龙眼SAP-PPD-KIX-TPL信号途径基因家族的全基因组鉴定与表达模式

Genome-wide identification and expression pattern of gene family of SAP-PPD-KIX-TPL signal pathway in Dimocarpus longan Lour.

STERILE APETALA(SAP)可调控PPD-KIX-TPL转录抑制复合体的稳定性,从而调节器官大小.基于龙眼基因组数据库,对龙眼SAP-PPD-KIX-TPL信号途径的基因家族进行全基因组鉴定,分析龙眼SAP、PEAPOD(PPD)和TOPLESS(TPL)家族成员的基本理化性质、基因结构及蛋白结构域、启动子顺式作用元件、蛋白互作网络、构建系统进化树;分析龙眼体胚发生过程及不同组织部位中的基因表达水平,并采用qRT-PCR检测体胚发生早期及不同激素处理下的表达模式.结果表明,DlSAP包含1个成员,具有WD40结构域,只有1个内含子.DlPPD包含7个成员,具有tify和CCT_2结构域,含有2-7个内含子,最保守基序为motif1.DlTPL包含6个成员,具有LisH、CTLH和WD40结构域,含有23-29个内含子,除motif7外,motif1-10中的剩余基序均保守.龙眼kinase-inducible domain interacting(KIX)家族包含8个成员,保守结构域为KIX.顺式作用元件预测表明,DlSAP、DlPPD和DlTPL启动子均包含大量光响应、激素应答和非生物胁迫响应元件.蛋白互作网络预测显示,SAP和PPD之间的互作关系较强,与TPL相关联的蛋白较多.qRT-PCR结果表明,DlSAP、DlTIFY4B和DlTPR2-1在球形胚阶段表达量最高;DlSAP、DlTIFY10B-1和DlTPR2-1在不同激素处理中均出现多种表达模式.总之,龙眼SAP-PPD-KIX-TPL信号途径的基因可能参与响应多种激素和非生物胁迫应答,也可能参与胚胎发育,具有多种生物学功能.(图9表2参33)

STERILE APETALA(SAP)can regulate the stability of the PPD-KIX-TPL transcriptional repressor complex,thus regulating organ size.Based on the longan genomic database,this study identified the gene family of SAP-PPD-KIX-TPL signaling pathway,analyzed the basic physical and chemical properties,gene structure and protein domain,cis-acting element of promoters,protein interaction network of SAP,PEAPOD(PPD),and TOPLESS(TPL)family in longan,and constructed a phylogenetic tree.Gene expression during longan embryogenesis and in different tissues was also analyzed,and qRT-PCR was used to detect the expression patterns in early somatic embryogenesis and different hormone treatments.DlSAP contains one member,has a WD40 domain,and only one intron.DlPPD contains seven members,has tify and CCT_2 domains,and contains 2–7 introns.The most conservative motif is motif1.DlTPL has six members,including the LisH,CTLH,and WD40 domains,and has 23–29 introns.Except for motif7,the remaining motifs in motif1-10 are conserved.The kinase-inducible domain interacting(KIX)family of longans contains eight members with the conserved domain KIX.The cis-acting element predicted that DlSAP,DlPPD,and DlTPL promoters contained a large number of light,hormone,and abiotic stress response components.Protein interaction network prediction revealed the strong interaction between SAP and PPD,with more proteins associated with TPL.qRT-PCR revealed that the expression of DlSAP,DlTIFY4B,and DlTPR2-1 was highest in spherical embryos.DlSAP,DlTIFY10B-1,and DlTPR2-1 exhibited multiple expression patterns under different hormone treatments.In conclusion,the SAPPPD-KIX-TPL signaling pathway genes in longan may participate in and respond to various hormones and abiotic stresses and may also be involved in embryonic development with a variety of biological functions.