title: Exogenous melatonin improved potassium content in Malus under different stress conditions.
abstract: Melatonin mediates many physiological processes in plants. We investigated its role in regulating growth, potassium uptake, and root system architecture under three types of stress: salinity or a deficiency of all nutrients in Malus hupehensis Rehd., as well as a K deficiency in Malus rockii Rehd. Each treatment caused a reduction in growth rates and disrupted the absorption of potassium. However, pretreatment with 0.1 mmol/L melatonin significantly alleviated such inhibitions. The addition of melatonin also upregulated genes for antioxidant enzymes involved in the ascorbate-glutathione cycle (MdcAPX, MdDHAR1, MdDHAR2, MdMDHAR, and MdcGR) and helped decrease the accumulation of H2 O2 while improving the expression of K transporters and genes for the CBL1-CIPK23 pathway. These results indicated that melatonin can regulate the ROS signal and activate the CBL1-CIPK23 pathway to regulate the expression of a potassium channel protein gene, thereby promoting the absorption of potassium ions. Our findings demonstrate that inducing melatonin production is an important mechanism for plant defenses that can serve as a platform for possible applications in agricultural or related fields of research.
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Bowen
authors.initials: B
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Chang
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Shasha
authors.initials: S
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Fengwang
authors.initials: F
authors.lastname: Ma
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D001205:Ascorbic Acid / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D027845:Malus / Q000378:metabolism*; D008550:Melatonin / Q000494:pharmacology*; D010088:Oxidoreductases / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000378:metabolism; D013312:Stress, Physiological / Q000187:drug effects*
chemical_list: D000975:Antioxidants; D010940:Plant Proteins; D015221:Potassium Channels; D010088:Oxidoreductases; D005978:Glutathione; D008550:Melatonin; D001205:Ascorbic Acid; D011188:Potassium
keywords: CBL-CIPK pathway; Malus; melatonin; potassium transporters; root system architecture; stress