scholarly journals Probing into the Effects of Grapevine Leafroll-Associated Viruses on the Physiology, Fruit Quality and Gene Expression of Grapes

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 593
Author(s):  
Yashu Song ◽  
Robert H. Hanner ◽  
Baozhong Meng

Grapevine leafroll is one of the most widespread and highly destructive grapevine diseases that is responsible for great economic losses to the grape and wine industries throughout the world. Six distinct viruses have been implicated in this disease complex. They belong to three genera, all in the family Closteroviridae. For the sake of convenience, these viruses are named as grapevine leafroll-associated viruses (GLRaV-1, -2, -3, -4, -7, and -13). However, their etiological role in the disease has yet to be established. Furthermore, how infections with each GLRaV induce the characteristic disease symptoms remains unresolved. Here, we first provide a brief overview on each of these GLRaVs with a focus on genome structure, expression strategies and gene functions, where available. We then provide a review on the effects of GLRaV infection on the physiology, fruit quality, fruit chemical composition, and gene expression of grapevine based on the limited information so far reported in the literature. We outline key methodologies that have been used to study how GLRaV infections alter gene expression in the grapevine host at the transcriptomic level. Finally, we present a working model as an initial attempt to explain how infections with GLRaVs lead to the characteristic symptoms of grapevine leafroll disease: leaf discoloration and downward rolling. It is our hope that this review will serve as a starting point for grapevine virology and the related research community to tackle this vastly important and yet virtually uncharted territory in virus-host interactions involving woody and perennial fruit crops.

2020 ◽  
Vol 139 ◽  
pp. 153-160
Author(s):  
S Peeralil ◽  
TC Joseph ◽  
V Murugadas ◽  
PG Akhilnath ◽  
VN Sreejith ◽  
...  

Luminescent Vibrio harveyi is common in sea and estuarine waters. It produces several virulence factors and negatively affects larval penaeid shrimp in hatcheries, resulting in severe economic losses to shrimp aquaculture. Although V. harveyi is an important pathogen of shrimp, its pathogenicity mechanisms have yet to be completely elucidated. In the present study, isolates of V. harveyi were isolated and characterized from diseased Penaeus monodon postlarvae from hatcheries in Kerala, India, from September to December 2016. All 23 tested isolates were positive for lipase, phospholipase, caseinase, gelatinase and chitinase activity, and 3 of the isolates (MFB32, MFB71 and MFB68) showed potential for significant biofilm formation. Based on the presence of virulence genes, the isolates of V. harveyi were grouped into 6 genotypes, predominated by vhpA+ flaB+ ser+ vhh1- luxR+ vopD- vcrD+ vscN-. One isolate from each genotype was randomly selected for in vivo virulence experiments, and the LD50 ranged from 1.7 ± 0.5 × 103 to 4.1 ± 0.1 × 105 CFU ml-1. The expression of genes during the infection in postlarvae was high in 2 of the isolates (MFB12 and MFB32), consistent with the result of the challenge test. However, in MFB19, even though all genes tested were present, their expression level was very low and likely contributed to its lack of virulence. Because of the significant variation in gene expression, the presence of virulence genes alone cannot be used as a marker for pathogenicity of V. harveyi.


Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1078 ◽  
Author(s):  
Albert Ros-Lucas ◽  
Florencia Correa-Fiz ◽  
Laia Bosch-Camós ◽  
Fernando Rodriguez ◽  
Julio Alonso-Padilla

African swine fever virus is the etiological agent of African swine fever, a transmissible severe hemorrhagic disease that affects pigs, causing massive economic losses. There is neither a treatment nor a vaccine available, and the only method to control its spread is by extensive culling of pigs. So far, classical vaccine development approaches have not yielded sufficiently good results in terms of concomitant safety and efficacy. Nowadays, thanks to advances in genomic and proteomic techniques, a reverse vaccinology strategy can be explored to design alternative vaccine formulations. In this study, ASFV protein sequences were analyzed using an in-house pipeline based on publicly available immunoinformatic tools to identify epitopes of interest for a prospective vaccine ensemble. These included experimentally validated sequences from the Immune Epitope Database, as well as de novo predicted sequences. Experimentally validated and predicted epitopes were prioritized following a series of criteria that included evolutionary conservation, presence in the virulent and currently circulating variant Georgia 2007/1, and lack of identity to either the pig proteome or putative proteins from pig gut microbiota. Following this strategy, 29 B-cell, 14 CD4+ T-cell and 6 CD8+ T-cell epitopes were selected, which represent a starting point to investigating the protective capacity of ASFV epitope-based vaccines.


Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 448
Author(s):  
Sineewanlaya Wichit ◽  
Nuttamonpat Gumpangseth ◽  
Rodolphe Hamel ◽  
Sakda Yainoy ◽  
Siwaret Arikit ◽  
...  

Chikungunya and Zika viruses, both transmitted by mosquito vectors, have globally re-emerged over for the last 60 years and resulted in crucial social and economic concerns. Presently, there is no specific antiviral agent or vaccine against these debilitating viruses. Understanding viral–host interactions is needed to develop targeted therapeutics. However, there is presently limited information in this area. In this review, we start with the updated virology and replication cycle of each virus. Transmission by similar mosquito vectors, frequent co-circulation, and occurrence of co-infection are summarized. Finally, the targeted host proteins/factors used by the viruses are discussed. There is an urgent need to better understand the virus–host interactions that will facilitate antiviral drug development and thus reduce the global burden of infections caused by arboviruses.


Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1290
Author(s):  
Chiara Arcangeli ◽  
Daniele Lucarelli ◽  
Martina Torricelli ◽  
Carla Sebastiani ◽  
Marcella Ciullo ◽  
...  

Maedi-visna virus (MVV) and caprine arthritis encephalitis virus (CAEV), referred to as small ruminant lentiviruses (SRLVs), belong to the genus Lentivirus of the Retroviridae family. SRLVs infect both sheep and goats, causing significant economic losses and animal welfare damage. Recent findings suggest an association between serological status and allelic variants of different genes such as TMEM154, TLR9, MYD88 and CCR5. The aim of this work was to investigate the role of specific polymorphisms of these genes in SRLVs infection in some sheep flocks in Italy. In addition to those already known, novel variants in the TMEM154 (P7H, I74V, I105V) gene were detected in this study. The risk of infection was determined finding an association between the serological status and polymorphisms P7H, E35K, N70I, I74V, I105V of TMEM154, R447Q, A462S and G520R in TLR9 gene, H176H* and K190K* in MYD88 genes, while no statistical association was observed for the 4-bp deletion of the CCR5 gene. Since no vaccines or treatments have been developed, a genetically based approach could be an innovative strategy to prevent and to control SRLVs infection. Our findings are an important starting point in order to define the genetic resistance profile towards SRLVs infection.


Vaccines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 364
Author(s):  
Jun Ma ◽  
Lulu Ma ◽  
Meiting Yang ◽  
Wei Wu ◽  
Wenhai Feng ◽  
...  

Porcine reproductive and respiratory syndrome virus (PRRSV) affects the global swine industry and causes disastrous economic losses each year. The genome of PRRSV is an enveloped single-stranded positive-sense RNA of approximately 15 kb. The PRRSV replicates primarily in alveolar macrophages of pig lungs and lymphatic organs and causes reproductive problems in sows and respiratory symptoms in piglets. To date, studies on how PRRSV survives in the host, the host immune response against viral infections, and pathogenesis, have been reported. PRRSV vaccines have been developed, including inactive virus, modified live virus, attenuated live vaccine, DNA vaccine, and immune adjuvant vaccines. However, there are certain problems with the durability and effectiveness of the licensed vaccines. Moreover, the high variability and fast-evolving populations of this RNA virus challenge the design of PRRSV vaccines, and thus effective vaccines against PRRSV have not been developed successfully. As is well known, viruses interact with the host to escape the host’s immune response and then replicate and propagate in the host, which is the key to virus survival. Here, we review the complex network and the mechanism of PRRSV–host interactions in the processes of virus infection. It is critical to develop novel antiviral strategies against PRRSV by studying these host–virus interactions and structures to better understand the molecular mechanisms of PRRSV immune escape.


