【摘要】 小麦在土壤渍水条件下,根部大量合成乙烯前体1-氨基环丙烷-1-羧酸(ACC),地上部ACC和乙烯随之增加。随着溃水时间的延长,地上部ACC和乙烯逐渐下降,而根部ACC在整个渍水期间一直保持很高水平。排水使地上部ACC含量和乙烯产生迅速.下降至对照水平。土壤溃水后根部MACC含量没有多大变化。而地上部MACC含量在整个溃水过程中一直保持上升趋势,排水后也不下降。受渍植株的叶片把外源ACC转变为MACC的能力明显提高。渍水后期大量的ACC转变为MACC,是乙烯下降的原因,说明MACC的形成是乙烯生物合成的又一调节方式。比较不同层次叶片对渍水的反应,老叶中的乙烯、ACC和MACC含量上升都比幼叶显著。对小麦适应渍水胁迫的生理意义作了讨论。更多还原

【Abstract】 When wheat seedlings were subjected to waterlogging,1-aminoxyclopropane-1-carboxylic acid (AOC),an ethylene precursor,accumulated in large quantity in roots.In shoots,AOC and ethylene production also increased,but declined with the prolonged periods of waterlogging.However,ACC content in roots maintained in high level during the whole period of waterlogging.Drainage caused a drastic drop in both ACC content and ethylene production in waterlogged plants to control level. l-(malonylamino) cyclopropane-1-carboxylic acid (MACC) level in roots subjected to waterlogging showed little changes.However,MACC content in shoots kept increasing during the 9-days period of waterlogging.At later period of waterlogging (longer than 5 days) when ACC and ethylene production had dropped,the level of MACC con- tinued to increase.Draining stopped this increasing,but did not reduced its level.When exogenous ACC was introduced into the leaves via transpiration stream,the aibility of leaves of waterlogged plant to convert ACC to MACC was much higher than control. The data presented showed that at the later stage of waterlogging,the conversion of a great quantity of ACC to MACC in waterlogged wheat plants is the cause of the reduction of ethylene production and ACC content.It was suggested that the formation of MACC is another way of regulation in ethylene biosynthesis.Among leaves of different ages,the enhancement of ethylene,ACC and MACC content was more pronounced in older leaves than in younger laves during the waterlogging period.The physiological significance of adaptation to waterlogging stress was discussed.更多还原