茭白肉质茎膨大发育的生化基础研究

STUDY ON THE BIOCHEMICAL CHANGES DURING STEM GALL FORMATION IN Zizania latifolia

文研究了茭白肉质茎不同发育阶段的碳水化合物、蛋白质以及几种酶的变化情况 ,分析了这些生化代谢与茭白肉质茎发育的可能关系。结果表明 :茭白肉质茎发育的早期主要表现为重量的快速增加 ,后期则为重量和体积均快速地增长。碳水化合物中总糖和还原糖在肉质茎发育的早期迅速上升 ,之后有所下降。而蔗糖则呈现先上升 ,后稳定的趋势。淀粉的含量在肉质茎发育过程中一直上升。木质素和纤维素在肉质茎发育的早期含量较高 ,随着茎的发育 ,其含量持续下降 ,发育后期二者的含量又明显上升。蛋白含量前期上升 ,后期下降。对茭白肉质茎发育过程中酶活性的研究表明 ,超氧化物歧化酶和过氧化氢酶活性不断下降 ,而过氧化物酶活性持续上升。苯丙氨酸解氨酶活性在茎发育过程中不断下降 ,后期又有所上升。

The contents of carbohydrates (total sugar, reducing sugar, sucrose, starch, lignin and cellulose), protein and activities of some enzymes (superoxide dismutase, catalase, peroxidase, and phenylalanine ammonia-lyase) in swollen stem, which is used as a vegetable in Chinese kitchen, of gausun (Zizania latifolia L.) were measured during stem swelling. The results showed that the stem weight increased rapidly at early phase, then both weight and volume of the swollen stem rose at later phase. The contents of sugar and reducing sugar increased during the early stage, then decreased. The sucrose content also increased during stem swelling, then kept a stable level. The contents of lignin and cellulose declined with stem swelling, they started to rise after reached the lowest level. An increase in protein was observed at early swelling stage, then decreased, while starch level rose during stem swelling. The activities of catalase and superoxide dismutase declined continuously during stem swelling. However, peroxidase activity increased slowly at earlier swelling stage, and rapid rise occurred afterwards. The possible correlation between these biochemical changes and the formation of the swollen stem were discussed.