About

Jason Londo is an Associate Professor in the School of Integrative Plant Science, Horticulture Section at Cornell AgriTech. His research focuses on fruit crop stress physiology and adaptation, graft physiology and phenotypic plasticity, as well as comparative genetics and genomics. Through his work, Professor Londo contributes to understanding how fruit crops respond to environmental stresses and how grafting techniques influence plant traits, leveraging genetic and genomic tools to advance knowledge in these areas.

Research topics

• Genetics
• Biology
• Food science
• Botany
• Computational biology
• Evolutionary biology

Selected publications

• Time-series transcriptomics of grapevine deacclimation reveals chilling-dependent genetic responses to temperature increase during dormancy

  2026-01-14

  articleOpen accessSenior author

  During winter, grapevine ( Vitis vinifera ) bud dormancy and cold hardiness are regulated by complex interactions between chilling accumulation and temperature cues. However, the molecular mechanisms underlying physiological transitions during winter remain poorly understood. In this study, we performed time-series RNA-seq on ‘Cabernet Sauvignon’ dormant buds with varying chilling accumulation, followed by warm temperature exposure. Using weighted gene co-expression network analysis, empirical modeling, and a novel calculation of molecular temperature response rate, we identified gene expression patterns responsive to temperature alone, chilling alone, and their interaction. Temperature-responsive genes showed rapid, chilling-independent activation and were primarily associated with metabolism, environmental sensing, and auxin signaling. Chilling-responsive genes were enriched for functions of chromatin remodeling and heat shock protein pathways, suggesting progressive cellular reprogramming under field conditions. Interaction-responsive genes, including those involved in ABA/auxin metabolism and cell wall modification, seem to function in both dormancy progression and deacclimation. These findings provide a mechanistic framework for how chilling and temperature synergistically regulate dormancy transitions in grapevine, which enhances the understanding of temperature sensing and response and the chilling-mediate dormancy progression underlying grapevine dormant season physiology.

  PublisherOA PDFDOI

• Cold hardiness dynamics predict budbreak and associated low‐temperature threats in grapevine

  New Phytologist · 2026-03-08

  articleOpen access

  Dormant buds of temperate woody perennial plants must attain cold hardiness to survive winters and timely lose it in spring to break bud while avoiding damage from low temperatures and late frosts. Therefore, we asked: Can a cold hardiness model be used to predict budbreak? Here, we used a previously published cold hardiness model to predict bud cold hardiness of three grapevine (Vitis spp.) varieties ('Cabernet-Sauvignon', 'Riesling', and 'Concord') from historical temperature records of eight locations in North America and Europe. Based on those predictions and thresholds of cold hardiness at budbreak from literature, budbreak date was extracted. Despite being untrained on budbreak data, the model resulted in good predictions (RMSE = 7.3d, n = 329), further improved based on expected delays from estimated cold damage (RMSE = 7.2d). Both increasing and decreasing freeze damage risk trends were predicted with increasing temperature, depending on the range of mean dormant season temperature (MDST; 1 Nov-30 Apr) in each location. Spring phenology predictions in relation to MDST also showed warming to advance (MDST < 10°C) or delay (MDST > 10°C) budbreak. Cold hardiness dynamics represent a key advancement in spring phenological modeling that provides information on low-temperature damage potential for the entire dormant season alongside improved predictions of budbreak timing.

  PublisherDOI

• Cold hardiness dynamics predict budbreak and associated low temperature threats in grapevine

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-01-14 · 5 citations

  preprintOpen access

  Temperate woody perennial plants form buds that develop into leaves or flowers that emerge in the following growth season. To survive winter, dormant buds must attain cold hardiness, and timely lose it in spring to break bud while avoiding damage from low temperatures and late frosts. Here, we use a process-based model to predict bud cold hardiness of three grapevine varieties ( V. vinifera 'Cabernet-Sauvignon' and 'Riesling', and V. hybrid 'Concord') from historical temperature records of eight different locations in North America and Europe (n=329). Based on those predictions, and thresholds of cold hardiness at budbreak from literature, timing of budbreak was extracted. Despite the model being untrained to budbreak data, the cold hardiness model resulted in good predictions (RMSE=7.3d) that were further improved based on expected delays from cold damage (RMSE=7.2d). Both increasing and decreasing trends in freeze damage risk were predicted with increasing temperature, depending on the range of mean dormant season temperature (MDST; 1 Nov-30 Apr) in each location. Predictions in timing of spring phenology in relation to MDST also showed warming to advance (MDST&lt;10°C) or delay (MDST&gt;10°C) budbreak. Cold hardiness dynamics represents an advancement in phenological modeling that provides information for the entirety of the dormant season, as well as budbreak.

