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Using a high-throughput sequencing (HTS) approach, we report the discovery of a new alphasatellite identified in a winter barley plant collected in France in 2022 that was also infected by wheat dwarf virus (WDV). The presence of the satellite and of WDV was confirmed by several independent PCR assays, and the complete genome sequence was determined. The circular satellite genome is 1424 nt long and shows typical hallmarks of members of the subfamily Geminialphasatellitinae, including a replication-associated hairpin with a CAGTATTAC sequence and a Rep-encoding open reading frame (ORF). It also possesses a second ORF, embedded in a different frame within the Rep ORF, which is also observed in clecrusatellites and a few other members of the family Alphasatellitidae. Pairwise sequence comparisons and phylogenetic analysis showed that this satellite represents a novel species. Its closest relatives are in the genus Colecusatellite, but it likely represents a new genus given its divergence from other genera of the subfamily Geminialphasatellitinae. Given that WDV was the only virus observed in coinfection with the satellite, the name "wheat dwarf virus-associated alphasatellite" is proposed for this novel agent., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

As part of a cereals virome project high throughput sequencing (HTS)-based viral indexing was performed on plants with symptoms of barley yellow dwarf disease collected in June (2017-2020) in the main French cereals production areas. Total RNAs from 32 individual plants were purified (RNeasy Plant Mini Kit, Qiagen, Courtaboeuf, France) and Illumina sequenced (2x150 nt) following ribodepletion (Genewiz-Azenta, Leipzig, Germany). Following quality trimming, reads for each sample were de novo assembled (CLC Genomics Workbench 21, Qiagen) [1] and contigs annotated by BlastX analysis. In four winter barley samples collected in 2018 (18-58, 18-325 and 18-326) and 2019 (19-30A), besides contigs representing diverse viruses such as barley yellow dwarf viruses-PAV and PAS, Hordeum vulgare endornavirus, cereal yellow dwarf virus-RPV (18-326), wheat dwarf virus (18-325 and 18-326) and a novel Polerovirus (18-58 and 18-326), large contigs with high identity to barley virus G (BVG) were identified. BVG, a tentative Polerovirus, was initially reported in barley in South Korea in 2016 [2] and has so far been identified in a few other hosts including wheat, oat, maize, proso and foxtail millets as well as switchgrass. It has been reported from the USA and Australia [3] and, in Europe, from the Netherlands, Germany, Hungary and Greece [4]. Large BVG scaffolds representing near complete genomes could be reconstructed for each sample, integrating a total of 128.339, 7.188, 8.078 and 20.073 reads, for samples 19-30A, 18-58, 18325 and 18-326 respectively. Given that between 17.2 and 20.5 million reads had been obtained per sample, these values translate into between 0.04% (18-58 and 18-325) and 0.6% (19-30A) of total reads, and to average coverages of between 158x (18-58) and 2866x (19-30A) for the genomic scaffolds. The four assembled sequences (5584-5610 nt) have been deposited in GenBank (ON419453-ON419456). They are nearly identical (98.4 to 99.5% nt identity) and share between 97.7% and 98.5% nt identity with a barley reference isolate from the South Korea (NC_029906). To confirm the presence of BVG, a primer pair was designed based on available BVG sequences. Primers BVG-F(5'-CTAGCCCAACGAGTTGCGGG-3') and BVG-R(5'-GGTACAGAAGCTCTACGGTTC-3') amplifying a 394 nt were used in a two-step RT-PCR on new RNA extracts obtained from the 18-325 and 18-326 infected plants. The amplicons were directly sequenced and showed respectively 99.2% (ON419457, 18-325) and 100% (18-326) nt identity with the corresponding de novo scaffolds. The four analyzed samples have been collected respectively in 2018 (18-58, 18-325, 18-326) and 2019 (19-30A) in three different regions of France (Auvergne-Rhône-Alpes, Occitanie and Centre-Val de Loire), indicating a wide distribution and a persistence over time of BVG in France. To our knowledge, this represents the first report of a natural infection of BVG in cultivated winter barley in France. Presence of BVG may have been overlooked in a range of situation, as indicated by its retrospective discovery in a 34 years old Australian sample [3], possibly explaining its broad distribution in France. While the mixed infection status of the analyzed plants precludes any conclusion on its pathogenicity in French cereals, BVG has been reported to be associated with a range of symptoms in various hosts so that further studies to evaluate its prevalence and impact in France and to begin to understand its epidemiology are clearly warranted by the present results.

