Wheat dwarf virus (WDV) poses a major limitation to global cereal production, yet reliable genetic sources of resistance remain scarce. In this study, 12 genetically diverse wheat (Triticum aestivum L.) genotypes exhibiting differential susceptibility to WDV were evaluated under controlled inoculation conditions. Viral titre and the expression profiles of nine candidate resistance genes-representing NBS-LRR family, kinase family and transcription factor families-were quantified using reverse transcription quantitative polymerase chain reaction. Phenotypic parameters, including plant height and biomass, were assessed to relate molecular responses to disease severity. Statistical analysis using one-way ANOVA revealed significant genotype-dependent differences in viral accumulation and resistance gene expression. Notably, genotype VS-H 09-4/3 exhibited an approximately 80% reduction in virus titre relative to susceptible lines, accompanied by a 2.5-fold upregulation of key R-genes associated with innate immune responses. In contrast, susceptible genotypes such as Ludwig displayed elevated viral loads and downregulation of these defence-related genes. Transcriptional modulation of kinase and transcription factor genes (e.g., MYB, GRAS) further supported the involvement of complex regulatory networks in WDV resistance. Collectively, these findings reveal actionable genetic markers and distinct resistance phenotypes, providing valuable resources for marker-assisted selection aimed at developing durable WDV-resistant wheat cultivars and enhancing crop resilience under changing environmental conditions.

Background: Rapid and objective characterisation of viral accumulation requires methods combining fast detection and temporal resolution. Aims: Develop a two-phase approach for screening sugar beet genotypes for beet yellows virus (BYV) accumulation dynamics. Methods: Phase 1 employed one-enzyme RTX-PCR for rapid BYV detection, followed by single-time-point RT-qPCR at 30 days post-inoculation (dpi) to screen ten genotypes. Phase 2 performed time-course RT-qPCR at six time points (10-60 dpi) on two contrasting genotypes selected from Phase 1, with assay performance validated by a standard curve. Results: One-enzyme RTX-PCR confirmed BYV infection, enabling quantification; single-time-point RT-qPCR at 30 dpi showed a 5.7-fold titre range (5.6 x 10(7) to 3.2 x 10(8) copies), while time-course RT-qPCR revealed distinct trajectories, relatively resistant GZs1 increased gradually (similar to 5.0 x 10(5) at 10 dpi to 1.7 - 2.3 x 10(7) at 40 - 60 dpi) whereas susceptible Masaryk rose rapidly early (similar to 3.1 x 10(6) at 10 dpi) and peaked at 3.7 x 10(7) by 40 dpi, dynamics not captured by single-time-point measurements; standard curve metrics indicated high assay quality (R-2 = 0.9976; efficiency = 103%). Conclusions: This two-phase method combines speed with precision for effective genotype comparison. It reveals BYV accumulation dynamics that are not captured by single-point assays.

Context. Tomato productivity is increasingly threatened by viral pathogens, particularly tomato brown rugose fruit virus (ToBRFV) and tomato spotted wilt virus (TSWV), which overcome classical resistance genes and cause severe yield losses. Aims. This study evaluated the leaf-level tolerance responses of 10 commercially grown tomato cultivars from the Czech Republic to ToBRFV and TSWV under controlled greenhouse conditions, on the basis of leaf symptom expression and virus accumulation in leaves. Methods. Viral accumulation in leaf tissue was quantified by reverse-transcription quantitative polymerase chain reaction. Cultivars were screened for resistance-associated markers (Tm-1, Tm-2 and Tm-22 for ToBRFV; Sw5, Sw5b and Sw7 for TSWV). Defence responses were assessed by expression analysis of PAL, HQT, NBR1a, WRKY33a, PR-1 and ATG7 at 21 days post-inoculation. Results. Viral titres varied markedly among cultivars. Stupick & eacute; poln & iacute; ran & eacute; and Vilma consistently exhibited reduced ToBRFV accumulation (2.3-4.2 & times; 10(6) copies), whereas Gallant and Odat showed high ToBRFV accumulation in leaves (>2.0 & times; 10(7) copies). For TSWV, Stupick & eacute; poln & iacute; ran & eacute; exhibited a more tolerant leaf response, associated with the presence of the Sw7 allele, whereas Start, Gallant and Perun showed the least favourable leaf-level responses. None of the cultivars carried classical Tm resistance alleles for ToBRFV. Reduced viral accumulation was associated with enhanced induction of phenylpropanoid (PAL, HQT) and immune-related (NBR1a, WRKY33a, PR-1 and ATG7) genes. Conclusions. Stupick & eacute; poln & iacute; ran & eacute; and Vilma displayed the highest leaf-level tolerance (reduced symptoms and/or reduced leaf virus accumulation). Cultivar responses and defence activation varied widely among commercial cultivars. Implications. These results support molecularly informed breeding strategies, focusing on gene stacking and novel resistance sources to achieve durable, improved outcomes against both viruses.

