Summary Avena fatua of the family Poaceae is one of the most common and economically damaging grass weeds. Resistance to herbicides that inhibit acetyl‐coenzyme A carboxylase and acetolactate synthase activities has recently been detected in A. fatua. The resistance may be due to mutations in the herbicide targets and/or enhanced herbicide metabolism resulting from changes in gene expression, including in genes involved in detoxifying herbicide active ingredients. To analyse gene expression, stable housekeeping genes must be experimentally determined and used for data normalisation. In this study, A. fatua plants were treated with different herbicide types and plant materials were harvested at three time points following treatment. Six candidate reference genes (18S rRNA, ACT, EF1α, GAPDH, TBP, and TUB) were selected, sequenced and analysed by RT‐qPCR. The resulting data were assessed using four algorithms from the RefFinder software to determine gene expression stability. We identified TBP and GAPDH as the most stably expressed A. fatua reference genes following herbicide treatment.

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Signaling in host plants is an integral part of a successful infection by pathogenic RNA viruses. Therefore, identifying early signaling events in host plants that play an important role in establishing the infection process will help our understanding of the disease process. In this context, phosphorylation constitutes one of the most important post-translational protein modifications, regulating many cellular signaling processes. In this study, we aimed to identify the processes affected by infection with Peanut stunt virus (PSV) and its satellite RNA (satRNA) in Nicotiana benthamiana at the early stage of pathogenesis. To achieve this, we performed proteome and phosphoproteome analyses on plants treated with PSV and its satRNA. The analysis of the number of differentially phosphorylated proteins showed strong down-regulation in phosphorylation in virus-treated plants (without satRNA). Moreover, proteome analysis revealed more down-regulated proteins in PSV and satRNA-treated plants, which indicated a complex dependence between proteins and their modifications. Apart from changes in photosynthesis and carbon metabolism, which are usually observed in virus-infected plants, alterations in proteins involved in RNA synthesis, transport, and turnover were observed. As a whole, this is the first community (phospho)proteome resource upon infection of N. benthamiana with a cucumovirus and its satRNA and this resource constitutes a valuable data set for future studies.

The pollen beetle (Meligethes aeneus F.) is the most devastating pest of oilseed rape (Brassica napus) and is controlled by pyrethroid insecticides. However, resistance to pyrethroids in Europe is becoming widespread and predominant. Pyrethroids target the voltage-sensitive sodium channel (VSSC), and mutations in VSSC may be responsible for pyrethroid insensitivity. Here, we analysed individual beetles that were resistant to esfenvalerate, a pyrethroid, from 14 populations that were collected from oilseed rape fields in Poland. We screened the VSSC domains that were presumed to directly interact with pyrethroids. We identified 18 heterozygous nucleic acid substitutions, amongst which six caused an amino acid change: N912S, G926S, I936V, R957G, F1538L and E1553G. Our analysis of the three-dimensional structure of these domains in VSSC revealed that some of these changes may slightly influence the protein structure and hence the docking efficiency of esfenvalerate. Therefore, these mutations may impact the susceptibility of the sodium channel to the action of this insecticide.

To confirm the priming effect of BTH on tomato resistance, the plants were infected with tomato mosaic virus (ToMV) seven days post-BTH treatment. ResultsThe combined functional analysis indicated the high impact of BTH on the plant's developmental processes and activation of the immune response early after the treatment. In the presented experimental model, the increased level of WRKY TRANSCRIP-TION FACTORS, ARGONAUTE 2A, thiamine and glutathione metabolism, cell wall reorganization, and detoxification processes, as well as accumulation of three phytohormones: abscisic acid, jasmonic acidisoleucine (JA-Ile), and indole-3-carboxylic acid (I3CA), were observed upon BTH application. Conclusion The immune response activated by BTH was related to increased expression of genes associated with the cellular detoxification process, systemic acquired resistance, and induced systemic

