RNA-sequencing reveals early, dynamic transcriptome changes in the corollas of pollinated petunias

BMC Plant Biology

Research Article

Michelle L Jones¹  Laura J Chapin¹  Shaun R Broderick¹  Saranga Wijeratne²  Asela J Wijeratn²  Tea Meulia² 

[1] Department of Horticulture and Crop Science, The Ohio Agricultural Research and Development Center, The Ohio State University, 1680 Madison Ave, 44691, Wooster, OH, USA;Molecular and Cellular Imaging Center, The Ohio Agricultural Research and Development Center, The Ohio State University, 1680 Madison Ave, 44691, Wooster, OH, USA;

关键词: RNA-seq;    WGCNA;    de novo assembly;    String;    KEGG;    Trinity;    Autophagy;    Calcium signaling;    Ethylene;    Petal senescence;   

DOI  :  10.1186/s12870-014-0307-2

 received in 2014-07-18, accepted in 2014-10-27,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundPollination reduces flower longevity in many angiosperms by accelerating corolla senescence. This response requires hormone signaling between the floral organs and results in the degradation of macromolecules and organelles within the petals to allow for nutrient remobilization to developing seeds. To investigate early pollination-induced changes in petal gene expression, we utilized high-throughput sequencing to identify transcripts that were differentially expressed between corollas of pollinated Petunia × hybrida flowers and their unpollinated controls at 12, 18, and 24 hours after opening.ResultsIn total, close to 0.5 billion Illumina 101 bp reads were generated, de novo assembled, and annotated, resulting in an EST library of approximately 33 K genes. Over 4,700 unique, differentially expressed genes were identified using comparisons between the pollinated and unpollinated libraries followed by pairwise comparisons of pollinated libraries to unpollinated libraries from the same time point (i.e. 12-P/U, 18-P/U, and 24-P/U) in the Bioconductor R package DESeq2. Over 500 gene ontology terms were enriched. The response to auxin stimulus and response to 1-aminocyclopropane-1-carboxylic acid terms were enriched by 12 hours after pollination (hap). Using weighted gene correlation network analysis (WGCNA), three pollination-specific modules were identified. Module I had increased expression across pollinated corollas at 12, 18, and 24 h, and modules II and III had a peak of expression in pollinated corollas at 18 h. A total of 15 enriched KEGG pathways were identified. Many of the genes from these pathways were involved in metabolic processes or signaling. More than 300 differentially expressed transcription factors were identified.ConclusionsGene expression changes in corollas were detected within 12 hap, well before fertilization and corolla wilting or ethylene evolution. Significant changes in gene expression occurred at 18 hap, including the up-regulation of autophagy and down-regulation of ribosomal genes and genes involved in carbon fixation. This transcriptomic database will greatly expand the genetic resources available in petunia. Additionally, it will guide future research aimed at identifying the best targets for increasing flower longevity by delaying corolla senescence.

【 授权许可】

Unknown   
© Broderick et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.