Mechanisms of Molecular Regulation of Nicotine Biosynthesis

尼古丁生物合成的分子调控机制

• 批准号: 10660086
• 负责人: HASHIMOTO Takashi
• 金额: $ 2.11万
• 依托单位: Nara Institute of Science and Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10660086/
• 关键词: nicotine; tobacco; putrescine; jasmonate; ethylene; gene expression; プロモーター; 根

Nicotine alkaloids are synthesized in the root of Nicotiana species, and their synthesis increases after insect attack, wounding and jasmonate treatment of the leaf. Putrescine N-methyltransferase (PMT) catalyzes the first committed step in nicotine biosynthesis. The expression patterns of the three Nicotiana sylvestris PMT genes (NsPMT1, NsPMT2, and NsPMT3) and of one Nicotiana sylvestris A622 gene are reported upon in this study. Transcripts of the NsPMT and A622 genes were detected only in the root, and were up-regulated by methyl jasmonate treatment. Ethylene antagonized the gene induction by jasmonate. When the 5'-flanking regions of NsPMT1, NsPMT2, NsPMT3 and A622 were fused independently to a β-glucuronidase reporter gene and introduced transgenes were expressed in the cortex, endodermis, and xylem in the root, as well as upregulated by methyl jasmonate treatment. These qualitatively similar patterns of expression for the NsPMT genes are achieved with only 0.25 kb of their 5'-flanking regions, which contain a short DNA sequence conserved among these four genes.

烟碱类生物碱在烟草属植物的根中合成，并且在昆虫攻击、受伤和茉莉酸盐处理叶片后其合成增加。腐胺N-甲基转移酶（PMT）催化尼古丁生物合成中的第一个关键步骤。本研究报道了三个欧洲烟草PMT基因（NsPMT 1、NsPMT 2和NsPMT 3）和一个欧洲烟草A622基因的表达模式。NsPMT和A622基因的转录只在根中检测到，茉莉酸甲酯处理上调。乙烯可拮抗茉莉酸对该基因的诱导作用。当NsPMT 1、NsPMT 2、NsPMT 3和A622的5 '侧翼区独立地融合到β-葡萄糖醛酸酶报告基因上时，引入的转基因在根的皮层、内皮和木质部中表达，并且被茉莉酸甲酯处理上调。NsPMT基因的这些定性相似的表达模式仅用0.25kb的其5 '侧翼区实现，其含有在这四个基因中保守的短DNA序列。