为探究桑树(Morus alba Linn.)四跨膜蛋白(TET)基因家族的功能，从桑树全基因组中筛选并克隆了9个MaTET基因(MaTET2、MaTET3、MaTET6、MaTET8、MaTET10、MaTET11、MaTET18、MaTET19A和MaTET19B)，通过生物信息学和分子生物学技术分析了其理化性质、保守基序、结构域、系统进化及顺式作用元件，利用实时荧光定量PCR技术检测了这9个基因在低温胁迫、脱落酸和茉莉酸甲酯处理及茄科劳尔氏菌(Ralstonia solanacearum)侵染下的表达模式，并结合原核表达和十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)进行了检测验证。结果显示：桑树MaTET基因家族9个成员的碱基长度为813~1 520 bp；除MaTET18、MaTET19A和MaTET19B外，其他6个MaTET蛋白的理论等电点高于pI 7.0；MaTET蛋白均为疏水蛋白，且均具有跨膜结构域，共有12个保守基序，且保守结构域基本一致。系统进化分析表明：MaTET2、MaTET3、MaTET6、MaTET8、MaTET10和MaTET11与拟南芥〔Arabidopsis thaliana (Linn.) Heynh.〕同源蛋白亲缘关系较近。9个MaTET基因启动子共有15种与非生物胁迫、激素响应和生长发育相关的顺式作用元件。基因表达分析结果显示：低温胁迫下MaTET3、MaTET6、MaTET8、MaTET10和MaTET18的相对表达量显著（P<0.05)变化；脱落酸处理1 h，MaTET2、MaTET3、MaTET11、MaTET19A和MaTET19B的相对表达量显著上调；茉莉酸甲酯处理1 h,9个MaTET基因的相对表达量均显著升高；茄科劳尔氏菌侵染72 h，除MaTET2和MaTET18外，其他7个MaTET的相对表达量不同程度地升高。原核表达及SDS-PAGE检测结果显示：桑树MaTET基因家族的9个成员中7个成员编码蛋白在相对分子质量处检测到条带，而MaTET3和MaTET6在更换表达条件后均未成功表达。综上所述，桑树MaTET基因家族在响应非生物胁迫、激素响应和病原菌侵染中发挥重要作用。

To explore the functions of tetraspanin (TET) gene family in Morus alba Linn., nine MaTET genes (MaTET2, MaTET3, MaTET6, MaTET8, MaTET10, MaTET11, MaTET18, MaTET19A, and MaTET19B) were screened and cloned from the whole genome of M. alba, their physicochemical properties, conserved motifs, domains, phylogenetic evolution, and cis-acting elements were analyzed by using bioinformatics and molecular biology technology, the expression patterns of these nine genes under low-temperature stress, abscisic acid and methyl jasmonate treatments, and Ralstonia solanacearum infection were detected by using real-time fluorescence quantitative PCR, and verification was performed by using prokaryotic expression combined with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The results show that the base lengths of the nine members in MaTET gene family in M. alba are 813-1 520 bp; except for MaTET18, MaTET19A, and MaTET19B, the theoretical isoelectric points of the other six MaTET proteins are higher than pI 7.0; all MaTET proteins are hydrophobic and contain transmembrane domains, with 12 conserved motifs, and the conserved domains are basically consistent. The phylogenetic analysis indicates that the genetic relationships between MaTET2, MaTET3, MaTET6, MaTET8, MaTET10, and MaTET11 and the homologous proteins in Arabidopsis thaliana (Linn.) Heynh. are relatively close. The promoters of the nine MaTET genes contain 15 types of cis-acting elements related to  abiotic stress, hormone response, and growth and development. The gene expression analysis results show that the relative expression of MaTET3, MaTET6, MaTET8, MaTET10, and MaTET18 changes significantly (P<0.05) under low-temperature stress; after 1 h of abscisic acid treatment, the relative expression  of MaTET2, MaTET3, MaTET11, MaTET19A, and MaTET19B is significantly upregulated; after 1 h of methyl jasmonate treatment, the relative expression  of all nine MaTET genes significantly increases; after 72 h of infection by R. solanacearum, the relative expression  of the other seven MaTET genes except MaTET2 and MaTET18 increases to different degrees. The prokaryotic expression and SDS-PAGE detection results show that the bands are detected at the relative molecular masses of the proteins encoded by seven of the nine members in the MaTET gene family, while MaTET3 and MaTET6 are not successfully expressed after changing expression conditions. In conclusion, the MaTET gene family in M. alba plays important roles in responding to abiotic stress, hormone response, and pathogen infection.