Integration of GC-MS Based Non-Targeted Metabolic Profiling with Headspace Solid Phase Microextraction Enhances the Understanding of Volatile Differentiation in Tobacco Leaves from North Carolina, India and Brazil

Abstract

In this report, gas chromatography-mass spectrometry (GC-MS) based non-targeted metabolomics is used to develop appropriate headspace solid phase microextractions (HS-SPME) to enhance the understanding of volatile complexity of flue-cured tobacco leaves. Non-targeted metabolic profiling of GC-MS shows that the extraction condition of HS-SPME at 100˚C for 30 min provides a better metabolite profile than other extraction conditions tested. GC-MS and principal component analyses (PCA) show that among five types of fibers tested, 100 μm polydimethylsiloxane (PMDS), 65 μm polydimethylsiloxane/divinylbenzene (PMDS/DVB) and 75 μm carboxen/polydimethylsiloxane (CAR/ PMS) provide a better reproducible metabolite profile. Based on an appropriate PDMS extraction condition optimized, we use GC-MS analysis and PCA to compare metabolite profiles in flue-cured leaves of tobacco plants grown in North Carolina, India and Brazil, respectively. The resulting data of PCA show that the global metabolic profiles in North Carolina samples are separated from those in Brazil and India samples, two groups of which are characterized by a partially overlapped pattern. Several peaks that were differentially accumulated in samples were annotated to known metabolites by deconvolution analysis, such as norsolanadione, solavetivone and rishitin. Norsolanadione is detected only in Brazil samples. Solavetivone is detected in samples of India and Brazil but not in those of North Carolina. Rishitin is detected in samples of North Carolina and India but not in Brazil samples. These data indicate that not only can a non-targeted metabolic profiling approach enhance the understanding of volatile complexity, but also can identify marker volatile metabolites in tobacco leaves produced in different growth regions.

Untargeted Metabolomics of Nicotiana tabacum Grown in United States and India Characterizes the Association of Plant Metabolomes With Natural Climate and Geography

“…Extraction of non-polar metabolites was performed as reported previously (Ma et al, 2013). In brief, 100 mg of powdered sample was suspended in 1.5 ml 100% hexane in a 2 ml Eppendorf tube.…”

“…One hundred microliter water-methanol phase was transferred to a new 1.5 ml Eppendorf tube and then was evaporated in a rotary vacuum at room temperature. The remaining residues at the bottom of tubes contained polar metabolites, which were used for derivatization as reported previously (Ma et al, 2013). In brief, the remaining residue was oximated using 40 µl methoxylamine hydrochloride (20 mg/ml) in anhydrous pyridine at 37°C for 2 h, and then were silylated at 37°C for 30 min using 70 µl of N-methyl-N-(trimethylsilyl)-trifluoro acetamide (MSTFA).…”

“…In this study, we used K326 tobacco to conduct a 2-year pilot study in order to understand the effects of climate change and two continental growth locations on plant metabolism. Based on our previous metabolic profiling of a small number of tobacco samples collected from tobacco companies in India, North Carolina and Brazil (Ma et al, 2013), we hypothesized that weather and growing sites in different continents differentially altered the tobacco metabolomes associated with abiotic and biotic stresses. To test this hypothesis, we selected two field locations, the Oxford tobacco research station in North Carolina, USA, and the ILTD research station (department) of ITC limited at Rajahmundry, in Andhra Pradesh, India.…”

Volatile Profiling of Aromatic Traditional Medicinal Plant, Polygonum minus in Different Tissues and Its Biological Activities

“…The Solid Phase Microextraction (Supelco) method was undertaken using 100 μm PDMS (Polydimethylsiloxane) fibers based on Huang [43]. PDMS fiber was reported to present good sensitivity and high reproducibility among the set of the other fibers [44,45,46]. PDMS fibre was used after optimization of major parameters (time, volume and temperature adsorptions).…”

A polyketide synthase gene cluster associated with the sexual reproductive cycle of the banana pathogen, Pseudocercospora fijiensis

“…Metabolite peaks detected by GC-MS were deconvoluted using the NIST 11 library and the Agilent MassHunter Mass Profile (MHMP) and Mass Profiler Professional (MPP) software as previously described [83, 84]. In brief, untargeted and unknown peaks were deconvoluted and annotated to metabolites using both ChemiStation and the NIST 11 standard library.…”