The Different Physiological Responses of Natural and Stationary Low Temperature on White Clover (Trifolium repens L.)

Abstract

Plants initiate lipid peroxidation or accumulate proteins to repair cell membrane damage caused by low temperatures. However, a stationary low temperature simulation cannot accurately explain plant tolerance to naturally low outside temperatures. Our study showed that there was a strong negative correlation between the natural temperature decrease and the protein contents in white clover roots, stems and leaves. The differences between the normal temperature (19 C) and low temperatures (0 C and 5 C) for lipid peroxidation, chlorophyll content, relative electrolyte leakage, malondialdehyde (MDA) content, and superoxide dismutase (SOD) activity under the stationary low temperature regime were significantly higher than under the natural low temperature regime. While the difference between low temperatures and normal temperatures for relative water content, free proline content, and superoxide anion radical production rates under the stationary low temperature regime did not significantly change compared to the levels recorded under the natural low temperature regime. This finding suggests that the results for low temperature tolerance by white clover under the stationary low temperature by manual simulation regime are different from the natural low temperature regime.