关键词: 烟草；施氮量；质体色素, 基因；超微结构

Abstract: In order to explore the impact of different nitrogen application rates on flue-cured tobacco plastid pigment content and metabolic pathway genes, this paper carried out studies on the plastid ultrastructure, plastid pigment contents, and plastid pigment metabolism-related gene expression patterns at middle leaf ripening stage under different nitrogen application rates by using electron microscopy, fluorescence quantitative PCR and liquid chromatography. The results revealed that high nitrogen application could markedly promote the chloroplast development and plastid pigment accumulation. Notably, the number and volume of osmiophilic granules and starch increased along with the increase of nitrogen application rate, while the number of thylakoid lamellas increased as well. Analysis of pigment metabolism-related gene expression patterns revealed that the transcript levels of PSY and CHL were adjusted and controlled by nitrogen, and the expression was inhibited at high nitrogen level, indicating PSY and CHL played crucial roles in metabolic pathway of plastid pigment.

Key words: tobacco, nitrogen application rate, plastid pigment, gene, ultrastructure