BackgroundTomato torrado virus (ToTV) infection manifests with burn-like symptoms on leaves, leaflets and upper stem parts of susceptible infected plants. The symptoms caused by ToTV may be considered as one of the most severe virus-induced forms of systemic necrosis, which spreads within the whole plant and leads to a lethal phenotype. However, to date there are no data revealing which viral genes encode for a specific pathogenicity determinant that triggers the plant necrotic response for any torradovirus. In this study we evaluated the influence of three coat protein subunits of ToTV: Vp23, Vp26 and Vp35, transiently expressed from a PVX-based vector, and checked their association with the induction of systemic necrosis in infected Solanum lycopersicum L. (cv. Beta Lux), a natural host of ToTV.MethodsTo estimate how ToTV coat protein subunits might contribute in plant response to virus infection we over-expressed the proteins from PVX-based vector in tomato and analyzed enzymatic activities related with plant defense response. By doing protein qualitative analysis performed by mass spectrometry we indicated the PR10 in protein fraction with induced ribonuclease activity.ResultsWe observed that only the Vp26 enhanced PVX pathogenicity causing severe necrosis of the infected plant. Moreover, we indicated increased RNase and oxidative activities in plants infected with PVX-Vp26 chimeras only. Importantly, we suspected that this increased RNase activity is associated with increased accumulation of PR10 mRNA and products of its translation.ConclusionsOn the basis of the obtained results, we indicated that Vp26 acts as the elicitor of hypersensitive response-like reactions of PVX-Vp26 manifesting with enhanced pathogenicity of the recombined PVX. This might be the first described suspected necrosis determinant of torradoviruses infecting tomatoes.Electronic supplementary materialThe online version of this article (10.1186/s12985-019-1117-9) contains supplementary material, which is available to authorized users.

Peanut stunt virus (PSV) is a widespread pathogen infecting legumes. The PSV strains are classified into four subgroups and some are defined by the association of satellite RNAs (satRNAs). In the case of PSV, the presence of satRNAs alters the symptoms of disease in infected plants. In this study, we elucidated the plant response to PSV-G strain, which occurs in natural conditions without satRNA. However, it was found that it might easily acquire satRNA, which exacerbated pathogenesis in Nicotiana benthamiana. To explain the mechanisms underlying PSV infection and symptoms exacerbation caused by satRNA, we carried out transcriptome profiling of N. benthamiana challenged by PSV-G and satRNA using species-specific microarrays. Co-infection of plants with PSV-G + satRNA increased the number of identified differentially expressed genes (DEGs) compared with the number identified in PSV-G-infected plants. In both treatments, the majority of up-regulated DEGs were engaged in translation, ribosome biogenesis, RNA metabolism, and response to stimuli, while the down-regulated DEGs were required for photosynthesis. The presence of satRNA in PSV-G-infected plants caused different trends in expression of DEGs associated with phosphorylation, ATP binding, and plasma membrane.

Herbicide resistance in weeds, including corn poppy (Papaver rhoeas L.), is an increasing problem compromising global crop production. The aims of this study were to evaluate the susceptibility of P. rhoeas populations in Poland to acetolactate synthase (ALS) inhibitors and elucidate their mechanisms of resistance. Between 2017 and 2020, 157 seed samples were collected nationwide and a dose-response study with various ALS-inhibiting herbicides was performed in glasshouses. This revealed 14 resistant populations with R/S ranges of 2.3–1450.2, 9.5–398.5 and 2–2.5 for tribenuron, iodosulfuron and florasulam, respectively. Eight of them were cross-resistant to both tribenuron and iodosulfuron, three and one populations were singly resistant to tribenuron and iodosulfuron, respectively, and one population had reduced susceptibility to florasulam only. In one population, cross-resistance to tribenuron, iodosulfuron and florasulam was identified. The ED50 of many populations susceptible to ALS inhibitors was close to half the recommended dose of the herbicides tested. In seven out of eight resistant P. rhoeas populations analysed, target-site resistance was identified. Six amino acid replacements were found (Ala197, Arg197, His197, Leu197, Ser197 and Thr197). In one population resistant to ALS inhibitors, no mutations in the ALS gene were detected. An efficient anti-resistance strategy is needed to reduce the development of herbicide resistance in P. rhoeas in Poland.