Co-Occurrence of Viruses, Plant Pathogens, and Symbionts in an Underexplored Hemipteran Clade

Interactions between insect symbionts and plant pathogens are dynamic and complex, sometimes involving direct antagonism or synergy and sometimes involving ecological and evolutionary leaps, as insect symbionts transmit through plant tissues or plant pathogens transition to become insect symbionts. Hemipterans such as aphids, whiteflies, psyllids, leafhoppers, and planthoppers are well-studied plant pests that host diverse symbionts and vector plant pathogens. The related hemipteran treehoppers (family Membracidae) are less well-studied but offer a potentially new and diverse array of symbionts and plant pathogenic interactions through their distinct woody plant hosts and ecological interactions with diverse tending hymenopteran taxa. To explore membracid symbiont–pathogen diversity and co-occurrence, this study performed shotgun metagenomic sequencing on 20 samples (16 species) of treehopper, and characterized putative symbionts and pathogens using a combination of rapid blast database searches and phylogenetic analysis of assembled scaffolds and correlation analysis. Among the 8.7 billion base pairs of scaffolds assembled were matches to 9 potential plant pathogens, 12 potential primary and secondary insect endosymbionts, numerous bacteriophages, and other viruses, entomopathogens, and fungi. Notable discoveries include a divergent Brenneria plant pathogen-like organism, several bee-like Bombella and Asaia strains, novel strains of Arsenophonus-like and Sodalis-like symbionts, Ralstonia sp. and Ralstonia-type phages, Serratia sp., and APSE-type phages and bracoviruses. There were several short Phytoplasma and Spiroplasma matches, but there was no indication of plant viruses in these data. Clusters of positively correlated microbes such as yeast-like symbionts and Ralstonia, viruses and Serratia, and APSE phage with parasitoid-type bracoviruses suggest directions for future analyses. Together, results indicate membracids offer a rich palette for future study of symbiont–plant pathogen interactions.

Can the Olive Genome Be a Miracle for Human DNA?

We aimed to compare the human genome with the olive genome on the hypothetical context of whether or not any human-plant genomic alignment similarities could give rise to genomic bioavailability when consumed likewise carbohydrates, proteins, fats. Many studies from past to present have shown beneficial effects of olives on cardiovascular diseases and some cancer pathways. Moreover, scientific and even religious resources highlighted the importance of the olive. In our project, we aligned the olive genome with the human genome in Pubmed Blast database. We detected several genes has had 100 percent matching sequences where pathological and non-pathological variations were identified in the human genome. Interestingly wild type variations were observed in the olive genome and those matching regions were consuming restriction sites. In our data, matching regions at cardiovascular and cancer-related genes could suggest a possible bioavailability of plant genomes even in vitro. Further studies, comparing other plant genomes with the human genome would beget more promising results.

PSV-37 Reemergence of cyathostomins species demonstrates anthelmintic resistance following drug administration in horses

Arbitrary administration of anthelmintics to control equine gastrointestinal worms has led to increased resistance to the three broad-spectrum drug classes; benzimidazoles, tetrahydropyrimidines, and macrocyclic lactones. With little promise of new drug classes to target cyathostomins being introduced to the market in the near future, anthelmintic drugs must be administered judiciously to prevent complete anthelmintic parasite resistance. The objective of this study is to determine the reemergence rate of cyathostomins following three commercial horse dewormers during summer. Nine horses housed at two locations were enrolled to the study and was repeated June–September through 2017–2019. Horses were removed from the study if sequencing failed due to low egg recovery for more than 50% of the timepoints. Ivermectin (macrocyclic lactones; n = 6), Moxidectin (macrocyclic lactones; n = 8) and Strongid (pyrantel pamoate; n = 8) were administered to horses and fecal samples were collected every 14d for 98d. Samples were tested using fecal egg counts with a modified McMaster technique and 18S rRNA profiling of the V5.8 and ITS1 regions. Sequences were clustered and taxonomy was assigned against a custom NCBI Blast+ database with the aligned sequences of 19 cyathostomins. Data were analyzed using presence/absence methods in R studio. Treatment and Day significantly impacted the average number of species present (P < 0.001). Moxidectin had the lowest number of species present followed by Strongid then Ivermectin (7.14, 10.17, 11.09, respectively). Equine shedder status had no effect on the average number of species present (P > 0.05). Six species, CO. labiatus, CS. catinatum, CY. auriculatus, CY. elongatus, CT. goldi and CT. longibursatus, showed resistance to the three treatments (P > 0.05). Moxidectin was the most effective at eradicating cyathostomins infestations (P < 0.05). Identifying resistance patterns at the species level will enable mechanistic molecular approaches to determine anthelmintic resistance in cyathostomins.

