普通烟草SWEET基因家族的鉴定与表达分析

  目的  为挖掘参与烟草糖代谢的SWEET（sugar will eventually be exported transported）基因家族成员。  方法  以拟南芥SWEET蛋白为参考，利用生物信息学方法，对栽培烟草的SWEET蛋白家族进行鉴定，分析蛋白理化性质、系统进化、染色体定位、基因结构和顺式作用元件，对其在不同组织和不同胁迫处理的表达模式进行检测。  结果  从普通烟草中鉴定到70个可能的SWEET基因，系统发育树将其划分为4个亚家族，大多数烟草SWEET基因在进化过程中经历纯化选择。不同烟草组织的表达模式分析显示，一些烟草SWEET基因具有组织表达特异性。不同胁迫处理的表达模式分析显示，部分烟草SWEET基因在葡萄糖、蔗糖、低温、干旱或者是盐胁迫处理下表达量变化明显。  结论  Ntab0097340和Ntab0727890是烟草植株重要的响应干旱与低温胁迫的基因，本研究为深入研究烟草SWEET基因功能提供有价值的参考信息。 

Identification and expression analysis of SWEET gene family in Nicotiana tabacum

  Objective  This study aims to identify the members of the SWEET (sugar will eventually be exported transported) gene family involved in sugar metabolism in tobacco.  Methods  Using SWEET protein in Arabidopsis as the reference, bioinformatics methods were used to identify the SWEET protein family in cultivated tobacco. Then, the protein physicochemical properties, phylogenetic evolution, chromosomal location, gene structure and cis-elements of the NtSWEET family members were analyzed, and expression patterns in different tissues under different stress treatments were detected.  Results  70 possible SWEET genes were identified from tobacco, which were divided into 4 subgroups by phylogenetic tree. Most of the tobacco SWEET genes underwent purification selection during evolution. The expression pattern analysis of different tobacco tissues showed that some NtSWEET genes are specifically expressed in certain tissues. The expression pattern analysis of different stress treatments showed that the expression level of some NtSWEET genes changed significantly under glucose, sucrose, low temperature, drought or salt stress treatments.  Conclusion  Ntab0097340 and Ntab0727890 are important genes for tobacco in response to the drought and low temperature stress. This study provides valuable reference information for further study of the NtSWEET genes in tobacco.