Abstract: 【Objective】In order to study the mechanism of lignification and research on the impacts of endogenous hormone (IAA, GA3, ABA) on lignification in excised bamboo shoots. 【Method】The relationship between endogenous hormone (IAA, GA3, ABA) levels and enzyme activities related to lignification of Phyllostachys praecox f. preveynalis and Phyllostachys pubescens Mazel were investigated. 【Result】The content of GA3 and IAA in the two bamboo shoots declined continuously, but ABA content increased initially and declined later. The content of endogenous hormone (IAA, GA3, ABA) in excised bamboo shoots of Phyllostachys praecox f. preveynalis were higher than those of Phyllostachys pubescens Mazel. The activities of phenylalanine ammonia lyase (PAL), 4-coumarate CoA ligase (4CL) and peroxidase (POD) increased initially and declined later during the storage. The content of lignin and cellulose and firmness of bamboo shoots continuously increased. The activities of PAL, 4CL and POD were significantly correlated with the ratio of ABA/GA3. 【Conclusion】These results indicated that the ratio of ABA/GA3 is very important for lignification in excised bamboo shoots. The lignification of excised bamboo shoots maybe retarded when the activities of PAL, 4CL and POD were inhibited by decreasing ABA/GA3 ratio.

Key words: bamboo shoot, lignification, endogenous hormone