Grapevine Red Blotch Disease Affects Carbohydrate Homeostasis and Cell Call Characteristics in Vitis Vinifera L.

Abstract BackgroundGrapevines are commonly infected with one or more viruses causing a significant threat to the sustainability of quality wine grape production worldwide. The recently identified Grapevine red blotch disease (GRBD) significantly affects the yield and quality of wine grapes. It is largely unknown how the red blotch disease affects carbohydrate homeostasis and regulate the source-to-sink relationship in grapevines. We took an integrative approach to determine the consequences of viral infection in commercially grown, two popular wine grape cultivars from distinct locations in the eastern Washington.ResultsThe deep sequencing approach revealed that Grapevine red blotch virus (GRBV) was found in all symptomatic vines, while asymptomatic vines were free of this virus. Analysis of mature berries at commercial harvest in virus-infected vines indicated significant changes in the soluble sugar accumulation along with the increase in leaf sucrose and starch content. To follow up with the altered carbohydrate homeostasis, we analyzed cell wall components in winter canes of virus-infected vines and compared them to their virus-free counterparts. Major cell wall monosaccharide contents and total lignin content was not affected due to red blotch disease in either cultivar. However, high-resolution glycome profiling revealed consistent changes in loosely bound cell wall pectin matrices and tightly bound non-fucosylated xyloglucans in virus-infected vines. Furthermore, in cv. Syrah, co-infection with other viruses leads to additional cell wall compositional variations.ConclusionsThese changes highlighted that virus infection in woody perennial leads to detrimental adjustments in the soluble and storage carbohydrates, and in the cell wall layers that could be attributed to lower vine performance or vine decline in a relatively short time. The information gained from such qualitative cell wall structural fine-tuning could be used in assessing how viruses or other pathogenic agents affect perennial longevity.