关键词: 烟草, 有机肥, 无机肥, 碳氮代谢, 基因表达

Abstract: In order to explore the effect of different fertilization patterns (organic and inorganic fertilizer) on balance of carbon and nitrogen metabolism in the middle leaves of flue-cured tobacco during mature period, this experiment taking Yuyan 87 as material, and set 2 treatments of conventional fertilizer and organic fertilizer on the basis of consistent amount of nitrogen fertilizer, and studied the structure of tobacco leaf cell and expression of related genes. The results of cell ultrastructure anaysis showed that organic fertilizer could increase starch granule during maturing stage. Inorganic fertilizer made the total sugar content significantly lower than that of inorganic fertilizer during mature stage (70~80 d), but their contents were basically the same untill 90 d, indicating the middle leaves possessed strong ability of sugar accumulation. Analysis of further cell gene expression analysis showed that organic fertilizer could significantly promote the expression of carbon metabolism genes during maturing stage (60~80 d). Organic fertilizer made the total nitrogen content of middle leaves reached the highest in 70 d, then experienced a trend of increasing first then decreasing. While, the inorganic fertilizer made the total nitrogen content decreased during the maturig stage. The total nitrogen contents of 2 treatments were almost the same at 90 d, indicating that the tabacco leaves had experienced a rapid but transitory nitrogen accumulation during maturing stage. The nicotine content by organic fertilizer was lower than that by the inorganic fertilizer, indicating that the lower nicotine content might be related to the transportation of nicotine from the middle leaves to upper leaves. The high expressions level of NRT1 and ODC genes under organic fertilization were the main reason for the accumulation of total nitrogen and nicotine during maturing stage (60~70 d). These results indicated that organic fertilization could enhance the accumulation of total sugar and total nitrogen, reduce nicotine content, and greatly influence the carbon and nitrogen metabolism in the middle leaves.

Key words: tobacco, organic fertilization, inorganic fertilization, carbon and nitrogen metabolism, gene expression