玉米和小麦种子中束缚态玉米赤霉烯酮的分离与鉴定

玉米赤霉烯酮（zearalenone，ZEN）是玉米赤霉菌（o双湖咄h一）的一种代谢产物，它不仅具有动物雌性激素的作用，还是某些真菌的性激素（Stob等1962）。自80年代初李季伦等（1980）发现在植物体内有玉米赤霉烯酮的存在以来，越来越多的证据（孟繁静等1988）表明玉米赤霉烯酮是一种能活跃地参与植物体生长发育过程的类似植物激素的内源活性物质。已知植物激素在植物体内存在着自由态和束缚态两种形式，通过两者之间的相互转化，影响和控制着某些生理生化过程的进行（Cohen和Bandurski1982）。为了探索玉米赤霉烯酮在高等植物体内是否也如…

Isolation and identification of Conjugated Zearalenone in Maize and Wheat Seeds

Since 1980 it has been found thatzearalenone (ZEN ), as a endogenousactive substance in plants, is closelyinvolved in certain processes of plantgrowth and development. To study thesaute of ZEN in higher plant, Westernblot was employed. Seed powders ofhe mays and Triticum aestivum L. weredissolved separately in ethanol andstirred for 0. 5 h. The material wascentrifuged, the proteins in the supernatant (prolamins) and sediment wereseparated after being dissolved in sample buffer by using SDS-PAGE andtransferred to nitrocelluose membranes. The transblots were subjected toAb1 and Ab2 (goat anti-rabbit IgG alkaline phosphatase ) respectively anddeveloped by nitrobluetetrazolium and5-bromo-4-chloro-3-indolyl phosphate. Two prominent avenins (19 and22. 5 kD) were found to be cross-reactive with anti-ZEN antibody in Asanys seeds(Fig. 1). The prolamins inthe two avenins were taken up fromthe gel separated by PAGE and hydrolyzed by HCl 6 mol/L. ZEN was identified by mass spectra (Fig. 2). Thesame behavior of it was obtained fromcommercial zein (Sigma) through thesame protocols. Meanwhile, in winterwheat seeds, two (20 and 23 kD)alcthhol-soluble and four (30, 38, 39 and41 kD ) water-soluble avenins werefound to react with specific anti- ZENserum. The Proteins recognizable bythe antiserum disappeared successivelyduring seed germination (Fig. 3). It isreasonable to suppose that ZEN is conjugated with proteins in seeds and is released during germination. It is postulated that bound formation and hydrolysis may constitute a homeostaticmechanism for regulating ZEN levelsin the plant. These results strongly indicate that zearalenone, as other planthormones,can exist both in free and inbound saute and the nitercoversion between them may play a part in the pro-cesses of growth and development ofplants.