Genome-wide Identification Of Serine Carboxypeptidase-like Gene Family In Poplar And The Disease-resistant Function Analysis Of PtSCPL27

Poplar(Populus L.)is an important tree species for ecological protection and industrial timber.It also has been the model plants for the studies of tree molecular biology and forest genetic engineering since its release of genomic information at 2006.The serine carboxypeptidase-like(SCPL)proteins played an important role in plant growth and stress response,but in woody plants,the study of this gene family was rarely reported.So this study by the poplar as the research material,using bioinformatics methods such as phylogenetic analysis,gene structure analysis,chromosomal location and micro collinearity and so on,studied the evolutionary mechanism of SCPL genes;at the same time,Pt SCPL27 was selected as candidate gene by analysis of promoter,tissue expression patterns and Me JA induced expression patterns to study its disease resistance.The results were as follows:(1)In this study,57 SCPL gene family members were identified from the poplar genome database and divided into 3 subfamilies.Gene structure and conservative motif analysis showed that the SCPL gene family members of poplar were conserved in gene sequences.(2)The SCPL genes of poplar were distributed on 19 chromosomes,unevenly.By BLASTP comparison,14 paralogous were identified,6 pairs of which were from large-scale replication and 1 pair from tandem replication;combined with the results of the micro collinearity analysis,it was shown that large-scale replication played an important role in the expansion of Pt SCPL genes.(3)Tissue expression pattern analysis showed that most of the Pt SCPL genes had relatively high expression in mature leaves of poplar.Promoter analysis showed that the number of cis acting elements related to Me JA was the largest in the promoter region.Under the induction of Me JA,the relative expression level of most Pt SCPL genes showed an upward trend,and the relative expression level of Pt SCPL27 was the highest.(4)Subcellular localization showed that the transient expression product of Pt SCPL27 was located in the cell membrane.(5)The Pt SCPL27 protein was obtained by purification,and its products of enzymatic reactions and antibacterial test were carried out.The results showed that the retention time of the enzymatic reaction product was the same as that of sinapinic acid,and the protein had a certain inhibitory effect on Rhizoctonia solani.(6)The Pt SCPL27 gene was over-expressed and the T1 generation seeds of transgenic Arabidopsis were obtained,which provided the basic material for phenotypic screening of transgenic plants.It also provides experimental materials for further screening of homozygotes and verification and related physiological and biochemical indexes.