辣椒CCO基因家族鉴定及其在果实发育中的表达分析OA

Members of the CCO gene family are ubiquitously distributed in bacteria,plants and animals,and perform pivotal functions in plant secondary metabolism.In this study,a total of 18 CCO family genes were identified in Capsicum annuum via bioinformatic approaches,designated CaCCO01-CaCCO18.These genes were mapped to eight chromosomes(Chr.1,3,5,6,7,8,10 and 11).The encoded amino acid sequences ranged from 102 to 646 amino acids(aa),with molecular weights varying from 11224.87 to 72718.77 Da and isoelectric points(pI)ranging between 5.13 and 9.19.Phylogenetic clustering classified these CaCCOs into six subgroups:nine genes belonged to the CCD subfamily,four to the NCED subfamily,and the remaining five genes(CaCCO11,CaCCO15,CaCCO16,CaCCO17,CaCCO18)were tentatively assigned to the CCDL subfamily.Cis-acting element prediction revealed cis-regulatory motifs associated with light responses,phytohormone signaling,growth and development,as well as stress responses across all CaCCO promoters.CaCCO02 harboured the largest number of TATC-box elements(7 copies),while CaCCO12 contained the highest abundance of RY-element motifs(18 copies).Transcriptome sequencing and expression profiling demonstrated distinct spatiotemporal expression patterns for key CaCCO genes:CaCCO02 and CaCCO12 exhibited high expression at early fruit developmental stages followed by gradual downregulation as fruit maturation proceeded;transcript abundance of CaCCO04 increased continuously from 12 days post-anthesis(DPA,stage S1)to 48 DPA(stage S4);CaCCO06 displayed stage-specific peak expression at 36 DPA(stage S3),representing a prominent mid-developmental expression maximum.Quantitative real-time PCR(qRT-PCR)validation yielded results largely consistent with transcriptome data,indicating that these four genes likely act as critical regulators governing fruit development and morphogenesis in pepper.