Comparative Analysis of Structure and Function of Upstream Sequences Adjoining Tuf Gene in Paulownia and Jujube Witches’-broom Phytoplasmas

【作者】 于少帅； 田国忠； LIN Caili； PIAO Chungen； WANG Laifa；

【Author】 YU Shaoshuai;TIAN Guozhong;LIN Caili;PIAO Chungen;WANG Laifa;Key Laboratory of Forest Protection of State Forestry Administration,Research Institute of Forest Ecology,Environment and Protection,Chinese Academy of Forestry;

【机构】 Key Laboratory of Forest Protection of State Forestry Administration,Research Institute of Forest Ecology,Environment and Protection,Chinese Academy of Forestry；

【摘要】 Both paulownia and jujube witches ’-broom are economically and environmentally harmful plant diseases caused by two distinct phytoplasmas belonging to 16 SrI and V group respectively.To better trace the mechanism of genomic organization and regulation of various kinds of phytoplasmas,we applied the methods of direct/TAIL(thermal asymmetric interlaced)-PCR and confusion expression system constructed with the promoter-probe vector pSUPV4 and E.coli competent cell to amplify and identify the upstream sequences of tuf gene,encoding EF-Tu factor,in paulownia witches’-broom phytoplasma(PaWB) and jujube witches’-broom phytoplasma(JWB).Structural comparative analysis of the two upstream sequences revealed that the order of fusA,encoding EF-G factor,and tuf gene arrangement was accordance.The sequence length of intergenic region(IRG)of fusA and tuf was different in PaWB(118bp) and JWB(53bp).A putative promoter in IRG of fusA and tuf in PaWB was predicted while that in JWB was absent.Subjected to the kanamycin resistance identification,comparative analysis of confusion expression system of the two upstream sequences demonstrated that 130 bp upstream sequence of tuf gene in PaWB was of promoter activity.However,no promoter activity was found in the study in 144 bp and 346 bp upstream sequence of tuf gene in JWB.It is suggested that the diversity of sequence and organization in non-coding flank of functional genes in phytoplasmas might be of great significant in providing insight into phytoplasma genetic variation and phylogenetic evolution relative to their gene expression and regulation as well as interaction with hosts(plant and insect vector).更多还原

【Abstract】 Both paulownia and jujube witches ’-broom are economically and environmentally harmful plant diseases caused by two distinct phytoplasmas belonging to 16 SrI and V group respectively.To better trace the mechanism of genomic organization and regulation of various kinds of phytoplasmas,we applied the methods of direct/TAIL(thermal asymmetric interlaced)-PCR and confusion expression system constructed with the promoter-probe vector pSUPV4 and E.coli competent cell to amplify and identify the upstream sequences of tuf gene,encoding EF-Tu factor,in paulownia witches’-broom phytoplasma(PaWB) and jujube witches’-broom phytoplasma(JWB).Structural comparative analysis of the two upstream sequences revealed that the order of fusA,encoding EF-G factor,and tuf gene arrangement was accordance.The sequence length of intergenic region(IRG)of fusA and tuf was different in PaWB(118bp) and JWB(53bp).A putative promoter in IRG of fusA and tuf in PaWB was predicted while that in JWB was absent.Subjected to the kanamycin resistance identification,comparative analysis of confusion expression system of the two upstream sequences demonstrated that 130 bp upstream sequence of tuf gene in PaWB was of promoter activity.However,no promoter activity was found in the study in 144 bp and 346 bp upstream sequence of tuf gene in JWB.It is suggested that the diversity of sequence and organization in non-coding flank of functional genes in phytoplasmas might be of great significant in providing insight into phytoplasma genetic variation and phylogenetic evolution relative to their gene expression and regulation as well as interaction with hosts(plant and insect vector).更多还原