A series of unreported novel dithioacetal derivatives containing a 4(3H)-quinazolinone pyrimidine ring were synthesized, and their antiviral activities were evaluated against tomato spotted wilt ...virus (TSWV). A three-dimensional quantitative structure–activity relationship (3D-QSAR) analysis was established, and compound D32 was designed and synthesized according to the analysis results of the CoMFA and CoMSIA models. The bioassay results showed that compound D32 exhibited excellent inactivation activity against TSWV, with EC50 values of 144 μg/mL, which was better than those of ningnanmycin (149 μg/mL) and the lead compound xiangcaoliusuobingmi (525 μg/mL). The binding ability of compound D32 to TSWV CP was tested by microscale thermophoresis (MST), and the binding constant value was 4.4 μM, which was better than those of ningnanmycin (6.2 μM) and xiangcaoliusuobingmi (59.1 μM). Therefore, this study indicates that novel dithioacetal derivatives containing a 4(3H)-quinazolinone pyrimidine ring may be applied as new antiviral agents.
We isolated and compared three tomato spotted wilt virus (TSWV) isolates from lettuce (TSWV-Let), pepper (TSWV-Pep), and tomato (TSWV-Tom) from central Mexico to determine their ability to infect a ...set of eighteen differential plant species from seven families. TWSV-Let was an aggressive isolate with the ability to infect up to 52% of the differential plants, including maize, under greenhouse conditions. The nucleotide (nt) sequences of the three isolates are more than 90% similar in the M and S RNA segments. In the M segment of the TSWV-Let isolate, we detected nt changes in their intergenic region (IGR) and, in the Gc gene, a region containing a recombination site, as well as a synapomorphy associated with one of three sites under positive selection with a change in one aa residue (a cysteine-to-valine mutation). We speculate on the association of these features in the Gc gene with host selection, adaptation, aggressiveness, and ability to infect maize plants.
•Auxin signaling is manipulated by TSWV to optimize its own spread in tomato.•Viral resistance is ensured through epigenetic regulation of the ARF8 promoter.•Joint and complementary action of miR167a ...and DNA cytosines methylation.•Reprograming auxin signaling pathways relies on hormone-related genes plasticity.
Tomato spotted wilt virus (TSWV) causes severe losses of tomato crops worldwide. To cope dynamically with such a threat, plants deploy strategies acting at the molecular and the epigenetic levels. We found that tomato symptoms progress in a specific-genotype-manner upon TSWV infection. Susceptible genotypes showed within the Auxin Response Factor (ARF8) promoter coupled to enhanced expression of miRNA167a, reduced ARF8 gene and decreased levels of the hormone auxin. This constitutes a deliberate attempt of TSWV to disrupt plant growth to promote spread in sensitive cultivars. Epigenetic regulation through the level of cytosine methylation and the miR167a-ARF8 module are part of a complex network modulating auxin-triggered synthesis and shaping tomato responses to TSWV. Furthermore, modulation of miR167a-ARF8 regulatory module could be applied in tomato-resistance breeding programs.
During the past three decades, the economic impact of tospoviruses has increased, causing high yield losses in a variety of crops and ornamentals. Owing to the difficulty in combating thrips vectors ...with insecticides, the best way to limit prevent tospovirus-induced diseases involves a management strategy that includes virus resistance. This review briefly presents current tospovirus taxonomy, diversity, molecular biology, and cytopathology as an introduction to a more extensive description of the two main resistance genes employed against tospoviruses: the
Sw5
gene in tomato and the
Tsw
in pepper. Natural and experimental resistance-breaking (RB) isolates allowed the identification of the viral avirulence protein triggering each of the two resistance gene products; epidemiology of RB isolates is discussed to reinforce the need for allelic variants and the need to search for new alternative resistance genes. Ongoing efforts for alternative resistance strategies are described not only for
Tomato spotted wilt virus
(TSWV) in pepper and tomato but also for other vegetable crops heavily impacted by tospoviruses.
•Phytohormone-related metabolites were significantly altered after TSWV inoculation.•ABA and JA-Ile decreased significantly while isopentenyladenine and SA increased.•TSWV infection reduced ...expression of genes involved in ABA and JA pathways.•Expression of ICS1 and PR1 genes were significantly increased after TSWV infection.
Tomato spotted wilt virus (TSWV) is ranked among the top 10 most destructive viruses globally. It results in abnormal leaf growth, stunting, and even death, significantly affecting crop yield and quality. Phytohormones play a crucial role in regulating plant-virus interactions. However, there is still limited research on the effect of TSWV on phytohormone levels, particularly growth hormones and genes involved in the phytohormone pathway. In our study, we combined phytohormone metabolomics and transcriptomics to examine the impact of TSWV infection on phytohormone content and gene expression profile. Metabolomic results showed that 41 metabolites, including major phytohormones and their precursors and derivatives were significantly altered after 14 days of TSWV inoculation tobacco plants cvK326, with 31 being significantly increased and 10 significantly reduced. Specifically, the levels of abscisic acid (ABA) and jasmonoyl-isoleucine (JA-Ile) were significantly reduced. The levels of indole-3-acetic acid (IAA) have remained unchanged. However, the levels of cytokinin isopentenyladenine (iP) and salicylic acid (SA) significantly increased. The transcriptome analysis revealed 2,746 genes with significant changes in expression. Out of these, 1,072 genes were significantly downregulated, while 1,674 genes were significantly upregulated. Among them, genes involved in ABA synthesis and signaling pathways, such as 9-cis-epoxycarotenoid dioxygenase (NCED), protein phosphatase 2C (PP2C), serine/threonine-protein kinase (SnRK2), and abscisic acid responsive element binding factor (ABF), exhibited significant downregulation. Additionally, expression of the lipoxygenase gene LOX, Jasmonate ZIM domain-containing protein gene JAZ, and transcription factor gene MYC were significantly down-regulated. In the cytokinin pathway, while there were no significant changes in the expression of the cytokinin synthesis genes, a significant downregulation of transcriptionally active factor type-B response regulators (type-B RRs) was observed. In terms of SA synthesis and signaling pathways, the isochorismate synthase gene ICS1 and the pathogenesis-related gene PR1 were significantly upregulated. These results can strengthen the theoretical foundation for understanding the interaction between TSWV and tobacco and provide new insights for the future prevention and control of TSWV.
