Cucumber (Cucumis sativus) fruit deterioration in cold storage is aggravated by cucumber green mottle mosaic virus infection

Cucumber ( Cucumis sativus L.), a widely cultivated and important crop, is susceptible to the Tobamovirus cucumber green mottle mosaic virus (CGMMV). CGMMV is known to reduce cucumber yield, yet little is known about its impact on the postharvest quality of the fruit. To examine the effect of CGMMV infection on the quality and storability of cucumber fruit after harvest, cucumber plants were inoculated with CGMMV at three different developmental stages: seedling infection, infection during the vegetative growth of the plants (along with trellis application), and infection during fruit set. Early-stage infections (seedling and trellising) led to significant reductions in yield and impaired fruit quality (shape, color, and weight). Conversely, infections during the fruit set stage produced marketable fruit that showed no apparent differences comparable to non-infected control fruit at harvest. Nevertheless, the quality of fruit after cold storage was significantly affected by CGMMV infection. Virus-infected fruit were more susceptible to chilling injuries, as evidenced by the degradation of fruit peel chlorophyll, increased ion leakage, elevated levels of Malondialdehyde, and higher values of auto-luminescence. Furthermore, CGMMV-infected fruits were more susceptible to gray mold disease caused by Botrytis cinerea . Transcriptomic profiling of infected fruit at harvest revealed upregulation of genes associated with phenylpropanoid and ethylene metabolism, ERF and WRKY transcription factors, suggesting the involvement of several pathways in mediating the differential physiological response of CGMMV-infected fruits to postharvest insults. These results indicate viral infection of fruit as an additional, previously unappreciated factor that affect quality and postharvest losses of fresh produce.