PROBLEM TO BE SOLVED: To provide methods and compositions for improving efficiency of bacterially-mediated plant cell transformation by using additional transformation enhancer sequences such as overdrive or TSS sequence operably linked to a T-DNA border sequence on a recombinant construct including T-DNA.SOLUTION: Provided is a method for increasing the efficiency of plant transformation mediated by a rhizobium bacterium for performing transformation of the plant cell with the rhizobium bacterium, where the rhizobium bacterium is carrying a plant transformation vector that comprises at least one T-DNA border sequence derived from Agrobacterium tumefaciens and a transformation enhancer sequence of which sequence is specified and operably linked to the T-DNA border sequence.【課題】Ｔ－ＤＮＡを含む組換え構築物上のＴ－ＤＮＡボーダー配列に作動可能に連結した、オーバードライブ又はＴＳＳ配列のような更なる形質転換エンハンサー配列の使用によって細菌－媒介植物細胞形質転換の効率を改善するための方法及び組成物の提供。【解決手段】リゾビウム属細菌－媒介植物形質転換の効率を増大させる方法であって、植物細胞をリゾビウム属細菌で形質転換し、該リゾビウム属細菌はアグロバクテリウム・ツメファシエンスからの少なくとも１のＴ－ＤＮＡボーダー配列および該Ｔ-ＤＮＡボーダー配列に作動可能に連結された形質転換エンハンサー配列を含む植物形質転換ベクターを含み、特定の形質転換エンハンサー配列を含む方法。【選択図】なし
