Melatonin enhances cold tolerance in drought-primed wild-type and abscisic acid-deficient mutant barley.
Melatonin is involved in multiple plant developmental processes and various stress responses. To explore the roles of melatonin played as well as its association with abscisic acid (ABA) in a process of drought priming-induced cold tolerance (DPICT), a wild-type barley and its ABA-deficient mutant Az34 counterpart were selected for comparison, in which the effects of melatonin application (either foliarly or rhizospherically) and/or drought priming on the cold tolerance of both types of barleys were systematically investigated. It was demonstrated that the early drought priming induced an increase of endogenous melatonin production, which is not ABA dependent. In addition, exogenously applied melatonin resulted in higher ABA concentration in the drought-primed plants than in the nonprimed plants when exposed to cold stress, indicating that ABA responded in a drought-dependent manner. The interplay of melatonin and ABA leads to plants maintaining better water status. Drought priming-induced melatonin accumulation enhanced the antioxidant capacity in both chloroplasts and mitochondria, which sustained the photosynthetic electron transport in photosynthetic apparatus of the plants under cold stress. These results suggest that the exogenous melatonin application enhances the DPICT by modulating subcellular antioxidant systems and ABA levels in barley.
Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Tåstrup, Denmark.
Xiangnan
X
Li
Department of Cellular and Structural Biology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
Dun-Xian
DX
Tan
National Engineering and Technology Center for Information Agriculture/Key Laboratory of Crop Physiology and Ecology in Southern China, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China.
Dong
D
Jiang
Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Tåstrup, Denmark. fl@plen.ku.dk.
Fulai
F
Liu
D000040:Abscisic Acid / Q000235:genetics* / Q000378:metabolism; D003080:Cold Temperature; D058639:Cold-Shock Response / Q000187:drug effects* / Q000235:genetics; D001467:Hordeum / Q000235:genetics / Q000378:metabolism*; D008550:Melatonin / Q000494:pharmacology*; D009154:Mutation
D000040:Abscisic Acid; D008550:Melatonin
Hordeum vulgare; abscisic acid; cold tolerance; melatonin; priming; stress memory