番茄TNAC基因的鉴定及表达分析

TNAC是一组茄科植物特有的NAC基因，目前尚未见有关番茄TNAC基因的报道。前期研究中，我们将来自于番茄、拟南芥和水稻三个物种的NAC蛋白构建进化树，发现有一分支仅包含番茄的26个SlNAC蛋白，本研究对其进一步鉴定和分析。结果显示，其中10个SlNAC蛋白具备TNAC典型序列特征。进而，采用实时定量PCR分析番茄TNAC基因在不同组织器官中的表达情况及对不同胁迫处理的响应模式。除一个番茄TNAC基因的转录产物未被检测到之外，2个在所有器官中均表达，7个均显示出明显的器官特异性。分别用250 mmol·L^-1 NaCl、15% PEG 6000和4℃处理番茄幼苗后，8个TNAC基因对至少一种胁迫有明显的响应。研究结果为预测这些SlNACs的生物学功能提供重要线索，也为深入理解这类茄科植物特有的NAC基因扮演的角色提供新的资料。

Characterization and Expression Analysis of TNAC Genes of Tomato

TNACs(tobacco NAC genes) is a novel subgroup of NACs unique to Solanaceaea. Now, little information was available about TNACs of tomato(Solanum lycopersicum). In our previous studies, based on the alignment of sequences from tomato, Arabidopsis and rice, we constructed a unrooted phylogenetic tree and found a subgroup included only 26 SlNACs(Solanum lycopersicum NAC). In this study, we characterized 26 SlNACs further. Of all, 10 SlNACs shared the typical characteristics with TNACs. By the real-time quantitative PCR, we analyzed the expression patterns of the tomato TNACs in different organs and under drought, high salinity and low temperature stresses, respectively. Except for one tomato TNAC, two were expressed in all tested organs and seven showed organ-specific expression patterns. Among ten tomato TNACs, eight were detected to respond to one or more stress treatments. Our findings will provide important clues for predicting the functions of tomato TNACs, and understanding the roles of the group NAC specific to Solanaceaea.