The wound‐healing responses of Antithamnion nipponicum and Griffithsia pacifica (Ceramiales, Rhodophyta) monitored by lectins

SUMMARY The binding of FITC labeled lectins to repair cells of Antithamnion nipponicum Yamada et Inagaki and Griffithsia pacifica Kylin, and their physiological effects on somatic cell fusion have been studied. Results indicate that repair cells strongly bind the lectins ConA and LCA, whereas other lectins did not bind to the cell, The binding of these lectins to the dead cell wall shows ConA and LCA specific substances are secreted from the tip of the repair cells. When fluorescently labeled ConA or LCA was added at various time intervals after wounding, it firstly bound (3 h post‐wounding) as a thin layer at the tips of the adjacent cells. Later (4–5 h post‐wounding) labeling also appeared at the tips of the repair ceils. Intense labeling at these sites continued throughout the wound‐healing process until repair cell fusion, at which time the lectin labeling was reduced to a narrow ring around the area of fusion, When added to plants prior to wounding and with continued monitoring, these same lectins were found to act as inhibitors to the wound‐healing response. Other control lectins showed no inhibitory effects. These results suggest that a signal glycoprotein with α‐D‐mannosyl residues is involved in the wound‐healing process of Antithamnion nipponicum. Lectins conjugated with visible tags can be used as a very fast and useful tool to monitor these signal substances.