The Effect Of Rice Sheath Blight Disease Affect The Relationship Among The Rice Plant,Brown Planthopper And The Natural Enenmy

Plant pathogen and herbivorous often co-occur on the plant which affect the growth and reproduction of the plant,at last lead the fitness loss of the plant.But most of the studies so far focused on their independent,to make sure how they affect the growth and development of plants,and how the plants defense the attack of them.Some studies of the interaction between plant pathogen and herbivorous focus on study the interactions between them at single time point.But the too high plant induced defense which inducing by plant pathogen can affect the fitness of plant,so the plant induced defense often after a period of start-up,there will be a significant decline and the concentration of a series of secondary metabolites will change along with it.This process must affect the interaction between plant pathogen and herbivorous,so the researches which focus on studying the dynamic change of the interaction between plant pathogen and herbivorous on the temporal scales can help us to understand the full picture of the effects of plant pathogens on herbivorous.On another hand,previous researches revealed that plant have a trade-off of the allocation of limiting resources between plant growth and defense,enabling it to fine-tune its phenotype in response to diverse environmental challenges.The infection of plant pathogen can affect the fitness of plant and change this trade-off on the temporal scales.So the study of the trade-off between plant growth and defense after the infection of plant pathogen will help us to understand the interaction between plant pathogen and herbivorous on the temporal scales.The rice sheath blight?cause by Rhizoctonia solani?is one of the most destructive diseases on rice in china,and the main rice pest brown rice plant hopper?BPH?Nilaparvata lugens?St?l?which need a similar condition to break out,and often appear at the same time and have a devastating impact on the rice field in China,especially in the middle and lower reaches of the Yangtze River area.It has been reported that BPH outbreak had impact on the rice sheath blight.However,the issues that whether R.solani infection would lead to changes in relationship among the rice plant,brown planthopper,the natural enenmy,and arthropod community,remains unclear.Therefore,our research use a lot of lab and field experiments to explore how R.solani infection affects the metabolism and development of rice plants on the temporal scales,and reval the influence to BPH,which will help us to understand the change of the interaction among R.solani,BPH and its natural enemies in the complex ecosystem.The main results are listed as follows:?1?The R.solani can affect the fertility and feeding behavior of BPH.The R.solani infection can improve the fertility of BPH,but there was no significant change in the hatchability of eggs,nymph development duration and hatchability,even more long winged adult appeared.The electrical penetration graph?EPG?results show that The R.solani infection can also affect the feeding behavior of BPH on the temporal scales.When BPH feeding on the rice plants which infected after 5 day,the longer duration of np waveform?finding feeding site?and the shorter duration of N4b waveform?ingestion on phloem sap?suggest there are obvious feeding resistance to BPH appear on the surface and vascular bundle of rice;When BPH feeding on the rice plants which infected after 20 day,the longer duration of N4b waveform,the shorter duration of N5 waveform?ingestion on the xylem sap?and ph waveform?the penetration in the plants?suggest the resistance in rice phloem,parenchyma cells and vascular bundle sheath to BPH feeding decreased significantly.?2?The R.solani infection affect the physiological and biochemical metabolism in rice plants.The R.solani infection affects the content of free amino acids in phloem,most kinds of amino acids show a significant decline than 5 day and 10 day healthy rice plants.The contents of salicylic acid and jasmonic acid decreased significantly 15and 20 days after R.solani infection after BPH feeding.The content of them was significantly lower than that of healthy rice 1.5 hours after the feeding of BPH,while when rice was infected by R.solani after 20 days,the concentration of salicylic acid and jasmonic acid can't be detected in infected rice.The contents of oxalic acid in susceptible rice,which has obvious feeding resistance to BPH,was significantly higher than that of healthy rice on the 5th day of infestation,and significantly lower than that of healthy rice on the 20th day of infestation.However,the change of the resistance to BPH and the nutritional status of the rice plants which infected by R.solani,affected the performance of BPH.?3?The R.solani infection affects the preferences of BPH and its natural enemy.Similar results were found from H-tube and semi-natural foraging tests show BPH choose the infected rice plant after 5 days infected by R.solani.Anagrus nilaparvatae which is one of the main natural enemies of BPH,showed obvious host preference only to the infected rice 5 and 10 days infected by R.solani after BPH feeding.?4?The R.solani infection affects the volatiles composition of rice plants.The change of rice volatiles is the main factor causing the preference change of BPH and its natural enemies.A total of 30 kinds of volatiles were detected by GC/MS.After R.solani infected,the volatiles contents emitted from R.solani infected and healthy plants exhibited changes on different time points,but all of the kinds of volatiles are same.The PLS-DA and Per MANOVA results show the composition of volatiles exhibited significant changes emitted from R.solani infected and healthy plants on 5d,10d,15d and 20d,camphene,?