Niagara Rosada (Vitis labrusca x Vitis vinífera) transcriptional response to rust fungi (Neophysopella tropicalis) and water déficit

• Ano de defesa: 2025
• Autor(a) principal: Rodrigues, Gustavo Lima
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: ‘Niagara Rosada’ Neophysopella tropicalis; Vitis labrusca; Ferrugem da videira; Grapevine leaf rust; Transcriptomica; Transcriptomics
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/11/11137/tde-12052025-094616/

Grapes are amongst the most cultivated crops in Brazil. ‘Niagara Rosada’ (Vitis labrusca x Vitis vinífera) is the most produced seed grape and has a lower price than seedless grapes, which makes it more accessible for consumers. Winemaking shares a small portion of the grape products in Brazil, while most grapes are destined for fresh fruit consumption or juice-making, and ‘Niagara Rosada’ is among those grapes. ‘Niagara Rosada’ arose from a somatic mutation in ‘Niagara Branca’ (Vitis labrusca x Vitis vinífera) cultivated in São Paulo in 1933. In grapevines, there are several transcriptomes from grapes due to its economic importance. Nevertheless, investigating the transcriptional response to pathogens can support the development of resistant varieties and increase productivity. We investigated the ‘Niagara Rosada’ transcriptional response to grapevine leaf rust (GLR) and water deficit. GLR is caused by the biotrophic fungi Neophysopella tropicalis. In the climatic change scenario, grapevines are expected to have GLR under water deficit. Previous studies demonstrated that GLR causes early leaf fall, reduces the carbon accumulation in the roots and photosynthesis, and that water deficit increases the disease severity, reducing grape yield. We conducted an experiment composed of two treatments on ‘Niagara Rosada’, one with rust fungi spore solution inoculation and a sporeless solution as control, and other of water deficit at 40% of the water available capacity (WAC) and WAC at 80% for the controls without water deficit. Leaves were sampled immediately after inoculation, 7 and 15 days post-inoculation. The RNA was extracted and the mRNA sequenced in the Illumina platform. The sequenced reads were mapped to the reference genome Vitis vinifera PN_T2T and the genes differential expression detected with the software Deseq2. Several defense genes were upregulated in response to rust infection and downregulated in response to water deficit. The infection caused strong photosynthesis genes downregulation, compromising the light harvesting complex, and photosystem I and II components. The water deficit caused the differential expression of several genes involved in cell wall organization. The joint effect of water deficit and GLR impairs the upregulation of some defense genes, which possibly contributes to the increased severity.