Genetic complexity of cassava brown streak disease: insights from qPCR-based viral titer analysis and genome-wide association studies.

Cassava, a vital global food source, faces a threat from Cassava Brown Streak Disease (CBSD). CBSD results from two viruses: Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV). These viruses frequently pose challenges to the traditional symptom-based 1-5 phenotyping method due to its limitations in terms of accuracy and objectivity.

Cut, Root, and Grow: Simplifying Cassava Propagation to Scale.

Cassava ( Crantz) is an essential crop with increasing importance for food supply and as raw material for industrial processing. The crop is vegetatively propagated through stem cuttings taken at the end of the growing cycle and its low multiplication rate and the high cost of stem transportation are detrimental to the increasing demand for high-quality cassava planting materials. Rapid multiplication of vegetative propagules of crops comprises tissue culture (TC) and semi-autotroph hydroponics (SAH) that provide cost-effective propagation of plant materials; however, they contrast the need for specific infrastructure, special media and substrates, and trained personnel.

Benchmarking of virome metagenomic analysis approaches using a large, 60+ members, viral synthetic community.

We report here efforts to benchmark performance of two widespread approaches for virome analysis, which target either virion-associated nucleic acids (VANA) or highly purified double-stranded RNAs (dsRNAs). This was achieved using synthetic communities of varying complexity levels, up to a highly complex community of 72 viral agents (115 viral molecules) comprising isolates from 21 families and 61 genera of plant viruses. The results obtained confirm that the dsRNA-based approach provides a more complete representation of the RNA virome, in particular, for high complexity ones.

Developing broad-spectrum resistance in cassava against viruses causing the cassava mosaic and the cassava brown streak diseases.

Growing cassava in Africa requires resistance against the viruses causing cassava mosaic disease (CMD) and the viruses causing cassava brown streak disease (CBSD). A dominant CMD2 resistance gene from a West African cassava landrace provides strong resistance against the cassava mosaic viruses. However, resistance against cassava brown streak viruses is limited to cassava varieties that show tolerance to the disease.

High molecular diversity of full-length genome sequences of zucchini yellow fleck virus from Europe.

Zucchini yellow fleck virus (ZYFV), genus Potyvirus, is the causal agent of a disease of cucurbits. The genome sequences of seven ZYFV isolates of different origin were determined, two of which were reconstructed from a squash (Cucurbita sp.) collected in 2017 in Greece, while the others, accessions from the DSMZ Plant Virus Collection, were from samples collected in Italy, Greece, and France in the 1980s and 1990s.

A novel nepovirus causing a chlorotic fleck disease on common bean (Phaseolus vulgaris L.).

Two common bean leaf samples from Ethiopia that had shown chlorotic fleck and veinal mosaic symptoms but tested ELISA-negative for known viruses were mechanically transmitted to herbaceous hosts to obtain virus isolates ET-773/4 and ET-779. Virus purification from Chenopodium quinoa systemically infected with ET-773/4 yielded icosahedral particles measuring ~ 30 nm in diameter and containing a single capsid protein of ~ 58 kDa, suggesting a nepovirus infection. Analysis of nucleotide sequences generated from RNA1 and RNA2 of the isolates indicated that they represent a distinct virus species in the genus Nepovirus.

Characterization of yam mosaic viruses from Brazil reveals a new phylogenetic group and possible incursion from the African continent.

Yam (Dioscorea spp.) is an important crop for smallholder farmers in the Northeast region of Brazil. Wherever yam is grown, diseases caused by yam mosaic virus (YMV) are prevalent.

The Amino-Proximal Region of the Coat Protein of Cucumber Vein Yellowing Virus (Family ) 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 - transmitted cucumber vein yellowing virus (CVYV; genus , family ) 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 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.

Investigating the practical viability of walk-sharing in improving pedestrian safety.

Walk-sharing is a cost-effective and proactive approach that promises to improve pedestrian safety and has been shown to be technically (theoretically) viable. Yet, the practical viability of walk-sharing is largely dependent on community acceptance, which has not, until now, been explored. Gaining useful insights on the community's spatio-temporal and social preferences in regard to walk-sharing will ensure the establishment of practical viability of walk-sharing in a real-world urban scenario.

Activation and detoxification of cassava cyanogenic glucosides by the whitefly Bemisia tabaci.

Two-component plant defenses such as cyanogenic glucosides are produced by many plant species, but phloem-feeding herbivores have long been thought not to activate these defenses due to their mode of feeding, which causes only minimal tissue damage. Here, however, we report that cyanogenic glycoside defenses from cassava (Manihot esculenta), a major staple crop in Africa, are activated during feeding by a pest insect, the whitefly Bemisia tabaci, and the resulting hydrogen cyanide is detoxified by conversion to beta-cyanoalanine. Additionally, B.

Identification of a Sulfatase that Detoxifies Glucosinolates in the Phloem-Feeding Insect and Prefers Indolic Glucosinolates.

Cruciferous plants in the order Brassicales defend themselves from herbivory using glucosinolates: sulfur-containing pro-toxic metabolites that are activated by hydrolysis to form compounds, such as isothiocyanates, which are toxic to insects and other organisms. Some herbivores are known to circumvent glucosinolate activation with glucosinolate sulfatases (GSSs), enzymes that convert glucosinolates into inactive desulfoglucosinolates. This strategy is a major glucosinolate detoxification pathway in a phloem-feeding insect, the silverleaf whitefly , a serious agricultural pest of cruciferous vegetables.

Differential Tropism in Roots and Shoots of Resistant and Susceptible Cassava ( Crantz) Infected by Cassava Brown Streak Viruses.

