Non-Feeding Transmission Modes of the Tomato Yellow Leaf Curl Virus by the Whitefly Do Not Contribute to Reoccurring Leaf Curl Outbreaks in Tomato.

Tomato yellow leaf curl virus (TYLCV) causes significant yield loss in tomato production in the southeastern United States and elsewhere. TYLCV is transmitted by the whitefly cryptic species in a persistent, circulative, and non-propagative manner. Unexpectedly, transovarial and sexual transmission of TYLCV has been reported for one strain from Israel.

Differential expression of "Candidatus Liberibacter solanacearum" genes and prophage loci in different life stages of potato psyllid.

Psyllid species, including the potato psyllid (PoP) Bactericera cockerelli (Sulc) (Triozidae) serve as host and vector of "Candidatus Liberibacter spp." ("Ca. Liberibacter"), which also infects diverse plant hosts, including citrus and tomato.

Molecular Surveillance, Prevalence, and Distribution of Cacao Infecting Badnavirus Species in Côte d'Ivoire and Ghana.

The cacao swollen shoot disease (CSSD) caused by a complex of badnavirus species presents a major challenge for cacao production in West Africa, especially Ghana and Côte d'Ivoire. In this study, CSSD species detection efficiency, diversity, and geographic distribution patterns in cacao plantations in Ghana and Côte d'Ivoire were investigated through field surveillance, PCR detection assays, sequencing of positive amplicons, and phylogeographic clustering. Cumulatively, the detection efficiency of the tested CSSD primer sets that were targeting the movement protein domain of the virus ranged from 0.

First report of sweepoviruses infecting L. cultivars and landraces in Trinidad.

Root crops, referred to as ground provisions in the Caribbean, are traditional staples in Trinidad. One widely consumed example is sweet potato (Ipomeas batatas L.).

Complete genome characterization of cacao leafroll virus, a newly described cacao-infecting polerovirus.

The complete genome sequence of cacao leafroll virus (CaLRV; family Solemoviridae, genus Polerovirus) was determined by high-throughput sequencing of total RNA isolated from symptomatic cacao Theobroma cacao L. plants (n = 4). The CaLRV genome sequences ranged from 5,976 to 5,997 nucleotides (nt) in length and contained seven open reading frames (ORFs).

Sub-optimal temperatures lead to altered expression of stress-related genes and increased 'C Liberibacter solanacearum' accumulation in potato psyllid.

Introduction: The potato psyllid is the insect vector of the fastidious bacterium ' Liberibacter solanacearum'. The bacterium infects both and plant species, causing zebra chip (ZC) disease of potato and vein-greening disease of tomato. Temperatures are known to influence the initiation and progression of disease symptom in the host plant, and seasonal transitions from moderate to high temperatures trigger psyllid dispersal migration to facilitate survival.

Genetic Variability Among U.S.-Sentinel Cotton Plot Cotton Leafroll Dwarf Virus and Globally Available Reference Isolates Based on ORF0 Diversity.

The aphid-transmitted polerovirus, cotton leafroll dwarf virus (CLRDV), first characterized from symptomatic cotton plants in South America, has been identified in commercial cotton plantings in the United States. Here, the CLRDV intraspecific diversity was investigated by comparative sequence analysis of the most divergent CLRDV coding region, ORF0/P0. Bayesian analysis of ORF0 sequences for U.

Optimal dsRNA Concentration for RNA Interference in Asian Citrus Psyllid.

The Asian citrus psyllid (ACP) is a citrus pest and insect vector of " Liberibacter asiaticus", the causal agent of citrus greening disease. Double-stranded RNA (dsRNA) biopesticides that trigger RNA interference (RNAi) offer an alternative to traditional insecticides. Standardized laboratory screening of dsRNA requires establishing the minimal effective concentration(s) that result in effective RNAi "penetrance" and trigger RNAi, resulting in one or more measurable phenotypes, herein, significant gene knockdown and the potential for mortality.

UV-LASER adjuvant-surfactant-facilitated delivery of mobile dsRNA to tomato plant vasculature and evidence of biological activity by gene knockdown in the potato psyllid.

Background: Double-stranded RNA (dsRNA) biopesticides are of interest for the abatement of insect vectors of pathogenic bacteria such as 'Candidatus Liberibacter', which infects both its psyllid and plant hosts. Silencing of genes essential for psyllids, or for Liberibacter, is anticipated to lead to mortality or impeded bacterial multiplication. Foliar delivery is preferred for biopesticide application; however, the cuticle impedes dsRNA penetration into the vasculature.

Differential gene expression of Asian citrus psyllids infected with ' Liberibacter asiaticus' reveals hyper-susceptibility to invasion by instar fourth-fifth and teneral adult stages.

The bacterial pathogen Liberibacter asiaticus (CLas) is the causal agent of citrus greening disease. This unusual plant pathogenic bacterium also infects its psyllid host, the Asian citrus psyllid (ACP). To investigate gene expression profiles with a focus on genes involved in infection and circulation within the psyllid host of CLas, RNA-seq libraries were constructed from CLas-infected and CLas-free ACP representing the five different developmental stages, namely, nymphal instars 1-2, 3, and 4-5, and teneral and mature adults.

