Table12_Genome-Wide Analysis of Major Facilitator Superfamily and Its Expression in Response of Poplar to Fusarium oxysporum.DOC

The major facilitator superfamily (MFS) is one of the largest known membrane transporter families. MFSs are involved in many essential functions, but studies on the MFS family in poplar have not yet been reported. Here, we identified 41 MFS genes from Populus trichocarpa (PtrMFSs). We built a phylogenetic tree, which clearly divided members of PtrMFS into six groups with specific gene structures and protein motifs/domains. The promoter regions contain various cis-acting elements involved in stress and hormone responsiveness. Genes derived from segmental duplication events are unevenly distributed in 17 poplar chromosomes. Collinearity analysis showed that PtrMFS genes are conserved and homologous to corresponding genes from four other species. Transcriptome data indicated that 40 poplar MFS genes were differentially expressed when treated with Fusarium oxysporum. Co-expression networks and gene function annotations of MFS genes showed that MFS genes tightly co-regulated and closely related in function of transmembrane transport. Taken together, we systematically analyzed structure and function of genes and proteins in the PtrMFS family. Evidence indicated that poplar MFS genes play key roles in plant development and response to a biological stressor.

主要促进因子超家族（major facilitator superfamily, MFS）是目前已知的最大膜转运蛋白家族之一。MFS参与诸多生命必需功能，但目前尚未见杨树中MFS家族的相关研究报道。本研究从毛果杨（Populus trichocarpa）中鉴定得到41个MFS基因（PtrMFSs）。我们构建了系统发育树，该树可将PtrMFS家族成员清晰划分为6个具有特异基因结构与蛋白质基序/结构域的类群。PtrMFS基因的启动子区域含有多种参与胁迫与激素响应的顺式作用元件。由片段复制事件产生的PtrMFS基因在杨树的17条染色体上分布不均。共线性分析结果显示，PtrMFS基因与另外4个物种的对应基因具有保守性且同源。转录组数据分析表明，经尖孢镰刀菌（Fusarium oxysporum）处理后，杨树中有40个MFS基因发生差异表达。MFS基因的共表达网络与功能注释结果显示，这些基因存在紧密的共调控关系，且在跨膜运输功能上密切相关。综上，本研究系统分析了PtrMFS家族基因及其编码蛋白的结构与功能，相关证据表明杨树MFS基因在植物发育及生物胁迫响应过程中发挥关键作用。