The Exchange Substance of Rootstock and Scion and Its Grafting Healing Effect
DU Hao, CHEN Yao, WU Qingxian, LIU Sitong, JIN Leni, YIN Zengfang*
Plant graft healing is regulated by rootstock/scion themselves and the external environmental factors. The interaction between rootstock and scion is not only present histological characteristic changes, but also involves complex physiological, biochemical and molecular regulatory mechanisms during the graft healing. Rootstock and scion have completed healing by undergoing four steps of isolation layer formation, callus formation, differentiation and vascular tissue redifferentiation. Essentially, the cells, tissues or organs of rootstock and scion interact with each other and frequently exchange substances, such as plant hormones, sugar, nucleic acids and proteins by short-distance transporting through plasmodesmata, as well as by long-distances transporting over phloem in the process of grafting healing. Thus, the recognition, acceptance and inclusion effect between the rootstock and scion is established, and the graft healing process is finished finally. It also plays an important role in the subsequent growth process of grafted seedlings. In this paper, the histological characteristic, exchanges substances property and the factors which are affected the healing process have been reviewed, and it will provide the basic theoretical guidance for the production practice of plant graft propagation