Calmodulin-Like (CML) Gene Family in Medicago truncatula: Genome-Wide Identification, Characterization and Expression Analysis

Calcium is an important second messenger in mediating adaptation responses of plants to abiotic and biotic stresses. Calmodulin-like (CML) protein is an important calcium-signaling protein that can sense and decode Ca2+ signal in plants. Medicago truncatula is a model legume plant; however, investigations of MtCML proteins are limited. Using genome analysis and BLAST database searches, fifty MtCML proteins that possess EF-hand motifs were identified. Phylogenetic analysis showed that CML homologs between M. truncatula, Arabidopsis thaliana and Oryza sativa shared close relationships. Gene structure analysis revealed that these MtCML genes contained one to four conserved EF-hand motifs. All MtCMLs are localized to eight chromosomes and underwent gene duplication. In addition, MtCML genes were differentially expressed in different tissues of M. truncatula. Cis-acting elements in promoter region and expression analysis revealed the potential response of MtCML protein to abiotic stress and hormones. The results provide a basis of further functional research on the MtCML gene family and facilitate their potential use for applications in the genetic improvement on M. truncatula in drought, cold and salt stress environments.

CHARACTERIZATION OF DART SEQUENCES REFLECTING GENOMICREGIONS INVOLVED IN ALUMINUM TOLERANCE IN TRITICALE (X TRITICOSECALE WITTMACK)

Aluminum toxicity is the major growth-limiting factor for crop cultivation on acid soils. Tolerance mecha-nisms for Al stress in triticale have not been systematically investigated so far. It is presumed, that in the case of this species they may be a function of the interaction between wheat and rye genes. In this study the se-quences of forty-six Diversity Arrays Technology markers associated with aluminum tolerance in triticale and under selection pressure were blasted against BLAST database for the identification of possible functions of the respective genome regions in Al-stress response. The analysis has showed sequences similarity to the domains involved in signaling, disease response and DNA repair mechanisms.

An improved de novo assembly and annotation of the tomato reference genome using single-molecule sequencing, Hi-C proximity ligation and optical maps

The original Heinz 1706 reference genome was produced by a large team of scientists from across the globe from a variety of input sources that included 454 sequences in addition to full-length BACs, BAC and fosmid ends sequenced with Sanger technology. We present here the latest tomato reference genome (SL4.0) assembled de novo from PacBio long reads and scaffolded using Hi-C contact maps. The assembly was validated using Bionano optical maps and 10X linked-read sequences. This assembly is highly contiguous with fewer gaps compared to previous genome builds and almost all scaffolds have been anchored and oriented to the 12 tomato chromosomes. We have found more repeats compared to the previous versions and one of the largest repeat classes identified are the LTR retrotransposons. We also describe updates to the reference genome and annotation since the last publication. The corresponding ITAG4.0 annotation has 4,794 novel genes along with 29,281 genes preserved from ITAG2.4. Most of the updated genes have extensions in the 5’ and 3’ UTRs resulting in doubling of annotated UTRs per gene. The genome and annotation can be accessed using SGN through BLAST database, Pathway database (SolCyc), Apollo, JBrowse genome browser and FTP available at https://solgenomics.net.

AcetoBase: a functional gene repository and database for formyltetrahydrofolate synthetase sequences

Acetogenic bacteria are imperative to environmental carbon cycling and diverse biotechnological applications, but their extensive physiological and taxonomical diversity is an impediment to systematic taxonomic studies. Acetogens are chemolithoautotrophic bacteria that perform reductive carbon fixation under anaerobic conditions through the Wood–Ljungdahl pathway (WLP)/acetyl-coenzyme A pathway. The gene-encoding formyltetrahydrofolate synthetase (FTHFS), a key enzyme of this pathway, is highly conserved and can be used as a molecular marker to probe acetogenic communities. However, there is a lack of systematic collection of FTHFS sequence data at nucleotide and protein levels. In an attempt to streamline investigations on acetogens, we developed AcetoBase - a repository and database for systematically collecting and organizing information related to FTHFS sequences. AcetoBase also provides an opportunity to submit data and obtain accession numbers, perform homology searches for sequence identification and access a customized blast database of submitted sequences. AcetoBase provides the prospect to identify potential acetogenic bacteria, based on metadata information related to genome content and the WLP, supplemented with FTHFS sequence accessions, and can be an important tool in the study of acetogenic communities. AcetoBase can be publicly accessed at https://acetobase.molbio.slu.se.

Magic-BLAST, an accurate DNA and RNA-seq aligner for long and short reads

ABSTRACTNext-generation sequencing technologies can produce tens of millions of reads, often paired-end, from transcripts or genomes. But few programs can align RNA on the genome and accurately discover introns, especially with long reads. We introduce Magic-BLAST, a new aligner based on ideas from the Magic pipeline. It uses innovative techniques that include the optimization of a spliced alignment score and selective masking during seed selection. We evaluate the performance of Magic-BLAST to accurately map short or long sequences and its ability to discover introns on real RNA-seq data sets from PacBio, Roche and Illumina runs, and on six benchmarks, and compare it to other popular aligners. Additionally, we look at alignments of human idealized RefSeq mRNA sequences perfectly matching the genome. We show that Magic-BLAST is the best at intron discovery over a wide range of conditions and the best at mapping reads longer than 250 bases, from any platform. It is versatile and robust to high levels of mismatches or extreme base composition, and reasonably fast. It can align reads to a BLAST database or a FASTA file. It can accept a FASTQ file as input or automatically retrieve an accession from the SRA repository at the NCBI.