渗透胁迫和D-Arg对小麦幼苗内源多胺、ACC和MACC含量及乙烯产生的影响

Effects of Osmotic Stress and D-Arg on Endogenous Polyamines,ACC,MACC Content and Ethylene Production in Wheat Seedlings

渗透胁迫能够诱导小麦幼苗内源多胺、ACC和MACC累积，增加乙烯释出；ADC的竞争性 抑制剂D-Arg可以有效地逆转内源PA，ACC以及乙烯在渗透胁迫下的累积和释出增加，但 能促进胁迫下MACC的累积.这是由于D-Arg竞争抑制了渗透胁迫下小麦幼苗内源PA的生物 合成，有可能造成氨丙基的累积，加速了Met循环，导致ACC过量形成并迅速转化为MACC，因 此，就表现出OS+D-Arg处理6 h和12 h小麦幼苗内源PA和ACC含量下降，MACC明显积累，乙 烯释出量减少.综合实验结果认为：D-Arg可能与植物体渗透胁迫下的“去毒代谢”保护 机制有关.

The accumulation of osmotic stress-induced endogenous polyamines,ACC and MACC and the production of ethylene in wheat seedlings were effectually reverted by D -Arg,a competitive inhibitor of ADC. Since the biosynthesis of endogenous polya m ines in the seedling was competitively inhibited by D-Arg under osmotic stress , it would be possible to cause the accumulation of aminopropyl group, further to accelerate the Met cycle and eventually to result in too much ACC which had to be rapidly co nversed into MACC. The experiment showed that the contents of endogenous polyami nes, ACC and ethylene production had decreased under OS+D-Arg for 6～12 h i n wheat seedlings. Instead,MACC was accumulated significantly. Therefore, we bel ieve that the incorporation of D-Arg into plant tissue under osmotic stress mi ght have play ed a key role in the mechanism of protection of the plant tissues against the t oxicity of metabolism under osmotic stress.