Location: Crops Pathology and Genetics Research
Project Number: 2032-30500-001-000-D
Project Type: In-House Appropriated
Start Date: Jan 28, 2025
End Date: Jan 27, 2030
Objective:
Water stress disrupts every phenological stage and impacts nutrient reserves, which are critical for the vine’s ability to withstand the dormant season and to have a productive growing season. With more convenient methods to evaluate water status and to establish vineyards, growers can better manage drought stress, especially given limits of the supply/quality of irrigation water. Soil health is a complex area of research, the gaps of which are a bottleneck to adopting new vineyard practices that conserve scarce resources. With a clearer understanding of how soil microbes are affected by novel uses of winery wastewater, more growers may be able to utilize this possible source of irrigation water, without harming vine nutrient availability in the soil. Diseases that become established in the nursery are spread to new vineyards all across the U.S. With early-detection tools for widespread and incurable diseases, vineyards will not have to be replanted so often. Exposure of wine grapes to wildfire smoke, and the risk of smoke taint developing in the resulting wine, can negate all of the year’s efforts for sustainable water, disease, and soil management. With reliable methods to connect smoke exposure in the vineyard to risk of smoke taint in the wine, growers can make more informed decisions, from harvest to bottling.
Objective 1: Integrate physiological and genetic approaches, to develop plant materials, low-input practices, and management technologies for resilience to biotic and abiotic stresses in vineyards.
Sub-objective 1.A: Develop better links between physiological stress across scales (i.e. leaf to canopy to vineyard) for varied genotypes and refine and integrate methodology to effectively measure these changes under hotter and drier growing conditions.
Sub-objective 1.B: Develop strategies for manipulating root system architectures through the auxin pathway to improve drought tolerance, using the CRISPR-Cas based genome editing technology.
Objective 2: Develop soil-management practices that utilize soil-microbial functionality as an aspect of vine health.
Objective 3: Develop and deploy pathogen-specific detection tools that minimize the risk of contamination of nursery stock and inform disease management in the vineyard.
Objective 4: Characterize the impacts of wildfire smoke exposure on grape metabolism, wine composition, and sensory characteristics through the development of methods to measure biomarkers, identifying novel smoke-derived compounds, and elucidating the biochemical fate of smoke-derived compounds in grapes.
Approach:
Sub-objective 1.A: Ground-based sensing systems can provide a combination of thermal and hyperspectral signals and changes in canopy structure that accurately reflect leaf physiological conditions unique to different crop genotypes. Experiments will be conducted under controlled conditions and in field settings for comparison across measurement scales and to isolate signals specific to different stressors and physiological targets (i.e. stress vs. water use). A central goal of this work is to develop tools for early detection of stress using non-visual methods. Sub-objective 1.B: Changes in the root system architectures, caused by alterations in the auxin pathway, contribute to drought stress resistance and such changes vary among grapevine genotypes. Next generation sequencing, bioinformatics, functional genomics, and genome editing will be used to identify molecular pathways or markers that relate to modified RSAs and drought stress resistance. This work will lead toward a novel screening or detection tool and generation of genetic resources.
Objective 2: Application of K+-rich winery waste water will impact the soil characteristics and soil microorganisms. These effects are soil-type dependent. The impacts of such waste water reuse on soil physicochemical characteristics, microbiome composition and function will be examined. A novel approach will be used to test how K+-rich waste water with varying EC and PAR behaves across soil development gradients in three major wine grape regions of California. These gradients will reflect different geologic parent material and secondary clay minerals. We posit that these inherent characteristics confer distinctions in the capacity for K-fixation and resistance to degradation from simulated irrigation water with high PAR and EC. Objective 3: The fungal pathogens that cause trunk diseases secrete fungal toxins, which are translocated through the xylem from the internal wood infection to asymptomatic leaves. If fungal toxins can be detected repeatably in asymptomatic leaves, then it may be possible to develop an assay for detecting trunk diseases by examining the leaves of apparently healthy plants. Greenhouse, laboratory, and field experiments will be conducted to determine when toxins are detectable in asymptomatic leaves, and whether toxin detection varies by cultivar/species. Objective 4: By intentionally exposing grapes to various levels of smoke and making wines, threshold levels of smoke-derived biomarkers can be determined utilizing established chromatographic mass spectrometry methods and a novel portable nanocerium detection tool. Novel smoke-derived compounds absorbed by grapes can be identified through exposing grapevines to smoke from various fuel types and to smoke from an isotopically labeled fuel source. Widely planted cultivars will be intentionally exposed to smoke in an in-house constructed smoking chamber. Wine fermentations from each treatment will be conducted. Grape and wine samples will be analyzed for smoke-derived biomarkers utilizing GC-MS/MS for analysis of VPs and LC-MS/MS for their glycoconjugates and the wines will be analyzed further for sensory attributes.