graft

Graft has several related meanings in biology and society. In botany and medicine, it refers to the joining of living tissue from two organisms so that they grow as a single unit. As a verb, graft means to perform such a join or to transplant tissue from one body part to another. In common language, graft can also denote illicit gains obtained through public office or influence.

In medicine, a graft is tissue moved from a donor site to a recipient site. Types include autografts (from the same individual), isografts (from a genetically identical individual), allografts (from another individual of the same species), and xenografts (from a different species). Skin grafts repair wounds; bone, tendon, or cartilage grafts restore or reinforce structures; organ transplants provide whole organs. Grafts may be vascularized or non-vascularized. Rejection occurs when the recipient’s immune system attacks the transplanted tissue; immunosuppressive therapy and careful tissue matching reduce risk. In bone marrow or stem cell transplantation, graft-versus-host disease can occur when donor cells attack the recipient’s tissues.

In horticulture, grafting is a propagation method that joins a scion from one plant to the rootstock of another to combine desirable traits. The graft must have compatible cambium layers, and alignment is important. Common techniques include whip-and-tongue grafts and budding. The rootstock provides vigor, disease resistance, or dwarfing, while the scion determines fruit, flower, or leaf characteristics. Grafted plants can establish quickly and maintain cultivar traits, but failures can occur from incompatibility or poor healing.

Historically, grafting has been used for millennia in agriculture. The term graft also appears in legal and political language to refer to corruption or illicit gains, though such usage is informal and varies by jurisdiction.