Tomato spotted wilt virus (TSWV; species Orthotospovirus tomatomaculae, family Tospoviridae) (Kuhn et al., 2023), is a negative strand RNA-virus containing envelope structures, which makes it unique among plant viruses (de Haan et al., 1991). TSWV ranks among the most destructive plant viruses worldwide. First described in Australia in 1919, TSWV has since attained a global distribution, infecting over 1 000 plant species across more than 85 families, including key agricultural crops such as tomato (Solanum lycopersicum), pepper (Capsicum annuum), groundnut (Arachis hypogaea), and various ornamentals (Parrella et al., 2003; Pappu et al., 2009). Infected plants typically exhibit chlorotic or necrotic spots, wilting, stunted growth, and in severe cases, complete crop failure, resulting in considerable economic losses, particularly in Solanaceous and Asteraceous crops (Roselló et al., 1996; Latham and Jones, 1998).

Wheat dwarf virus (WDV) is a major constraint to global wheat production, causing severe yield losses and economic disruption. Understanding the molecular basis of wheat–WDV interactions is essential for developing resistant cultivars. Non-coding RNAs (ncRNAs), including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), are key regulators of gene expression and defence. This study identified ncRNAs involved in wheat responses to WDV, including host lncRNAs, miRNAs, and viral small interfering RNAs (siRNAs) targeting WDV genomic regions. High-throughput sequencing revealed extensive ncRNA reprogramming under WDV infection. A total of 437 differentially expressed lncRNAs (DElncRNAs) and 58 miRNAs (DEmiRNAs) were detected. Resistant genotypes displayed more DElncRNAs (204 in Svitava; 163 in Fengyou 3) than the susceptible Akteur (141). In Akteur, 66.7% of DElncRNAs were downregulated, whereas in Svitava, 56.9% were upregulated. Akteur also exhibited more DEmiRNAs (28) than resistant genotypes (15), with predominant downregulation. A co-expression network analysis revealed 391 significant DElncRNA–mRNA interactions mediated by 16 miRNAs. The lncRNA XLOC_058282 was linked to 298 transcripts in resistant genotypes, suggesting a central role in the host defence. Functional annotation showed enrichment in signalling, metabolic, and defence-related pathways. Small RNA profiling identified 1166 differentially expressed sRNAs targeting WDV, including conserved hotspots and 408 genotype-specific sites in Akteur versus Fengyou 3. Infected plants displayed longer sRNAs, a sense-strand bias, and a 5′ uridine preference, but lacked typical 21–24 nt phasing. These findings highlight the central roles of ncRNAs in orchestrating wheat antiviral defence and provide a molecular framework for breeding virus-resistant wheat.

