耐寒性ケール（Brassica oleracea L. var. acephala）遺伝子型の露地栽培条件下における寒冷応答性代謝変化を通じたスクリーニング

Kale (Brassica oleracea L. var. acephala) is a cold-tolerant leafy vegetable whose metabolic plasticity under frost stress remains underexplored. In this study, leaf tissues from 26 kale accessions grown under open-field conditions were metabolically profiled, focusing on soluble sugars, glucosinolates, and photosynthetic pigments before and after exposure to short-term frost. Frost stress induced significant quantitative and compositional shifts in sugar profiles, notably an accumulation of sucrose, suggesting its role as a key osmoprotectant. Among the twelve glucosinolates identified, indolic compounds dominated the unfrosted profile (67.4 %) but declined post-frost (51.6 %), coinciding with a marked increase in aliphatic glucosinolates (from 20.7 % to 38.6 %). Chlorophyll and carotenoid contents declined in most accessions following frost exposure. Notably, the metabolic profile of Accession_4 indicates a potentially resilient phenotype, characterised by limited pigment degradation and a shift toward aliphatic glucosinolates. This may reflect a stress-adaptation strategy and could be explored as a candidate for breeding or metabolotype selection approaches.