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:For decades the tobacco plant has served as a model organism in plant biology to answer fundamental biological questions in the areas of plant development, physiology, and genetics. Due to the lack of sufficient coverage of genomic sequences, however, none of the expressed sequence tag (EST)-based chips developed to date cover gene expression from the whole genome. The availability of Tobacco Genome Initiative (TGI) sequences provides a useful resource to build a whole genome exon array, even if the assembled sequences are highly fragmented. Here, the design of a Tobacco Exon Array is reported and an application to improve the understanding of genes regulated by cadmium (Cd) in tobacco is described. From the analysis and annotation of the 1,271,256 Nicotiana tabacum fasta and quality files from methyl filtered genomic survey sequences (GSS) obtained from the TGI and ~56,000 ESTs available in public databases, an exon array with 272,342 probesets was designed (four probes per exon) and tested on two selected tobacco varieties. Two tobacco varieties out of 45 accumulating low and high cadmium in leaf were identified based on the GGE biplot analysis, which is analysis of the genotype main effect (G) plus analysis of the genotype by environment interaction (GE) of eight field trials (four fields over two years) showing reproducibility across the trials. The selected varieties were grown under greenhouse conditions in two different soils and subjected to exon array analyses using root and leaf tissue to understand the genetic make-up of the Cd accumulation. An Affymetrix Exon Array was developed to cover a large (~90%) proportion of the tobacco gene space. The Tobacco Exon Array will be available for research use through the Affymetrix array catalogue. As a proof of the exon array usability, we have demonstrated that the Tobacco Exon Array is a valuable tool for studying Cd accumulation in tobacco leaves. Data from field and greenhouse experiments supported by gene expression studies strongly suggested that the difference in leaf Cd accumulation between the two specific tobacco cultivars is dependent solely on genetic factors and genetic variability rather than on the environment.
Project description:Transgenic tobacco plants expressing begomoviral AC2 RNA silencing suppressor were used to compare transcriptional changes in the transcriptome between transgenic and wild type tobacco plants. Transcriptional analysis using Agilent 4x44k tobacco array was performed of six week-old leaves and 3-5 month-old flowers taken from the same plants as leaf samples.
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:Leaf senescence is the final developmental process that includes the mobilization of nutrients from old leaves to newly growing tissues. The progression of leaf senescence requires dynamic but coordinated changes of gene expression. Although several transcription factors (TFs) are known to be involved in both negative and positive modes of regulation of leaf senescence, detailed mechanisms that underlie the progression of leaf senescence are largely unknown. We report here that the class II ERF transcriptional repressors are controlled by proteasome and regulate the progression of leaf senescence in Arabidopsis. Since we had previously demonstrated that NtERF3, a model of tobacco class II ERFs, specifically interacts with a ubiquitin-conjugating enzyme, we examined the stability of NtERF3 and found that bacterially produced NtERF3 was rapidly degraded by plant protein extracts in vitro. Whereas NtERF3 accumulation was low in plants, it was increased by treatment with a proteasome inhibitor. Arabidopsis class II ERFs, namely, AtERF4 and AtERF8, were also controlled by proteasome and stabilized by aging of plants. The transgenic plants in which NtERF3, AtERF4, and AtERF8 were individually expressed under the control of the 35S promoter exhibited the precocious leaf senescence. Our microarray and RT-PCR analyses revealed that AtERF4 regulated expression of genes involving in various stress responses and leaf senescence. In contrast, aterf4 aterf8 mutant exhibited delayed leaf senescence. Taken together, we present the important role of class II ERFs in the regulation of leaf senescence. Transcriptomes of 35S:AtERF4-HA and 35S:NLS-GFP-HA (control) Arabidopsis two-weeks seedling were compared.
Project description:For decades the tobacco plant has served as a model organism in plant biology to answer fundamental biological questions in the areas of plant development, physiology, and genetics. Due to the lack of sufficient coverage of genomic sequences, however, none of the expressed sequence tag (EST)-based chips developed to date cover gene expression from the whole genome. The availability of Tobacco Genome Initiative (TGI) sequences provides a useful resource to build a whole genome exon array, even if the assembled sequences are highly fragmented. Here, the design of a Tobacco Exon Array is reported and an application to improve the understanding of genes regulated by cadmium (Cd) in tobacco is described. From the analysis and annotation of the 1,271,256 Nicotiana tabacum fasta and quality files from methyl filtered genomic survey sequences (GSS) obtained from the TGI and ~56,000 ESTs available in public databases, an exon array with 272,342 probesets was designed (four probes per exon) and tested on two selected tobacco varieties. Two tobacco varieties out of 45 accumulating low and high cadmium in leaf were identified based on the GGE biplot analysis, which is analysis of the genotype main effect (G) plus analysis of the genotype by environment interaction (GE) of eight field trials (four fields over two years) showing reproducibility across the trials. The selected varieties were grown under greenhouse conditions in two different soils and subjected to exon array analyses using root and leaf tissue to understand the genetic make-up of the Cd accumulation. An Affymetrix Exon Array was developed to cover a large (~90%) proportion of the tobacco gene space. The Tobacco Exon Array will be available for research use through the Affymetrix array catalogue. As a proof of the exon array usability, we have demonstrated that the Tobacco Exon Array is a valuable tool for studying Cd accumulation in tobacco leaves. Data from field and greenhouse experiments supported by gene expression studies strongly suggested that the difference in leaf Cd accumulation between the two specific tobacco cultivars is dependent solely on genetic factors and genetic variability rather than on the environment. 22 samples were used with 3 different experimental factors: [1] 2 different tissues (leaves and roots/lateral), [2] 2 different mutations (V5 and V21), and [3] 2 different stimuli (Soil 1 and Soil 2). 2-3 biological replicates were used. One sample did not pass QC and is not included in this submission.