  PublisherOA PDFDOI

• VineColD: an integrative database for global historical tracing and real-time monitoring of grapevine cold hardiness

  Database · 2025-01-01

  articleOpen accessSenior author

  Cold hardiness is a crucial physiological parameter that determines the survival of grapevines during the dormant season. Accurate modelling and large-scale prediction of grapevine cold hardiness are essential for assessing the potential geographic distribution of grapevine cultivation, quantifying the impact of climate change on grapevine habitats, and ensuring the sustainability of the grape and wine industries worldwide in the regions characterized by cool or cold dormant seasons. However, until now, no comprehensive database has been available. In this research, we combined advanced automated machine learning techniques with extensive historical and current weather data to create an integrative database for grapevine cold hardiness: VineColD (https://cornell-tree-fruit-physiology.shinyapps.io/VineColD/). We developed the NYUS.2.1 model, an automated machine learning-based system for predicting grapevine cold hardiness and applied it to global historical weather data from 17,985 curated weather stations between latitudes 30° and 55° in both hemispheres from 1960 to 2024, resulting in the development of an integrative grapevine cold hardiness database and monitoring system, VineColD. VineColD integrates both a global historical dataset and a daily updated regional cold hardiness system, offering a comprehensive resource to study grape cold hardiness for 54 grapevine cultivars. The platform provides multiple download options, from single-station data to complete datasets, and the interactive multifunctional R Shiny application facilitates data analysis and visualization. VineColD delivers critical insights into the impact of climate change on grapevine cultivation and supports a range of analytical functions, making it a valuable tool for grape growers and researchers.

  PublisherOA PDFDOI

• Tetralone-ABA enhances winter cold acclimation, reduces deacclimation, and delays budbreak in V. vinifera and V. hybrid grapevines

  Plant Stress · 2025-04-17 · 1 citations

  articleOpen accessSenior authorCorresponding

  • Tetralone-ABA accelerated chlorophyll degradation and defoliation in grapevine. • Tetralone-ABA enhanced cold acclimation and slowed deacclimation. • Tetralone-ABA delayed budbreak without impacting growing season physiology or yield. • There was a cultivar-specific response to tetralone-ABA treatment. • Tetralone-ABA delayed the activation of growth-related pathways during deacclimation. Climate change-related acute winter freezes and unseasonal false springs have become significant and predictable risks for grape growers across North America and Eurasia. Novel strategies to enhance resilience during the dormant season, particularly by improving bud cold hardiness and delaying budbreak, are urgently needed for the sustainability of grape and wine production. In this study, we evaluated a synthetic abscisic acid (ABA) analog, tetralone-ABA (ABA-1102), as a sprayable product for inducing these traits in three grapevine cultivars: ‘Riesling’, ‘Cayuga White’, and their progeny, ‘Aravelle’. Post-harvest foliar application of tetralone-ABA accelerated leaf senescence, enhanced bud cold hardiness during cold acclimation, and slowed deacclimation under both controlled and field conditions. It also delayed the budbreak in spring without altering growing season phenology, physiology, or harvest yield. Transcriptomic analysis during deacclimation assays suggests that tetralone-ABA’s effect on delaying deacclimation may result from its suppression of the activation of growth-related pathways under growth-permissive conditions. Detailed investigations of these pathways indicate that tetralone-ABA may have modulated critical biological processes such as cell wall remodeling, sugar metabolism, and ABA signaling. Overall, this study provides novel insights into the genetic control of grapevine deacclimation, highlights ABA’s role in grapevine dormant season physiology, and demonstrates tetralone-ABA’s potential as a promising tool for improving dormant season viticulture resilience, offering a new strategy to protect grapevines against the increasing threats posed by climate change.

  PublisherDOI

• Evolutionary conservation of the grape sex-determining region in angiosperms and emergence of dioecy in Vitaceae

  Nature Communications · 2025-07-01 · 3 citations

  articleOpen access

  In bunch grapes (Vitis spp.), flower sex is controlled by a ~ 200-kilobase sex-determining region (SDR) that contains genes involved in floral development. Here, we show that this region evolved from an ancient, highly conserved locus across angiosperms. Comparative genomic analysis of 56 plant genomes identifies homologous regions in all flowering plants but not in non-flowering lineages, suggesting a conserved role in floral function. Within the grape family (Vitaceae), we assemble and phase SDR haplotypes from six species, plus Leea coccinea as an outgroup, and find strong structural conservation, with size variation largely attributable to repetitive elements. Among the dioecious genera, Vitis and Muscadinia exhibit suppressed recombination in the SDR and share candidate sex-determining genes, whereas in Tetrastigma, the region appears to remain recombining, pointing to an alternative mechanism of sex determination. Altogether, our results suggest that dioecy emerged in grapes from a deeply conserved, collinear genomic region composed of multiple genes involved in floral development, morphology, and sexual fertility.

