Genome-Wide Identification of Differentially Expressed Genes Associated with the High Yielding of Oleoresin in Secondary Xylem of Masson Pine (Pinus massoniana Lamb) by Transcriptomic Analysis

Qinghua Liu; Zhichun Zhou; Yongcheng Wei; Danyu Shen; Zhongping Feng; Shanping Hong

doi:10.1371/journal.pone.0132624

Genome-Wide Identification of Differentially Expressed Genes Associated with the High Yielding of Oleoresin in Secondary Xylem of Masson Pine (Pinus massoniana Lamb) by Transcriptomic Analysis

PLoS One. 2015 Jul 13;10(7):e0132624. doi: 10.1371/journal.pone.0132624. eCollection 2015.

Authors

Qinghua Liu¹, Zhichun Zhou¹, Yongcheng Wei¹, Danyu Shen², Zhongping Feng³, Shanping Hong³

Affiliations

¹ Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Fuyang, Zhejiang, People's Republic of China; Zhejiang Provincial Key Laboratory of Tree Breeding, Fuyang, Zhejiang, People's Republic of China.
² Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Fuyang, Zhejiang, People's Republic of China.
³ Laoshan Forest Farm of Chunan County, Chunan, Zhejiang, People's Republic of China.

Abstract

Masson pine is an important timber and resource for oleoresin in South China. Increasing yield of oleoresin in stems can raise economic benefits and enhance the resistance to bark beetles. However, the genetic mechanisms for regulating the yield of oleoresin were still unknown. Here, high-throughput sequencing technology was used to investigate the transcriptome and compare the gene expression profiles of high and low oleoresin-yielding genotypes. A total of 40,690,540 reads were obtained and assembled into 137,499 transcripts from the secondary xylem tissues. We identified 84,842 candidate unigenes based on sequence annotation using various databases and 96 unigenes were candidates for terpenoid backbone biosynthesis in pine. By comparing the expression profiles of high and low oleoresin-yielding genotypes, 649 differentially expressed genes (DEGs) were identified. GO enrichment analysis of DEGs revealed that multiple pathways were related to high yield of oleoresin. Nine candidate genes were validated by QPCR analysis. Among them, the candidate genes encoding geranylgeranyl diphosphate synthase (GGPS) and (-)-alpha/beta-pinene synthase were up-regulated in the high oleoresin-yielding genotype, while tricyclene synthase revealed lower expression level, which was in good agreement with the GC/MS result. In addition, DEG encoding ABC transporters, pathogenesis-related proteins (PR5 and PR9), phosphomethylpyrimidine synthase, non-specific lipid-transfer protein-like protein and ethylene responsive transcription factors (ERFs) were also confirmed to be critical for the biosynthesis of oleoresin. The next-generation sequencing strategy used in this study has proven to be a powerful means for analyzing transcriptome variation related to the yield of oleoresin in masson pine. The candidate genes encoding GGPS, (-)-alpha/beta-pinene, tricyclene synthase, ABC transporters, non-specific lipid-transfer protein-like protein, phosphomethylpyrimidine synthase, ERFs and pathogen responses may play important roles in regulating the yield of oleoresin. These DEGs are worthy of special attention in future studies.

Publication types

Research Support, Non-U.S. Gov't
Validation Study

MeSH terms

China
Genome, Plant*
Pinus / genetics*
Plant Extracts / metabolism*
Transcriptome*
Xylem / metabolism*

Substances

Plant Extracts
oleoresins

Grants and funding

This work was supported by funds from: 1) National Science & Technology Pillar Program of China (No. 2012BAD01B02, http://kjzc.jhgl.org/), ZZ. The funders had a role in decision to publish; 2) National Natural Science Foundation of China (31100491), QL. The funders had a role in study design; 3) Major Science & Technology Project of New Agricultural Variety Cultivation of Zhejiang Province, China (2012C12908-12), ZZ. The funders had a role in data collection and analysis, decision to publish.