The Influence Of Gene Expression In Different Species (Varieties) Of Paulownia Under Drought Stress

Paulownia is a fast growing woody plant native to China,it has a very important economic and ecological value,which make it widely used for landscaping and silviculture.It was widely distributed in chin.In present,Paulownia is divided into 9 species 2 varieties and many types of variation,the interspecific relationship between those species is very complex.To understand the molecular mechanism between different species in paulownia,16 cDNA and sRNA libraries were constructed from diploid,tetraploid and their drought treatments groups of Paulownia fortunei(PF2,PF2T,PF4,PF4T),Paulownia tomentosa(PT2,PT2T,PT4,PT4T),Paulownia australis(PA2,PA2T,PA4,PA4T)and Paulownia tomentosa× Paulownia fortunei(PTF2,PTF2T,PTF4,PTF4T)samples.The excellent characters of molecular mechanisms and their genetic relationship between different species were analyzed.The main results are list in blew:(1)In study,the 16 cDNA and sRNA libraries were constructed and sequenced on a GAIIx platform,the result reads were mapped to P.fortunei genome,genome-wide transcriptome analysis is able to capture an unbiased view of the complete RNA transcript profile than transcriptome-wide analysis,allowing the transcriptional level of each gene in its life cycle to be monitored,indicating the data use in this study is more accuracy.In this study,the transcript gene and miRNA from 16 samples were identified,and the common and specific genes and miRNAs among four species were analyzed.Totally,27178 gene were obtained from 16 samples,among them,25674,25350,25821 and 25439 gene were from four diploid samples,diploid drought treatments,tetraploid samples,and trtraploid treatment,respectively.Furthermore,517 miRNA were obtained from 16 samples,among them,364,298,297 and 369 miRNA were from four diploid samples,diploid drought treatments,tetraploid samples,and trtraploid treatments,respectively.Throught the differentially expressed gene analysis,127 and 556 differentially expressed genes were obtained from eight comparisons.(2)In this study,a total of 27178 genes were obtained from 16 samples,among them,17626 genes were common in 16 samples,All those gene were existed in the process of paulounia growth and development.In addition,the conmmon and special genes in four groups were obtained,respectively.All common gene in 16 samples were enrichment in 128 pathway,the main pathway were '"RNA degradation",;"Purine metabolism" and "Spliceosome".The result show that the gene in diploid and tetraploid Paulownia response to drought stress were mainly enrichment in "Pyruvate metabolism"'',"Glycerolipid metabolism","Galactose metabolism","Lysine degradation","Ascorbate metabolism'',"Photosynthesis","Carbon fixation in photosynthetic organisms","Photosynthesis-antenna proteins","Photosynthesis-antenna proteins'',"Biosynthesis of secondary metabolites".In this study,a lot of' common and specific gene were identified in Diploid and tetraploid paulownia under drought stress,and we found that the specific gene between different species were enrichment in similar pathway through the kegg analysis,indicating the molecular mechanism of different paulownia species response to drought stress were similar.(3)In this study,9552 genes and 422 miRNAs were used to performed the genetic similarity coe:fficient and map between four paulownia species.Using transcriptome and miRNA to calculate the genetic similarity coefficient have several obvious advantage,such as a large volume of data,more accurate of the sequences and results.The result show that the genetic similarity coefficient and map change in a little between different groups,and Paulownia fortunei,Paulownia australis and Paulownia tomentosax Paulownia fortunei belong to one group,Paulownia tomentosa belong to another group.