Physiological effects of the combined stresses of freezing-thawing, acid precipitation and deicing salt on alfalfa seedlings

Abstract

Background Frequent freeze-thaw phenomena, together with widely used deicing salt and intense acid precipitation, often occur in northeastern China, causing damage to various aspects of plants, such as the permeability of biological membranes, osmotic adjustment, and photosystems. Aiming to explore the resistance of alfalfa to freezing-thawing (F), acid precipitation (A) and deicing salt (D), this study used Medicago sativa cv. Dongmu-70 as the experimental material, and the contents of malondialdehyde (MDA), soluble protein, soluble sugars, proline and chlorophyll were evaluated. Results As the temperature decreased, the MDA content in the seedlings of the group under combined stress (A-D-F) increased and was significantly higher than that of group F (by 69.48 ~ 136.40%). Compared with those in the control (CK) group, osmotic substances such as soluble sugars and proline in the treatment groups were higher, while the soluble protein content was lower. The chlorophyll contents in the seedlings of the treatment groups were lower than those of the CK group; however, the chlorophyll content displayed a non-significant change during the free-thaw cycle. Conclusion Injury to the permeability of the biological membranes and photosystems of alfalfa results from stress. Moreover, alfalfa maintains osmotic balance by adaptively increasing the potential of osmotic substances such as soluble sugars and proline. Furthermore, the influence of stress from freezing-thawing and deicing salt is highly substantial, but the combined stresses of acid precipitation with the two factors mentioned above had little effect on the plants.

Improved Tolerance of Mycorrhizal Torreya grandis Seedlings to Sulfuric Acid Rain Related to Phosphorus and Zinc Contents in Shoots

“…Previous studies have shown that SAR can induce soil and water acidification, forest decline, and damage to buildings, resulting in heavy economic losses to local governments [ 9 , 10 ]. Furthermore, SAR has complex ecological consequences in plants, such as stunting their height, degrading root system growth, interrupting the accumulation of low-molecular-weight solutes, and obstructing the transportation of nutrients, which can adversely influence biomass accumulation, decrease plant resistance to unfavorable conditions, and induce mortality [ 11 , 12 , 13 ]. Therefore, physical, chemical, and/or biological approaches applied to remediate the detrimental effects of SAR or improve resistance to SAR have received increased attention [ 12 , 14 , 15 , 16 , 17 ].…”

Physiological response of Kobresia pygmaea to temperature changes on the Qinghai-Tibet Plateau

“…The MDA content is a reflection of lipid peroxidation and is usually used to measure stress-induced damage at the cellular level [ 27 ]. In this study, Kobresia pygmaea in different months showed responses to temperature changes.…”

Response To Light Intensity of Sun And Shade On Two Cool Season Turfgrass

“…In this study, the changes in MDA content of the two grass species were different. O2-belongs to oxygen-containing free radicals, and when plants are exposed to external stimuli, they will cause the accumulation of O2-in cells [71,72]. This may be because, for plants, too strong or weak light has a stress effect on the plants, which increases the amount of active oxygen in the plant, and reduces the activity of the antioxidant enzyme system, which is caused by the inability to clean up the excess active oxygen in time [73].…”