Bacterial Symbionts of the Brown Planthopper,Nilaparvata lugens(Homoptera: Delphacidae)

Abstract

The brown planthopper (Nilaparvata lugens Stål), the most destructive pest of rice, has been identified, including biotypes with high virulence towards previously resistant rice varieties. There have also been many reports of a yeast-like symbiont of N. lugens, but little is known about the bacterial microbes. In this study, we examined the bacterial microbes in N. lugens and identified a total of 18 operational taxonomic units (OTUs) representing four phyla (Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes) by sequencing and analyzing 16S rRNA gene libraries obtained from three populations of N. lugens, which were maintained on the rice varieties TN1, Mudgo, and ASD7. Several of the OTUs were similar to previously reported secondary symbionts of other insects, including an endosymbiont of the psyllid Glycapsis brimblecombei, an Asaia sp. found in the mosquito Anopheles stephensi, and Wolbachia, found in the mite Metaseiulus occidentalis. However, the species and numbers of the detected OTUs differed substantially among the N. lugens populations. Further, in situ hybridization analysis using digoxigenin-labeled probes indicated that OTU 1 was located in hypogastrium tissues near the ovipositor and ovary in biotype 1 insects, while OTU 2 was located in the front of the ovipositor sheath in biotype 2 insects. In addition, masses of bacterium-like organisms were observed in the tubes of salivary sheaths in rice plant tissues that the insects had fed upon. The results provide indications of the diversity of the bacterial microbes harbored by the brown planthopper and of possible associations between specific bacterial microbes and biotypes of N. lugens.

Virulensi Wereng Batang Cokelat (Nilaparvata lugens Stål) dan Strategi Pengelolaannya

“…Simbiosis ini membantu serangga mendapatkan nutrisi, membantu perkembangan, reproduksi, dan pertahanan terhadap musuh alami (Chen et al 2011;Dong et al 2011;Tang et al 2010). Endosimbion WBC terdiri atas jamur berfilamen atau khamir (yeast-like symbiotes, YLS) yang bersifat obligat dan bakteri obligat maupun fakultatif (Dong et al 2011;Fan et al 2015).…”

“…Analisis transkriptom fat body WBC menemukan 317 unigen yang homolog dengan gen-gen dari 12 genus YLS dan bakteri Wolbachia . Sementara itu, tujuh genus dan 18 operational taxonomic units (OTUs) bakteri yang berasosiasi dengan berbagai populasi WBC telah diidentikasi, namun belum diketahui manakah di antara bakteri tersebut yang obligat atau fakultatif (Tang et al 2010;Wang et al 2015).…”

“…OTU 1 pada serangga lain dapat memanipulasi reproduksi dan kematian keturunan individu jantan, sedangkan OTU 2 (Asia) pada nyamuk Anopheles stephensi dan wereng daun Scaphoideus titanus diduga menyediakan fungsi metabolik yang membantu adaptasi serangga pada varietas tahan. OTU 2 hanya terdeteksi pada selubung ovipositor biotipe 2, sehingga OTU2 diduga membantu fungsi metabolik untuk adaptasi pada varietas Mudgo (Tang et al 2010). …”

“…Walaupun demikian, adanya peningkatan level mRNA 20 gen esensial Wolbachia untuk prosesproses sel (perakitan ribosomal dan pembelahan sel) dari populasi M mengindikasikan adanya aktivitas perkembangbiakan bakteri ini pada populasi M. Aktivitas biosintesis de novo metabolisme kofaktor dan protein, serta transpor pada populasi M juga meningkat dibanding dengan populasi T . Pada kutu daun dan kutu kebul bakteri endosimbion telah diketahui berperan dalam pembentukan biotipe atau populasi yang virulen (Tang et al 2010). Peran bakteri simbion sebagai penentu virulensi pada WBC masih perlu diklarifikasi lebih lanjut dengan membandingkan daya adaptasi WBC aposimbiotik bakteri dengan WBC simbiotik pada varietas diferensial selama beberapa generasi.…”

Isolation, characterization, and cross-transferability of microsatellite markers from the whitebacked planthopper (Sogatella furcifera)

“…Genomic DNA was extracted from a single individual using the cetyltrimethylammonium bromide method (Tang et al, 2010). The fast isolation by amplified fragment length polymorphism of sequences containing repeat protocols was employed to construct the (AC) 13 -and (AG) 13 -enriched partial genomic libraries (Zane et al, 2002).…”