efficient and reliable markers for discriminating wild and cultivated fig. The high level of polymorphism (95.65) detected suggests the effectiveness of RGAs for both genetic fingerprinting and relationships assessment in wild and cultivated fig. The detected markers may represent candidate genes for disease resistance and could be further used to facilitate the identification of candidate genes and accelerate the genetic improvement of disease resistance in breeding programs of Ficus carica species

Exploring the potential of a Ephedra alata leaf extract: Phytochemical analysis, antioxidant activity, antibacterial properties, and green synthesis of ZnO nanoparticles for photocatalytic degradation of methylene blue

Ephedra alata leaf extracts have therapeutic properties and contain various natural compounds known as phytochemicals. This study assessed the phytochemical content and antioxidant effects of a Ephedra alata leaf extract, as well as zinc oxide (ZnO) nanoparticle production. The extract contained phenolic acids, including vanillic acid, chlorogenic acid, gallic acid, p-coumaric acid, vanillin and rutin. Its total phenolic content and total flavonoid content were 48.7 ± 0.9 mg.g-1 and 1.7 ± 0.4 mg.g-1, respectively. The extract displayed a DPPH inhibition rate of 70.5%, total antioxidant activity of 49.5 ± 3.4 mg.g-1, and significant antimicrobial activity toward Gram-positive and negative bacteria. The synthesized ZnO nanoparticles had spherical shape, crystallite size of 25 nm, particle size between 5 and 30 nm, and bandgap energy of 3.3 eV. In specific conditions (90 min contact time, pH 7, and 25°C), these nanoparticles efficiently photodegraded 87% of methylene blue, suggesting potential applications for sustainable water treatment and pollution control

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

A landscape genetic analysis of important agricultural pest species in Tunisia: The whitefly Bemisia tabaci.

Combining landscape ecology and genetics provides an excellent framework to appreciate pest population dynamics and dispersal. The genetic architectures of many species are always shaped by environmental constraints. Because little is known about the ecological and genetic traits of Tunisian whitefly populations, the main objective of this work is to highlight patterns of biodiversity, genetic structure and migration routes of this pest. We used nuclear microsatellite loci to analyze B. tabaci populations collected from various agricultural areas across the country and we determine their biotype status. Molecular data were subsequently interpreted in an ecological context supplied from a species distribution model to infer habitat suitability and hereafter the potential connection paths between sampling localities. An analysis of landscape resistance to B. tabaci genetic flow was thus applied to take into account habitat suitability, genetic relatedness and functional connectivity of habitats within a varied landscape matrix. We shed light on the occurrence of three geographically delineated genetic groups with high levels of genetic differentiation within each of them. Potential migration corridors of this pest were then established providing significant advances toward the understanding of genetic features and the dynamic dispersal of this pest. This study supports the hypothesis of a long-distance dispersal of B. tabaci followed by infrequent long-term isolations. The Inference of population sources and colonization routes is critical for the design and implementation of accurate management strategies against this pest

Use of morphological traits and microsatellite markers to characterize the Tunisian cultivated and wild figs ([i]Ficus carica L.)[/i]

We used 8 morphological traits and 17 simple sequence repeats loci to characterize 71 cultivated and wild Tunisian fig trees (Ficus carica L.). Significant morphological differences were inferred from leaf traits. The statistical analysis showed two major fig groups that indicated a common morphological basis. A total of 74 SSR alleles was revealed, defining 63 unique multilocus genotypes indicating a substantial genetic diversity. Based on multilocus SSR genotypes an identification key was established using MFC30, MFC3, MFC11 and MFC19 loci to identify figs. Analysis of variance components of linkage disequilibrium shown that among 136 pairs of loci, 32 present a significant gametic disequilibrium. The parameter D'(2)(IS) (0.1284) was greater than D'(2)(ST) (0.0079), a pointer of close to zero variance in total simple, and consequently the more pronounced independence of the 17 SSR loci. The majority of Ohta's variance components of linkage disequilibrium followed a pattern caused by genetic drift or a non-systematic disequilibrium profiles and natural selection occurs only for LMFC24-MFC8 pair loci in cultivated figs. Our results suggest that the morphological and SSR markers are suitable to characterize figs and should be recommended in conservation management strategy

Multiple co-inertia analysis (MCOA) analysis.

<p>Single markers coordinated for the first two axes of the PCA. Corresponding plots are drawn on the same scale for the seven markers involved. The first two axes of the % PCA are shown. The three groups of populations are labeled within confidence ellipses (P = 0.95), with an envelope formed by the most discriminating alleles that are joined by lines. The shown barplot of Eigen-values indicates the relative magnitude of each axis with respect to total variance. Distribution of groups based on the common congruence values (Cos²) for the two components of the first axis.</p

Discriminated analysis of principal components (DAPC) using SSR-based genotypes.

<p>(a) DAPC first and second ordination axes. (b) Neighbor-joining tree constructed on the DAPC distances representing the genetic relationship between the inferred 3 clusters as well as the distribution of geographic groups within each of them. (c) Location of the populations (points) and their probabilities for membership in each geographic groups. The colors correspond to the genetic clusters defined by the DAPC analysis.</p