毛竹笋体生长和退败过程中吲哚乙酸氧化酶活性的研究

吲哚乙酸氧化酶(IAAO)与植物的生长和衰老有密切关系。本文对毛竹正常生长笋体和退败笋体的IAAO进行了研究。结果表明,正常生长笋体的IAAO活性随生长速率的升高而下降,各种高度的正常笋体IAAO活性都表现出明显的向基性增加。退败笋体的IAAO活性随退败程度加深而增大。在正常笋体和初期、中期退笋中,IAAO活性表现出向基性增加,而在后期退笋中,则转变为笋体上部酶活性最大。竹笋IAAO的最适温度为60℃,最适pH为5.0,一价金属离子对IAAO有不同程度的激活作用,二价金属离子对IAAO有不同程度的抑制作用。黄酮类化合物桂皮酸和根皮苷对酶活性有明显的激活作用,而咖啡酸和槲皮青对酶活性有明显的抑制作用。

STUDY ON INDOLEACETIC ACID OXIDASE IN THE GROWING AND DEGRADED BAMBOO SHOOTS OF PHYLLOSTACHY PUBESCENS

This paper reports the study of the activity of indoleacetic acid oxidase(IAAO) in the growing and degraded bamboo shoots of Phyllostachy pubescens. Results indicated that the activity of IAAO of growing shoots decreased with the increase of relative growth rate. The activity of IAAO increased basipetally in the shoots of different heights. The activity of IAAO of degraded shoots increased with the increase of degrading degree. The activity of IAAO showed a basipetal increase in growing shoots and degraded shoots at early and middle stages of degrading, but the highest activity was found in the upper part of degraded shoots at later stage of degrading. The change in the activity of IAAO regulated the growth and degradation of bamboo shoots by affecting the endogenous IAAO level. The activity of IAAO of bamboo shoot was highest at 60'C and pH5.0. The enzyme activity was inhibited and stimulated by bivalelent metallic ions and univalent metallic ions respectively. The enzyme activity was stimulated significently by cinnamic acid and phloridzin but it was inhibited by caffeic acid and quercetin.