An object of the present invention is to provide a technique for modifying the structure of a plant phloem tissue. A plant in which functions of NTL9 and a transcription factor that is a homolog thereof are inhibited. [Selection diagram] None【課題】植物師部組織の構造を改変する技術の提供。【解決手段】NTL9及びそのホモログである転写因子の機能が阻害されている、植物体。【選択図】なし