ABSTRACT: Characterizing the Rhizosphere Microbiome of Flue-Cured Tobacco (Nicotiana tabacum): Implications for Soil Health and Sustainable Cultivation
Project description:Nitrogen stress is the main abiotic stress factor affecting the carbon and nitrogen balance of flue-cured tobacco. Tandem mass tag (TMT) proteomics was used to compare the differently expressed proteins (DEPs) of flue-cured tobacco under high- (HN) and low- (LN) nitrogen stress, and Gene Ontology (GO) function annotation, Kyoto Encyclopedia for Genes and Genomes (KEGG) analysis, and protein-protein interaction (PPI) analysis were conducted. The results showed that the difference between LN and HN stress was mainly reflected in the formation pathways of carbon and nitrogen metabolism.
Project description:Up to now, the mechanism of the effect of topping on tobacco hormone regulation is not clear, and most studies on plant hormone signal transduction pathways rely on gene or transcriptional pathways. In this study, the regulatory mechanism of hormones in roots and leaves of topped and untopped tobacco was studied at the protein level.
Project description:In this study, a comparative proteomics analysis was performed through the iTRAQ technique and the activity of defense-related enzymes was assessed. We evaluated the expression of differentially expressed proteins and defense response in two flue-cured tobacco cultivars, i.e., K326 (resistant) and Hongda (susceptible) with contrasting resistance to black shank.
Project description:Background :Nitrogen (N) supply directly impacts growth and quality in flue-cured tobacco. To decipher molecular responses to N gradients, we integrated transcriptomics and weighted gene co-expression network analysis (WGCNA) on leaves from four N treatments: 0 (inherent soil fertility), 60 (low), 105 (standard), and 150 kg/hm² (high). Results :Phenotypic analysis revealed dose-dependent increases in leaf nitrogen content with higher N application, accompanied by excessive vegetative growth and delayed maturity at 150 kg/hm². Transcriptome sequencing identified 47,216 genes, with differentially expressed genes (DEGs) increasing linearly with N levels (1,458–2,147 DEGs). Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment highlighted nitrogen metabolism pathways, yielding 14 DEGs (11 in assimilation, 3 in transport). Weighted gene co-expression network analysis (WGCNA) uncovered two modules (lightcyan1 and black) strongly associated with N responses, harboring transcription factors NtERF11 (AP2/ERF), NtWRKY3 (WRKY), and NtSRM1 (MYB). Sub-network analysis within these modules identified five hub genes: NtGLN1-1, two uncharacterized genes, NtDFC , and NtGDSL. NtGDSL may enhance nitrogen use efficiency (NUE) through stress-responsive mechanisms, while NtDFC could integrate N signaling with developmental processes. These findings provide novel insights into N regulatory networks in flue-cured tobacco. Conclusions :This study reveals the effects of nitrogen application rates on flue-cured tobacco growth and gene expression. By identifying key transcription factors and genes regulating nitrogen metabolism, it provides a theoretical basis for dissecting nitrogen regulatory mechanisms, optimizing fertilization strategies, and improving nitrogen use efficiency in tobacco production.
