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ARS Home » Pacific West Area » Pullman, Washington » Plant Germplasm Introduction and Testing Research » Research » Publications at this Location » Publication #422751
Research Project: Genetic Resource and Information Management for Pulse, Temperate Forage Legume, Oilseed, Vegetable, Grasses, Sugar, Ornamental, and Other Crops

Location: Plant Germplasm Introduction and Testing Research

Title: Foliar starch accumulation precedes the cascade of grapevine red blotch disease symptoms

Author
item COPP, CODY - Oregon State University
item DESHIELDS, JOSEPH - Oregon State University
item KAR, SURAJ - Oregon State University
item CLARK, RICKY - Oregon State University
item KC, ACHALA - Oregon State University
item Hallwachs, Bailey
item BONDADA, BHASKAR - Washington State University
item LEVIN, ALEXANDER - Oregon State University

Submitted to: American Journal of Enology and Viticulture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/30/2024
Publication Date: 1/1/2025
Citation: Copp, C.R., DeShields, J.B., Kar, S., Clark, R.W., KC, A.N., Hallwachs, B.S., Bondada, B., Levin, A.D. 2025. Foliar starch accumulation precedes the cascade of grapevine red blotch disease symptoms. American Journal of Enology and Viticulture. 76. Article 0760001. https://doi.org/10.5344/ajev.2024.24045.
DOI: https://doi.org/10.5344/ajev.2024.24045

Interpretive Summary: Grapevine Red Blotch Virus (GRBV) is a major pathogen of Vitis vinifera L. which negatively impacts proper berry ripening and subsequent quality of grape products. The virus infection disrupts carbon assimilation before and after berry ripening, whereby sugar produced by the chloroplast becomes backed up causing damage to the structure and function of the organelle. This study demonstrates the development of starch in infected leaves which disrupts proper source (leaf) to sink (berry) sugar accumulation and may have sustained effects on leaf metabolism and ripening prior to the visible appearance of characteristic red blotch symptoms.

Technical Abstract: Grapevine Red Blotch Virus is a major pathogen of Vitis vinifera L. which reduces carbon assimilation and delays berry ripening. Recent work suggests that the virus alters leaf carbon metabolism prior to emergence of visible symptoms. Diurnal and seasonal measurements were conducted to quantify changes in leaf carbon balance and chronologize symptom progression in leaves and fruit. Leaf-level physiology was measured as a function of water relations, photosynthesis, and nonstructural carbohydrates in a commercial vineyard containing both healthy and infected vines. Additionally, fruit sugar and anthocyanin accumulation were monitored during ripening. Virus infection reduced carbon assimilation pre- and postveraison, but the impact was more pronounced postveraison and during the afternoon. Similarly, virus infection significantly increased leaf starch concentration pre- and postveraison. Starch granules accumulated in the chloroplasts and caused apparent damage to their structural and functional integrity. The virus had no sustained impact on chlorophyll fluorescence, suggesting that changes in fluorescence were a transient response to reduced carbon assimilation and export. This study provides evidence that Grapevine Red Blotch Virus infection causes starch accumulation in infected leaves which disrupts carbon assimilation and may have downstream effects on leaf metabolism and ripening prior to the appearance of visible symptoms.