Metabolomics Analysis of Cigar from China's Major Tobacco Growing Regions

Abstract

Abstract Background Despite the flourishing international trade of cigar tobacco leaves and China's significant cigar market, there has been limited systematic reports on the main characteristics of cigar tobacco leaves from different regions of China. These characteristics include the agro-ecological adaptability of cigar tobacco to major tobacco producing areas in China and the characteristics of cigar metabolite accumulation among different regions in China. Therefore, the cigar industry developed in various provinces in China lacks reference for agricultural and ecological adaptability assessment, reference for the selection of planting areas, and reference databases for cigar and tobacco metabolite characteristics. Results The agronomic traits of the cigar tobacco varieties across the four regions displayed considerable value for harvesting. All four regions possessed the necessary agricultural conditions for conducting cigar tobacco agroecological adaptability research. A total of 793 metabolites were detected and annotated, including 80 volatile metabolites, 209 semi-volatile metabolites, and 504 endogenous metabolites. These comprised 113 alcohols, 97 sugars, 73 amino acids, 56 ketones, 45 alkanes, and 26 aldehydes. By selecting for VIP≥1, FC＞2, or FC＜0.5, 36.65% of metabolites exhibited differences between at least two experimental points. A preliminary reference database encompassing characteristics of metabolites accumulation of cigar tobacco was constructed, providing a reference for future metabolite research in various domestic cigar tobacco producing regions. Conclusions Positive correlations between cigar tobacco yield and primary metabolite accumulation were observed. Prolonged high-temperature and rainy conditions were found to be detrimental to the accumulation of secondary metabolites responsible for aroma in cigar tobacco. Shifang, Sichuan (N: 31.127°, E: 104.168°) demonstrated significant advantages in the accumulation of various aroma-related metabolites such as aldehydes, sugars and amino acids. It was selected as a reference point for subsequent comparisons of metabolite accumulation levels in cigar tobacco, offering insights and references for the cultivation site selection and in-depth metabolite research of cigar tobacco in China.