Active environmental surveillance of SARS-CoV-2 in Midwestern United States meatpacking plants

This pilot project investigated environmental SARS-CoV-2 presence in seven Midwestern meatpacking plants from May 2020 to January 2021. This study investigated social distancing and infection control practices and incorporated environmental sampling of surfaces and air in employee common areas. All plants increased their social distancing efforts, increased the frequency of cleaning and disinfecting worker areas, and screened for symptomatic people to prevent entry into the workplace. 575 samples from common areas were collected and evaluated with RT-qPCR for the presence of SARS-CoV-2. 42/367 surface samples were positive, while no virus was detected in air samples. Case positive data from the counties surrounding each plant showed peak positive SARS-CoV-2 cases from 12–55 days before the virus was detected in the plant, indicating that environmental sampling is likely a lagging indicator of community and plant infection.

Epidemiological and ecological consequences of virus manipulation of host and vector in plant virus transmission

Many plant viruses are transmitted by insect vectors. Transmission can be described as persistent or non-persistent depending on rates of acquisition, retention, and inoculation of virus. Much experimental evidence has accumulated indicating vectors can prefer to settle and/or feed on infected versus noninfected host plants. For persistent transmission, vector preference can also be conditional, depending on the vector’s own infection status. Since viruses can alter host plant quality as a resource for feeding, infection potentially also affects vector population dynamics. Here we use mathematical modelling to develop a theoretical framework addressing the effects of vector preferences for landing, settling and feeding–as well as potential effects of infection on vector population density–on plant virus epidemics. We explore the consequences of preferences that depend on the host (infected or healthy) and vector (viruliferous or nonviruliferous) phenotypes, and how this is affected by the form of transmission, persistent or non-persistent. We show how different components of vector preference have characteristic effects on both the basic reproduction number and the final incidence of disease. We also show how vector preference can induce bistability, in which the virus is able to persist even when it cannot invade from very low densities. Feedbacks between plant infection status, vector population dynamics and virus transmission potentially lead to very complex dynamics, including sustained oscillations. Our work is supported by an interactive interface https://plantdiseasevectorpreference.herokuapp.com/. Our model reiterates the importance of coupling virus infection to vector behaviour, life history and population dynamics to fully understand plant virus epidemics.

The Amino-Proximal Region of the Coat Protein of Cucumber Vein Yellowing Virus (Family Potyviridae) Affects the Infection Process and Whitefly Transmission

Most plant viruses rely on vector transmission for their spread and specific interactions between vector and virus have evolved to regulate this relationship. The whitefly Bemisia tabaci- transmitted cucumber vein yellowing virus (CVYV; genus Ipomovirus, family Potyviridae) is endemic in the Mediterranean Basin, where it causes significant losses in cucurbit crops. In this study, the role of the coat protein (CP) of CVYV for B. tabaci transmission and plant infection was investigated using a cloned and infectious CVYV cDNA and a collection of point and deletion mutants derived from this clone. Whitefly transmission of CVYV was abolished in a deletion mutant lacking amino acids in position 93–105 of the CP. This deletion mutant caused more severe disease symptoms compared to the cDNA clone representing the wild-type (wt) virus and movement efficiency was likewise affected. Two virus mutants carrying a partially restored CP were transmissible and showed symptoms comparable to the wt virus. Collectively, our data demonstrate that the N-terminus of the CVYV CP is a determinant for transmission by the whitefly vector and is involved in plant infection and symptom expression.

