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

Dong-Ming Ma,Saiprasad V S Gandra,Raman Manoharlal,De-Yu Xie,Christophe La Hovary

doi:10.3389/fpls.2019.01370

Dong-Ming Ma, Saiprasad V S Gandra + Show 3 more

Open Access

https://doi.org/10.3389/fpls.2019.01370

Copy DOI

Abstract

Climate change and geography affect all the living organisms. To date, the effects of climate and geographical factors on plant metabolome largely remain open for worldwide and local investigations. In this study, we designed field experiments with tobacco (Nicotiana tabacum) in India versus USA and used untargeted metabolomics to understand the association of two weather factors and two different continental locations with respect to tobacco metabolism. Field research stations in Oxford, North Carolina, USA, and Rajahmundry, Andhra Pradesh India were selected to grow a commercial tobacco genotype (K326) for 2 years. Plant growth, field management, and leaf curing followed protocols standardized for tobacco cultivation. Gas chromatography–mass spectrometry based unbiased profiling annotated 171 non-polar and 225 polar metabolites from cured tobacco leaves. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) showed that two growing years and two field locations played primary and secondary roles affecting metabolite profiles, respectively. PCA and Pearson analysis, which used nicotine, 11 other groups of metabolites, two locations, temperatures, and precipitation, revealed that in North Carolina, temperature changes were positively associated with the profiles of sesquiterpenes, diterpenes, and triterpenes, but negatively associated with the profiles of nicotine, organic acids of tricarboxylic acid, and sugars; in addition, precipitation was positively associated with the profiles of triterpenes. In India, temperature was positively associated with the profiles of benzenes and polycyclic aromatic hydrocarbons, but negatively associated with the profiles of amino acids and sugar. Further comparative analysis revealed that nicotine levels were affected by weather conditions, nevertheless, its trend in leaves was independent of two geographical locations and weather changes. All these findings suggested that climate and geographical variation significantly differentiated the tobacco metabolism.

Highlights

The global warming trend has taken place over the last 100 years (Keller, 2007; Schnoor, 2007)
The 84 biological samples from North Carolina were composed of seven groups of leaves and the 96 biological samples from India were composed of eight groups of leaves
We integrate unbiased un-targeted metabolomics with standard farming practices followed for commercial cultivation of tobacco to understand the formation of root-specific effects of field environments on plant metabolism

Summary

Introduction

The global warming trend has taken place over the last 100 years (Keller, 2007; Schnoor, 2007). All completed global research has led to numerous accomplishments which provide fundamental evidence that climate change significantly affects the global and regional ecosystems (Polley et al, 2013; Schmitz, 2013; Kizildeniz et al, 2015; Park et al, 2015; Hauser et al, 2016; Taylor and Kumar, 2016), agriculture, such as biotic and abiotic stresses (Adams et al, 1998; Dwivedi et al, 2013; Chauhan et al, 2014; Abberton et al, 2016; Kollah et al, 2016), and human health, such as the increase of infectious diseases and other public health problems (Patz et al, 1996; Rom and Pinkerton, 2014; Clayton et al, 2015; Kjellstrom et al, 2016) All of those data are fundamentally informative for different countries and global organizations to develop strategies and policies to slow down the global warming. Development of such a system is necessary to comprehensively enhance our understanding of the biological consequences of climate change

Methods

Results

Discussion

Conclusion