Abstract
TMV (
Tobacco mosaic virus
) and TSWV (
Tomato spotted wilt virus
) are the most common virus diseases that causes loss of productivity in pepper cultivation. The most effective method in ...the fight against viral diseases is the use of resistant cultivars. This study was conducted to determine the similarities and differences of 120 Capia pepper lines in the S2 stage, consisted of local populations, standard and hybrid cultivars, in terms of morphological variation and to determine the resistance levels of the lines to TSWV and TMV. As a result of molecular analysis, genotypes 34, 35, 36, 46, 47, 48, 84, and 85 were found to be homozygous resistant to
L4
allele and the
Tsw
gene. Cluster analysis and principal component analysis (PCA) were applied to determine the relationship between the lines determined as a result of single plant selection. A dendrogram was prepared to evaluate morphological similarity between the lines. In the cluster analysis, 10 groups were identified based on 25 variables. The PCA explained 69.9% of the total variation based on 10 PC axes. At the end of the study, morphological variability was found high among the pepper lines. This evaluation of plant trait variability can assist geneticists and breeders to identify populations with desirable characteristics for inclusion in pepper breeding programs. In addition, the levels of resistance to these two diseases are crucial for breeding programs aimed at developing cultivars resistant to diseases.
Tomato (Solanum lycopersicum) is a crucial vegetable globally, pivotal in securing the world's food supply. However, viral diseases pose a significant threat to tomato cultivation, resulting in ...considerable yield losses. Employing sensitive, rapid, and cost‐effective detection methods is imperative for mitigating such losses in agricultural production. In response, we developed a Taqman® probe‐based real‐time multiplex PCR method capable of concurrently detecting three major plant viruses: Tomato brown rugose fruit virus (ToBRFV), tomato spotted wilt orthotospovirus (TSWV), and pepino mosaic virus (PepMV), all of which are prominent viral pathogens affecting tomato production. Utilizing envelope protein encoding sequences of these pathogens, we designed primers and probes, assigning the FAM reporter for ToBRFV, the HEX reporter for TSWV, and the Cy5 reporter for PepMV detection. The multiplex RT‐qPCR experiment yielded successful results, with Ct values of 29.34, 25.93, and 27.47 for ToBRFV (at 10−6 dilution), TSWV (at 10−2 dilution), and PepMV (at 10−3 dilution), respectively. Developed primers facilitate the early detection of destructive pathogens ToBRFV, TSWV, and PepMV using both RT‐PCR and RT‐qPCR, offering a user‐friendly and cost‐effective approach.
Abstract
Plant immunity relies on nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) that detect microbial patterns released by pathogens, and activate localized cell death to ...prevent the spread of pathogens. Tsw is the only identified resistance (R) gene encoding an NLR, conferring resistance to tomato spotted wilt orthotospovirus (TSWV) in pepper species (Capsicum, Solanaceae). However, molecular and cellular mechanisms of Tsw-mediated resistance are still elusive. Here, we analysed the structural and cellular functional features of Tsw protein, and defined a hydrophobic module to improve NLR-mediated virus resistance. The plasma membrane associated N-terminal 137 amino acid in the coiled-coil (CC) domain of Tsw is the minimum fragment sufficient to trigger cell death in Nicotiana benthamiana plants. Transient and transgenic expression assays in plants indicated that the amino acids of the hydrophobic groove (134th–137th amino acid) in the CC domain is critical for its full function and can be modified for enhanced disease resistance. Based on the structural features of Tsw, a super-hydrophobic funnel-like mutant, TswY137W, was identified to confer higher resistance to TSWV in a SGT1 (Suppressor of G-two allele of Skp1)-dependent manner. The same point mutation in a tomato Tsw-like NLR protein also improved resistance to pathogens, suggesting a feasible way of structure-assisted improvement of NLRs.
The 137-amino acid plasma membrane-associated coiled-coil domain of Tsw NLR protein from pepper functions in Tsw-mediated resistance.
Kac is a model for all acylation modification studies. Kac plays a critical role in eukaryotes and prokaryotes. It is mainly involved in six major biological functions: gene expression, signal ...transduction, cell development, protein conversion, metabolism, and metabolite transport.
We investigated and compared the acetylation modification of proteins in healthy and tomato spot wilt virus (TSWV)-infected
leaves.
We identified 3,418 acetylated lysine sites on 1962 proteins acetylation of proteins in the TSWV-infected and control groups were compared; it was observed that 408 sites on 294 proteins were upregulated and 284 sites on 219 proteins (involved in pentose phosphate, photosynthesis, and carbon fixation in photosynthesis) were downregulated after the infection. Overall, 35 conserved motifs were identified, of which xxxkxxxxx_K_ Rxxxxxxxxx represented 1,334 (31.63%) enrichment motifs and was the most common combination. Bioinformatic analysis revealed that most of the proteins with Kac sites were located in the chloroplast and cytoplasm. They were involved in biological processes, such as cellular and metabolic processes.
In conclusion, our results revealed that Kac may participate in the regulation of TSWV infection in
.