The structural repertoire of Fusarium oxysporum f. sp. lycopersici effectors revealed by experimental and computational studies

Plant pathogens secrete proteins, known as effectors, that function in the apoplast and inside plant cells to promote virulence. Effectors can also be detected by cell-surface and cytosolic receptors, resulting in the activation of defence pathways and plant immunity. Our understanding of fungal effector function and detection by immunity receptors is limited largely due to high sequence diversity and lack of identifiable sequence motifs precluding prediction of structure or function. Recent studies have demonstrated that fungal effectors can be grouped into structural classes despite significant sequence variation. Using protein x-ray crystallography, we identify a new structural class of effectors hidden within the secreted in xylem (SIX) effectors from Fusarium oxysporum f. sp. lycopersici (Fol). The recognised effectors Avr1 (SIX4) and Avr3 (SIX1) represent the founding members of the Fol dual-domain (FOLD) effector class. Using AlphaFold ab initio protein structure prediction, benchmarked against the experimentally determined structures, we demonstrate SIX6 and SIX13 are FOLD effectors. We show that the conserved N-domain of Avr1 and Avr3 is sufficient for recognition by their corresponding, but structurally-distinct, immunity receptors. Additional structural prediction and comparison indicate that 11 of the 14 SIX effectors group into four structural families. This revealed that genetically linked effectors are related structurally, and we provide direct evidence for a physical association between one divergently-transcribed effector pair. Collectively, these data indicate that Fol secretes groups of structurally-related molecules during plant infection, an observation that has broad implications for our understanding of pathogen virulence and the engineering of plant immunity receptors.

Synthesis of Different Nanoparticles for Biological Application

Compared with traditional materials, the application of nanomaterials in biomedical fields will bring many excellent performances. This review summarizes some new developments and applications of nanoparticles in recent years from the perspective of biology and medicine, including magnetic resonance imaging, treatment for Alzheimer’s disease, diabetes and plant infection disease, oxygen-releasing scaffolds, engineered water nanostructures (EWNS) based sanitizer, drug loading system and cancer treatment. This article summarized and discussed the synthesis methods, characterization, advantages, and applications based on these aspects. Introducing nanoparticles into biomedical fields can provide useful ideas for applying nanoparticles in biology and pharmacy in the future.

Protein Phosphatase CgPpz1 Regulates Potassium Uptake, Stress Responses and Plant Infection in Colletotrichum gloeosporioides

Protein phosphatases (PPs) play important roles in the regulation of various cellular processes in eukaryotes. The ascomycete Colletotrichum gloeosporioides is a causal agent of anthracnose disease on some important crops and trees. In this study, CgPPZ1, a protein phosphate gene and a homolog of yeast PPZ1, was identified in C. gloeosporioides. Targeted gene deletion showed that CgPpz1 was important for vegetative growth and asexual development, conidial germination, and plant infection. Cytological examinations revealed that CgPpz1 was localized to the cytoplasm. The Cgppz1 mutant was hypersensitive to osmotic stresses, cell wall stressors, and oxidative stressors. Taken together, our results indicated that CgPpz1 plays important role in fungal development and virulence of C. gloeosporioides and multiple stress responses.

Identification of plant diseases and distinct approaches for their management

Background Globally in the agricultural industry the major loss faced by is due to plant diseases. Various pathogens are responsible for causing plant bacterial and viral diseases, the treatment of them is very important in order to bring out the best quality and quantity of the agricultural yield. Before Technology came into practice the plant disease were identified by visual examination, the main symptoms such as curling of leaves and change of colour were observed. With advancements in science the microscopic examination for more clarity regarding diseases came into existence. Main body The distinct methods involve use of nucleic acids and serological assays were implemented to study bacterial and viral characteristics of the infecting pathogen. Traditionally, seed coating and mulching techniques were more common among farmers to generate better quality of the crops and prevent plants from any disease but currently new innovative methods are used. Microbial bio control agents are now one of the widely used approach in which microbial species are used to eliminate or inhibit the growth of pathogens in order to reduce the severity of the infection. Similarly, like microbial agent’s different chemicals are present in order to kill the pathogens. These chemicals are classified as bactericides, fungicides and nematicides which suppress the plant infection caused by bacteria, fungal and nematodes, respectively. Conclusions In the forthcoming years, the development of more innovative agricultural-related techniques is prime that will help in increase of the yield and provides resistance to plants. Some of them are developed earlier but there is still need to develop more pathogen-resistant species for example in case of silencing of genes with insertion of a viral segment.