Identification Of MADS-Box Transcription Factors Regulating Male Sterility In Salvia Miltiorrhiza

The issue of male infertility in Salvia miltiorrhiza(Danshen)distributed in Sichuan(SCDS)has a significant impact on its industrial growth.Various investigations have indicated that the MADS-box gene family plays a crucial role in controlling the fertility of flowering plants and the development of flower organs.In this manuscript,a thorough and systematic investigation of the MADS-box gene family in Danshen was performed,elucidating its subfamily categorization and abundance,gene structure characteristics,protein structure attributes,phylogenetic evolution,gene duplication occurrences,and cooccurrence in the two ecotypes of Danshen(SCDS which distributed in Sichuan and SDDS which distributed in Shandong),as well as other characteristics.By means of homologous gene mining,protein-protein interaction network prediction,and analysis of expression abundance in anthers at different stages,the MADS-box transcription factors that govern male sterility in SCDS were identified,and the principal outcomes are presented below.1.In this study,63 and 71 MADS-box genes of SCDS and SDDS have been identified,respectively,the MADS-box genes of SCDS have been classified into 17 subfamilies.There are 14 and 49 genes of I and Ⅱ subfamilies of MADS-box genes in SCDS,respectively,while the members are 18 and 53 of that in SDDS respectively.There are differences in the number of members in M-α 、 M-β 、 M-γ 、 AGL2-like,AGL6-like,TM3-like,AG-like,STMADS11-like,AGL15-like,SQUA-like,and MIKC*subfamilies in the I and Ⅱ subfamilies of MADS-box genes.2.The members of the same subfamily of MADS-box genes in the two ecotypes of Danshen have differences in gene length,exon-intron number,and conserved motifs.However,the members of the same subfamily have similar structures,indicating that they have similar function.3.Through prediction of the MADS-box protein-protein interaction network,it was found that the MADS-box of SCDS lacked two important protein nodes which are AP1 and SEP3.Compared to SDDS,SCDS lacked their homologous genes in Arabidopsis,and this may be due to the loss of important conserved regions during evolution.The absence of AP1-like genes may be the reason for the late flowering of SCDS,while the absence of SEP3-like genes may be the reason for abnormal stamen development.4.The MADS-box genes of SCDS and SDDS formed over 400 collinear pairs with other species,and that established the correspondence between the Danshen MADS-box genes and known functional genes of other species.5.The analysis of the expression levels of MADS-box genes in anthers at different stages revealed that SmMADS63 of the DEF-like subfamily,SmMADS31,SmMADS32,SmMADS33 of the AG-like subfamily,SmMADS10,SmMADS11 and SmMADS47 of AGL6-like subfamily and SmMADS4,SmMADS7,SmMADS8,SmMADS18 of the MIKC* subfamily may be the important factors affecting the stamen fertility of SCDS.