6-甲氧基-2-并噁唑啉酮的一些生理作用

已有研究证实，６－甲氧基－２－并噁唑啉酮（６－ｍｅｔｈｏｘｙ－２－ｂｅｎｚｏｘａｚｏｌｉｎｏｎｅ，ＭＢＯＡ）是引起玉米胚芽鞘向光性运动的主要物质。本文采用生物测定和ＨＰＬＣ分析等方法，对ＭＢＯＡ的生理作用特点做进一步的探讨，结果表明：１．光刺激下收集的胚芽鞘分泌物主要成份是ＭＢＯＡ，该物质明显抑制鸡冠花和水芹下胚轴的伸长。２．将ＭＢＯＡ与ＩＡＡ混合处理胚芽鞘，产生相互拮抗的效果。３．单侧放置含ＭＢＯＡ琼脂块能引起去顶胚芽鞘弯曲生长。４．伤害胁迫使胚芽鞘ＭＢＯＡ含量增加。因此，ＭＢＯＡ不仅是引起植物向光性运动的物质，也是与抗伤害胁迫有关的天然抑制物质，其生理功能之一是与生长素的作用相互拮抗，并抑制植物生长。

PHYSIOLOGICAL EFFECTS OF 6-METHOXY-2-BENZOXAZOLINONE (MBOA) FROM MAIZE COLEOPTILE

Some experiments had proved that 6-methoxy-2-benzoxazolinone (MBOA) was themain substance in phototropism of maize coleoptile. The physiological effects of MBOAwere studied by using the methods of bioassay and HPLC. The results showed that: 1. Thegrowth rate of hypocotyl of cress and cockscomb were inhibited obviously when treatedwith the substance excreted from maize coleoptile. The main component of the substancewas MBOA. 2. Antagonistic effects was found when the maize coleoptiles were treated withIAA and MBOA in combination. 3. When an agar piece containing MBOA was plaeed onunilateral side of coleoptile with tip exised, the coleoptile could bend to growth. 4. Thecontent of MBOA increased when maize coleoptile was injured. It was shown that MBOAwas the natural inhibitor which played important function in inducing plant phototropismas well as in protection against injury. It can be concluded that MBOA is a substanee thatantagonizes IAA and inhibits the plant growth.