The Study On Regulation Of Abscisic Acid In Rice Callose And Enzyme And Functions In Rice Resistance To Nilaparvata Lugens St(?)l(Hemiptera: Delphacidae)

The brown planthopper, Nilaparvata lugens Stal (Hemiptera:Delphacidae)is one of monophagous rice pests.BPH has become a major pest of rice in Southeast Asia and our country in recent years. It brought many problems due to the irrational use of chemical pesticides.Resistant varieties has proved to be the most economical,safe,and effective prevention methods.Abscisic acid(ABA) is an important plant hormone.Research showedthatplants often activate plants’own immune system by accumulation of ABA when plants encounter stress.Butwe all neglected the importance of ABA when BPH invaded rice.This paper focused onthe change of callose enzyme activities, callose deposition and effect of BPH feeding in TNI and IR42after treated with exogenous ABA and BPH feeding.1. Effect of exogenous ABA on BPH feeding behavior on rice.Two rice varieties are significantly more than control on total number of Nl wave after ABA treated.ABA also extended total duration of N2 wave and cut downtotal duration of N4 wave.This indicated a significant increase in rice resistance to insect after exogenous ABA treatments.2. Change of callose deposition site and area of rice after exogenous ABA treatments and BPH feeding.The callose deposited mainly in the xylem tissue and catheter after ABA treatents.Callose also appeared in epidermal tissue,parenchyma and bundle sheath in IR42 after BPH feeding.This suggests that ABA increased deposition site in IR42after BPH feeding.The callose deposition area continued to increase with BPH feedingafter ABA treatments.It showedthat ABA treatments and BPH feeding increased further promotion of callose synthesis in IR42.3. Change of callose enzyme activity after exogenous ABA treatments and BPH feedingCallose enzymecontainshydrolase and synthetase.β-1,3-glucanase activity was significantly lower than controlafter 10 mg/L and 20 mg/L ABA treatment for0.5h,1 h,3 h,6 h,12 h,24 h,48 h,72 h.Callose synthase activity of 10 mg/L and 20 mg/L treatment was significantly higher than the control.Then 10 mg/L and 20 mg/L exogenous ABA are the most favorable concentration for callose synthesis.