为探讨烤烟叶面化学特征及其形成机制,本文以K326、红花大金元、中烟100、翠碧1号、豫烟11等代表性烤烟品种为试验材料,采用超景深显微技术、GC-MS分析检测技术和荧光定量PCR技术,对叶面腺毛形态、叶面化学成分以及腺毛分泌物合成关键基因表达进行了比较分析.结果发现:(1)烤烟腺毛由长柄分泌型腺毛、短柄分泌型腺毛和非分泌保护毛等不同类型组成,翠碧1号和豫烟11中分泌型腺毛含量较高,而中烟100中非分泌型腺毛相对丰富.(2)西柏烷类化合物是烤烟叶面的主要化学成分,以K326中的含量为最高;赖百当类化合物在烤烟中含量极少,但豫烟11中顺冷杉醇和赖百当二醇含量较高.(3)西柏烷类合成酶关键基因CYC和CYP71D16在K326中表达活跃,赖百当合成酶关键基因CPS2在豫烟11中的表达量明显高于其它品种.不同烤烟品种之间叶面腺毛形态、基因表达及分泌物含量所存在的明显差异,可能与品种特色密切相关.%To characterize the formation mechanism of tobacco trichome exudates,five representative flue-cured tobacco cultivars were studied in trichome morphology,leaf surface chemical components,and expression patterns of genes related to trichome exudates biosynthesis using super depth of field microscopy,GC-MS analysis,and real-time fluorescent quantitative PCR techniques,respectively.Results indicated that (1) Two leaf trichome types of flue-cured tobacco were identified,including glandular trichomes and non-glandular trichomes.The proportion of each type was different in these tobacco cultivars with glandular trichomes being more abundant and dense in "Cuibi1" and "Yuyan11" compared to other cultivars,while non-glandular trichomes were most abundant in "Zhongyan 100".(2) Cembranoids were main compounds in tobacco trichome exudates.Among these cultivars,cembranoids were most abundant in "K326".As the main trichome exudates of oriental tobacco,labdanoids were rarely detected in these flue-cured tobacco cultivars except "Yuyan1 1".(3) Expression pattern analysis showed that the expression level of cembranoid biosynthetic related genes (CYC and CYP71D16) was high in "K326".Meanwhile,labdanoids biosynthetic related genes (CPS2 and ABS) expressed strongly in "Yuyan 11".These results provided new perspectives for tobacco breeding and metabolic engineering of trichome exudates.
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