Concentrations of lignin and wall-bound ferulic acid after wounding in the phloem of Chamaecyparis obtusa

The changes of lignin and wall-bound ferulic acid induced by wounding were quantitatively and histochemically investigated in the phloem of Chamaecyparis obtusa. Histochemical staining of lignin was first observed in the necrotic region of the phloem 7 days after wounding and developed in 14 days. Increases of the wall-bound ferulic acid and lignin concentrations were detected in the necrotic tissue at 7 and 14 days, respectively. The concentrations continued to increase until 28 days. The lignin concentration of the callus tissue was observed to be lower than that of the healthy tissue at 14 days, and reached a similar level after 28 days. No quantitative changes of lignin and wall-bound ferulic acid were observed in other tissues. The results indicated that lignin synthesis could be maintained after the phloem cells were discolored and seemed to be necrotic. Distribution and timing of the wall-bound ferulic acid and lignin accumulation suggested that the increased wall-bound ferulic acid was involved in the lignin synthesis after wounding.