Cloning and Expression Analysis of HbPR-1b and HbPR-3 in Hevea brasiliensis During Inoculation with Rigidoporus microporus

Pak J Biol Sci. 2017;20(5):233-243. doi: 10.3923/pjbs.2017.233.243.


Background and objective: Pathogenesis-related (PR) proteins are dramatically accumulated after pathogen infection. Innate defense response through increasing PR-proteins is important for rubber rootstock selection that is tolerant to the white root disease caused by Rigidoporus microporus. This study was aimed to investigate the expression levels of PR-1 and PR-3 genes in tolerant (PB5/51) and susceptible (BPM24 and RRIM600) rubber clones after R. microporus infection.

Materials and methods: The mRNA of HbPR-1b and HbPR-3 was isolated and characterized from rubber leaves. Gene expression levels of HbPR-1b and HbPR-3 were compared among three rubber clones (PB5/51, BPM24 and RRIM600) after R. microporus infection at 0, 12, 24, 48, 72 and 96 h using quantitative real-time PCR. The relative transcript abundances between inoculated and control plants were compared using the means of gene expression between time points and by Tukey's HSD test. A probability value (p<0.05) was used to determine the significance of difference between time points.

Results: The open reading frame of HbPR-1b is 492 bp with deduced 163 amino acid residues and the phylogenetic analysis showed it shared significant evolutionary history and clustering into group I of PR-protein. Moreover, the partial HbPR-3 was isolated with 390 bp. Gene expression levels of HbPR-1b and HbPR-3 showed marked differences in both transcripts depending on the rubber clones. Two genes demonstrated up-regulation of both tolerance and susceptibility in response to attack by R. microporus. The highest expression levels were found in seedlings of PB5/51 after inoculation. In RRIM600, low expression levels of HbPR-1b and HbPR-3 were initially observed but gradually increased at 24 h post inoculation. The transcription profile of HbPR-1b was stable expression in BPM24.

Conclusion: The results demonstrated that the level ofHbPR-1b and HbPR-3 transcription can distinguish between tolerant and susceptible clones. The candidate defense genes to the white root disease were observed in PB5/51 seedlings, particularly HbPR-1b.

Keywords: Hevea brasiliensis; Rigidoporus microporus; gene expression; pathogenesis-related protein; white root disease.

MeSH terms

  • Cloning, Molecular / methods*
  • Evolution, Molecular
  • Fungi / pathogenicity*
  • Gene Expression Regulation, Plant
  • Hevea / genetics*
  • Hevea / growth & development
  • Hevea / microbiology*
  • Host-Pathogen Interactions
  • Phylogeny
  • Plant Diseases / genetics*
  • Plant Diseases / microbiology*
  • Plant Leaves / genetics
  • Plant Leaves / microbiology
  • Plant Proteins / genetics*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Plant / genetics
  • RNA, Plant / metabolism
  • Seedlings / genetics
  • Seedlings / microbiology
  • Time Factors


  • Plant Proteins
  • RNA, Messenger
  • RNA, Plant