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: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: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:Nitrogen physiology is important in tobacco because of its role in generation of leaf yield and accumulation of nitrogen-containing alkaloids and that can react with nitrosating agents in the formation of carcinogenic tobacco specific nitrosamines. Cultivars of the burley tobacco market class are homozygous for deleterious alleles at the duplicate Yb1 and Yb2 loci which have previously been associated with decreased nitrogen use and utilization efficiency,; increased leaf nitrate, total nitrogen, and alkaloid levels,; and reduced yields. How mutant alleles at these two loci affect these traits is not well understood. Recent identification of the Yb1 and Yb2 genes enabled overexpression of the wild-type Yb1 allele in yb1yb1yb2yb2 plants to determine if observed unfavorable effects were due to linkage or pleiotropy, and to determine if overexpression could lead to beneficial modifications in any of these traits in transgenic plants relative to naturally-occurring wild-type genotypes. Yb1 overexpression was found to confer an agronomic benefit to yb1yb1yb2yb2 genotypes but no advantage to wild-type genotypes. RNA-Seq was used to carry out a comparative transcriptome analyses of genetically engineered and wild-type NILs to gain insight on metabolic pathways affecting carbon and nitrogen metabolism that might be altered as the result of genetic variability at the Yb1 and Yb2 loci. Results indicate that complex changes in the transcriptome of tobacco can be manifested by altered expression of Yb1.
Project description:We used two hybrid combinations and their 4 parents as materials. One week after topping the tobacco plant, samples were taken, including three tissues: root, stalk, and leaf. The RNA of these samples was extracted, and transcriptome sequencing analysis was carried out to explore the transcriptional profile differences between hybrids and their parents, and to analyze the gene differential expression between different tissues.