The Role And Mechanism Of N-acylethanolamines Metabolism In Tomato Defense Against Leaf Speck Diseases And Its Application

Tomato(Solanum lycopersicum L.)is one of the largest vegetable species cultivated area of our country and the world.In 2013,planting area of processing tomato was 997,000 acres in China.But diseases and pests seriously affected plant growth,yield and quality.Bacterial diseases(such as Pseudomonas syringae pv.Tomato DC3000,Pst DC3000)and fungic diseases(such asBotrytis cinerea),which can cause damage to the leaves,stems,flowers,and fruits.They often cause large-area of economical loss in many provinces and cities of our country.At present,diseases control mainly depend on chemical pesticide,but it may generates drug resistance,agricultural product security and environmental pollution and other issues:As the own existence of lipid active substances in plants,studying the metabolisms of N-acyl-ethanolamine(NAEs)in plant disease resistance has important theoretical guidance and practical significance for improving plant itself resistance and reducing the use of chemical fungicides.In this study,the response,mechanism and application of N-acylethanolamine(NAEs)metabolism to main leaf diseases(Pst DC3000 and B-cinerea)were studied in tomato plants.The details are as follows:1?The response and role of the NAEs metabolic pathways in defense against bacterial leaf speck were studied.The metabolic pathways of NAEs are widespread in plant and are actively involved in plant growth and disease regulation.The results showed that PLD3,PLD6 and PLD11 genes controlled synthesis of phospholipase D were down-regulated and FAAH1,FAAH5,FAAH6,FAAH11 genes controlled amide hydrolysis enzyme synthesis were up-regulated after Pst DC3000 inoculation.On this basis,using VIGS gene-silencing technology,as compared with TRV:00 control plants,TRV:FAAH1 and TRV:FAAH11 were more susceptible to Pst DC3000,while the defense against Pst-DC3000 were increased in TRV:PLD3 and TRV:PLD6 tomato plants.Research results showed that the formation of the tomato based resistance of Pst DC3000 may be associated with NAEs metabolic pathways.Meanwhile,determination of content of plant endogenous NAE components found that after inoculation with Pst DC3000 the NAE content of TRV:PLD3 and TRV:FAAH11 leaves was reduced in varying degrees,the former NAE content is lower than the latter.Further,the transient expression of PLD3 and PLD6 tobacco leaves were significantly aggravated,while the transient overexpression of FAAH1 and FAAH11 were on the contrary after Pst DC3000 inoculation.These results suggested that NAE degradation induced by FAAH1 and FAAH11 contributed to the induction of resistance to Pst DC3000,whereas PLD3 and PLD11 participated in the NAE synthesis process may have the opposite effect.2?The relationship between the involvement of NAEs metabolic and disease resistance hormones in defense against bacterial leaf speck was studied.From the previous chapter,we found that NAEs metabolism could significantly affect tomato resistance to bacterial leaf speck disease.For tomato leaves after inoculation with Pst DC3000 in addition to the ICS gene,the SA signaling pathways related gene NPR1,PR1b,EDS1,PAD4,PAL10 expression were induced,while their expression were inhibited by exogenous NAE 22:5.The contents of JA and IAA in leaves of Pst DC3000 inoculated with NAE 22:5 treatment were significantly higher,but the SA content presents the opposite tendency.The resistance to Pst DC3000 of PLD3 gene-silenced plants significantly increased compared with the control.However,in the NahG transgenic plants that didn't accumulate SA,the TRV:PLD3 plants had the most severe disease after Pst DC3000 infection,which had no difference with TRV:00.These results indicated that the effect of PLD3 gene silencing on plant resistance was related to S A pathway.3?The function and application of N-acylethanolamine metabolism in preventing B.-cinerea diseases was studied.Based on the study that NAE 22:5 treatment could increase the content of JA in leaves of tomato plants.Then we found that exogenous NAE 18:0,NAE 22:5 and NAE 18:2 could increase the resistance of Botrytis cinerea,especially NAE 18:2.Meanwhile,exogenous NAE 18:2 treatment did not improve the resistance of jai1 mutant plants to B.cinerea.In addition,the expression of JA signal transduction genes(Coil,PI1,PI2)in leaves treated with NAE was significantly higher than that of control plants.The incidence of B.cinerea decreased by 70%after exogenous NAEs treatment,by which the relative expression of B.cinerea actin was also reduced 68.6%.In autumn and winter,the application of NAE mixed agents increased the resistance of tomato plants to B,cinereain the high-stage of gray mold,and the treated plants decreased by 55.7%compared with the control plants.These results suggested that NAEs could induce tomato resistance to B.cinerea through JA signaling pathway,and NAE mixed agents had some effects on the control of B.cinerea in production.