Barley yellow dwarf viruses (BYDVs) are one of the most widespread and economically important plant viruses affecting many cereal crops. Growing resistant varieties remains the most promising approach to reduce the impact of BYDVs. A Recent RNA sequencing analysis has revealed potential genes that respond to BYDV infection in resistant barley genotypes. Together with a comprehensive review of the current knowledge on disease resistance in plants, we selected nine putative barley and wheat genes to investigate their involvement in resistance to BYDV-PAV infection. The target classes of genes were (i) nucleotide binding site (NBS) leucine-rich repeat (LRR), (ii) coiled-coil nucleotide-binding leucine-rich repeat (CC-NB-LRR), (iii) LRR receptor-like kinase (RLK), (iv) casein kinase, (v) protein kinase, (vi) protein phosphatase subunits and the transcription factors (TF) (vii) MYB TF, (viii) GRAS (gibberellic acid-insensitive (GAI), repressor of GAI (RGA) and scarecrow (SCR)), and (ix) the MADS-box TF family. Expression of genes was analysed for six genotypes with different levels of resistance. As in previous reports, the highest BYDV-PAV titre was found in the susceptible genotypes Graciosa in barley and Semper and SGS 27-02 in wheat, which contrast with the resistant genotypes PRS-3628 and Wysor of wheat and barley, respectively. Statistically significant changes in wheat show up-regulation of NBS-LRR, CC-NBS-LRR and RLK in the susceptible genotypes and down-regulation in the resistant genotypes in response to BYDV-PAV. Similar up-regulation of NBS-LRR, CC-NBS-LRR, RLK and MYB TF in response to BYDV-PAV was also observed in the susceptible barley genotypes. However, no significant changes in the expression of these genes were generally observed in the resistant barley genotypes, except for the down-regulation of RLK. Casein kinase and Protein phosphatase were up-regulated early, 10 days after inoculation (dai) in the susceptible wheat genotypes, while the latter was down-regulated at 30 dai in resistant genotypes. Protein kinase was down-regulated both earlier (10 dai) and later (30 dai) in the susceptible wheat genotypes, but only in the later dai in the resistant genotypes. In contrast, GRAS TF and MYB TF were up-regulated in the susceptible wheat genotypes while no significant differences in MADS TF expression was observed. Protein kinase, Casein kinase (30 dai), MYB TF and GRAS TF (10 dai) were all up-regulated in the susceptible barley genotypes. However, no significant differences were found between the resistant and susceptible barley genotypes for the Protein phosphatase and MADS FT genes. Overall, our results showed a clear differentiation of gene expression patterns in both resistant and susceptible genotypes of wheat and barley. Therefore, further research on RLK, NBS-LRR, CC-NBS-LRR, GRAS TF and MYB TF can lead to BYDV-PAV resistance in cereals.

Turnip yellows virus (TuYV), is one of the most important pathogens of oilseed rape, which has caused enormous yield losses in all growing regions of the world in recent years. Therefore, there is a need for resistant varieties for sustainable crop protection. We have investigated the resistance of known varieties and newly developed advanced-breeding lines of oilseed rape to TuYV in greenhouse and field trials. We have analysed the TuYV titre of individual genotypes inoculated with the virus using viruliferous aphids Myzus persicae. The genotypes 'DK Temptation' and 'Rescator' had the lowest and highest virus titres, respectively, and were used as resistant and susceptible models for comparative analyses with other genotypes. In the greenhouse, the best results were obtained with the genotypes 'OP-8143 DH' (2.94 × 105 copies), OP-BN-72 (3.29 × 105 copies), 'Navajo' (3.58 × 105 copies) and 'SG-C 21215' (4.09 × 105 copies), which reached virus titres about 2 times higher than the minimum virus concentration measured in 'DK Temptation' (1.80 × 105 copies). In the field trials, the genotypes 'Navajo' (3.39 × 105 copies), 'OP-8148 DH' (4.44 × 105 copies), 'SG-C 21215' (6.80 × 105 copies) and OP-8480 (7.19 × 105 copies) had the lowest virus titres and reached about 3 times the virus titre of DK Temptation (2.54 × 105 copies). Both trials showed that at least two commercial varieties (e.g., DK Temptation, Navajo) and three advanced breeding lines (e.g., OP-8143 DH, OP-BN-72, SG-C 21215) had low titres of the virus after TuYV infection. This indicates a high level of resistance to TuYV in 'Navajo' or the newly developed breeding lines and the basis of resistance is probably different from R54 (as in 'DK Temptation'). Furthermore, the greenhouse trials together with RT -qPCR-based virus titre analysis could be a cost-effective and efficient method to assess the level of resistance of a given genotype to TuYV infection compared to the field trials. However, further research is needed to identify the underlying mechanisms causing this difference in susceptibility.

