GC-MS Metabolites and Gene Expression Characteristics in Fibrous Roots of Dioscorea zingiberensis in Response to Low Phosphorus Stress / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo investigate the metabolites and gene expression characteristics in fibrous roots of Dioscorea zingiberensis in response to low phosphorus stress. MethodThe severe stress group， the moderate stress group， and the normal group were set up to stimulate the low phosphorus stress experiment. The fibrous roots of D. zingiberensis were collected during initial stress. The metabolites and transcriptomic characteristics were analyzed by gas chromatography-mass spectrometry （GC-MS） derivatization and RNA-seq techniques. Through multivariate statistical analysis of metabolites treated by different methods，functional analysis of differentially expressed genes， and data mining， the metabolism markers produced in fibrous roots of D. zingiberensis under low phosphorus stress were screened out， and the metabolic pathway characteristics of different genes were analyzed. ResultA total of 116 GC-MS metabolites were detected from the fibrous roots of D. zingiberensis. The metabolic characteristics of fibrous roots of D. zingiberensis under different low phosphorus treatments were obviously different. Orthogonal partial least squares discriminant analysis（OPLS-DA） model was used to screen six differential metabolites represented by sugars and alcohols from metabolites of fibrous roots treated with different methods，and these components were presumedly metabolism markers of fibrous roots of D. zingiberensis in response to low phosphorus stress. The differential genes screened out from the severe stress group and the normal group were mainly enriched in peroxidase pathway，phosphate and hypophosphate metabolism pathway，while the differential genes screened out from the severe stress group and the moderate stress group were mainly enriched in glutathione metabolism pathway and phosphopentose pathway. A total of 177 differential genes in response to low phosphorus stress were screened out from fibrous roots， involving many pathways such as terpenoid skeleton and inositol biosynthesis，which was consistent with the fact that the metabolic differential components in fibrous roots in response to low phosphorus stress were mainly saccharides and inositol. ConclusionThe metabolites and gene expression in fibrous roots of D. zingiberensis responded to low phosphorus stress，and the differential metabolites were closely related to differentially expressed genes. This study is expected to provide a theoretical basis for the research on the molecular mechanism of D. zingiberensis in response to low phosphorus stress.