Differential Gene Expression Reveals Candidate Genes for Drought Stress Response in Abies alba (Pinaceae)

PLoS One. 2015 Apr 29;10(4):e0124564. doi: 10.1371/journal.pone.0124564. eCollection 2015.

Abstract

Increasing drought periods as a result of global climate change pose a threat to many tree species by possibly outpacing their adaptive capabilities. Revealing the genetic basis of drought stress response is therefore implemental for future conservation strategies and risk assessment. Access to informative genomic regions is however challenging, especially for conifers, partially due to their large genomes, which puts constraints on the feasibility of whole genome scans. Candidate genes offer a valuable tool to reduce the complexity of the analysis and the amount of sequencing work and costs. For this study we combined an improved drought stress phenotyping of needles via a novel terahertz water monitoring technique with Massive Analysis of cDNA Ends to identify candidate genes for drought stress response in European silver fir (Abies alba Mill.). A pooled cDNA library was constructed from the cotyledons of six drought stressed and six well-watered silver fir seedlings, respectively. Differential expression analyses of these libraries revealed 296 candidate genes for drought stress response in silver fir (247 up- and 49 down-regulated) of which a subset was validated by RT-qPCR of the twelve individual cotyledons. A majority of these genes code for currently uncharacterized proteins and hint on new genomic resources to be explored in conifers. Furthermore, we could show that some traditional reference genes from model plant species (GAPDH and eIF4A2) are not suitable for differential analysis and we propose a new reference gene, TPC1, for drought stress expression profiling in needles of conifer seedlings.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abies / genetics*
  • Abies / growth & development
  • Adaptation, Physiological / genetics
  • Droughts*
  • Expressed Sequence Tags
  • Gene Expression Regulation, Plant
  • Seedlings / genetics*
  • Seedlings / growth & development
  • Stress, Physiological / genetics*
  • Water

Substances

  • Water

Grants and funding

Support was provided by LinkTree: Linking genetic variability with ecological responses to environmental changes: forest trees as model systems (Grant number: 01LC0822A). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.