Author(s):  
Shiyi Tian ◽  
Jue Wang ◽  
Jing Wang ◽  
Weiyun Zhu

Recently, we have proved that the early-life galactooligosaccharides (GOS) intervention could improve the colonic function by altering the bacterial composition in the suckling piglets. However, whether the early-life GOS (ELG) intervention could have a long influence of the colonic microbiota, and the ELG and post-weaning GOS (PWG) combined intervention would have an interaction effect on maintaining colonic health in weaning piglets remain to be explored. Thus in this study, we illustrated the differential effect of ELG and PWG intervention on colonic microbiota and colonic function of weaning piglets. Our results showed that both the ELG and PWG intervention decreased the diarrhea frequency of weaning piglets, while the PWG intervention increased colonic indexes. After 16S rRNA MiSeq sequencing of gut bacteria belonged to colonic niches (mucosa and digesta), the PWG increased the α-diversity of colonic mucosal bacteria was revealed. In addition, we found both the ELG and PWG intervention enriched the abundance of short chain fatty acids (SCFAs) producer in different colonic niches and increased total SCFAs concentrations in colonic digesta. These changes selectively modulated the mRNA expression of pattern recognition receptors and barrier proteins in the colonic mucosa. Of note, the combined effect of ELG and PWG effectively enhanced colonic SCFAs producer enrichment and up-regulated the butyrate concentration. Meanwhile, the gene expression of MyD88-NFκB signaling and the pro-inflammatory cytokines contents were markedly reduced under the combined effect of ELG and PWG. Importance Reducing the disorders of gut ecosystem is an effective way to relieve weaning stresses of piglets and save economic losses in the modern swine industry. To this end, prebiotics were often added in diet during the weaning transition. In present study, we demonstrated that the ELG and PWG intervention had shown different effects on the bacterial composition of different colonic niches and colonic function in the weaning piglets. Especially under the combined effect of ELG and PWG intervention, the gene expression of MyD88-NFκB signaling and the contents of pro-inflammation cytokines decreased with the increasing concentration of butyrate, which is one of the important microbial metabolites in the colon of weaning piglets. These findings further provided new insights into nutritional interventions to alleviate intestinal ecosystem dysbiosis and gut dysfunction in the piglets during the weaning transition.


Genes ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 591
Author(s):  
Tsung-Lin Tsai ◽  
Chen-Chang Su ◽  
Ching-Chi Hsieh ◽  
Chao-Nan Lin ◽  
Hui-Wen Chang ◽  
...  

In 2013, the outbreak of porcine epidemic diarrhea (PED) in Taiwan caused serious economic losses. In this study, we examined whether the variations of the cis-acting elements between the porcine epidemic diarrhea virus (PEDV) Taiwan (TW) strain and the prototype strain CV777 alter gene expression. For this aim, we analyzed the variations of the cis-acting elements in the 5’ and 3’ untranslated regions (UTRs) between the PEDV TW, CV777, and other reference strains. We also determined the previously unidentified transcription regulatory sequence (TRS), a sequence motif required for coronavirus transcription, and found that a nucleotide deletion in the TW strain, in comparison with CV777 strain, immediately downstream of the leader core sequence alters the identity between the leader TRS and the body TRS. Functional analyses using coronavirus defective interfering (DI) RNA revealed that such variations in cis-acting elements for the TW strain compared with the CV777 strain have an influence on the efficiency of gene expression. The current data show for the first time the evolution of PEDV in terms of cis-acting elements and their effects on gene expression, and thus may contribute to our understanding of recent PED outbreaks worldwide.


2021 ◽  
Vol 12 ◽  
Author(s):  
Shuai Liu ◽  
Keji Zhao

The code of life is not only encrypted in the sequence of DNA but also in the way it is organized into chromosomes. Chromosome architecture is gradually being recognized as an important player in regulating cell activities (e.g., controlling spatiotemporal gene expression). In the past decade, the toolbox for elucidating genome structure has been expanding, providing an opportunity to explore this under charted territory. In this review, we will introduce the recent advancements in approaches for mapping spatial organization of the genome, emphasizing applications of these techniques to immune cells, and trying to bridge chromosome structure with immune cell activities.


