Research on Alleviating Effect of Exogenous Melatonin on Cold Damage to Sorghum at Seedling Stage
Zhou Guangyi
Liu Xiaojuan
Wang Rui
An Yuxia
Qin Xianjiao
Ren Mingjian
Wang Yunbang
Abstract：Low temperature often produces irreversible damage to sorghum seedlings.In order to clarify the alleviating effect of exogenous melatonin(MT)pretreatment on sorghum seedlings under low temperature,the experiment on the ecophysiological effects of different MT concentrations on sorghum seedlings under low-temperature stress was conducted firstly in order to screen out the optimum MT concentration,and then four treatments of ambient temperature control(CK),ambient temperature+melatonin(CK+MT),low-tempera-ture control(LT)and low temperature+melatonin(LT+MT)were set to study the alleviating effect of MT pretreatment on cold damage to sorghum seedlings.The results showed that 200 μmol/L MT pretreatment had the best effect on alleviating cold damage to sorghum seedlings through promoting the synthesis of photosynthet-ic pigments,increasing the activity of antioxidant enzymes,enhancing the stability of cell membranes,in-creasing the content of osmotic substances,and improving the efficiency of AsA-GSH cycle,so as to promote the growth of plants.In addition,the content of indoleacetic acid,indolebutyric acid,gibberellin A1,gibber-ellin A7 and abscisic acid were mostly significantly increased,and that of indolecarboxylic acid,gibberellin A3,jasmonic acid and dihydrojasmonic acid were significantly decreased in the sorghum seedlings under exog-enous MT pretreatment.The results of this study might provide a reference for the use of MT to alleviate cold damage to sorghum seedlings.
Keywords：SorghumMelatoninLow temperature stressPhysiological mechanismsEndogenous hor-mones
Publication Date：2025-02-28
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：9( 55-63 )