The Distribution And Evolution Of Three Full-longth LTR Retrotransposons,and Characteriation And Functional Analysis Of PHRE5 From Phyllostachys Edulis

Retrotransposons were widely present in plants,which play an important role on the structure,function,and evolution of plant genomic.In this thesis,three LTR retrotransposons,which named PHRE3,PHRE4 and PHRE5,were investigated and analyzed.PHRE5 was selected to observe the transposition under stress condition,and discuss the relation between transposition of PHRE5 and morphological differences of Phyllostachys edulis.1.Three LTR retrotransposons were identified by LTR-STRUC software in bamboo genome database.Finally,PHRE3,PHRE4 and PHRE5 were selected for bioinformatics analysis.The PHRE3(13160 bp)has 37 completed copies and 21 solo-LTR in Ph.edulis genome,which contains the GAG,PAP,RT,RH,INT genes that is similar to the structure of Ty3-gypsy family,and LTR domains,PBS and PPT,all of which are necessary for transpositio-n.PHRE3 prefer to insert to in the sequences of T(G/A)(A/G)(C/A)(G/A)(G/C)(T/A)(T/A)G(G/C)(G/T/C)C(G/A)T(up)and A(G/T/C)(A/T)(T/G/C)(A/G)A(G/T/C)(A/C)(A/T)T(A/C)CT(down).LTR sequence homology is up to 95.40%with the insertion time of 1462 thousa-nds years ago.The PHRE4(5471bp)has 3 complete copies,2 solo-LTR,and 46 short ele-ments,which contains the GAG,PAP,RT,RH,INT genes,LTR domains,PBS and PPT,and belong to the Ty3-gypsy family.PHRE4 prefer to insert to in the sequences of T(T/G/C)(A/G)(C/A)(G/C/A)(T/C/A)(T/G/A)(T/A)(G/T/C)(C/A)(G/A)A(T/A)(G/T/C)(T/C)(T/G/C)(T/G/C)C(up)and A(T/G/C)(C/T)CAG(T/A)T(C/A)(C/G/A)(G/T/G)A(G/C)A(down).LTR sequ-ence homology is up to 99.45% with the insertion time of 231 thousands years ago.The PHRE5(5774 bp)has 2 complete copies,1 solo-LTR,and 45 short elements,which contai-ns the GAG,PAP,RT,RH,INT genes,LTR domains,PBS and PPT.PHRE5 prefer to ins-ert to in the sequences of C(T/A)(C/T/A)NA(G/T)TC(T/A)(A/C)(G/C)(A/G)(G/C)N(G/T)(G/T)(T/G)(G/T)A(up)and CCAC(C/T)(C/G)(A/T)(A/G)(A/T)(C/T)(C/G)A(T/C)C(A/T)T(T/A)C(down).LTR sequence homology is up to 99.26% with the insertion time of 269 thousands[DT1] years ago.2.Due to its complete structure and suitable length,PHRE5 is elected to analyze the changes of copies by three kinds of stress such as ?-ray radiation,methylation inhibitor(5-Azacytidine)and Colchicine with the SYBR Green real-time PCR.It is found that the copy number of PHRE5 in the seedlings increased by 50 Gy,70Gy,90 Gy dose of radiation,concentrations of 5-Azacytidine with 50?mol/l?100?mol/l?150?mol/l?200?mol/l?250?mol/l and polyploid seedlings with Colchicine treated;the copies of tetrapioid have increased to 2.5 times,and the hexaploid just increased to 2.5 times.3.For further test the transposition,the insertion polymorphism was detected with LA PCR in vitro cloning technology and Native-PAGE.The results show obvious polymorphism in radiation of 50 Gy,70Gy,90 Gy dose and 5-Azacytidine of 50?mol/l?100?mol/l?150?mol/l?200?mol/l?250?mol/l.4.Moso bamboo generates many variants during the cultivation,such as the stem shape,stem colour,leaf colour and so on,but these variants can not be inherited steadily and will have back mutation when the environment changes.PHRE5?s copies and insertion polymorphism were analyzed in eight Ph.edulis Cultivars.Compared with moso bamboo,the copy number was increased in these cultivars,which was verified by the polymorphism.But more research is needed about whether transposition is directly related to phenotypic changes.