水分胁迫使两个抗旱性不同的春小麦 (TriticumaestivumL .)品种“8139”(抗旱性较弱 )和“5 0 4”(抗旱性较强 )叶片ACC和MACC含量于胁迫初期下降后期升高 ,ACC合酶活性持续升高 ,乙烯释放量在 8139中下降而在5 0 4中先大幅升高而后下降。两种作用效果相反的抑制剂MGBG (抑制SAMDC活性 )和AOA (抑制ACC合酶活性 )均明显影响了两品种春小麦叶片以上各指标的变化。结果表明 ,水分胁迫下作物乙烯的释放量并不与其合成直接前体ACC的量成正相关 ;胁迫乙烯在抗性品种中于胁迫初期的升高可能是植物胁迫信号传导的响应之一 ,是一种干旱适应现象 ,可能与作物的干旱忍耐形成有关 ,而MACC具有调节胁迫乙烯释放的特殊生理作用。 Under water stress, the contents of ACC and MACC in leaves of two cultivars with different drought resistance (Triticum aestivum L.) “8139” (weaker drought resistance) and “504” (more drought-tolerant) increased at the late stage of stress and ACC The activity of synthase continued to increase, the ethylene emission decreased in 8139 and then increased sharply and then decreased in 504. Two kinds of antagonists, MGBG (inhibiting SAMDC activity) and AOA (inhibiting ACC synthase activity), which had the opposite effect, obviously affected the change of each index above two leaves of spring wheat. The results showed that the release of ethylene under water stress did not correlate with the amount of ACC directly synthesized in the resistant varieties. The increased ethylene stress resistance in resistant varieties may be one of the responses of plant stress signal transduction The phenomenon of drought adaptation may be related to the formation of drought tolerance in crops, whereas MACC has a special physiological role in regulating the release of ethylene under stress.