Alkaloids are plant secondary metabolites that are widely distributed in Nicotiana species and contribute greatly to the quality of tobacco leaves. Some alkaloids, such as nornicotine and myosmine, have adverse effect...Alkaloids are plant secondary metabolites that are widely distributed in Nicotiana species and contribute greatly to the quality of tobacco leaves. Some alkaloids, such as nornicotine and myosmine, have adverse effects on human health. To reduce the content of harmful alkaloids in tobacco leaves through conventional breeding, a genetic study of the alkaloid variation among different genotypes is required. In this study, alkaloid profiles in leaves of five Nicotiana tabacum cultivars and Nicotiana tomentosiformis were investigated. Six alkaloids were identified from all six genotypes via gas chromatograph-mass spectrometry(GC-MS). Significant differences in alkaloid content were observed both among different leaf positions and among cultivars. The contents of nornicotine and myosmine were positively and significantly correlated(R2=0.881), and were also separated from those of other alkaloids by clustering. Thus, the genotype plays a major role in alkaloid accumulation, indicating a high potential for manipulation of alkaloid content through traditional breeding.展开更多
Recent reports suggest that exposure to stress is capable of influencing the frequency and pattern of inherited changes in various parts of the genome. In this review, we will discuss the influence of viral pathogens ...Recent reports suggest that exposure to stress is capable of influencing the frequency and pattern of inherited changes in various parts of the genome. In this review, we will discuss the influence of viral pathogens on somatic and meiotic genome stability of Nicotiana tabacum and Arabidopsis thaliana. Plants infected with a compatible pathogen generate a systemic recombination signal that precedes the spread of pathogens and results in changes in the somatic and meiotic recombination frequency. The progeny of infected plants exhibit changes in global and locusspecific DNA methylation patterns, genomic rearrangements at transgenic reporter loci and resistance gene-like-loci, and even tolerance to pathogen infection and abiotic stress. Here, we will discuss the contribution of environmental stresses to genome evolution and will focus on the role of heritable epigenetic changes in response to pathogen infection.展开更多
基金supported by the National Natural Science Foundation of China(No.31000137)the China National Tobacco Company and Zhengzhou Tobacco Research Institute Science and Technology Project(No.122009CZ0410)the PhD Programs Foundation of Ministry of Education of China(No.2012M510149)
文摘Alkaloids are plant secondary metabolites that are widely distributed in Nicotiana species and contribute greatly to the quality of tobacco leaves. Some alkaloids, such as nornicotine and myosmine, have adverse effects on human health. To reduce the content of harmful alkaloids in tobacco leaves through conventional breeding, a genetic study of the alkaloid variation among different genotypes is required. In this study, alkaloid profiles in leaves of five Nicotiana tabacum cultivars and Nicotiana tomentosiformis were investigated. Six alkaloids were identified from all six genotypes via gas chromatograph-mass spectrometry(GC-MS). Significant differences in alkaloid content were observed both among different leaf positions and among cultivars. The contents of nornicotine and myosmine were positively and significantly correlated(R2=0.881), and were also separated from those of other alkaloids by clustering. Thus, the genotype plays a major role in alkaloid accumulation, indicating a high potential for manipulation of alkaloid content through traditional breeding.
文摘Recent reports suggest that exposure to stress is capable of influencing the frequency and pattern of inherited changes in various parts of the genome. In this review, we will discuss the influence of viral pathogens on somatic and meiotic genome stability of Nicotiana tabacum and Arabidopsis thaliana. Plants infected with a compatible pathogen generate a systemic recombination signal that precedes the spread of pathogens and results in changes in the somatic and meiotic recombination frequency. The progeny of infected plants exhibit changes in global and locusspecific DNA methylation patterns, genomic rearrangements at transgenic reporter loci and resistance gene-like-loci, and even tolerance to pathogen infection and abiotic stress. Here, we will discuss the contribution of environmental stresses to genome evolution and will focus on the role of heritable epigenetic changes in response to pathogen infection.
