A Simple, Rapid Method for Determination of Melatonin in Plant Tissues by UPLC Coupled with High Resolution Orbitrap Mass Spectrometry.
Melatonin (MLT) was involved in regulating various stages of plant growth and development. However, due to the low concentration and complex matrixes of plant, the analysis of MLT is a challenging task. In this study, we developed a rapid and efficient method with simplified sample preparation by employing UPLC coupled with a high resolution Orbitrap mass spectrometry, and stable isotope-labeled MLT (MLT-d4) was first used as internal standard in the developed analytical method. In the developed method, we used one-step liquid-liquid extraction to purify the crude extracts both from shoot and root of rice for the analysis, which remarkably simplify the sample preparation process. The method exhibits high specificity and recovery yield (>96.4%). Good linearities were obtained for MLT ranging from 0.01 to 20 ng/ mL with determination coefficient (R2) of 0.9991. The limit of detection for MLT was 0.03 pg. Reproducibility of the method was evaluated by intra-day and inter-day measurements and the results showed that relative standard deviations were less than 7.2%. Moreover, MLT quantification was accomplished by using only 100 mg fresh plant tissues. Additionally, the established method was successfully applied to investigate the spatiotemporal distributions of MLT in rice under cadmium (Cd) stress condition. We found that the content of MLT in shoot and root of rice increased under Cd stress, suggesting that MLT would play a crucial role in modulating the responses to Cd stress in different plant tissues.
Key Laboratory of Analytical Chemistry for Biology and Medicine, Department of Chemistry, Ministry of Education, Wuhan University Wuhan, China.
Tiantian
T
Ye
Key Laboratory of Analytical Chemistry for Biology and Medicine, Department of Chemistry, Ministry of Education, Wuhan University Wuhan, China.
Yan-Hong
YH
Hao
Key Laboratory of Analytical Chemistry for Biology and Medicine, Department of Chemistry, Ministry of Education, Wuhan University Wuhan, China.
Lei
L
Yu
Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan University Haikou, China.
Haitao
H
Shi
Department of Cellular and Structural Biology, The University of Texas Health Science Center, San Antonio TX, USA.
Russel J
RJ
Reiter
Key Laboratory of Analytical Chemistry for Biology and Medicine, Department of Chemistry, Ministry of Education, Wuhan University Wuhan, China.
Yu-Qi
YQ
Feng
LC-MS; Orbitrap; melatonin; rice; stable isotope