Effects of combined application of selenium and various plant hormones on the cold stress tolerance of tomato plants

Abstract

Abstract Aims The roles of selenium (Se) in relieving the harmful effect of cold stress have been reported, but there are few studies on the interaction between Se and various plant hormones in plants in response to cold stress. Here, the effects of Se and various plant hormones on tomato plants under cold stress have been investigated. Methods The biomass, relative electrical conductivity, photosynthetic pigments, malondialdehyde, chlorophyll fluorescence, soluble sugar, proline contents, as well as the regulation of plant hormones were examined. Results Among several plant hormones, the co-application of Se and SA was the most effective in reducing the cold stress of tomato plants. The co-application of Se and SA prevented the oxidative damage caused by cold stress on tomato chloroplasts and preserved the plasma membrane integrity and regulated the osmotic substances under cold stress. The interaction between Se and SA modulated the expression of some cold-induced genes thereby conferring cold tolerance of tomato plants. But the pretreatment with a SA biosynthesis inhibitor (AIP) eliminated the favorable influence of Se on the cold resistance of tomato, indicating that enhancing the cold resistance of plants by regulating the synthesis of SA might be one of the mechanisms by which Se enhanced tomato’s resistance to cold stress. Conclusions Our results clarified the roles of Se and its regulation mechanisms in plant cold stress tolerance and the critical involvement of SA in this process, which might offer a theoretical foundation for using Se fertilizer to increase the production of crops under adversity stresses.