GA_3处理对采后竹笋木质化及内源激素水平的影响

Effects of GA_3 Treatment on Lignification and Endogenous Hormone Levels of Postharvest Bamboo Shoots

研究了外源GA3浸泡处理对采后竹笋木质化的生理生化变化及内源激素水平的影响。结果表明:竹笋贮藏期间,苯丙氨酸解氨酶(PAL)、肉桂酸-4-羟化酶(C4H)和过氧化物酶(POD)活性先增加后减少,木质素含量和组织硬度逐渐增加,而可食用率逐渐下降,GA3和IAA含量逐渐减少,ABA含量先增加后减少。PAL、C4H和POD活性与ABA/GA3的比值呈正相关。外源GA3处理能增加内源GA3含量,降低ABA/GA3的比值,并抑制PAL、C4H和POD活性的上升,降低木质素含量和硬度,提高可食用率,从而延缓竹笋木质化进程。推测外源GA3处理可能通过降低ABA/GA3的比值来延缓竹笋木质化进程。

The effect of treatment with 50 mg·kg^(-1) GA_3 solution for 30 min on lignification and endogenous hormone levels in postharvest bamboo(Phyllostachys praecox f. preveynalis)shoots were investigated. Results showed that the activities of phenylalanine ammonia lyase(PAL),cinnamate 4-hydroxylase(C4H) and peroxidase(POD) increased initially and declined later during the 30 days storage at 2 ℃. The lignin content and firmness continuously increased, but edible rate decreased gradually. The contents of GA_3 and IAA declined continuously, whereas ABA content increased firstly and then declined. The activities of PAL, C4H and POD were correlated with the rate of ABA/GA_3. Exogenous GA_3 treatment increased endogenous level of GA_3 content and decreased the rate of ABA/GA_3 as well as inhibited the increase of PAL, C4H and POD activities in bamboo shoots. The firmness and lignin content in GA_3 treated bamboo shoot were lower than those of control, while the edible rate was higher than that of control. It is suggested that GA_3 treatment retarded lignification through decreasing the rate of ABA/GA_3 in postharvest bamboo shoots.