How hydrangea cultivars react under low temperature stress

Hydrangea, which has large and vivid flowers, is a crucial ornamental plant used in landscape design. However, its limited tolerance to cold restricts its widespread application in regions with low temperatures. To investigate the effects of low-temperature stress on hydrangea, four common cultivars were examined.

By comparing leaf anatomical structures and physiological parameters—including soluble substance levels, antioxidant enzyme activities, and cold resistance-related gene expression levels—under different low-temperature conditions (4°C, 0°C, -4°C, -8°C, and -12°C), cold resistance was comprehensively evaluated. The semilethal temperature (LT50) values of the four cultivars ranged from -2.404°C to -3.133°C, with ‘Magic Coral’ and ‘Forever Summer’ having the lowest values. Under low-temperature stress, the malondialdehyde (MDA) production rate in hydrangea leaves increased significantly, whereas antioxidant enzyme activity and soluble substance contents initially increased but subsequently decreased with decreasing temperature. Moderate low-temperature stress increased the expression of antioxidant enzymes and cold resistance-related genes (ERF, POD, CHS, and ANS), thereby increasing the activity of intracellular antioxidant defense systems. This mechanism contributed to enhanced cell membrane stability and increased overall cold resistance in hydrangeas. A comprehensive evaluation was conducted using the membership function method, which allowed for the analysis of both leaf anatomical structure indices and physiological indicators.

The results revealed differences in cold resistance among the four selected hydrangea cultivars, indicating that the cold tolerance of ‘Forever Summer’ and ‘Magic Coral’ was superior to that of ‘Tabei’ and ‘Huabao’. Therefore, ‘Forever Summer’ and ‘Magic Coral’ are recommended as priority cultivars for landscape applications in regions with low temperatures.

Qiao, Qian & Wang, Chenyu & Li, Jing & Liu, Kan & Tang, Hao & Wang, Jiangyong & Gao, Yun. (2026). Anatomical, biochemical and gene expression studies in four hydrangea cultivars under low temperature stress. Frontiers in Plant Science. 16. 10.3389/fpls.2025.1655585.

Source: ResearchGate