Changes in soluble sugars and the expression of sugar transporter protein genes in strawberry crowns responding to infection.

UNLABELLED

Strawberry ( × ) production has been greatly hampered by anthracnose crown rot caused by . Crown, the modified stem of strawberry, is a sink organ involved in sugar allocation. Some Sugar Transport Proteins (STPs) are involved in competition for sugars between pathogen and host. However, the chemical nature and involvement of strawberry s (s) in crown rot development is largely elusive. To reveal how strawberry alters soluble sugars and upregulates s in responses to , high performance liquid chromatograph and  expression analysis were performed in the crowns of three strawberry varieties, following a genome-wide identification of s. Both and mock treatment/control changed glucose, fructose and sucrose accumulation in strawberry crowns. With increasing infection duration, the hexose/sucrose ratio increased in all varieties; no such trend was clearly visible in mock-treated plants. A total of 56 loci scattered across four subgenomes were identified in octoploid strawberry, and most of the protein products of these genes had a preferential location on plasma membrane. Putative fungal elicitor responsive cis-elements were identified in the promoters of more than half s. At least eight members were upregulated in strawberry crowns during invasion. Of them, expression was markedly enhanced in three varieties at all time points except for 3 dpi in 'Jiuxiang'. RNAseq data retrieval further validated the expression responses of s to spp. In summary, this work identified several candidate genes responsive to invasion, demonstrated changes in soluble sugar levels in strawberry crowns as a result of infection, and laid the groundwork for future efforts to engineer strawberry resistance to spp.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s12298-024-01523-9.