CRISPR-Cas9 genome editing reveals that the Pgs gene of Fusarium circinatum is involved in pathogenicity, growth and sporulation.

Fusarium circinatum, the causal agent of pine pitch canker, is one of the most destructive pathogens of Pinus species worldwide. Infections by this pathogen result in serious mortality of seedlings due to root and root collar disease, and growth reduction in trees due to canker formation and dieback. Although much is known about the population biology, genetics, and genomics of F.

Harnessing exogenous membrane vesicles for studying Fusarium circinatum and its biofilm communities.

Extracellular vesicles (EVs) are tiny messengers that convey bioactive molecules from donor to recipient cells, leading to changes in their physiology and function. We investigated the role of EVs in shaping growth and the biofilm biology of the tree pathogen Fusarium circinatum and its interaction with the susceptible host, Pinus patula. Vesicles were collected from fungal planktonic and biofilm cultures and from pine seedling needles and roots.

Mesorhizobium salmacidum sp. nov. and Mesorhizobium argentiipisi sp. nov. are symbionts of the dry-land forage legumes Lessertia diffusa and Calobota sericea.

Legumes Lessertia diffusa and Calobota sericea, indigenous to South Africa, are commonly used as fodder crops with potential for sustainable livestock pasture production. Rhizobia were isolated from their root nodules grown in their respective soils from the Succulent Karoo biome (SKB) in South Africa, identified and characterized using a polyphasic approach. Sequence analysis of the 16S rRNA gene confirmed all isolates as Mesorhizobium members, which were categorized into two distinct lineages using five housekeeping protein-coding genes.

Genomic characterization of novel viruses associated with Olea europaea L. in South Africa.

South Africa has a small but growing olive industry. Until now, no virological research has been carried out on this crop locally. Seventeen samples were collected from various olive cultivars from a single producer in the Stellenbosch growing area of South Africa.

Options and considerations for validation of prokaryotic names under the SeqCode.

Stable taxon names for Bacteria and Archaea are essential for capturing and documenting prokaryotic diversity. They are also crucial for scientific communication, effective accumulation of biological data related to the taxon names and for developing a comprehensive understanding of prokaryotic evolution. However, after more than a hundred years, taxonomists have succeeded in valid publication of only around 30 000 species names, based mostly on pure cultures under the International Code of Nomenclature of Prokaryotes (ICNP), out of the millions estimated to reside in the biosphere.

Complete mitochondrial genome sequence of the white root rot pathogen (Xylariaceae: Xylariales).

The mitochondrial genome of is 121,350 base pairs in length with a G + C content of 30.19%. Phylogenetic analysis showed that grouped with other members of the Xylariaceae, with which its mitogenome also shares a broadly similar architecture and gene content.

Sex Pheromone Receptor Ste2 Orchestrates Chemotropic Growth towards Pine Root Extracts in the Pitch Canker Pathogen .

In ascomycetous fungi, sexual mate recognition requires interaction of the Ste2 receptor protein produced by one partner with the α-factor peptide pheromone produced by the other partner. In some fungi, Ste2 is further needed for chemotropism towards plant roots to allow for subsequent infection and colonization. Here, we investigated whether this is also true for the pine pitch canker fungus, , which is a devastating pathogen of pine globally.

Correction: Hough et al. Fungal Viruses Unveiled: A Comprehensive Review of Mycoviruses. 2023, , 1202.

In the original publication [...

SeqCode facilitates naming of South African rhizobia left in limbo.

South Africa is well-known for the diversity of its legumes and their nitrogen-fixing bacterial symbionts. However, in contrast to their plant partners, remarkably few of these microbes (collectively referred to as rhizobia) from South Africa have been characterised and formally described. This is because the rules of the International Code of Nomenclature of Prokaryotes (ICNP) are at odds with South Africa's National Environmental Management: Biodiversity Act and its associated regulations.

Characterization of the Fusarium circinatum biofilm environmental response role.

The capacity to form biofilms is a common trait among many microorganisms present on Earth. In this study, we demonstrate for the first time that the fatal pine pitch canker agent, Fusarium circinatum, can lead a biofilm-like lifestyle with aggregated hyphal bundles wrapped in extracellular matrix (ECM). Our research shows F.

Chromosome-Level Assemblies for the Pine Pitch Canker Pathogen .

The pine pitch canker pathogen, , is globally regarded as one of the most important threats to commercial pine-based forestry. Although genome sequences of this fungus are available, these remain highly fragmented or structurally ill-defined. Our overall goal was to provide high-quality assemblies for two notable strains of , and to characterize these in terms of coding content, repetitiveness and the position of telomeres and centromeres.

Unidirectional mating-type switching is underpinned by a conserved MAT1 locus architecture.

Unidirectional mating-type switching is a form of homothallic reproduction known only in a small number of filamentous ascomycetes. Their ascospores can give rise to either self-sterile isolates that require compatible partners for subsequent sexual reproduction, or self-fertile individuals capable of completing this process in isolation. The limited studies previously conducted in these fungi suggest that the differences in mating specificity are determined by the architecture of the MAT1 locus.