  PublisherOA PDFDOI

• Cold hardiness, deacclimation, and budbreak phenology in grapevine

  Open MIND · 2025-01-01

  dataset1st authorCorresponding

  To survive the harsh conditions of winter, woody perennial species such as grapevine have adapted to use environmental cues to trigger physiological changes to induce dormancy, acquire cold hardiness, and measure the length of winter to properly time spring budbreak. Human induced climate change disrupts these cues by prolonging warm temperatures in fall, reducing the depth and consistency of midwinter, and triggering early budbreak through false spring events. We evaluated variation in dormant bud cold hardiness and chilling hour requirements of 31 different grapevine varieties over 3 years. Differential thermal analysis was used to track changes in cold hardiness and deacclimation resistance was assessed throughout the season to track dormancy progression. Results demonstrate wide variation in maximum deacclimation rate (1.03 – 2.87 °C/day) among varieties under forcing conditions. Absolute maximum rates of deacclimation show signatures of species-level responses to forcing temperatures. When integrated with variation in cold hardiness, these rates revealed a relationship between winter cold hardiness, changes in deacclimation rate and budbreak phenology. Standardizing rates among varieties as deacclimation potential demonstrated a conserved response to chilling exposure among varieties that alters our interpretation of the concept of high and low chill varieties and chilling requirement in grapevine.

• Integrating cold hardiness and deacclimation resistance demonstrates a conserved response to chilling accumulation in grapevines

  Journal of Experimental Botany · 2025-02-08 · 5 citations

  article1st authorCorresponding

  To survive the harsh conditions of winter, woody perennial species such as grapevine have adapted to use environmental cues to trigger physiological changes to induce dormancy, acquire cold hardiness, and measure the length of winter to properly time spring budbreak. Human-induced climate change disrupts these cues by prolonging warm temperatures in autumn, reducing the depth and consistency of midwinter, and triggering early budbreak through false spring events. We evaluated variation in dormant bud cold hardiness and chilling hour requirements of 31 different grapevine varieties over 3 years. Differential thermal analysis was used to track changes in cold hardiness, and deacclimation resistance was assessed throughout the season to track dormancy progression. Results demonstrate wide variation in the maximum deacclimation rate (1.03-2.87 °C d-1) among varieties under forcing conditions. Significant correlations were noted of wild species distributions or cultivar provenance with cold hardiness and deacclimation rates, demonstrating the likely climate-adaptive nature of these traits. When integrated with variation in cold hardiness, these rates revealed a relationship between winter cold hardiness, changes in deacclimation rate, and budbreak phenology. Standardizing rates among varieties as deacclimation potential demonstrated a conserved response to chilling exposure among varieties that alters our interpretation of the concept of high and low chill varieties and chilling requirement in grapevine.

  PublisherDOI

• Tetralone-ABA enhances winter cold acclimation, reduces deacclimation, and delays budbreak in V. vinifera and V. hybrid grapevines

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-01-01

  preprintSenior authorCorresponding

  Abstract Climate change-related acute winter freezes and unseasonal false springs have become significant and predictable risks for grape growers across North America and Eurasia. Novel strategies to enhance resilience during the dormant season, particularly by improving bud cold hardiness and delaying budbreak, are urgently needed for the sustainability of grape and wine production. In this study, we evaluated a synthetic abscisic acid (ABA) analog, tetralone-ABA (ABA-1102), as a sprayable product for inducing these traits in three grapevine cultivars: ‘Riesling’, ‘Cayuga White’, and their progeny, ‘Aravelle’. We determined that post-harvest foliar application of tetralone-ABA promoted early leaf senescence, induced cultivar-specific bud cold hardiness enhancement during cold acclimation, slowed deacclimation under controlled and field conditions, and delayed budbreak in spring without affecting growing season phenology, physiology or harvest yield. Transcriptomic analysis of during deacclimation assays suggests that tetralone-ABA’s effect on delaying deacclimation may result from its suppression of the activation of growth-related pathways under growth-permissive conditions. Detailed investigations of these pathways indicate that tetralone-ABA may have modulated critical biological processes such as cell wall remodeling, sugar metabolism, and ABA signaling. Overall, this study provides novel insights into the genetic control of grapevine deacclimation, highlights ABA’s role in grapevine dormant season physiology, and demonstrates tetralone-ABA’s potential as a promising tool for improving dormant season viticulture resilience, offering a new strategy to protect grapevines against the increasing threats posed by climate change.

  PublisherDOI

• Tetralone-Aba Enhances Winter Cold Acclimation, Reduces Deacclimation, and Delays Budbreak in V. Vinifera and V. Hybrid Grapevines

  SSRN Electronic Journal · 2025-01-01 · 1 citations

  preprintOpen accessSenior author
  PublisherDOI

Frequent coauthors

• Rachel P. Naegele

  115 shared

• Alisson P. Kovaleski

  University of Wisconsin–Madison

  85 shared

• Cheng Zou

  73 shared

• Amy Tabb

  Appalachian Fruit Research Laboratory

  72 shared

• Bernard Prins

  Cornell University

  68 shared

• Qi Sun

  Cornell University

  66 shared

• Laise de Sousa Moreira

  University of Minnesota

  65 shared

• Hui-Ching Yang

  65 shared

Education

• PhD, Plant Biology

  Washington University in St. Louis

  2006