Wheat dwarf virus (WDV) is one of the most important pathogens of cereal crops worldwide. To understand the molecular mechanism of resistance, here we investigated the comparative transcriptome of wheat genotypes with different levels of resistance (Svitava and Fengyou 3) and susceptibility (Akteur) to WDV. We found a significantly higher number of differentially expressed transcripts (DETs) in the susceptible genotype than in the resistant one (e.g., Svitava). The number of downregulated transcripts was also higher in the susceptible genotype than in the resistant one (Svitava) and the opposite was true for the upregulated transcripts. Further functional analysis of gene ontology (GO) enrichment identified a total of 114 GO terms for the DETs. Of these, 64 biological processes, 28 cellular components and 22 molecular function GO terms were significantly enriched. A few of these genes appear to have a specific expression pattern related to resistance or susceptibility to WDV infection. Validation of the expression pattern by RT-qPCR showed that glycosyltransferase was significantly downregulated in the susceptible genotype compared to the resistant genotypes after WDV infection, while CYCLIN-T1-3, a regulator of CDK kinases (cyclin-dependent kinase), was upregulated. On the other hand, the expression pattern of the transcription factor (TF) MYB (TraesCS4B02G174600.2; myeloblastosis domain of transcription factor) was downregulated by WDV infection in the resistant genotypes compared to the susceptible genotype, while a large number of TFs belonging to 54 TF families were differentially expressed due to WDV infection. In addition, two transcripts (TraesCS7A02G341400.1 and TraesCS3B02G239900.1) were upregulated with uncharacterised proteins involved in transport and regulation of cell growth, respectively. Altogether, our findings showed a clear gene expression profile associated with resistance or susceptibility of wheat to WDV. In future studies, we will explore the regulatory network within the same experiment context. This knowledge will broaden not only the future for the development of virus-resistant wheat genotypes but also the future of genetic improvement of cereals for resilience and WDV-resistance breeding.

BACKGROUND:The cabbage moth, Mamestra brassicae, is a polyphagous pest that attacks several crops. Here, the sublethal and lethal effects of chlorantraniliprole and indoxacarb were investigated on the developmental stages, detoxification enzymes, reproductive activity, calling behavior, peripheral physiology, and pheromone titer of M. brasssicae. Methods: To assess pesticide effects, the second instar larvae were maintained for 24 h on a semi-artificial diet containing insecticides at their LC10, LC30, and LC50 concentrations.RESULTS:M. brassicae was more susceptible to chlorantraniliprole (LC50 = 0.35 mg/L) than indoxacarb (LC50 = 1.71 mg/L). A significantly increased developmental time was observed with both insecticides at all tested concentrations but decreases in pupation rate, pupal weight, and emergence were limited to the LC50 concentration. Reductions in both the total number of eggs laid per female and the egg viability were observed with both insecticides at their LC30 and LC50 concentrations. Both female calling activity and the sex pheromone (Z11-hexadecenyl acetate and hexadecenyl acetate) titer were significantly reduced by chlorantraniliprole in LC50 concentration. Antennal responses of female antennae to benzaldehyde and 3-octanone were significantly weaker than controls after exposure to the indoxocarb LC50 concentration. Significant reductions in the enzymatic activity of glutathione S-transferases, mixed-function oxidases, and carboxylesterases were observed in response to both insecticides.

Turnip yellows virus (TuYV) is one of the most important pathogens of oilseed rape worldwide. The virus has a large host range including many crop species (e.g., oilseed rape, pea, chickpea) and weeds from more than twenty plant families. Other than oilseed rape, we detected TuYV in many commonly grown weed species that share the fields and vegetation period together with canola crops in Czech and Slovak Republics. TuYV was detected by reverse-transcription polymerase chain reaction (RT-PCR) in at least 26 species including main crop hosts (oilseed rape), intercrops and weeds such as Amaranthus retroflexus, Atriplex patula (Amaranthaceae), Arctium lappa, Lactuca serriola, Taraxacum officinale, Tripleurospermum inodorum (Asteraceae), Phacelia tanacetifolia (Boraginaceae), Brassica napus, Capsella bursa–pastoris, Descurainia Sophia, Raphanus raphanistrum, Sinapis alba, Sisymbrium officinale, Thlaspi arvense (Brassicaceae), Silene alba, Stellaria media (Caryophyllaceae), Euphorbia helioscopia (Euphorbiaceae), Geranium rotundifolium (Geraniaceae), Lamium purpureum (Lamiaceae), Fumaria officinalis, Papaver rhoeas (Papaveraceae), Veronica persica (Plantaginaceae syn. Scrophulariaceae), Fallopia convolvulus (Polygonaceae), Solanum nigrum (Solanaceae), Urtica dioica (Urticaceae) and Viola arvensis (Violaceae). The detection of TuYV was further confirmed by RT-qPCR as well as Sanger sequencing of the PCR fragments. We discovered four new weed species as hosts of TuYV such as T. inodorum, S. alba, G. rotundifolium and E. helioscopia, representing their three respective plant families. The readthrough domain (RTD) gene sequence analysis of the Czech and Slovak TuYV isolates from oilseed rape and weed species showed similar within-group nucleotide divergence (7.1% and 5.6%, respectively) and the absence of geographical- or host-based phylogenetic clustering. The high-throughput sequencing of the P. rhoeas sample enabled the obtention of a nearly complete genome of TuYV and revealed the mixed infection of TuYV with turnip mosaic virus and cucumber mosaic virus. Our results thus show that weed species are an important TuYV reservoir and play a significant role in the spread and incidence of the disease in field crops such as oilseed rape.

