苹果TIPs亚家族成员的鉴定与干旱胁迫响应分析

【目的】鉴定并分析苹果液泡膜内在蛋白 (Tonoplast intrinsic proteins, TIP) 亚家族成员，探究该亚家族成员在苹果干旱胁迫下的表达模式。【方法】通过生物信息学方法对苹果MdTIPs全基因组进行鉴定，分析其家族成员的理化性质、基因结构、保守基序、顺式作用元件、系统进化树等，并结合实时荧光定量PCR (qRT-PCR) 对其在干旱胁迫下不同器官中的表达模式进行分析。【结果】在苹果基因组中，共检索得到了13个MdTIP基因，大部分成员亚细胞定位预测在质膜上，分布于10条染色体上，且每条染色体定位有1~3个成员；该基因家族成员的启动子区域包含多种响应激素和逆境胁迫的应答元件；qRT-PCR显示，MdTIPs亚家族成员在根中除MdTIP1;1外其余均都受上调表达，且MdTIP1;3和MdTIP1;4与对照相比，分别上调表达了5.27倍和5.69倍，推测是参与调控干旱胁迫的关键基因。【结论】初步鉴定并提供了MdTIPs亚家族成员信息，10个MdTIPs亚家族成员在根、茎、叶中差异表达，12个亚家族成员在根中高表达。结果为进一步研究苹果抗旱性基因资源的挖掘和利用提供了有价值的信息。

Identification and Expression Patterns in Response to Drought Stress of TIPs Subfamily in Apple

Objective] To identify and analyze the members of the tonoplast intrinsic proteins (TIP) subfamily in apple, and to investigate the expression patterns under drought stress. Methods] The whole genome of apple MdTIPs was identified by bioinformatics methods, and the physicochemical properties, gene structures, conserved motifs, cis-regulatory elements, phylogenetic trees, etc. of the subfamily members were analyzed, and the expression patterns of the MdTIPs were also analyzed under drought stress in different organs by real-time fluorescence quantitative PCR (qRT-PCR). Results] A total of 13 MdTIP genes were identified in the apple genome, most of members were subcellularly localized on the plasma membrane. The chromosome localization suggested that all members were distributed on 10 chromosomes, with 1-3 members localized on each chromosome. Besides, the promoter regions of the subfamily members contained a variety of response elements in response to hormonal and adversity stresses. The qRT-PCR showed that MdTIPs subfamily members were up-regulated in roots except MdTIP1;1, of which MdTIP1;3 and MdTIP1;4 were up-regulated 5.27 times and 5.69 times, respectively, compared with the control. Therefore, these two genes were presumed to be the key genes involved in the regulation of drought stress. Conclusion] Preliminary identification and information of MdTIPs subfamily members were provided. 10 MdTIPs subfamily members were differentially expressed in roots, stems and leaves, and 12 members were highly expressed in roots. The results provide valuable information for further research on utilization of drought resistance gene resources in apple.