TITLE:
Anthocyanin-Related Gene Expression and Heat Tolerance in Kale
AUTHORS:
Jingyin Mai, Weixi Li
KEYWORDS:
Anthocyanin, Gene Expression, Heat Tolerance, Kale (Brassica oleracea), Cell Membrane Stability
JOURNAL NAME:
Agricultural Sciences,
Vol.17 No.10,
October
9,
2026
ABSTRACT: This study investigated the relationship between anthocyanin-related gene expression, pigment accumulation, and heat tolerance in kale (Brassica oleracea) with different leaf colors: green, pink, and purple. The expression levels of three key genes—bHLH1, DFR4, and ANS4—were analyzed using qPCR, alongside measurements of anthocyanin content and cell membrane stability under high-temperature stress. Purple kale exhibited the highest expression levels of ANS4 and DFR4, at more than 40-fold and 45-fold, respectively, relative to the green group, and the highest anthocyanin content (18.09 mg/g FW). Heat tolerance tests showed that green kale had the highest critical temperature (Tcrit, 63.26˚C), while pink and purple kale showed lower Tcrit values of 59.58˚C and 59.29˚C, respectively. These findings indicate an association between higher expression of anthocyanin-related genes and greater anthocyanin accumulation, while higher anthocyanin content coincided with lower membrane thermostability under the tested conditions. The observed differences may reflect the combined effects of anthocyanin accumulation and other physiological differences among the kale groups. This study provides molecular and physiological insights into the variation in leaf coloration and heat responses among kale with different leaf colors.