2021 ◽  
Vol 12 ◽  
Author(s):  
Alongkorn Kurilung ◽  
Vincent Perreten ◽  
Nuvee Prapasarakul

Leptospira weilii belongs to the pathogenic Leptospira group and is a causal agent of human and animal leptospirosis in many world regions. L. weilii can produce varied clinical presentations from asymptomatic through acute to chronic infections and occupy several ecological niches. Nevertheless, the genomic feature and genetic basis behind the host adaptability of L. weilii remain elusive due to limited information. Therefore, this study aimed to examine the complete circular genomes of two new L. weilii serogroup Mini strains (CUDO6 and CUD13) recovered from the urine of asymptomatic dogs in Thailand and then compared with the 17 genomes available for L. weilii. Variant calling analysis (VCA) was also undertaken to gain potential insight into the missense mutations, focusing on the known pathogenesis-related genes. Whole genome sequences revealed that the CUDO6 and CUD13 strains each contained two chromosomes and one plasmid, with average genome size and G+C content of 4.37 Mbp and 40.7%, respectively. Both strains harbored almost all the confirmed pathogenesis-related genes in Leptospira. Two novel plasmid sequences, pDO6 and pD13, were identified in the strains CUDO6 and CUD13. Both plasmids contained genes responsible for stress response that may play important roles in bacterial adaptation during persistence in the kidneys. The core-single nucleotide polymorphisms phylogeny demonstrated that both strains had a close genetic relationship. Amongst the 19 L. weilii strains analyzed, the pan-genome analysis showed an open pan-genome structure, correlated with their high genetic diversity. VCA identified missense mutations in genes involved in endoflagella, lipopolysaccharide (LPS) structure, mammalian cell entry protein, and hemolytic activities, and may be associated with host-adaptation in the strains. Missense mutations of the endoflagella genes of CUDO6 and CUD13 were associated with loss of motility. These findings extend the knowledge about the pathogenic molecular mechanisms and genomic evolution of this important zoonotic pathogen.


2021 ◽  
Vol 12 ◽  
Author(s):  
Demetrio Marcianò ◽  
Valentina Ricciardi ◽  
Elena Marone Fassolo ◽  
Alessandro Passera ◽  
Piero Attilio Bianco ◽  
...  

Downy mildew, caused by the oomycete Plasmopara viticola, is one of the diseases causing the most severe economic losses to grapevine (Vitis vinifera) production. To date, the application of fungicides is the most efficient method to control the pathogen and the implementation of novel and sustainable disease control methods is a major challenge. RNA interference (RNAi) represents a novel biotechnological tool with a great potential for controlling fungal pathogens. Recently, a candidate susceptibility gene (VviLBDIf7) to downy mildew has been identified in V. vinifera. In this work, the efficacy of RNAi triggered by exogenous double-stranded RNA (dsRNA) in controlling P. viticola infections has been assessed in a highly susceptible grapevine cultivar (Pinot noir) by knocking down VviLBDIf7 gene. The effects of dsRNA treatment on this target gene were assessed by evaluating gene expression, disease severity, and development of vegetative and reproductive structures of P. viticola in the leaf tissues. Furthermore, the effects of dsRNA treatment on off-target (EF1α, GAPDH, PEPC, and PEPCK) and jasmonic acid metabolism (COI1) genes have been evaluated. Exogenous application of dsRNA led to significant reductions both in VviLBDIf7 gene expression, 5 days after the treatment, and in the disease severity when artificial inoculation was carried out 7 days after dsRNA treatments. The pathogen showed clear alterations to both vegetative (hyphae and haustoria) and reproductive structures (sporangiophores) that resulted in stunted growth and reduced sporulation. Treatment with dsRNA showed signatures of systemic activity and no deleterious off-target effects. These results demonstrated the potential of RNAi for silencing susceptibility factors in grapevine as a sustainable strategy for pathogen control, underlying the possibility to adopt this promising biotechnological tool in disease management strategies.


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