Project description:The degree of yellowing in tobacco leaves is an important indicator for determining the maturity and harvesting time of tobacco leaves. Reduction in chlorophyll is of utility for promoting the concentrated maturation of tobacco leaves and achieving mechanised harvesting and mining, and utilising tobacco yellow leaf regulatory genes is of great significance for the selection and breeding of tobacco varieties suitable for mechanised harvesting and the resolution of the molecular mechanisms controlling leaf colouration. In this study, the phenotypes of the yellow-leaf K326 and K326 varieties were analysed, and it was observed that the yellow-leaf K326 variety exhibited a distinct yellow leaf phenotype with a significant reduction in chlorophyll content. Subsequently, using a combination of BSA-seq, transcriptomic sequencing (RNA-seq), and proteomic sequencing approaches, we identified the candidate gene Nitab4.5_0008674g0010 that encodes dihydroneopterin aldolase as a factor associated with tobacco leaf yellowing. Finally, by measuring the folate content in K326 and Huangye K326, the folate content in Huangye K326 was observed to be significantly lower than that in K326, thus indicating that folate synthesis plays a crucial role in phenotypic changes in tobacco yellow leaves. This study is the first to use BSA-seq combined with RNA-seq and proteomic sequencing to identify candidate genes in tobacco yellow leaves. The results provide a theoretical basis for the analysis of the mechanism of tobacco yellow leaf mutations.
Project description:Tobacco (Nicotiana tabacum L.) is an important cash crop, and the size of its leaves significantly influences both yield and quality. However, the upper part of tobacco leaves, due to its dense tissue structure, often faces issues such as narrow and thick leaves during the production of roasted cigarettes. These problems have a severe impact on the yield and quality of the upper leaf. Although the mechanism of leaf size regulation in Arabidopsis thaliana has been extensively studied, it remains unclear for tobacco. Therefore, this research aimed to investigate the role of the NtAN3 gene in regulating tobacco leaf size by utilizing the NC82 variety. The researchers created both an overexpression mutant (G27) and a silencing mutant (M21) of the NtAN3 gene and examined their impact on leaf size using cell morphology observation and transcriptome analysis. These research findings offer valuable insights for molecular breeding aimed at improving tobacco yield and enhancing the availability of upper leaves.
Project description:Subsequently, using a combination of BSA-seq, transcriptomic sequencing (RNA-seq), and proteomic sequencing approaches, we identified the candidate gene Nitab4.5_0008674g0010 that encodes dihydroneopterin aldolase as a factor associated with tobacco leaf yellowing.
Project description:Tobacco, as an important cash crop and model plant, has been studied and explored in various aspects. In China, Yunyan 87 was recognized as a flue-cured tobacco variety and had been widely concerned due to its excellent product quality characteristics. The quality of tobacco products depends on the compound collection of tobacco leaves, including pigments, carbohydrates, amino acids, polyphenols and alkaloids. Present study investigated tobacco seedlings, with the assistant of the untargeted metabonomic technology and the label-free proteomic technology to analyze metabolites and proteins differences in leaf, stem, and root groups respectively. From 298 metabolites and 4993 proteins obtained, there were significant differences in both primary and secondary metabolism involved aroma precursors biosynthesis in seedling tobacco leaves, stems, and roots, such as carbohydrate metabolism, energy metabolism, and amino acid biosynthesis, and secondary metabolism phenylpropanoids, flavonoids and alkaloid biosynthesis in this study. Especially alkaloids metabolites identification results showed nornicotine, anatabine, anatalline, and myosmine, were significantly higher in tobacco roots than in leaves, and stems at seedling stage.
Project description:Tobacco in its smoke and smokeless form are major risk factors for ESCC (esophageal squamous cell carcinoma). However, molecular alterations associated with smokeless tobacco exposure are poorly understood. In the Indian subcontinent, tobacco is predominantly consumed in chewing form. An understanding of molecular alterations associated with chewing tobacco exposure is vital for identifying molecular markers and potential targets. We developed an in-vitro cellular model by exposing non-transformed esophageal epithelial cells to chewing tobacco over eight month period. Chronic exposure to chewing tobacco led to increase in cell proliferation, invasive ability and anchorage independent growth indicating cell transformation. Molecular alterations associated with chewing tobacco exposure were characterized by carrying out exome sequencing and quantitative proteomic profiling of parental cells and chewing tobacco exposed cells. Quantitative proteomic analysis revealed that established cancer stem cell markers are elevated in tobacco treated cells. Decreased expression of enzymes associated with the glycolytic pathway and increased expression of a large number of mitochondrially localized proteins involved in the electron transport chain as well as enzymes of TCA cycle were also identified. Electron micrographs revealed increase in number and size of mitochondria. Based on these observations, we hypothesise that chronic treatment of esophageal epithelial cells with tobacco leads to a cancer stem cell-like phenotype. These cells also show characteristic OXPHOS phenotype which can be potentially targeted as a therapeutic strategy.