| Wheat(Triticum aestivum L.)is one of the most important crops in the world.However,there are a variety of abiotic stresses that seriously threaten the safety of wheat production.Genetic improvement by molecular breeding is of great significance for high yield and stable yield of wheat.Mining candidate genes related to crop stress resistance is the key to achieve the goal of molecular breeding.The serine carboxypeptidases(SCPL)family plays an important role in plant growth and development and in response to abiotic stress.In this study,we identified the members of wheat SCPL gene family,analyzed their phylogenetic relationship,chromosome location,gene duplication,gene structure,conserved motifs,promoter cis-acting elements and expression characteristics,and also predicted the simple repeat sequence(SSR)and mi RNA(Micro RNA)targeting TaSCPL genes.The main findings are as follows:1.A total of 210 candidate genes encoding SCPL protein were identified.And these genes are divided into three subfamilies: CPI,CPII and CPIII.Each subfamily contains 74,101 and35 TaSCPL genes,respectively.The chromosomes location analysis of the genes showed that209 TaSCPL genes are unevenly distributed on 21 chromosomes of wheat.Gene duplication analysis showed that approximately 10.5% and 64.8% of TaSCPL genes are derived from tandem duplication and fragmental duplication events,respectively.The Ka/Ks ratios of all TaSCPL duplication gene pairs are lower than 0.6,which indicated that they are under strong purification selection pressure.2.Gene structure analysis showed that most TaSCPL genes contain multiple introns.The results of conservative motif analysis showed that the motifs contained in the members of each subfamily were basically the same.The analysis of cis-acting elements showed that the promoter sequences of TaSCPL gene are rich in drought,ABA and Me JA response elements.3.The analysis of the expression level of TaSCPL genes under drought stress revealed that 57 TaSCPL genes respond to drought stress.The expression levels of the four TaSCPL genes were verified by q RT-PCR,and TaSCPL184-6D was selected for further downstream analysis.4.The transcript length of TaSCPL184-6D gene is 1983 bp,and the length of CDS is1515 bp,encoding 504 amino acids.The molecular weight of the protein is 55.67 k Da,and the isoelectric point is 5.70.Its promoter region contains multiple hormone-responsive elements that respond to Me JA and ABA,as well as drought responsive elements and response elements involved in defense and stress.5.The identification of resistance to drought and salt stress of TaSCPL184-6D transgenic Arabidopsis found that under stress conditions,the germination rate,total root length,root fresh weight,survival rate and proline content of TaSCPL184-6D transgenic Arabidopsis are significantly higher than those of the wild type,the content of malondialdehyde is significantly lower than that of the wild type.These results indicated that overexpression of TaSCPL184-6D can significantly enhance the drought resistance and salt tolerance of transgenic Arabidopsis plants.In conclusion,this study reveals the important value of the TaSCPL gene family in responding to abiotic stress.On the one hand,it provides candidate genes for the resistance molecular breeding of wheat,which is of great significance for further enhancing the resistance of wheat.On the other hand,it provides a theoretical basis for realizing high and stable yield of wheat. |
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