The role of adipokinetic hormone (AKH) in the firebug Pyrrhocoris apterus adults infected by the entomopathogenic nematode (EPN) Steinernema carpocapsae was examined in this study. It was found that co-application of EPN and AKH enhanced firebug mortality about 2.5 times within 24h (from 20 to 51% in EPN vs. EPN+AKH treatments), and resulted in metabolism intensification, as carbon dioxide production in firebugs increased about 2.1 and 1.6times compared to control- and EPN-treated insects, respectively. Accordingly, firebugs with reduced expression of AKH receptors showed a significantly lower mortality (by 1.6 to 2.9-folds), and lower general metabolism after EPN+AKH treatments. In addition, EPN application increased Akh gene expression in the corpora cardiaca (1.6times), AKH level in the corpora cardiaca (1.3times) and haemolymph (1.7times), and lipid and carbohydrate amounts in the haemolymph. Thus, the outcomes of the present study demonstrate involvement of AKH into the anti-stress reaction elicited by the nematobacterial infection. The exact mechanism by which AKH acts is unknown, but results suggested that the increase of metabolism and nutrient amounts in haemolymph might play a role.

Entomopathogenic nematodes are multicellular insect parasites which are symbiotically associated with particular species of bacteria forming together highly pathogenic complex. This complex represents a severe stress for the infected insect that must activate its anti-stress defence system. It is supposed that adipokinetic hormone (AKH), important stress hormone responsible for keeping homeostasis in insect body, and adenosine, a purine nucleotide that serves as signalling factor in anti-stress reaction on both cellular and organismal levels, play a role in defence reaction against the infection. To verify this, the Drosophila melanogaster mutants producing (1) defect non-functional AKH (AKH-def) and (2) impaired adenosine receptor (AdoR-def), and two nematodal species Steinernema carpocapsae and Heterorhabditis bacteriophora were used in our study. The results revealed that both AKH-def and AdoR-def flies infected by the nematodes showed significantly lower mortality (1.9 and 1.7 times, respectively) than the control with AKH- and AdoR-normal production. Further, application of external AKH by dipping of experimental larvae into the Drome-AKH solution (3 pmol Drome-AKH/ul 20% MeOH) significantly increased the mortality (up to 1.8 fold). It seems that the AKH absence reduced production of nutrients into the haemolymph, which inhibited the infection development. And vice versa the application of AKH restored production of energy rich metabolites and supported the infection. Indeed, a level of trehalose was significantly lower (0.6 fold) in untreated AKH-def, and higher in untreated AdoR-def (1.8 fold) Drosophila mutants than that in control. In nematode treated mutants the trehalose level was significantly lower in both AKH-def (0.4 times) and AdoR-def (0.7 times). Those indicate clear stimulatory role of AKH, and minor modulatory role of adenosine in regulation of the trehalose level in Drosophila haemolymph. Similar changes, however not so considerable, were recorded for level of glucose and also lipids; negligible changes were recorded for proteins. It is indisputable that the nematode infection is stressing for the Drosophila organism and that is accompanied by higher production of Drome-AKH by the corresponding cells in the ring gland (up to 1.6 fold), and by the raising of all studied nutrients (with the exception of proteins) in haemolymph (max. trehalose 2.6 times). Nevertheless, the mechanism of action of the nematode infection is not quite clear yet, because the results of the total metabolism determination monitored by the carbon dioxide production suggest that more players are involved in the phenomenon. Our research was supported by the grants KONTAKT No. LH 14047 (Ministry of Education, Youth and Sports, CR) and No. 14-07172S (Czech Science Foundation). The stay of EI in the University of South Bohemia was supported by the Missions Department in Cairo, Egypt.