6-甲氧基-2-苯并唑啉酮(MBOA)分布不均匀是引起玉米胚芽鞘向光性运动的主要原因

Unequal Distribution of 6 methoxy 2 benzoxazolinone (MBOA) is the Main Reason for Phototropism in Maize Coleoptiles

采用高效液相色谱分析等方法，对玉米（ＺｅａｍａｙｓＬ．）胚芽鞘在单侧蓝光作用下产生的生物活性物质进行分析发现：１．在单侧蓝光作用下，胚芽鞘向光侧的生长抑制物质６甲氧基２苯并唑啉酮（ＭＢＯＡ）含量比背光侧多１．５倍。２．向光性刺激后，胚芽鞘向光侧和背光侧生长素的含量没有出现明显的差异。３．于胚芽鞘一侧外施ＭＢＯＡ及其类似物５，６ｄｉｍｅｔｈｏｘｙ２ｂｅｎｚｏｘａｚｏｌｉｎｏｎｅ（ＤＭＢＯＡ）和２ｃｈｌｏｒｏ５，６ｄｉｍｅｔｈｏｘｙ２ｂｅｎｚｏｘａｚｏｌｉｎｏｎｅ（ＣｌＤＭＢＯＡ）等抑制物质，均使胚芽鞘产生弯曲生长，表明引起玉米胚芽鞘向光性运动的直接原因是ＭＢＯＡ分布不均匀。

The distribution of 6 methoxy 2 benzoxazolinone (MBOA) which is induced by blue light stimulation in maize ( Zea mays L.) coleoplile was investigated by HPLC analysis. The results showed that: 1. The MBOA content on the irradiated side of the coleoptile was 1.5 fold more than that on the shaded side. 2. There was little change of IAA on both sides of the coleoptile which was treated with phototropic stimulation. 3. The growing coleoptile bent towards the side which was treated with MBOA、 5,6 dimethoxy 2 benzoxazolinone (DMBOA) or 2 chloro 5,6 dimethoxy 2 benzoxazolinone (Cl DMBOA). The above results indicated that the phototropic bending of the coleoptile was attributed to unequal distribution of MBOA.