Recipient Organization
University of Maryland Eastern Shore
11868 College Backborne Road
Princess Anne,MD 21853
Performing Department
(N/A)
Non Technical Summary
Climate change-related heat stress adversely affects grapevine production by causing sunburn incidence, which results in poor fruit color, cluster browning, and reduced post-harvest shelf life. Conventional breeding has achieved limited success due to extreme heterozygosity of the grape genome that results in cultivars with poor fruit quality following hybridization. Precision breeding and genome editing, which involves modification of grape genomic DNA sequences, is consumer and ecofriendly inasmuch it disrupts the genome much less than traditional breeding and should cause no GMO-related concerns. The project will utilize precision breeding and genome editing for development of grape cultivars with improved fruit color and shelf-life, and increase grower awareness of management practices for mitigating heat stress in vineyards. Grape cultivars with stable color accumulation and decreased browning will provide an impetus for growers to produce high quality fruit. Organization of extension events will generate grower awareness regarding management strategies to mitigate effects of heat stress. The multi-disciplinary expertise of collaborators will strengthen linkages among 1890 institutions, universities and the industry. It will enhance institutional research and teaching capacity through minority student training in plant breeding.
Animal Health Component
40%
Research Effort Categories
Basic
60%
Applied
40%
Developmental
(N/A)
Goals / Objectives
The goal of the project is to overcome climate change induced-limitations (heat/high temperature stress) in grapevine production by developing cultivars with improved color and shelf-life and increase grower awareness of canopy management practices to mitigate heat stress in vineyards. Specific objectives include 1) identification and isolation of Vitis-derived Myb transcription factors, polyphenol oxidase genes and their related genetic elements for the development of precision bred and editing constructs, 2) establishment of embryogenic cultures and transformation for the development of precision bred (PB) and edited plant lines, 3) screening plant lines for color development and stability, browning/necrosis and post-harvest shelf-life, 4) conduct molecular and metabolomic analyses of PB and edited plant lines for anthocyanin accumulation, PPO enzymes, and antioxidants and 5) conduct extension events to train farmers in identifying sunburn damage to fruit and poor berry coloration, fruit maturity and ripening parameters including fruit color, sugars, acids and polyphenol compounds under varying climates.
Project Methods
A detailed sequence analysis of the MybA genes across various cultivars and species will provide information on the sequences to select for precision bred constructs and consensus regions to target using CRISPR/Cas9. The Pinot Noir reference genome will be used along with other online genomic databases to identify target gene sequences. Once candidate sequences are characterized, they will be inserted, along with their native promoters into binary vector backbones. Additionally, we have identified the PPO gene families from V. vinifera 'Thompson Seedless and developed guide RNA sequences that target the PPO-1 and PPO-2 genes. These sequences will be utilized to generate CRISPR-Cas9 constructs. All constructs will be transferred to Agrobacterium and used for transformation experiments. Embryogenic cultures will be used to generate precision bred grapevine lines expressing the MybA genes and edited lines for the PPO genes. Regenerated plant lines will be transferred to a greenhouse and grown for the production of fruit that will be used to test quality traits and post-harvest shelf life. Detailed molecular analyses of precision bred and edited vines will be carried out along with the estimation of anthocyanins and phenolic compounds. Phenotypic, molecular and biochemical analysis will be correlated to identify promising lines with improved color development and decreased browning.