Leaf senescence is an important event in plant development.It associates with protein degradation and the mobilization of the nitrogen to other vegetative tissues or to developing fruits.In the other hand,the degradation of protein would influence the rate of photosynthesis.So this was negative to plant products.Consequently,it is necessary to elucidate proteolytic mechanism and the characters of senescence-related proteases.Cucumber (Cucumis sativus L.) is a very important vegetable crop in China...