Cassava brown streak disease (CBSD) is a destructive disease of cassava in Eastern and Central Africa. Because there was no source of resistance in African varieties to provide complete protection against the viruses causing the disease, we searched in South American germplasm and identified cassava lines that did not become infected with the cassava brown streak viruses. These findings motivated further investigations into the mechanism of virus resistance.

Virus Surveys in Olive Orchards in Greece Identify Olive Virus T, a Novel Member of the Genus .

Field surveys were conducted in Greek olive orchards from 2017 to 2020 to collect information on the sanitary status of the trees. Using a high-throughput sequencing approach, viral sequences were identified in total RNA extracts from several trees and assembled to reconstruct the complete genomes of two isolates of a new viral species of the genus (), for which the name olive virus T (OlVT) is proposed. A reverse transcription-polymerase chain reaction assay was developed which detected OlVT in samples collected in olive growing regions in Central and Northern Greece, showing a virus prevalence of 4.

Molecular analysis of Greek isolates of cucumber mosaic virus from vegetables shows a low prevalence of satellite RNAs and suggests the presence of host-associated virus strains.

Cucumber mosaic virus (CMV) is a generalist pathogen that infects many economically important crops in Greece. The present study was designed to evaluate the genetic variability of Greek CMV isolates in combination with their satellite RNAs (satRNAs). To achieve this goal, 77 CMV isolates were collected from symptomatic Greek vegetables, mainly tomatoes and cucurbits, alongside their neighboring crops, during a four-year period from 2015 to 2018.

Paths to social licence for tracking-data analytics in university research and services.

While tracking-data analytics can be a goldmine for institutions and companies, the inherent privacy concerns also form a legal, ethical and social minefield. We present a study that seeks to understand the extent and circumstances under which tracking-data analytics is undertaken with social licence-that is, with broad community acceptance beyond formal compliance with legal requirements. Taking a University campus environment as a case, we enquire about the social licence for Wi-Fi-based tracking-data analytics.

Virus and Viroid-Derived Small RNAs as Modulators of Host Gene Expression: Molecular Insights Into Pathogenesis.

Virus-derived siRNAs (vsiRNAs) generated by the host RNA silencing mechanism are effectors of plant's defense response and act by targeting the viral RNA and DNA in post-transcriptional gene silencing (PTGS) and transcriptional gene silencing (TGS) pathways, respectively. Contrarily, viral suppressors of RNA silencing (VSRs) compromise the host RNA silencing pathways and also cause disease-associated symptoms. In this backdrop, reports describing the modulation of plant gene(s) expression by vsiRNAs via sequence complementarity between viral small RNAs (sRNAs) and host mRNAs have emerged.

"You're still worth it": The moral and relational context of politically motivated unfriending decisions in online networks.

Political disagreements in social media can result in removing (i.e., "unfriending") a person from one's online network.

Pest categorisation of beet necrotic yellow vein virus.

Following a request from the EU Commission, the Panel on Plant Health performed a categorisation of beet necrotic yellow vein virus (BNYVV), the causal agent of the sugar beet rhizomania disease. The virus is currently listed in Annex III as a protected zone (PZ) quarantine pest of the Commission Implementing Regulation (EU) 2019/2072. The identity of the BNYVV is well established.

A Recurrent Deep Network for Estimating the Pose of Real Indoor Images from Synthetic Image Sequences.

Recently, deep convolutional neural networks (CNN) have become popular for indoor visual localisation, where the networks learn to regress the camera pose from images directly. However, these approaches perform a 3D image-based reconstruction of the indoor spaces beforehand to determine camera poses, which is a challenge for large indoor spaces. Synthetic images derived from 3D indoor models have been used to eliminate the requirement of 3D reconstruction.

Glucosylation prevents plant defense activation in phloem-feeding insects.

The metabolic adaptations by which phloem-feeding insects counteract plant defense compounds are poorly known. Two-component plant defenses, such as glucosinolates, consist of a glucosylated protoxin that is activated by a glycoside hydrolase upon plant damage. Phloem-feeding herbivores are not generally believed to be negatively impacted by two-component defenses due to their slender piercing-sucking mouthparts, which minimize plant damage.

Origin-Destination Flow Estimation from Link Count Data Only.

All established models in transportation engineering that estimate the numbers of trips between origins and destinations from vehicle counts use some form of a priori knowledge of the traffic. This paper, in contrast, presents a new origin-destination flow estimation model that uses only vehicle counts observed by traffic count sensors; it requires neither historical origin-destination trip data for the estimation nor any assumed distribution of flow. This approach utilises a method of statistical origin-destination flow estimation in computer networks, and transfers the principles to the domain of road traffic by applying transport-geographic constraints in order to keep traffic embedded in physical space.

Impact of two different dehydration methods on saffron quality, concerning the prevalence of Saffron latent virus (SaLV) in Iran.

The dehydration process is a prerequisite to preserve saffron for a long time. According to this process, saffron shows differences in the main compounds responsible for its quality (colour, taste, aroma, and flavonol content). At present, the freeze-drying method obtains dried products with the highest quality.

Pest categorisation of tomato leaf curl New Delhi virus.

Following a request from the European Commission, the Panel on Plant Health performed a pest categorisation on tomato leaf curl New Delhi virus (ToLCNDV). ToLCNDV is a well-defined bipartite Begomovirus species, sometimes associated with satellite molecules. It is transmitted by to a wide range of hosts.

Pest categorisation of non-EU viruses of L.

The Panel on Plant Health of EFSA conducted a pest categorisation of 17 viruses of L. that were previously classified as either non-EU or of undetermined standing in a previous opinion. These infectious agents belong to different genera and are heterogeneous in their biology.