bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.64898/2025.12.23.696282

Haplotype graph analysis of PdR1 uncovers resistance diversity to Pierce's Disease in Vitis arizonica and its hybrids

Massonnet, M.·Zaccheo, M.·Cochetel, N.·Figueroa-Balderas, R.·Riaz, S.·Cantu, D.
View original source ↗Export metadata ↓

Abstract

Previous genetic mapping studies indicate that multiple haplotypes of the Pierces disease (PD) Resistance 1 (PdR1) locus occur in Vitis arizonica and its hybrids. To characterize sequence diversity at this locus, we assembled chromosome-scale diploid genomes for four PD-resistant (PD-R) accessions: b43-17 (PdR1a/PdR1b), the backcross 07744-094 (PdR1c/PdR1-), b46-43 (PdR1e/PdR1f), and b42-26 (PdR1-/PdR1-), which displays quantitative PD resistance not associated with PdR1. Haplotype resolution of PdR1a, PdR1b, PdR1c, and PdR1e revealed substantial variation in intergenic repeat content and gene composition between PdR1 and their alternative haplotype at the PdR1 locus not associated with PD resistance phenotype (PdR1-), as well as among PdR1 haplotypes, demonstrating extensive sequence diversity at the PdR1 locus. Sequence graph analysis uncovered substantial structural divergence concentrated in approximately one quarter of the locus, together with smaller-scale variation across haplotypes. This analysis identified PdR1-specific graph nodes, showing that PdR1a and PdR1b share most of their PdR1-specific features, whereas PdR1c contains the highest number of private nodes, followed by PdR1e. Integration of sequence graph features with gene expression data further refined a set of defense-related candidate genes within PdR1c. Together, these results identify candidate genes for functional validation and indicate that multiple resistance determinants co-localized within the PdR1 locus may contribute to PD resistance, highlighting opportunities for targeted genetic improvement strategies.

Source connections

Explore related subjects

genomicsPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Massonnet, M., Zaccheo, M., Cochetel, N., Figueroa-Balderas, R., Riaz, S., Cantu, D.. 2025-12-26. Haplotype graph analysis of PdR1 uncovers resistance diversity to Pierce's Disease in Vitis arizonica and its hybrids. https://doi.org/10.64898/2025.12.23.696282

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

RNA isoform-resolved multiplexed sequencing with bioorthogonal barcoding

RNA isoform dysregulation drives disease pathogenesis and is the target of FDA-approved splice-switching therapeutics. However, multiplexed sequencing methods discard splice junction information because only 3' termini are barcoded and counted. Here, we repurpose acylation and click chemistries to conjugate bioorthogonal barcodes (bobcodes) directly onto multiple internal positions along cellular RNAs. Bobcoded RNAs from multiple samples are pooled for multiplexed cDNA synthesis, during which reverse transcriptase switches from each RNA template onto its tethered bobcode with greater than 99% accuracy in species mixing experiments. Bobcode attachment intervals set cDNA insert sizes without a library fragmentation step, and priming with poly(dT) or random hexamers selects between 3'-end counting and full-length isoform capture. A bioorthogonal barcode-sequencing (BOB-seq v0.1) drug screen identifies transcriptome-wide on- and off-target RNA splicing effects and outperforms existing multiplexing RNA sequencing methods in workflow simplicity, sample-to-sample variability, and barcoding accuracy. Bobcodes add isoform resolution to scalable multiplexed RNA sequencing.

genomics↗
bioRxiv2026

Integrative Nanopore and Illumina sequencing reveals age-associated tRNA modification and CCA-tail dynamics in yeast

Aging is characterized by a progressive loss of proteostasis. Transfer RNAs (tRNAs) are essential regulators of translation, yet their dynamics during aging remain poorly understood due to challenges in sequencing highly modified RNAs. Here we present a benchmarked Nanopore direct RNA sequencing (RNA004 chemistry) resource that profiles the Saccharomyces cerevisiae tRNAome during replicative aging at single-molecule resolution. Using in vitro transcribed tRNA controls, we establish modification detection thresholds and validate key findings with orthogonal Illumina sequencing. While overall tRNA abundance remains largely stable, our resource reveals age-associated terminal A cleavage at the 3' CCA tail of mature tRNAs, targeted T-loop and anticodon modification changes, and single-molecule evidence of modification co-occurrence. This dataset provides a resource for exploring tRNA regulation, translation fidelity, and longevity.

genomics↗
bioRxiv2026

A hydrogen-producing mitochondrion in an anaerobic eukaryotrophic rhizarian

Diverse eukaryotes thrive under low oxygen conditions, in part through highly modified mitochondrion-related organelles (MROs) that use alternate metabolic pathways to support ATP production and cofactor recycling. Anaerobic lifestyles have evolved repeatedly across the eukaryotic tree of life, each providing an independent opportunity to understand how eukaryotes adapt to life in low oxygen conditions. Here, we use single-cell transcriptomics to reconstruct the MRO metabolism of PCE SSF, a benthic eukaryotrophic flagellate and the first cultivated representative of Novel Clade 12 (NC12; Rhizaria), an independently anaerobic rhizarian lineage. PCE SSF possesses an anaerobic hydrogen-producing mitochondrion capable of hydrogenosome-type substrate-level phosphorylation. It also retains a nearly complete but likely branched tricarboxylic acid pathway that lacks citrate synthase and malate dehydrogenase. The function of citrate synthase may instead be fulfilled by the typically cytosolic ATP citrate lyase, previously reported in this context only in the anaerobic cercozoan, Brevimastigomonas motovehiculus. Unlike B. motovehiculus, however, PCE SSF retains only Complex II and the NuoE/NuoF subunits of the electron transport chain and lacks a mitochondrial genome. Together, these features indicate an atypical and reduced mitochondrial metabolism, highlighting the diversity of evolutionary solutions to anaerobic energy metabolism in eukaryotes.

genomics↗