外界生物和非生物的胁迫诱导烟草内源茉莉素（JA）的积累，进而促进根部合成尼古丁，并通过木质部运输到地上部分参与植物的胁迫应答反应。但是，这一过程中茉莉素诱导尼古丁合成的分子机制并不清楚。在拟南芥中外源JA能诱导含TIFY结构域的JAZ蛋白(AtJAZs) 的表达，它们作为一类重要的转录抑制因子参与茉莉素诱导基因的表达调控。这些发现为揭示烟草中茉莉素的信号转导途径提供了一个有用的线索。进化树分析显示烟草中NtJAZs与AtJAZs同源性较高，且都含有保守的tify和Jas结构域。在烟草BY-2细胞JA能诱导5个JAZ基因（NtJAZ1、NtJAZ3、NtJAZ5、NtJAZ7和NtJAZ10）的表达。NtJAZs定位于细胞核中，外源茉莉素诱导NtJAZs的被降解，这一过程依赖于泛素化介导的26S蛋白酶体途径。酵母双杂交和BiFC实验表明，除NtJAZ10外，NtJAZs蛋白之间能形成同源或异源二聚体，而且它们之间的相互作用发生在细胞核内。转烟草BY-2细胞获得了NtJAZs过表达株系。初步研究结果发现，过表达NtJAZ1、NtJAZ3和NtJAZ5株系中JA诱导前后PMT的表达与对照组相比没有明显区别。而NtJAZ7和NtJAZ10的过表达株系中PMT的表达显示部分抑制作用。对尼古丁含量的影响等实验正在进行之中。这些结果表明，部分NtJAZs蛋白以不同的作用形式参与茉莉素诱导的烟草尼古丁合成关键酶的转录调控中。本论文结果为茉莉素调控尼古丁合成分子机理的解析及实际应用提供一定的理论基础。

Biotic and abiotic stresses lead to endogenous accumulation of jasmonates (JA) in Tobacco (Nicotiana tabacum). These responses stimulate nicotine and related pyridine alkaloids synthesis in the roots, then transport to leaves through xylem sap to defense against herbivore attack or environmental stresses. However, the molecular mechanism of JA regulating nicotine formation is still not clear. In Arabidopsis, JA-induced TIFY-domain containing proteins (AtJAZs) have been found to be the critical transcriptional repressors linking CORONATINE INSENSTIVE1 (COI1)-mediated jasmonate-regulated transcriptional regulation. These findings give us some clues for revealing jasmonate signaling in Tobacco.Phylogenic analysis showed that NtJAZs share high homology with AtJAZs, which contain conserved ZIM and Jas motifs in their protein sequence. Expression of five tobacco JAZ genes (NtJAZ1, NtJAZ3, NtJAZ5, NtJAZ7 and NtJAZ10) was induced by JA in Tobacco Bright Yellow-2 cells. NtJAZs-GFP fusion proteins were accumulated preferentially in the BY-2 nucleus and appeared to be rapidly degraded after JA treatment, which rely on the ubiquitin-mediated protein degradation pathway via the 26S proteasome. Yeast two-hybrid and bimolecular fluorescence complementation (BiFC) approaches indicated that NtJAZs, except for NtJAZ10, form homo- and heteromeric dimers in yeast and plant cell, and their interaction is localized in the nucleus. Tobacco suspension cell lines overexpressed NtJAZs were produced and analysed the expression of PMT gene after JA treatment. Preliminary results showed that there were no difference of the transcriptional levels of PMT between the control and transgenic lines overexpressed NtJAZ1, NtJAZ3 and NtJAZ5. However, the expression of PMT was slightly inhibited in the lines overexpressed NtJAZ7 and NtJAZ10. The measurement of nicotine content in the transgenic lines is still in progress. Our results therefore suggested that several NtJAZs involved the transcription regulation of PMT, and provide the basis for understanding the mechanism of jasmonate regulating nicotine formation in Tobacco.