A Genome-Wide Identification Of The NAC Family Genes?A Survey Of NAC-DNA Interaction And Expression Analysis Of FCA Gene In Dendrobium Officinale Kimura Et Migo

The NAC transcription factor family is widely distributed in various plants and is involved in regulating plant growth and development,from embryogenesis to senescence,abiotic stress in response to plant environmental effects,and various stress responses.Based on the genome of Dendrobium officinale Kimura et Migo,this study used bioinformatics methods to comprehensively identify the NAC transcription factor family of D.officinale Kimura et Migo.A total of 118 DoNAC members were found,and 91 DoNACs remained after redundancy.Phylogenetic tree analysis showed that the gene family can be divided into 7 groups;the gene structure and protein sequence conservation of all its members were analyzed,and its protein sequence was conserved in the N-terminal NAC domain.Promoter analysis revealed that there is a response to abiotic stress sites,hormone response sites,protein binding sites and binding sites associated with biological functions in the promoter region of this gene family.Expression analysis indicated that 30 DoNAC genes were involved in seed germination,protocormogenesis and transformation of D.officinale,and 16 of them were more obvious.The three-dimensional structure of the proteins of nine AtNAC members(AtNAC025,AtNAC043,AtNAC046,AtNAC055,AtNAC058,AtNAC080,AtNAC083,AtNAC092,NTL9)was constructed by homology modeling,and the specific binding process of NAC and DNA was studied by docking and molecular dynamics simulation.The complex analysis showed that the nine different functional NAC proteins have similar binding patterns,mainly interacting with the major groove of the DNA molecule through the second ? folding of the C subdomain.The binding of DNA and NAC affects the overall stability of the complex.The decomposition of NAC and DNA interaction energy revealed that the same NAC acts similarly when binding to different DNA,and it is found that the A subdomain reduces the ability to bind to NAC and DNA.In the NAC domain,three subdomains of C,D,and E form a nonbonding effect with DNA.The DoFCA study found that the open reading frame of the DoFCA gene is 2,301 bp,containing 19 exons,18 introns,encoding 766 amino acid residues at the Nterminus(131-210,220-298).There are two RRM domains,and one WW domain exists at the C-end(605-634).Promoter analysis revealed that there are regulatory elements in the promoter region of this gene that are closely related to meristem-specific activation,endosperm expression,and expression regulation of anther-specific genes.Phylogenetic analysis showed that FCA protein differentiated during the evolution of monocotyledonous and dicotyledonous plants.Expression pattern analysis indicated that this gene may play an important role in the occurrence and formation of flowers with D.officinale;it also plays a role in the induction of flowering at low temperature.