Complex evolutionary history of photosynthesis in .

comprises a diverse group of bacteria with various lifestyles. Although best known for their nodule-based nitrogen-fixation in symbiosis with legumes, a select group of bradyrhizobia are also capable of photosynthesis. This ability seems to be rare among rhizobia, and its origin and evolution in these bacteria remain a subject of substantial debate.

Bradyrhizobium xenonodulans sp. nov. isolated from nodules of Australian Acacia species invasive to South Africa.

A genealogical concordance approach was used to delineate strains isolated from Acacia dealbata and Acacia mearnsii root nodules in South Africa. These isolates form part of Bradyrhizobium based on 16S rRNA sequence similarity. Phylogenetic analysis of six housekeeping genes (atpD, dnaK, glnII, gyrB, recA and rpoB) confirmed that these isolates represent a novel species, while pairwise average nucleotide identity (ANIb) calculations with the closest type strains (B.

A survey of patient and public perceptions and awareness of SARS-CoV-2-related risks among participants in India and South Africa.

A cross-sectional survey among participants in India and South Africa to explore perceptions and awareness of SARS-CoV-2-related risks. Main outcome measures-proportion of participants aware of SARS-CoV-2, and their perception of infection risks as it related to their views and perceptions on vaccination, i.e.

Evidence of Biparental Mitochondrial Inheritance from Self-Fertile Crosses between Closely Related Species of .

Hybridization is recognized as a notable driver of evolution and adaptation, which closely related species may exploit in the form of incomplete reproductive barriers. Three closely related species of (i.e.

Fungal Viruses Unveiled: A Comprehensive Review of Mycoviruses.

Mycoviruses (viruses of fungi) are ubiquitous throughout the fungal kingdom and are currently classified into 23 viral families and the genus by the International Committee on the Taxonomy of Viruses (ICTV). The primary focus of mycoviral research has been on mycoviruses that infect plant pathogenic fungi, due to the ability of some to reduce the virulence of their host and thus act as potential biocontrol against these fungi. However, mycoviruses lack extracellular transmission mechanisms and rely on intercellular transmission through the hyphal anastomosis, which impedes successful transmission between different fungal strains.

An in Silico Approach to Identifying TF Binding Sites: Analysis of the Regulatory Regions of BUSCO Genes from Fungal Species in the Family.

Transcriptional regulation controls gene expression through regulatory promoter regions that contain conserved sequence motifs. These motifs, also known as regulatory elements, are critically important to expression, which is driving research efforts to identify and characterize them. Yeasts have been the focus of such studies in fungi, including in several in silico approaches.

A LAMP Assay for Rapid Detection of the Pitch Canker Pathogen .

The pine pitch canker pathogen is endemic in the southeastern United States and Central America and represents an invasive threat globally. This ecologically adaptable fungus readily infects all parts of its pine hosts, leading to widespread mortality of nursery seedlings and decline in the health and productivity of forest stands. Because trees infected by can remain asymptomatic for long periods of time, accurate and rapid tools are needed for real-time diagnostics and surveillance at ports, in nurseries, and in plantations.

Genomic characterization of a novel potyvirus infecting Barleria repens in South Africa.

The complete RNA genome sequence of a novel member of the genus Potyvirus infecting Barleria repens has been determined. A plant showing symptoms of virus-like leaf mosaic was sampled in the Western Cape province of South Africa, and the associated virus has been tentatively named "Barleria repens mottle virus" (BaRMoV). The genome of BaRMoV consists of 9,561 nucleotides and encodes a typical potyvirus polyprotein that is 3,105 amino acids long.

Nodulation and Growth Promotion of Chickpea by Isolates from Diverse Sources.

The cultivation of chickpea (Cicer arietinum L.) in South Africa is dependent on the application of suitable Mesorhizobium inoculants. Therefore, we evaluated the symbiotic effectiveness of several Mesorhizobium strains with different chickpea genotypes under controlled conditions.

Survey of healthcare worker perceptions of changes in infection control and antimicrobial stewardship practices in India and South Africa during the COVID-19 pandemic.

Objective: To identify perceptions and awareness of changes in infection prevention and control (IPC) and antimicrobial stewardship (AMS) practices among healthcare workers (HCWs) during the COVID-19 pandemic in India and South Africa (SA).

Method: A self-administered online survey which included participant demographics, knowledge and sources of COVID-19 infection, perceived risks and barriers, and self-efficacy. Data were analysed using descriptive statistics.

Identification and Characterization of a QTL for Growth of on Pine-Based Medium.

is an economically important pathogen of pine and resides in the species complex. Here we investigated the molecular processes underlying growth in by exploring the association between growth and the nutritional environment provided by the pine host. For this purpose, we subjected a mapping population consisting of X hybrid progeny to an analysis of growth rate on a pine-tissue derived medium.

Relevance of prokaryotic subspecies in the age of genomics.

The availability of multiple gene sequences, and in particular full genome sequence data, for microbial strains has changed how taxonomists delineate subspecies belonging to the Archaea and Bacteria. Well-defined phylogenetic lineages that share higher genome similarity values compared to the widely used species thresholds are often described as subspecies, despite clear evidence of genetic isolation between them. These well-defined lineages, reflecting notable genetic isolation of the core genome represent more recently evolved, unique and evolutionary units.