蒙古冰草肉桂醇脱氢酶基因序列鉴定及功能分析OA北大核心CSTPCD

As an essential enzyme in plant secondary metabolism,cinnamyl alcohol dehydrogenase(CAD)plays a key role in regulating plant growth and development,as well as biological/abiotic stress resistance.Agropyron mongolicum is a traditional forage grass widely distributed in the desert grassland areas of northern China,which exhibited high tole-rance to drought and cold stresses.To explore the role of cinnamyl alcohol dehydrogenase in A.mongolicum,in this study,a CAD gene was identified from the full-length transcriptome data of A.mongolicum and subsequentially analyzed in vitro.The 1 083 bp coding sequence of AmCAD encodes 361 amino acids,which has typical conserved CAD region containing two Zn2+ binding motifs and NADP(H)cofactor binding motifs,belongs to the typical CAD protein,and its three-dimensional structure is similar to AtCAD5.AmCAD is highly expressed in the stem.The AmCAD recombinant protein showed a robust catalytic ability to different cinnamaldehyde substrates,with the highest substrate affinity of coniferyl aldehyde and sinapaldehyde.Under drought stress condition,the expression level of AmCAD was significantly induced,indicating a potential function of this gene in stress tolerance.The experimental results indicate that AmCAD may play an important role in lignin biosynthesis and drought stress tolerance in A.mongolicum.Our research provided potentially valuable genetic resources for molecular breeding of A.mongolicum to improve biomass quality and stress resistance.