‘Sultanina’ leaves increase their trehalose content in response to grapevine brown leaf spot infection by regulating the pentose and glucuronate interchange pathway

Abstract

Since the first discovery of grapevine brown leaf spot disease in Turpan, Xinjiang, China, in 2007, it has been a common occurrence in grapevine-growing regions. Grapevine brown leaf spot seriously decreases fruit yield and has become one of the most important leaf diseases in the Turpan region. However, thus far, there have been no reports on the evaluation of grapevine germplasm resources for resistance to brown leaf spot disease. In addition, the response mechanism of grapevine leaves to brown leaf spot infection has not been revealed. To better understand the resistance of grapevine germplasm resources to brown leaf spot disease, we first evaluated resistance in grapevine varieties. On this basis, the most susceptible variety ‘Sultanina’ was selected as the experimental material for this study. Transcriptome analysis and carbohydrate content analysis were performed on ‘Sultanina’ leaves with different levels of disease susceptibility. As the severity of the disease increased, the content of fructose gradually decreased, while the content of trehalose gradually increased. Transcriptome data revealed that differentially expressed genes were enriched in the pentose and glucuronate interchange pathway. These results suggest that the sugar trehalose may play an important role in the response of ‘Sultanina’ leaves to brown leaf spot infection. In addition, the pentose and glucuronate interchange pathway may be involved in the response mechanism of brown leaf spot disease. Our work provides new insights into the mechanism of the ‘Sultanina’ leaf response to brown leaf spot infection.