Melatonin mediates selenium-induced tolerance to cadmium stress in tomato plants.
Both selenium (Se) and melatonin reduce cadmium (Cd) uptake and mitigate Cd toxicity in plants. However, the relationship between Se and melatonin in Cd detoxification remains unclear. In this study, we investigated the influence of three forms of Se (selenocysteine, sodium selenite, and sodium selenate) on the biosynthesis of melatonin and the tolerance against Cd in tomato plants. Pretreatment with different forms of Se significantly induced the biosynthesis of melatonin and its precursors (tryptophan, tryptamine, and serotonin); selenocysteine had the most marked effect on melatonin biosynthesis. Furthermore, Se and melatonin supplements significantly increased plant Cd tolerance as evidenced by decreased growth inhibition, photoinhibition, and electrolyte leakage (EL). Se-induced Cd tolerance was compromised in melatonin-deficient plants following tryptophan decarboxylase (TDC) gene silencing. Se treatment increased the levels of glutathione (GSH) and phytochelatins (PCs), as well as the expression of GSH and PC biosynthetic genes in nonsilenced plants, but the effects of Se were compromised in TDC-silenced plants under Cd stress. In addition, Se and melatonin supplements reduced Cd content in leaves of nonsilenced plants, but Se-induced reduction in Cd content was compromised in leaves of TDC-silenced plants. Taken together, our results indicate that melatonin is involved in Se-induced Cd tolerance via the regulation of Cd detoxification.
Department of Horticulture, Zhejiang University, Hangzhou, China.
Meng-Qi
MQ
Li
Department of Horticulture, Zhejiang University, Hangzhou, China.
Md Kamrul
MK
Hasan
Department of Horticulture, Zhejiang University, Hangzhou, China.
Cai-Xia
CX
Li
Department of Horticulture, Zhejiang University, Hangzhou, China.
Golam Jalal
GJ
Ahammed
Department of Horticulture, Zhejiang University, Hangzhou, China.|Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Hangzhou, China.
Xiao-Jian
XJ
Xia
Department of Horticulture, Zhejiang University, Hangzhou, China.|Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Hangzhou, China.
Kai
K
Shi
Department of Horticulture, Zhejiang University, Hangzhou, China.|Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Hangzhou, China.
Yan-Hong
YH
Zhou
Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA.
Russel J
RJ
Reiter
Department of Horticulture, Zhejiang University, Hangzhou, China.|Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Hangzhou, China.|Key Laboratory of Horticultural Plants Growth, Development and Quality Improvement, Agricultural Ministry of China, Hangzhou, China.
Jing-Quan
JQ
Yu
Geological Research Center for Agricultural Applications, China Geological Survey, Hangzhou, China.|Zhejiang Institute of Geological Survey, Hangzhou, China.
Ming-Xing
MX
Xu
Department of Horticulture, Zhejiang University, Hangzhou, China. jie@zju.edu.cn.|Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Hangzhou, China. jie@zju.edu.cn.
Jie
J
Zhou
D001142:Aromatic-L-Amino-Acid Decarboxylases / Q000096:biosynthesis; D002104:Cadmium / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D020868:Gene Silencing / Q000187:drug effects; D018551:Solanum lycopersicum / Q000378:metabolism*; D008550:Melatonin / Q000378:metabolism*; D010940:Plant Proteins / Q000096:biosynthesis; D064586:Selenic Acid / Q000494:pharmacology*; D012643:Selenium / Q000494:pharmacology; D017279:Selenocysteine / Q000493:pharmacokinetics*; D018038:Sodium Selenite / Q000494:pharmacology*; D013312:Stress, Physiological / Q000187:drug effects*
D010940:Plant Proteins; D002104:Cadmium; D017279:Selenocysteine; D001142:Aromatic-L-Amino-Acid Decarboxylases; D012643:Selenium; D018038:Sodium Selenite; D064586:Selenic Acid; D008550:Melatonin
cadmium; glutathione; melatonin; phytochelatins; selenium; tomato; tryptophan decarboxylase