Changes in polyamine oxidase activity and polyamine contents during fruit development of kidney bean

The changes in activity of polyamine oxidase(PAO)and contents of putrescine(Put),spermidine(Spd) and spermine(Spm)during the fruit development of kidney bean(Phaseolus vulgaris L.)were investigated.The results showed that PAO activity in pericarp obviously decreased along with the fruit development,while it could not be detected in seeds.The content of Spd in pericarp was highest at day 2 after flowering,thereafter the contents of Spd and Spm in pericarp changed somewhat like 'W-type' curve,and the content of Put in pericarp increased during day 2~8 after flowering,and then decreased.The contents of Put,Spd and Spm in seeds were remarkably higher than their contents in pericarp,and all deceased dramatically during day 2~8 after flowering,and then decreased slowly.The total contents of 3 PAs in pericarp and in seeds both decreased along with the fruit development,and the former were much higher than the later during day 2~8 after flowering.