| Symbiosis is a well-known common phenomenon in nature,especially between symbiotic microbes and their hosts.Symbiotic microbe plays an important role in the host,including nutrition metabolism,development and reproduction,anti-bacterial infection and the enhancement of the host's detoxification ability.In arthropods,especially in insects,the study of symbiotic microbes mainly focused on the gut.However,there have been few reports on microbes in other internal organs of the host.Pardosa pseudoannulata is an import ant predatory natural enemy in rice field and plays important roles in preventing and controlling rice pests and maintaining ecological balance in rice fields.In this study,in order to explore the difference of the composition of the symbiotic microbes in the host organism,and enrich the related information of the symbiotic microbes of different internal organs of the host,the comparison in the molecular polymorphism and functional analysis of the symbiotic microbes was performed among different internal tissues of P.pseudoannulata and other species from Pardosa.The comparison was also performed between P.pseudoannulata and its prey Nilaparvata lugens.1.Comparative analysis of symbiotic fungus diversity in different internal organs of P.pseudoannulataSymbiotic fungi play a major role in nutrient metabolism in the host.The structure of the symbiotic fungi of various organs of P.pseudoannulata is the basis for exploring the function of the symbiotic fungi.In this study,a total of 378,990 high quality sequences were produced by fungal diversity sequencing,with an average length of 401 bp.12 core OTU were obtained,and 4,6,3 and 5 OTU were only found in the tissues of ovary,fat body,intestinal tract and venom gland,respectively.The fungal diversity index of the fat body and ovary was higher than that of intestinal tract and venom gland.There was no significant difference in the fungal richness index of the various tissues in P.pseudoannulata.The result of Unweighted UniFrac PCoA showed that symbiotic fungi in various tissues were clustered together on PC1 and the PC1 values had significant difference among intestinal tract,ovary and fat body.The result of Weighted UniFrac PCoA showed that symbiotic fungi in the ovary,venom gland and intestinal tract were clustered together on PC1 and the PC1 values had none significant difference.At the phylum level,the predominant phylum in the four tissues was Ascomycota,with the abundance of 78%,74%,68%and 77%in the tissues of intestinal tract,fat body,ovary and venom gland,respectively.Basidiomycota was the second phylum in four tissues.Furthermore,the relative abundance of Ascomycota and Basidiomycota in four tissues had no significant difference.These results provide a theoretical basis for understanding the molecular polymorphism of symbiotic fungi in the internal organs of P.pseudoannulata.2.Comparison analysis of symbiotic bacterial diversity in different internal organs of P.pseudoannulataSymbiotic bacteria play an important role in the host,including nutrition metabolism,development and reproduction,anti-bacterial infection,and enhancement of the host's detoxification ability.Studies of host symbiotic bacteria mainly focused on the intestinal tract,but symbiotic bacteria in other internal tissues of the host are rarely reported.In this study,a total of 564,924 high quality sequences with an average length of 446bp were produced by bacterial diversity sequencing.Nine core OTU were obtained,and 32,0,18,544 and 262 OTU were only found in the tissues of ovary,fat body,intestinal tract,venom gland and brain,respectively.The bacterial diversity index of venom gland was the highest and significant higher than other four internal tissues.The indexes of bacterial diversity and richness in fat body were the lowest.The bacterial diversity index from high to low was venom gland,brain,ovary,intestinal tract and fat body.According to the results of Unweighted/Weighted UniFrac PCoA,the bacterial community structure of five tissues was separated completely,indicating that the microbial community structures were different.At the phylum level,the predominant phylum in ovary was Firmicutes with the abundance of 96%;the predominant phylum in fat body was Chlamydiae(98%).At the genus level,the dominant bacterial genus in each tissue was different.The dominant bacterial genera in the tissues of fat body,ovary,intestinal tract,brain and venom gland were Neochlamydia(94%),Bacillus(70%),Rickettsiella(57%),Ralstonia(39%),Enterococcus(10%),respectively.3.Comparison analysis of symbiotic bacterial diversity in Pardosa and different geographical populations of P.pseudoannulataThis chapter mainly focused on this feature that Neochlamydia existed in the fat body with high abundance in P.pseudoannulata.In this study,a total of 368,015 high quality sequences were produced by bacterial diversity sequencing,with an average length of 445bp.Eleven core OTU were obtained,and 7,4,14 and 4 OTU were only found in the the fat body of Pardosa laura,Pardosa astrigera,and P.pseudoannulata of Japan(Koshi)and Nanjing,respectively.The indexes of bacterial diversity and richness in the fat body of P.laura and P.astrigera were significantly higher than those of the different geographical populations of P.pseudoannulata.According to the results of Unweighted/Weighted UniFrac PCoA,the bacterial community structure of P.pseudoannulata was far away from P.laura and P.astrigera,and the PC1 values had significant difference.In addition,the bacterial community structure of the fat body of P.laura and P.astrigera were clustered together on PC1.The results indicated that,although belong to Pardosa,their bacterial community structure in the fat body is different among species.At the phylum level,the predominant phylum in the fat body of different geographical populations of P.pseudoannulata was Chlamydiae(98%).The predominant phylum in the fat body of P.laura and P.astrigera were Proteobacteria(73%and 68%).At the genus level,the predominant genus in the fat body of different geographical populations of P.pseudoannulata was Neochlamydia and the relative abundance was significantly higher than the other Pardosa.The results indicated that this feature was only limited in P.pseudoannulata,and was not affected by geographical population.4.Comparison analysis of symbiotic bacterial diversity in P.pseudoannulata and N.lugensN.lugens is an important pest of rice in Asia,and P.pseudoannulata is an important predatory natural enemy against N.lugens.This chapter mainly focused on the composition and structure of symbiotic bacteria in the tissues of fat body and ovary in P.pseudoannulata and N.lugens.A total of 437,014 high quality sequences were produced by bacterial diversity sequencing,with an average length of 449bp.Nineteen core OTU were obtained,and 10,4,10 and 1 OTU were only found in the ovary(N.lugens),fat body(N.lugens),fat body(P.pseudoannulata)and ovary(P.pseudoannulata),respectively.The indexes of bacterial diversity and richness in the fat body of P.pseudoannulata were significantly lower than that of other three tissues.According to the results of Unweighted/Weighted UniFrac PCoA,the bacterial community structure of ovary(N.lugens),fat body(N.lugens)and ovary(P.pseudoannulata)were closely clustered on PC1.The bacterial community structure of fat body(P.pseudoannulata)was isolated from these three groups on PC1.The results showed that the bacterial community structure of the ovary(N.lugens),fat body(N.lugens)and ovary(P.pseudoannulata)were more similar.At the genus level,the fat body and ovary of N.lugens had few Neochlamydia,with the abundance of less than 0.1%. |
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