Accumulation of tocopherols and transcriptional regulation of their biosynthesis during cold storage of mandarin fruit

Tocopherols are plant-derived isoprenoids with potent antioxidant activity, which have been implicated in the tolerance of plants to different stresses. However, tocopherol accumulation and biosynthesis fruit, their potential implication postharvest chilling injury (CI), has scarcely studied. Therefore, this work, we investigated peel mandarin fruit three cultivars contrasting susceptibility CI during storage at 2 °C (‘Fortune’>‘Nova’> ‘Nadorcott’). α- γ-tocopherol were isoforms detected flavedo a direct relationship between tocopherols content CI-tolerance was found, since CI-tolerant accumulated highest whereas CI-sensitive lowest. Moreover, transcriptional profiling 14 genes related specific steps biosynthesis, precursor’s synthesis, analyzed. Upstream DXS1 DXS2 (1-deoxy-d-xylulose-5-phosphate synthase) GGDR (geranylgeranyl diphosphate reductase), involved supply phytyl pyrophosphate, VTE3 (2-methyl-6-phytyl-1,4-benzoquinol methyltransferase) appear be key for differences total among harvest. During cold storage, most precursors up-regulated, tocopherol-core pathway general repressed. Changes VTE4 may account cultivars. Collectively, results suggest that concentration harvest play function natural CI, changes expression cold-regulated responses, rather than tolerance.