A Comparative Study on the Microbial Communities of Rhynchophorus ferrugineus (Red Palm Weevil)-Infected and Healthy Palm Trees

Several studies have investigated palm trees’ microbiota infected with red palm weevil (RPW) (Rhynchophorus ferrugineus), the major pest of palm trees. This study compared the microbial communities of infected and uninfected palm trees in the Hail region, Northern Saudi Arabia, determined by high-throughput 16S rRNA gene sequencing by Illumina MiSeq. The results indicated that taxonomic diversity variation was higher for infected tree trunk than the healthy tree trunk. Soil samples from the vicinity of healthy and infected trees did not have a significant variation in bacterial diversity. Myxococcota, Acidobacteriota, and Firmicutes were the dominant phyla in RPW-infected tree trunk, and Pseudomonadaceae was the most prominent family. This study is the first report on the characterization of RPW-infected and healthy palm trees’ microbiome.

Association of citrus virus A to citrus impietratura disease symptoms.

Citrus impietratura disease (CID) is a graft transmissible, virus-like disease observed in old-line citrus trees; its characteristic symptom is the appearance of gum in the albedo of the affected fruits. To identify the causal agent of the disease, high throughput sequencing (HTS) was performed on symptomatic orange fruits. The analysis of the obtained data revealed in all samples, mixed infections of viroids commonly found in citrus trees together with the recently described citrus virus A (CiVA). Examination of additional symptomatic fruits with conventional RT-PCRs led to the identification of a single CiVA infection in one tree, which was verified by HTS. Indexing of the single CiVA-infected tree on indicator plants resulted in the appearance of characteristic symptoms in the leaves that were correlated with virus accumulation. Moreover, a comparative analysis among symptomatic and asymptomatic fruits derived from the same trees was performed and included the single CiVA-infected orange tree. The analysis revealed a positive correlation between the appearance of symptoms and the accumulation of CiVA RNAs. To facilitate CiVA detection during certification programs of propagation material a quantitative RT-qPCR targeting the movement protein of the virus, was developed and evaluated for reliable and sensitive detection of the virus. To the best of our knowledge this is the first study that associates CiVA with the appearance of impietratura disease symptoms.

Assessment of Phytoviral Status of some New Plum Orchards Established in Iaşi County, Romania

Four young plum orchards from Iaşi county, two of these established by using propagated material in Romania, and the other two with material from Austria, Czech Republic and Netherlands, were surveyed by visual observation of viral symptoms. Then, trees were sampled and tested for the presence of six viruses (PPV, PDV, PNRSV, ACLSV, ApMV and MLRSV) by serologic assays. A high rate of PPV infection (78% and 79%, respectively) was determinated in the two orchards established with planting material propagated in Romania, and a rate of 5% PDV infection was found in one of them. A rate of 2.5% PPV infection was determined in the orchard established with propagated material in Austria and Czech Republic, and no PPV infected tree was found in the orchard set up with material propagated in Netherlands. The infections with PNRSV, ACLSV, ApMV and MLRSV were not detected in the four orchards surveyed.

Correction to: Longitudinal transcriptomic characterization of viral genes in HSV-1 infected tree shrew trigeminal ganglia

An amendment to this paper has been published and can be accessed via the original article.

Longitudinal transcriptomic characterization of viral genes in HSV-1 infected tree shrew trigeminal ganglia

Background Following acute infection, Herpes Simplex virus-1 (HSV-1) establishes lifelong latency and recurrent reactivation in the sensory neurons of trigeminal ganglia (TG). Infected tree shrew differs from mouse and show characteristics similar to human infection. A detailed transcriptomic analysis of the tree shrew model could provide mechanistic insights into HSV-1 infection in humans. Methods We sequenced the transcriptome of infected TGs from tree shrews and mice, and 4 human donors, then examined viral genes expression up to 58 days in infected TGs from mouse and tree shrew, and compare the latency data with that in human TGs. Results Here, we found that all HSV-1 genes could be detected in mouse TGs during acute infection, but 22 viral genes necessary for viral transcription, replication and viral maturation were not expressed in tree shrew TGs during this stage. Importantly, during latency, we found that LAT could be detected both in mouse and tree shrew, but the latter also has an ICP0 transcript signal absent in mouse but present in human samples. Importantly, we observed that infected human and tree shrew TGs have a more similar LAT region transcription peak. More importantly, we observed that HSV-1 spontaneously reactivates from latently infected tree shrews with relatively high efficiency. Conclusions These results represent the first longitudinal transcriptomic characterization of HSV-1 infection in during acute, latency and recurrent phases, and revealed that tree shrew infection has important similar features with human infection.

Fungal pathogens associated with crown and collar rot of apple trees in southern Syria

<p>Crown and collar rot of apple trees is a destructive and widespread disease in most areas of the world. Surveys have been done to describe disease symptoms, estimate the disease incidence, and identify the pathogens associated with this disease in southern Syria. Disease incidence was 0.08 – 10 % in most studied sites, only in Alroom location it was up to 14.7 % in 2014 and 17.8 % in 2015, with average of 11.8 %. Symptoms included small pale green leaves, sparse foliage, and a reddish-brown discoloration of inner bark of the infected area at the base of infected tree. The isolated fungi belonged to genera and form genera <em>Phytophthora</em>, <em>Rosellinia</em>, <em>Rhizoctonia</em>, <em>Phialophora</em>, <em>Acremonium</em>, <em>Pestalotiopsis</em>, <em>Cylindrocarpon</em> and <em>Verticillium</em>.<em> Phytophthora </em>was isolated from all infected trees, and was the most frequent pathogen (53.7 % of total isolates). <em>Phytophthora</em> isolates recovered from crown cankers of apple were identified as <em>P. cactorum </em>(91.5 %) and <em>P. cambivora</em> (8.5 %). The results of this study are the first report of crown and collar root rot of apple in Syria.</p>