The bird cherry-oat aphid (Rhopalosiphum padi (L.)) is one of the most detrimental pests of cereals, causing harm mainly by transmitting Barley yellow dwarf virus (BYDV). R. padi migration has been monitored since 1992 using suction traps at five sites in the Czech Republic. The count data were subjected to the following different analyses: (i) the minimum temperature thresholds for the aphids to take off were determined; (ii) a partial redundancy analysis using the minimum, average, and maximum temperatures, as well as the wind speed, the precipitation total, and past aphid migration descriptors was performed to explain the relationship between aphid occurrences and weather patterns; and (iii) three types of models from the field of machine learning were used to predict aphid occurrences. According to our findings, (i) in Central Europe, 8°C is the temperature threshold for R. padi migration unless insufficient daylight delays the take-off; (ii) weather conditions occurring roughly 9 months before R. padi migration influence the migration size; (iii) the duration of the summer migration influences the autumn migration size; and (iv) the daytime and nighttime temperatures in the autumn determine the summer peak, whereas winter frosts and precipitation influence the autumn peak.
- MeSH
- ječmen (rod) * virologie MeSH
- Luteovirus * fyziologie MeSH
- migrace zvířat * MeSH
- mšice * fyziologie virologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
This study reports the complete genomic sequence of a novel virus isolated from red clover. According to its genomic organization, its similarity to luteoviruses, and a greater than 10% difference in all genes, this virus isolate likely represents a new luteovirus species. As seen in nectarine stem pitting-associated virus (NSPaV) and NSPaV-South Korea (SK) luteoviruses, it differs from typical luteoviruses through the absence of ORF3a and ORF4 encoding movement proteins. Furthermore, its P5 protein (responsible for aphid transmission) is more similar to the P5 of enamoviruses than that of luteoviruses. The virus isolate has been named red clover-associated luteovirus (RCaV).
The complete genomic sequence of a new virus from cherry trees was determined. Its genome is 5857 nt long and resembles that of members of the genus Luteovirus in its genomic organization and nucleotide sequence. Based on the species demarcation criteria for luteoviruses, the virus represents a new luteovirus species. Furthermore, a 47-nt-long inverted repeat was found at the 3' end of its genome. The virus has been provisionally named cherry-associated luteovirus (ChALV) and is the fourth member of the family Luteoviridae reported to naturally infect woody plants.
- MeSH
- 3' přiléhající oblast DNA MeSH
- délka genomu MeSH
- fylogeneze * MeSH
- genom virový * MeSH
- Luteovirus klasifikace genetika izolace a purifikace MeSH
- mapování chromozomů MeSH
- nemoci rostlin virologie MeSH
- obrácené repetice MeSH
- otevřené čtecí rámce MeSH
- RNA virová genetika MeSH
- sekvence nukleotidů MeSH
- slivoň švestka virologie MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Reference genes are commonly used as the endogenous normalisation measure for the relative quantification of target genes. The appropriate application of quantitative real-time PCR (RT-qPCR), however, requires the use of reference genes whose level of expression is not affected by the test, by general physiological conditions or by inter-individual variability. For this purpose, seven reference genes were investigated in tissues of the most important cereals (wheat, barley and oats). Titre of Barley yellow dwarf virus (BYDV) was determined in oats using relative quantification with different reference genes and absolute quantification, and the results were compared. RESULTS: The expression of seven potential reference genes was evaluated in tissues of 180 healthy, physiologically stressed and virus-infected cereal plants. These genes were tested by RT-qPCR and ranked according to the stability of their expression using three different methods (two-way ANOVA, GeNorm and NormFinder tools). In most cases, the expression of all genes did not depend on abiotic stress conditions or virus infections. All the genes showed significant differences in expression among plant species. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), beta-tubulin (TUBB) and 18S ribosomal RNA (18S rRNA) always ranked as the three most stable genes. On the other hand, elongation factor-1 alpha (EF1A), eukaryotic initiation factor 4a (EIF4A), and 28S ribosomal RNA (28S rRNA) for barley and oat samples; and alpha-tubulin (TUBA) for wheat samples were consistently ranked as the less reliable controls.The BYDV titre was determined in two oat varieties by RT-qPCR using three different quantification approaches. There were no significant differences between the absolute and relative quantifications, or between quantification using GAPDH + TUBB + TUBA +18S rRNA and EF1A + EIF4A + 28S rRNA. However, there were discrepancies between the results of individual assays. CONCLUSIONS: The geometric average of GAPDH, 18S rRNA and TUBB is suitable for normalisation of BYDV quantification in barley tissues. For wheat and oat samples, a combination of four genes is necessary: GAPDH, 18S rRNA, TUBB and EIF4A for wheat; and GAPDH, 18S rRNA, TUBB and TUBA for oat is recommended.
- MeSH
- jedlá semena genetika virologie MeSH
- Luteovirus fyziologie MeSH
- polymerázová řetězová reakce s reverzní transkripcí metody MeSH
- reprodukovatelnost výsledků MeSH
- RNA ribozomální 18S analýza genetika MeSH
- rostlinné geny genetika MeSH
- rostlinné proteiny genetika metabolismus MeSH
- stanovení celkové genové exprese metody MeSH
- virová nálož MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
