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Begomovirus-associated epidemics currently threaten tomato production worldwide due to the emergence of highly pathogenic virus species and the proliferation of a whitefly B biotype vector that is adapted to tomato. To generate an efficient defence against begomovirus, we modulated the activity of the immune defence receptor nuclear shuttle protein (NSP)-interacting kinase (NIK) in tomato plants; NIK is a virulence target of the begomovirus NSP during infection. Mutation of T474 within the kinase activation loop promoted the constitutive activation of NIK-mediated defences, resulting in the down-regulation of translation-related genes and the suppression of global translation. Consistent with these findings, transgenic lines harbouring an activating mutation (T474D) were tolerant to the tomato-infecting begomoviruses ToYSV and ToSRV. This phenotype was associated with reduced loading of coat protein viral mRNA in actively translating polysomes, lower infection efficiency and reduced accumulation of viral DNA in systemic leaves. Our results also add some relevant insights into the mechanism underlying the NIK-mediated defence. We observed that the mock-inoculated T474D-overexpressing lines showed a constitutively infected wild-type transcriptome, indicating that the activation of the NIKmediated signalling pathway triggers a typical response to begomovirus infection. In addition, the gain-of-function mutant T474D could sustain an activated NIK-mediated antiviral response in the absence of the virus, further confirming that phosphorylation of Thr-474 is the crucial event that leads to the activation of the kinase. [ABSTRACT FROM AUTHOR]

An emerging soybean disease observed in Cuba was investigated in view of the possibility that a phytoplasma could be involved in its aetiology. Thirty-five soybean plants showing symptoms of stunting, chlorosis, crinkle and aborted seed pods were collected in Las Tunas and Holguin provinces during 2013, and analysed by nested-PCR with primers targeting the 16S ribosomal DNA (16S rDNA). Phytoplasmas were detected in 83% of symptomatic soybean plants. Conventional and virtual RFLP analyses of 16S rDNA sequences revealed the presence of strains of 'Candidatus Phytoplasma asteris' (16SrI group). Phytoplasmas belonging to ribosomal subgroup 16SrI-B and two putative new ribosomal subgroups 16SrI-W and 16SrI-Y were identified. Phylogenetic analysis corroborated the RFLP analyses, in which the Cuban strains formed a clade with representative sequences of the 16SrI group. 16SrI-B was the most prevalent subgroup (45% of positive samples) and mixed infections of different subgroups were observed (10% of the positive samples). The partial 16S rDNA sequences of three strains showed 99% nucleotide identity to several GenBank sequences of group 16SrI phytoplasmas, including a phytoplasma associated with a soybean disease in Brazil. This is the first report of a phytoplasma belonging to the 16SrI subgroup occurring in soybean in Cuba. [ABSTRACT FROM AUTHOR]

The paper evaluates and models helminth eggs removal in a combined UASB (Upflow Anaerobic Sludge Blanket) reactor -- maturation pond system (one baffled and one unbaffled pond in parallel). The system is comprised of demonstration-scale units, treating actual domestic sewage from Itabira city, Brazil. The paper addresses the following points: (i) removal of helminth eggs from the wastewater in the system; (ii) comparison of the observed removal efficiency with the predictions using the Ayres et al. model; (iii) accumulation of helminth eggs in the sludge; (iv) viability of eggs in the sludge; (v) distribution of helminth species in the sludge. The removal efficiency of helminth eggs from the wastewater in both ponds was 100% for most of the time (0 counts in the final effluent). The predictions of helminth eggs removal according to the Ayres et al. model can be considered reasonable. After one year of operation, 88% of the eggs in the sludge remained viable. Helminth eggs counts in the sludge tended to decrease along the baffled pond length (from first to last compartment). The prevailing helminth species found in the sludge from both ponds was Ascaris lumbricoides. [ABSTRACT FROM AUTHOR]

Summary. Tomato-infecting begomoviruses have been reported throughout Brazil since the introduction of the B biotype of Bemisia tabaci. Here, we report a large scale survey on the distribution and genetic diversity of tomato-infecting begomoviruses. Tomato samples with typical begomovirus symptoms were collected in seven different states, comprising the major tomato growing areas of the country. Viruses were detected by polymerase chain reaction (PCR) using universal primers for the genus Begomovirus. PCR-amplified fragments were cloned and sequenced. Based on sequence comparisons and phylogenetic analyses, at least seven previously undescribed species of begomoviruses were found. Four of the new viruses were found exclusively in the Southeastern states, two exclusively in the Northeastern states, and one was found in both regions. Sequence comparisons reveal strong evidence of recombination among the Brazilian begomoviruses. Together, the results indicate the existence of a high degree of pre-existing genetic diversity among tomato-infecting begomoviruses in Brazil and suggest that these viruses have emerged after being transferred from natural hosts to tomatoes, due to the introduction into Brazil of a novel polyfagous biotype of the whitefly vector. [ABSTRACT FROM AUTHOR]