A metabolomics study delineating geographical location-associated primary metabolic changes in the leaves of growing tobacco plants by GC-MS and CE-MS.

Yanni Zhao,Wenzheng Li,Xiaojun Peng,Lili Li,Huina Zhou,Jieyu Zhao,Xin Lu,Junjie Zhang,Guowang Xu,Yanli Li,Chunxia Zhao,Fucheng Lin,Chunxiu Hu

doi:10.1038/srep16346

Abstract

Ecological conditions and developmental senescence significantly affect the physiological metabolism of plants, yet relatively little is known about the influence of geographical location on dynamic changes in plant leaves during growth. Pseudotargeted gas chromatography-selected ion monitoring-mass spectrometry and capillary electrophoresis-mass spectrometry were used to investigate a time course of the metabolic responses of tobacco leaves to geographical location. Principal component analysis revealed obvious metabolic discrimination between growing districts relative to cultivars. A complex carbon and nitrogen metabolic network was modulated by environmental factors during growth. When the Xuchang and Dali Districts in China were compared, the results indicated that higher rates of photosynthesis, photorespiration and respiration were utilized in Xuchang District to generate the energy and carbon skeletons needed for the biosynthesis of nitrogen-containing metabolites. The increased abundance of defense-associated metabolites generated from the shikimate-phenylpropanoid pathway in Xuchang relative to Dali was implicated in protection against stress.

Highlights

Overexpressing the allene oxide synthase (AOS) gene showed enhanced tolerance to zinc stress compared with wild-type samples[7]
We developed a pseudotargeted metabolomics approach based on Gas chromatography-mass spectrometry (GC-MS) with selective ion monitoring (SIM), in which the characteristic ions of metabolites were identified in untargeted metabolic profiling data from quality-control samples[18]
Carbon (C) (Fig. 4) and nitrogen (N) metabolism (Fig. 5) represent intuitive parameters for comparing time-dependent metabolic fluctuations in tobacco leaves that are associated with environmental factors

Summary

Introduction

Overexpressing the allene oxide synthase (AOS) gene showed enhanced tolerance to zinc stress compared with wild-type samples[7]. We developed a pseudotargeted metabolomics approach based on GC-MS with selective ion monitoring (SIM), in which the characteristic ions of metabolites were identified in untargeted metabolic profiling data from quality-control samples[18]. This approach integrates the advantages of targeted and untargeted methods[2] and has been used to study the metabolic profiles of various tissues samples[12,19]. We investigated the impact of the planting environment (Dali and Xuchang) on tobacco leaf metabolism during the growth and senescence period (Fig. 1a,b) by using pseudotargeted GC-SIM-MS and CE-MS methods. The metabolic signatures associated with geographical origin and development stage were defined, and the effects of environment factors to complex metabolic regulatory systems were identified

Methods

Results

Conclusion