S U M M A R YAvian trichomonosis, caused by the flagellated protozoan Trichomonas gallinae, is a recently emerged infectious disease of British passerines. The aetiological agent, a clonal epidemic strain of the parasite, has caused unprecedented finch mortality and population-level declines in Britain and has since spread to continental Europe. To better understand the potential origin of this epidemic and to further investigate its host range, T. gallinae DNA extracts were collected from parasite culture and tissue samples from a range of avian species in Britain. Sequence typing at the ITS1/5.8S rRNA/ITS2 region resolved three distinct ITS region types circulating in free-ranging British birds. Subtyping by sequence analyses at the Fe-hydrogenase gene demonstrated further strain variation within these ITS region types. The UK finch epidemic strain was preponderant amongst columbids sampled, however, wide strain diversity was encountered in isolates from a relatively small number of pigeons, suggesting further strains present in columbid populations across the UK are yet to be identified. Fe-hydrogenase gene sequence data in isolates from birds of prey with disease were predominantly identical to the UK finch epidemic strain, demonstrating its presence as a virulent strain in UK birds of prey since at least 2009.

Osmotic stress signaling in higher plants is crucial to cope with abiotic stress. RAF-like MAPKKKs are activated by hyperosmotic stress and activate downstream ABAunresponsive and ABA-activated SnRK2s, integrating early osmotic stress and ABA signaling cascades. The connection of B2/ B3/B4 RAF-like MAPKKKs with SnRK2s is a new paradigm in signal transduction.

No abstract

No abstract

No abstract

Trichomonas gallinae is a single-celled protozoan parasite and causative agent of trichomonosis.Trichomonosis is a disease with a worldwide distribution, and has recently been highlighted as a pandemic threat to several wild bird species. The aim of this study is to investigate the prevalence and genotypic diversity of Trichomonas gallinae in Riyadh, Saudi Arabia. A total of 273 oral swab samples from birds were collected and tested for T. gallinae infection, and the overall prevalence of Trichomonas gallinae in these samples was 26.4% (72 of 273). We compared the rates of infections with T. gallinae between wild and domestic pigeons and found that the infection was significantly higher in domestic pigeons; a finding which should be considered by the Ministry of Environment, Water and Agriculture of Saudi Arabia when evaluating the role of poultry markets in the transmission of trichomonosis. Sequence analyses of the internal transcribed spacer (ITS) region indicated genetic variation in these parasite strains, as found in the samples collected. Among 48 sequences 15 different ribotypes were found, 12 of which were novel, and 3 of which were previously-described ribotypes: ribotype A, C, and II. This study demonstrates the diversity of T. gallinae strains in Saudi Arabian birds for the first time, and revealed that ribotypes A and C are predominant among Riyadh birds.

No abstract

Post-translational modifications play a fundamental role in regulating protein function and stability. In particular, protein ubiquitylation is a multifaceted modification involved in numerous aspects of plant biology. Landmark studies connected the ATP-dependent ubiquitylation of substrates to their degradation by the 26S proteasome; however, nonproteolytic functions of the ubiquitin (Ub) code are also crucial to regulate protein interactions, activity, and localization. Regarding proteolytic functions of Ub, Lys-48-linked branched chains are the most common chain type for proteasomal degradation, whereas promotion of endocytosis and vacuolar degradation is triggered through monoubiquitylation or Lys63-linked chains introduced in integral or peripheral plasma membrane proteins. Hormone signaling relies on regulated protein turnover, and specifically the half-life of ABA signaling components is regulated both through the ubiquitin-26S proteasome system and the endocytic/vacuolar degradation pathway. E3 Ub ligases have been reported that target different ABA signaling core components, i.e., ABA receptors, PP2Cs, SnRK2s, and ABFs/ABI5 transcription factors. In this review, we focused specifically on the ubiquitylation of ABA receptors and PP2C coreceptors, as well as other post-translational modifications of ABA receptors (nitration and phosphorylation) that result in their ubiquitination and degradation.