Pepper whitefly-borne vein yellows virus (PeWBVYV): a major factor underlying fruit discoloration in pepper (Capsicum annuum L.)

Abstract Following the discovery of the polerovirus pepper whitefly-borne vein yellows virus (PeWBVYV), fruit discoloration has continually affected pepper production across the Jordan Valley, a key pepper-producing region in Israel. This color pattern, resembling symptoms previously associated with several pepper-infecting poleroviruses, causes significant losses to local pepper production. To assess the potential link between fruit discoloration and PeWBVYV infection, we monitored fruit color profiles in commercial fields throughout the region, as well as in a controlled inoculation plot. Using the CIELab system for color evaluation, we found a consistent association between infection and fruit discoloration in both commercial fields and controlled inoculation. Across three red-fruited cultivars, infected fruits exhibited measurable reductions in redness and color intensity. Meanwhile, a color shift toward orange hues was recorded only in two of the three cultivars, suggesting intervarietal differences in response to infection. Comparison of infected and non-infected discolored fruits further demonstrated a clear separation between color profiles. Nevertheless, unlike field infections, controlled inoculation failed to reproduce overt discoloration. Beyond symptom development, PeWBVYV exhibited differential distribution across plant tissues. The virus was undetectable or detected at low levels in most central-canopy and basal leaves, but was consistently detected in symptomatic fruits, most young leaves, and in root tissues, with inter-plant variation. Collectively, these findings identify PeWBVYV as a major factor associated with pepper fruit discoloration and support efforts to dissect the mechanisms underlying virus-associated pigmentation changes, tissue-specific accumulation, and potential mitigation strategies.