A bicistronic baculovirus expression vector and fluorescent protein-based assays were used to identify the sequences that possess internal translation activity in baculovirus-infected insect cells. We demonstrated that the 5' untranslated region (5'UTR; 473 nucleotides) of Perina nuda virus (PnV) and the 5'UTR (579 nucleotides) of Rhopalosiphum padi virus (RhPV), but not the IRES sequence of Cr...

Chlorophyll degradation enzyme (i.e., chlorophyllase, Mg-dechelatase, and chlorophyll oxidase) activities of aphid-infested and uninfested 'Tugela' and Tugela near-isogenic wheat lines (i.e., Tugela-Dn1, Tugela-Dn2, and Tugela-Dn5) were assayed. Chlorophyllase activity was higher in bird cherry-oat aphid, Rhopalosiphum padi (L.) (Homoptera: Aphididae),-infested wheat lines compared with Russian...

Genetic variation for fitness-relevant traits may be maintained in natural populations by fitness differences that depend on environmental conditions. For herbivores, plant quality and variation in chemical plant defences can maintain genetic variation in performance. Apart from plant secondary compounds, symbiosis between plants and endosymbiotic fungi (endophytes) can produce herbivore-toxic ...

A virus with picorna-like biophysical properties was isolated from South African honey bees. On the basis of serology, it was identified as an isolate of black queen-cell virus (BQCV). Nucleotide sequence analysis revealed an 8550 nt polyadenylated genome containing two large ORFs. The 5'-proximal ORF (ORF 1) represented 4968 nt while the 3'-proximal ORF (ORF 2) represented 2562 nt. The ORFs we...

The effect of weeds, plant diseases and insect pests on spring barley (Hordeum vulgare) wheat (Triticum aestivum) grain nutrient yield was examined. Long-term field trial data used to assess the impact different yield. In absence pesticides, fungal caused largest annual yield-reduction in barley, 500 kg ha?1 average. Converting loss this represented reductions 8.1 9.2 nitrogen 1.5 1.6 phosphoru...