【摘要】 为探明外源萘乙酸(NAA)对烤烟上部叶可用性形成的代谢机制，本试验以云烟87为供试品种，采用双因素随机区组试验设计，设置NAA喷施时期(打顶当天、打顶后15 d和打顶后30 d)与喷施浓度(0、10、30 mg/L和50 mg/L)共12个处理，研究其对烤烟上部叶碳代谢产物含量、碳代谢关键酶活性及其基因表达量的影响。结果表明：打顶当天喷施高浓度NAA及打顶后15 d喷施低浓度NAA均能促进上部叶淀粉的积累，而打顶后15 d喷施NAA均能促进总糖及还原糖的积累，但打顶后30 d喷施NAA却会减少总糖、还原糖含量；碳代谢关键酶活性方面，打顶后15 d喷施中高浓度NAA,蔗糖合成酶(SS)、蔗糖磷酸合酶(SPS)活性最高，但喷施NAA会抑制上部叶转化酶(INV)活性；碳代谢关键酶基因表达量方面，喷施NAA均会降低蔗糖合成酶基因(NtSS)、转化酶基因(NtINV)表达量。综合来看，在贵州毕节市威宁烟区生态条件下，打顶后15 d喷施30 mg/L NAA最有利于改善云烟87上部叶碳代谢关键酶活性，提升其基因表达量，协调烟株上部叶成熟期间的碳代谢过程，提高烟叶品质。更多还原

【Abstract】 In order to explore the metabolic mechanism of spraying exogenous naphthylacetic acid(NAA) on the formation of availability in the upper leaves of flue-cured tobacco, Yunyan 87 was used as test material in this study. A two-factor randomized block trial with 12 treatments of NAA spraying period(on the topping day, at 15 days after topping, at 30 days after topping) and spraying concentration(0, 10, 30, 50 mg/L) was designed, and their effects on content of carbon metabolites, key enzymes activities and related gene expressions in the upper leaves of flue-cured tobacco were studied. The results showed that spraying high concentration of NAA on the topping day and spraying low concentration of NAA at 15 days after topping could promote the accumulation of starch in the upper leaves, and spraying NAA at 15 days after topping could promote the accumulation of total sugar and reducing sugar, while spraying NAA at 30 days after topping reduced the content of total sugar and reducing sugar. In terms of key enzymes activities, the sucrose synthetase(SS) and sucrose phosphate synthase(SPS) activities were the highest when NAA was sprayed with medium high concentration at 15 days after topping, but the invertase(INV) activity of the upper leaves were inhibited by spraying NAA. In terms of the expression levels of key enzyme genes, spraying NAA reduced the expression levels of SS gene NtSS and INV gene NtINV. In conclusion, under the ecological conditions in Weining tobacco area, Bijie City, Guizhou Province, spraying 30 mg/L NAA at 15 days after topping was the most beneficial to improve the key enzymes activities of carbon metabolism in the upper leaves of Yunyan 87, increas the expression of enzyme genes, and coordinate the carbon metabolism process during the maturity of upper leaves of tobacco.更多还原