冬小麦低温春化过程中茎尖细胞超微结构的变化与玉米赤霉烯酮的关系

RELATIONSHIP BETWEEN ULTRASTRUCTURAL CHANGES AND ZEARALENONE IN TRITICUM AESTIVUM DURING VERNALIZATION

玉米赤霉烯酮(zearalenone, ZEN)是Stob等于1962年首先从玉米赤霉菌培养物中分离出的次生代谢产物,它具有动物雌性激素的作用,也能促进某些真菌形成子实体,被认为是真菌的一种性激素,80年代初发现亦存在于高等植物体内。多年的研究结果表明,ZEN与植物的许多发育过程,包括春化作用、光周期诱导以及授粉受精过程均有密切的关系,可能ZEN参与了小麦成花诱导过程的调控,但其调控机制不明。为进一步研究小麦春化过程中茎尖细胞超微结构的变化与ZEN的相关性,我们以春化过程中的冬小麦幼芽为材料,对茎尖细胞超微结构以及与之相应的ZEN含量变化进行了分析。

The zearalenone (ZEN) levels and cell ultrastructure in the shoot apex of winter wheat ( Triticum aestivum L. cv. Yanda 1817) during vernalization were studied by immunosorbent assays and electron microscopy. The main results showed that the ZEN content in seed embryo increased during vernalization, and reached the maximum at week 4, and decreased thereafter. The obvious ultrastructural changes of apex appeared after 4 weeks of low temperature. The apex cells enriched organelles, such as plastids, mitochondria, rough endoplasmic reticula. A lot of plastids and mitochondria were irregular being budding or dumbbell shaped. The invagination of the plasma membrane and the nuclear substance transpassing though cell wall were visualized. Application of malathion (MAL) , an inhibitor of ZEN biosyntheses, inhibited the formation of ZEN during vernalization ; also affected the ultrastructure of apex cells of the induced seedling. The application of exogenous ZEN might promote the development of plastid, mitochondrion, rough endoplasmic reticu-lum and dictyosome.