-pinene,?-pinene,cetane,nonanal,2-ethylhexyl alcohol,decanal,Tricyclic terpenes,paracymene,octadecane and camphor are the main volatiles contents that leads to the difference composition of volatiles.The composition of herbivore induced plant volatiles?HIPVs?caused by BPH was affected by R.solani infected,but the amount of 30 kinds volatiles were not significantly affected,only the amount of Camphene and Limonene show a significantly high release from the infected rice plants than healthy rice plants on 15d.The PLS-DA and Per MANOVA results also show the composition of HIPVs exhibited no significant changes emitted from R.solani infected and healthy plants on5d,10d,15d and 20d.?5?The R.solani infection affects the wax composition of rice plants.23 kinds of components of wax were detected on the surface of rice.The composition of the wax on the surface of rice leaf and leaf sheath are significant different.The infection of R.solani significantly affected the composition of the wax on the surface of rice,but the kinds of wax are same in both leaf and leaf sheath.The difference between infected and healthy leaf mainly appeared from the 10^th day to 20^th day after infection.Hexadecanoic acid,octadecanoic acid,nonacosanoic acid,triacontanoic acid,dotriacontanoic acid,tritriacontanoic acid,hentriacontane,tritriacontane,triacontanal,dotriacontanal,etratriacontanal,nonacosanol and dotriacontanol are the main wax contents that leads to the difference composition of wax in leaf;Hexadecanoic acid,octadecanoic acid,nonacosanoic acid,triacontanoic acid,tritriacontanoic acid,tetratriacontanoic acid,tritriacontanal,octacosanol,nonacosanol and tetratriacontanol are the main wax contents that leads to the difference composition of wax in leaf sheath.?6?The R.solani infection affects the development of rice plants.The R.solani infection affects the accumulation rate of dry matter content decreased begin at 15 day after infection,and was significantly lower than that of healthy rice at 20 day after infection.The SPAD value of the infected leaves rice was higher than that of healthy rice at 5 and 20 day after infection.It may be due to the rice plants need to increase the photosynthetic rate in order to obtain normal development after R.solani infection.?7?The R.solani infection affects the arthropod community of in the field.In the two years field experiments,30 common species from rice field were analyzed.The number of most common species had no significant difference in each investigation,only the rice pest rice leaf roller?Cnaphalocrocis medinalis?had a downward trend in the infection fields,and there are fewer Chloropidae sp.²?10d?,leafhopper?15d?and Paederus fuscipes Curtis?20d?in the infection fields in 2015,more Scelionidae sp.¹?5d?in the uninfection fields in 2016.The number of BPH and A.nilaparvatae also had no significant difference in each investigation.The PLS-DA and Per MANOVA results show the composition of the arthropod community have no significant changes from R..solani infected and healthy field,but there are some different appear in the composition of the arthropod community.Dibrachys xavus,Chironomidae sp.³,Tetragnatha nitens,Chironomidae sp.¹,Scelionidae sp.²,Lauxaniidae sp.,Oligosita sp.,Chironomidae sp.²,Scelionidae sp.¹,Elasmus sp.,Haplogonatopus japonicus and Paederus fuscipes Curtis are the main species that leads to the difference composition of the arthropod community in 2015,and Trichomalopsis apanteloctenus,Scelionidae sp.¹,Phoridae sp.,Haplogonatopus japonicus,Pardosa laura,Coleosoma octomaculatum,Pirata subpiraticus,Chironomidae sp.²,leafhopper,Chironomidae sp.¹,Cnaphalocrocis medinalis,Hylyphantes graminicola and Cyrtorhinus lividipennis are the main species that leads to the difference composition of the arthropod community in 2016.?8?R.solani infection induced changes in gene expression which are associated with BPH feeding in rice.In time associated R.solani infection and BPH feeding transcriptome analysis,5 day and 15 day R.solani infected rice resulted in 3616 and2269 differential expressed genes?DGEs?,respectively.there were 26 and 6 common shared DGEs associated R solani infection and BPH feeding at 5 day and 15 day.Expression of two wax synthesis genes?Os MH?07G0349200 and Os MH?04G0179000?,one salicylic acid binding protein 2?SABP2;Os MH?01G0556300?and 13 WRKY transcription factor were significant differential expressed among in time associated R.solani-infected and healthy rice,indicating that these gene may play a role in the trade-off between rice growth,pest and disease resistance.In summary,We investigated the effects of the pathogenic fungus R.solani infection of rice plants on BPH and its parasitoid A.nilaparvatae at the temporal scale,and found the relationship among them can change by the change of the trade-off between plant growth and defense after R.solani infection on the temporal scale.Our results contribute to the researches on the plant strategies to deal with plant pathogen and herbivorous in further,and also can help people to control the diseases and pests on rice.