@article{oai:miyazaki-u.repo.nii.ac.jp:00003356,
 author = {城, 惣吉 and Shiro, Sokichi and 山本, 昭洋 and Yamamoto, Akihiro and 吉田, ナオト and Yoshida, Naoto and 吉田, 直人 and 佐伯, 雄一 and Saeki, Yuichi and 城, 惣吉 and Shiro, Sokichi},
 journal = {宮崎大学農学部研究報告, Bulletin of the Faculty of Agriculture University of Miyazaki},
 month = {Feb},
 note = {The study of the bradyrhizobial adaptation for pH and temperature of the soil is an important subject to reveal the mechanism of the indigenization and the predominance of bradyrhizobia in various environmental conditions. In this study, we examined the horizontal gene transfer about the exogenous gene acquisition relevant the adaptability to the environmental gradient of bradyrhizobia by the hydrogel exposure method and the diparental mating method.
 Five Bradyrhizobium strains (Bradyrhizobium japonicum USDA 6T, 110, 124, 135, B. elkonii USDA 76T) and a transposon (Tn5) vector including the gfp (green fluorescence protein) gene as maker gene were used in this study. For the hydrogel exposure method, strains tested and marker gene were mixed with nano-sized acicular clay minerals, and performed the gene transfer by hydrogel exposure. On the other hand for the diparental mating method, Escherichia coli strain S17-1 that held the maker gene and each Bradyrhizobium strains were mixed, and performed the gene transfer by the diparental mating. In the hydrogel exposure method, we were not able to obtain the Bradyrhizobium strains showing the fluorescence character of GFP. On the other hand, in the diparental mating, we were able to obtain transformed clones. Furthermore, the rates of viable cell by each strains tested were different when we investigated survival characteristic of bradyrhizobia by hydrogel exposure.
 From these results, about the exogenous gene acquisitions of bradyrhizobia, it is suggested that the possibility by the conjugation of between bacteria was higher tban possibility of physicochemical horizontal gene transfer by puncture of nano-sized acicular clay minerals., ダイズ根粒菌の土着化, 優占化のメカニズムを明らかにするためには, 土壌のpHや温度に対する適応機構の獲得様式の解明が大きな課題となっている. 本研究では, ダイズ根粒菌における環境傾度への適応性に関する外来遺伝子獲得機構について, ハイドロゲル曝露法と二親接合法によって検討を行った.
 試験菌株としてダイズ根粒菌5菌株(B. japonicum USDA 6T, 110, 124, 135, B. elkanii USDA 76T) を, マーカー遺伝子としてgfp(緑色蛍光タンパク質) 遺伝子を含むトランスポゾン(Tn5) ベクターを用いた. これらを微細針状粘土鉱物と混在し, ハイドロゲル曝露による遺伝子導入を行った. また, ダイズ根粒菌5菌株とマーカー遺伝子を保有する大腸菌とを混在させ, 二親接合による遺伝子導入を行った. ハイドロゲル曝露法では, gfp遺伝子由来の蛍光形質を示した菌株を得ることが出来なかったが, 二親接合法では,gfp遺伝子由来の蛍光形質を示した菌株を得ることが出来た. また, ハイドロゲル曝露によるダイズ根粒菌の生残性を調査してみたところ, 試験菌株によって生残性に差が見られ, 酸性-中性土壌に生息する根粒菌には高い感受性が認められた.以上の結果から, Bradyrhizobium属ダイズ根粒菌の外来遺伝子の獲得は, 微細針状粘土鉱物の穿刺による無生物的な外来遺伝子の獲得の可能性と比較して, 細菌同士の接合による可能性が高いと考えられた.},
 pages = {79--87},
 title = {ダイズ根粒菌の外来遺伝子獲得に関する菌株間差異の解析},
 volume = {56},
 year = {2010},
 yomi = {シロ, ソウキチ and ヤマモト, アキヒロ and ヨシダ, ナオト and サエキ, ユウイチ and シロ, ソウキチ}
}