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

摘要： 为探明不同施肥（有机肥和无机肥）对烤烟成熟期中部叶碳氮代谢的影响，以云烟87为试材，在保障用氮量一致的基础上，设置了无机肥、有机肥两个处理，研究了烟叶细胞的结构及相关基因的表达。细胞超微结构分析显示有机肥处理在成熟期时淀粉颗粒增多；有机肥处理的中部叶在成熟期（70~80 d）总糖含量显著低于无机肥处理，直到移栽90 d时含量基本一致，表明其中部叶具有较强的糖积累能力；进一步基因表达分析表明施用有机施肥显著促进了碳代谢基因在成熟期（60~80 d）的表达。有机肥处理的中部叶在成熟期总氮含量在70 d最高，经历一个先升高再降低的趋势，而无机肥处理在成熟期烟叶总氮含量呈下降趋势，到90 d时两个处理全氮含量基本一致，表明施用有机肥的烟叶在成熟期经历一个氮素的快速短暂积累。有机肥处理烟碱含量整体低于无机肥处理，分析表明较低的烟碱含量可能与烟碱从中部叶向上部叶的运输相关。氮代谢途径关键基因NRT1和ODC在有机施肥条件下的高表达量是导致中部叶总氮、烟碱在成熟期（60~70 d）积累的主要原因。上述结果表明有机肥增强了总糖、总氮积累能力，降低了烟碱含量，对中部叶碳氮代谢影响较大。

关键词: 烟草, 有机肥, 无机肥, 碳氮代谢, 基因表达