The Effect Of Polyamines On The Delopment And Polyamines Titres Of Diamondback Moth, Plutella Xylostella L.

Polyamines, such as putrescine, spermidine and spermine, are ubiquitous physiologicalcations, have two or more than two amines. They occur in almost all living species, bothprokaryotes and eukaryotes. Polyamines are essential for the synthesization of largebiologic molecule,cell growth and differentiation. They can also regulate thephysiological process of insect such as growth and development et al.. Whereas theregulation mechanism is unclear because of the complexity of the physiological processof insect and the metabolism of polyamines.So, studying the effect on growth anddevelopment,protective enzyme and contents of polyamines in larva are essential forunderstanding the regulation function of polyamines on the physiological process ofinsect. In this study, on the basis of studied the function of polyamines on the growth anddevelopment and the food consumption of diamondback moth larva, we Analysis therelationship between polyamines and protective enzyme activities and the effect on themetabolism of polyamines and hormone.The main results as follows:1. The effect on the food consumption of diamondback moth larvaCompared with distilled water, the food consumption mortality rate of the diamondbackmoth larva which treated by the three polyamines (spermine, spermidine, putrecine)isobviously higher; under this experimental condition there is no differences of foodconsumption between the same polyamine of different concentration;but at the sameconcentration there is no differences of food consumption between the three polyaminesin 24h, but after the 24h the food consumption of diamondback moth larva which treatedby spm is obviously higher than those treated by put and spd. treated. lower andpercentage of pupation is higher.2. The effect on the growth and development of diamondback moth larvaWe studied the effect of polyamines on survival, pupation, pupal weight and emergencerate of diamondback moth larva at indoor condition. The results showed that compare withdistilled water treated the survival and pupation of the lavra which treated by put and spd is obviously higher. But there is no difference on pupal weight and emergence ratebetween distilled water treated and polyamines treated.3. Effect of polyamines on protective enzyme activities in the diamondback larvaThe results showed that three kinds of polyamines (putrescine, spermine, spermidine)have a great effect on protective enzyme activities in the larva of diamondback moth. Theactivities of SOD and POD in treated groups were significantly higher than the distilledwater control. While there was no difference of CAT activities between treated groups andcontrol. There is no difference of protective enzyme activities between differentconcentration of the same polyamine, but differences are there between the sameconcentration of the three polyamines.4. The effect on the titer of polyamines of polyamines and hormonesThe titer of polyamines in diamondback larva which treated by polyamines, hormonesand DFMO is determined by HPLC.The results show that the metabolism of polyaminesfrom larva of diamondback moth was dynamic changed from time to time; and themetabolism of polyamines was obviously affected by polyamines and DFMO, and thiseffect changed in different period. The metabolism of polyamines was stimulated byfarnesol and 20E.The titer of polyamines in the larva which treated by farnesol and 20E ismuch more than the control.There are polyamines in hemolymph, fat, midgut andbrain, but the most high titer is in hemolymph. After different treated the titer of spm andspm in hemolymph is lower than control, but there is no difference of the titer ofpolyamines in other organization between treated and control.