Constructing the major biosynthesis pathways for amino acids in the brown planthopper, Nilaparvata lugens Stål (Hemiptera: Delphacidae), based on the transcriptome data

Authors

  • P-J. Wan,

    1. State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
    2. Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
    Search for more papers by this author
  • L. Yang,

    1. State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
    2. Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
    Search for more papers by this author
  • W-X. Wang,

    1. State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
    Search for more papers by this author
  • J-M. Fan,

    1. Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
    Search for more papers by this author
  • Q. Fu,

    Corresponding author
    1. State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
    • Correspondence: Qiang Fu, State Key Laboratory of Rice Biology, China National Rice Research Institute, 359 Tiyuchang Road, Hangzhou 310006, China. Tel.: +86 571 63372472; fax: +86 571 63370348; e-mail: fuqiang@caas.cn

      Guo-Qing Li, Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Weigang No. 1, Nanjing 210095, China. Tel./Fax: +86 25 84395248; e-mail: ligq@njau.edu.cn

    Search for more papers by this author
  • G-Q. Li

    Corresponding author
    1. Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
    • Correspondence: Qiang Fu, State Key Laboratory of Rice Biology, China National Rice Research Institute, 359 Tiyuchang Road, Hangzhou 310006, China. Tel.: +86 571 63372472; fax: +86 571 63370348; e-mail: fuqiang@caas.cn

      Guo-Qing Li, Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Weigang No. 1, Nanjing 210095, China. Tel./Fax: +86 25 84395248; e-mail: ligq@njau.edu.cn

    Search for more papers by this author

Abstract

Nilaparvata lugens is a serious phloem-feeding pest of rice throughout Asia. Rice phloem sap can meet its nutrition requirement for sugars but not for some essential amino acids such as isoleucine, leucine, methionine, phenylalanine, tryptophan, lysine, arginine and histidine. N. lugens harbours yeast-like symbionts in mycetocytes formed by abdominal fat body cells. Removal of the symbionts results in negative physiological effects, suggesting that the symbionts play a pivotal role in the nitrogen metabolism. In the present paper, 521 mRNA expressed sequence tags (ESTs) encoding 126 enzymes that were involved in amino acid biosynthesis were identified based on a transcriptome data, reverse transcription (RT)-PCR and rapid amplification of cDNA ends. Similarity analysis, codon usage bias, along with tissue-biased expression and phylogenetic analysis of a subset of ESTs, suggest that 437 ESTs out of the 521 originate from symbionts, and the remaining 84 mRNA fragments come from N. lugens. Accordingly, the biosynthesis pathways for 20 amino acids were manually constructed. It is postulated that both N. lugens and its symbiont can independently assimilate ammonia and biosynthesize seven non-essential amino acids: glutamate; glutamine; aspartate; asparagine; alanine; serine; and glycine. N. lugens and symbiont enzymes may work collaboratively to catalyse the biosynthesis of proline, methionine, valine, leucine, isoleucine, phenylalanine and tyrosine. We infer from this that symbionts function in the biosynthesis of lysine, arginine, tryptophan, threonine, histidine and cysteine. Our data support the previously proposed hypothesis, i.e. the yeast-like symbionts compensate for, at least partially, the amino acid needs of N. lugens.

Ancillary