De novo transcriptome assembly and comparative analysis of differentially expressed genes in Prunus dulcis Mill. in response to freezing stress

PLoS One. 2014 Aug 14;9(8):e104541. doi: 10.1371/journal.pone.0104541. eCollection 2014.

Abstract

Almond (Prunus dulcis Mill.), one of the most important nut crops, requires chilling during winter to develop fruiting buds. However, early spring chilling and late spring frost may damage the reproductive tissues leading to reduction in the rate of productivity. Despite the importance of transcriptional changes and regulation, little is known about the almond's transcriptome under the cold stress conditions. In the current research, we used RNA-seq technique to study the response of the reproductive tissues of almond (anther and ovary) to frost stress. RNA sequencing resulted in more than 20 million reads from anther and ovary tissues of almond, individually. About 40,000 contigs were assembled and annotated de novo in each tissue. Profile of gene expression in ovary showed significant alterations in 5,112 genes, whereas in anther 6,926 genes were affected by freezing stress. Around two thousands of these genes were common altered genes in both ovary and anther libraries. Gene ontology indicated the involvement of differentially expressed (DE) genes, responding to freezing stress, in metabolic and cellular processes. qRT-PCR analysis verified the expression pattern of eight genes randomly selected from the DE genes. In conclusion, the almond gene index assembled in this study and the reported DE genes can provide great insights on responses of almond and other Prunus species to abiotic stresses. The obtained results from current research would add to the limited available information on almond and Rosaceae. Besides, the findings would be very useful for comparative studies as the number of DE genes reported here is much higher than that of any previous reports in this plant.

Publication types

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

MeSH terms

  • Freezing
  • Gene Expression Profiling / methods
  • Gene Expression Regulation, Plant / genetics
  • Genes, Plant / genetics*
  • Molecular Sequence Annotation / methods
  • Plant Proteins / genetics
  • Prunus / genetics*
  • Sequence Analysis, RNA / methods
  • Stress, Physiological / genetics*
  • Transcriptome / genetics*

Substances

  • Plant Proteins

Associated data

  • SRA/SRP041269

Grants and funding

This study supported partly by Shahrekord University. Also, the authors contributed personally in supporting this work. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.