Sentinel plot surveillance of cotton leaf curl disease in Pakistan- a case study at the cultivated cotton-wild host plant interface.

A sentinel plot case study was carried out to identify and map the distribution of begomovirus-betasatellite complexes in sentinel plots and commercial cotton fields over a four-year period using molecular and high-throughput DNA 'discovery' sequencing approaches. Samples were collected from 15 study sites in the two major cotton-producing areas of Pakistan. Whitefly- and leafhopper-transmitted geminiviruses were detected in previously unreported host plant species and locations.

The Bemisia tabaci cryptic (sibling) species group - imperative for a taxonomic reassessment.

The taxonomy of the Bemisia tabaci cryptic species group remains a challenge due to the lack of morphological differentiation and porous species boundaries among its members. Additionally, it is unclear whether B. tabaci consists of several species in evolutionary stasis with limited morphological change or is the result of a recent adaptive radiation characterized by great ecological diversity but little morphological divergence.

Native and Non-Native NAFME Haplotypes Can Be Implicated in Dispersal of Endemic and Introduced Begomoviruses in Oman.

Irrigated agriculture and global trade expansion have facilitated diversification and spread of begomoviruses (), transmitted by the (Gennadius) cryptic species. Oman is situated on major crossroads between Africa and South Asia, where endemic/native and introduced/exotic begomoviruses occur in agroecosystems. The 'B mitotype' belongs to the North Africa-Middle East (NAFME) cryptic species, comprising at least eight endemic haplotypes, of which haplotypes 6 and/or 8 are recognized invasives.

In Silico Identification of Cassava Genome-Encoded MicroRNAs with Predicted Potential for Targeting the ICMV-Kerala Begomoviral Pathogen of Cassava.

Cassava mosaic disease (CMD) is caused by several divergent species belonging to the genus () transmitted by the whitefly cryptic species group. In India and other parts of Asia, the Indian cassava mosaic virus-Kerala (ICMV-Ker) is an emergent begomovirus of cassava causing damage that results in reduced yield loss and tuber quality. Double-stranded RNA-mediated interference (RNAi) is an evolutionary conserved mechanism in eukaryotes and highly effective, innate defense system to inhibit plant viral replication and/or translation.

Characteristics of environmental RNAi in potato psyllid, (Sulc) (Hemiptera: Psylloidea: Triozidae).

RNA interference (RNAi) has potential to become a major tool for integrated management of insect pests of agricultural crops based on sequence-specificity and low doses of rapidly biodegradable dsRNA. Deploying 'environmental RNAi' for control of insect vectors of plant pathogens is of increasing interest for combatting emerging plant diseases. Hemipteran insect vectors, including psyllids, are vascular feeders, making their development difficult to control specifically by targeting with pesticidal chemistries.

A Previously Undescribed Polerovirus () Infecting Germplasm.

Cacao L. (Malvaceae) is an economically important crop cultivated in tropical climates for the bean from which chocolate and other products are made (Zarrillo et al., 2018).

Differential Transcriptional Responses in Two Old World Cryptic Species Post Acquisition of Old and New World Begomoviruses.

Begomoviruses are transmitted by several cryptic species of the sweetpotato whitefly, (Gennadius), in a persistent and circulative manner. Upon virus acquisition and circulative translocation within the whitefly, a multitude of molecular interactions occur. This study investigated the differentially expressed transcript profiles associated with the acquisition of the Old World monopartite begomovirus, tomato yellow leaf curl virus (TYLCV), and two New World bipartite begomoviruses, sida golden mosaic virus (SiGMV) and cucurbit leaf crumple virus (CuLCrV), in two invasive cryptic species, Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED).

Comparison of and spp. Chloroplast Genomes: Evidence for Endosymbiosis and Horizontal Virus-like Gene Transfer.

Resequencing of the chloroplast genome (cpDNA) of UTEX 25 was completed (GenBank Accession no. KC631634.1), revealing a genome size of 84,576 base pairs and 30.

Knockdown of ecdysteroid synthesis genes results in impaired molting and high mortality in Bactericera cockerelli (Hemiptera: Triozidae).

Background: RNA-mediated interference (RNAi) has become a promising biopesticide technology with which to direct sequence-specific gene knockdown of key targets in the potato psyllid (PoP) Bactericera cockerelli, resulting in significant mortality. In this study, three strategically selected target genes, ATF4, C7 and D24, essential for the biosynthesis and regulation of ecdysteroids, were evaluated for knockdown and mortality using oral delivery of individual, paired and all three double-stranded RNAs (dsRNAs), in five replicated experiments. Knockdown was determined as the fold-change in gene expression using a quantitative polymerase chain reaction.

Earlier than expected introductions of the B mitotype in Brazil reveal an unprecedented, rapid invasion history.

During 1991, in Brazil, the presence of the exotic B mitotype was reported in São Paulo state. However, the duration from the time of initial introduction to population upsurges is not known. To investigate whether the 1991 B mitotype outbreaks in Brazil originated in São Paulo or from migrating populations from neighboring introduction sites, country-wide field samples of .