Contamination with enniatins A, A1, B and B1 was investigated in 1240 samples of small grain cereals (470 wheat, 260 durum wheat, 282 spring barley, 172 triticale and 56 winter barley) from the French harvests of 2012 to 2014. Associations with Fusarium avenaceum, F. tricinctum and F. poae were assessed, with the identification of Fusarium species by real-time PCR and mycotoxin quantification by LC-MS/MS. Enniatins were common in the fields sampled. Enniatin concentrations varied between years but were consistently highest on spring barley (mean values of 199 to 1316 μg/kg) and triticale (mean values from 131 to 1218 μg/kg), and lower on wheat (mean values from 47 to 142 μg/kg) and durum wheat (mean values from 55 to 596 μg/kg). The concentrations of the various enniatins were strongly correlated with each other (Pearson's correlation coefficient of 0.61 to 0.98). Enniatin B was the most frequent (68% of the total enniatin content), followed by enniatin B1 (22%), enniatin A1 (7%) and enniatin A (3%). Fusarium species were quantified by calculating arithmetic mean total DNA levels. F. tricinctum was the most abundant (0.177 pg/ng total DNA), followed by F. avenaceum (0.141 pg/ng total DNA) and F. poae (0.091 pg/ng total DNA). Total DNA levels for each species, and the predominant species varied between years and crops. Small grain cereal species (p value < 0.001), harvest year (p value = < 0.001) and the presence of F. avenaceum (p value < 0.001), F. tricinctum (p value < 0.001) or F. poae (p value = 0.017) affected enniatin content. F. tricinctum was the leading enniatin producer on durum wheat (29% to 45%) and spring barley (23 to 37%). F. avenaceum produced large amounts of enniatins on durum wheat (13% to 17%) and wheat (1% to 18%) and was the leading producer on triticale (30% to 55%). F. poae made a minor contribution on all crops, never accounting for more than 2% of total enniatin content. Enniatins are, thus, highly prevalent in French small grain cereals and are mostly produced by F. avenaceum and F. tricinctum.

Despite the generalized use of cultivars carrying the rym4 resistance gene, the impact of viral mosaic diseases on winter barleys increased in recent years in France. This change could reflect i) an increased prevalence of the rym4 resistance-breaking pathotype of Barley yellow mosaic virus Y (BaYMV-2), ii) the emergence of rym4 resistance-breaking pathotypes of Barley mild mosaic virus (BaMMV) or iii) the emergence of other viruses. A study was undertaken to determine the distribution and diversity of viruses causing yellow mosaic disease. A collection of 241 symptomatic leaf samples from susceptible, rym4 and rym5 varieties was gathered from 117 sites. The viruses present in all samples were identified by specific RT-PCR assays and, for selected samples, by double-stranded RNA next-generation sequencing (NGS). The results show that BaYMV-2 is responsible for the symptoms observed in varieties carrying the resistance gene rym4. In susceptible varieties, both BaYMV-1 and BaYMV-2 were detected, together with BaMMV. Phylogenetic analyses indicate that the rym4 resistance-breaking ability independently evolved in multiple genetic backgrounds. Parallel analyses revealed a similar scenario of multiple independent emergence events in BaMMV for rym5 resistance-breaking, likely involving multiple amino acid positions in the viral-linked genome protein. NGS analyses and classical techniques provided highly convergent results, highlighting and validating the power of NGS approaches for diagnostics and viral population characterization.

An unexpected interaction with a thioglycerol matrix appeared in the liquid secondary ion mass spectrometry (LSIMS) spectra of two pyranosyl mercaptans [2,3,4,6-tetra-O-acetyl-1-thio-β-D-glucopyranose (1a) and 2,3,4,6-tetra-O-acetyl-1,5-dithio-β-D-glucopyranose (1b)] often used to prepare glucosinolates, important thiosaccharidic metabolites found in all plants of the order Brassicales. The reactions, probably occurring in the solvent cage, seem to involve radical mechanisms., (Copyright © 2011 John Wiley & Sons, Ltd.)

A new alkaloid of Aconitum karacolicum Rapcs, from the Ranunculaceae family, collected in Kirghizstan, was isolated from the roots of this plant, using a purification scheme based upon its in vitro antiproliferative properties against three human tumour cell lines in culture. Structural identification was performed using high resolution MS-MS mass spectrometry and (1)H, (13)C, 2D NOESY NMR spectroscopy analysis. This compound consists of a 14-benzoylaconine moiety substituted on C-8 by an azeloyl chain. It presents in vitro cytotoxicity with an IC(50) of about 10-20 microM, which warrants further investigation on its possible interest in cancer chemotherapy.