Genetius

The study used a portable near‑infrared spectrometer to track sugar and acid changes in individual berries of ten grapevine varieties over two years, developing partial least‑square regression models validated for glucose, fructose, and malic acid. The models revealed that single berries ripen twice as fast as aggregated berry samples, highlighting a precise quantitative approach for assessing ripening physiology under climate change.

The study reports the first breakdown of the Rpv1 resistance locus in grapevine by a Plasmopara viticola strain from Reunion Island, which also overcomes Rpv3.1 and Rpv10. Pathogenicity assays and whole‑genome sequencing revealed a novel homozygous deletion in the corresponding avirulence gene and a genetic background related to mainland French populations, indicating the emergence of a multivirulent lineage.

In southeastern France, grapevine variety Artaban (carrying Rpv1 and Rpv3.1 resistance genes) experienced severe downy mildew caused by Plasmopara viticola, with 21 isolates showing virulence on resistant cultivars. Notably, four distinct isolates overcame the pyramided Rpv1‑Rpv3.1 resistance, marking the first documented breakdown of these resistances in Europe, likely due to convergent evolution.

The study applied the FAO‑56 dual crop coefficient method to estimate irrigation water balance, water stress, and crop coefficients for irrigated vineyards across 48 sites in South Australia over three seasons, revealing high spatial and temporal variability in actual evapotranspiration, crop coefficients, and water productivity. Site‑specific estimates of Kc act and Kcb act highlighted the limitations of using uniform coefficients and demonstrated potential water savings by focusing on transpiration‑driven water use. The findings support locally calibrated coefficients to improve freshwater efficiency in wine grape production.

Using a multi‑omics approach, the study examined how different soil types (sand, peat, peat‑manure) and sterilisation treatments affect the grapevine holobiont, revealing that soil composition strongly influences leaf element composition and rhizosphere bacterial and fungal communities. Autoclaving soils reduced bacterial diversity, while root sterilisation had minor microbial effects but altered root transcription and leaf macronutrient levels, underscoring the soil’s active role in shaping plant‑microbe interactions.

The study demonstrates that the IRE1/bZIP60 and bZIP17 arms of the unfolded protein response are conserved and transcriptionally active in Vitis vinifera, with VvbZIP60 undergoing unconventional splicing under ER stress. Both abiotic stresses (heat, osmotic, copper) and biotic challenges (Plasmopara viticola, Botrytis cinerea) strongly induce UPR‑related genes, indicating a broad role for these pathways in grapevine stress responses.

Using dual‑organism single‑nucleus RNA‑seq, we generated atlases of over 100,000 grapevine leaf nuclei and more than 3,000 Erysiphe necator nuclei at 1 and 5 days post‑infection, annotating major host cell types and fungal structures. The analysis uncovers cell‑type specific defense gene expression and fungal transcriptional programs, supporting spatially distinct pattern‑triggered and effector‑triggered immunity in grapevine.

The study investigated symptomatic and asymptomatic leaves of grapevines affected by esca, using metabolite profiling, RNA‑seq, and whole‑genome bisulfite sequencing. Metabolic and transcriptomic reprogramming were confined to symptomatic leaves, while DNA‑methylation changes occurred both locally and systemically, with some epigenetic marks detectable before symptoms appear, suggesting their use as early biomarkers.

The study used time‑series RNA‑seq and weighted gene co‑expression network analysis to dissect how chilling accumulation and warm temperature cues individually and jointly influence gene expression in dormant Cabernet Sauvignon buds. Distinct gene sets responded to temperature alone (metabolism, sensing, auxin signaling), chilling alone (chromatin remodeling, heat‑shock proteins), and their interaction (ABA/auxin metabolism, cell‑wall modification), revealing a mechanistic framework for dormancy progression and deacclimation in grapevine.

The study combined wood metatranscriptomics, metabolomics, and metabarcoding to examine how drought and esca leaf symptom expression affect 30‑year‑old grapevines and associated wood‑pathogenic fungi. Both stresses reduced transpiration and activated similar plant pathways (phenylpropanoid and stilbenoid synthesis), yet they triggered distinct fungal responses, with drought favoring Phaeomoniella chlamydospora and esca favoring Fomitiporia mediterranea. The authors suggest that drought‑induced defense mechanisms and reduced virulence of F. mediterranea underlie the inhibition of esca symptoms during water deficit.