Transcriptome analysis uncovers key regulatory and metabolic aspects of soybean embryonic axes during germination

• Published in: Scientific reports 2016-11, Vol.6 (1), p.36009, Article 36009
• Main Authors: Bellieny-Rabelo, Daniel, de Oliveira, Eduardo Alves Gamosa, Ribeiro, Elane da Silva, Costa, Evenilton Pessoa, Oliveira, Antônia Elenir Amâncio, Venancio, Thiago Motta
• Format: Article
• Language: English
• Subjects: 38; 45; 631/337/2019; 631/92/1643; Abscisic acid; Cell walls; Developmental stages; Embryos; Environmental conditions; Ethylene; Gene expression; Gene Expression Profiling; Gene Expression Regulation, Plant; Gene regulation; Genomes; Germination; Glycine max; Glycine max - growth & development; Glycolysis; Humanities and Social Sciences; Inactivation; Kinases; Metabolic Networks and Pathways - genetics; multidisciplinary; Post-transcription; Protein kinase; Protein sources; Ribonucleic acid; RNA; Science; Sequence Analysis, RNA; Signal transduction; Soybeans; Transcription activation; Transcription factors; Tricarboxylic acid cycle
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep36009

Soybean ( Glycine max ) is a major legume crop worldwide, providing a critical source of protein and oil. The release of the soybean genome fuelled several transcriptome projects comprising multiple developmental stages and environmental conditions. Nevertheless, the global transcriptional patterns of embryonic axes during germination remain unknown. Here we report the analysis of ~1.58 billion RNA-Seq reads from soybean embryonic axes at five germination stages. Our results support the early activation of processes that are critical for germination, such as glycolysis, Krebs cycle and cell wall remodelling. Strikingly, only 3 hours after imbibition there is a preferential up-regulation of protein kinases and transcription factors, particularly from the LOB domain family, implying that transcriptional and post-transcriptional regulation play major roles early after imbibition. Lipid mobilization and glyoxylate pathways are also transcriptionally active in the embryonic axes, indicating that the local catabolism of oil reserves in the embryonic axes contributes to energy production during germination. We also present evidence supporting abscisic acid inactivation and the up-regulation of gibberellin, ethylene and brassinosteroid pathways. Further, there is a remarkable differential activation of paralogous genes in these hormone signalling pathways. Taken together, our results provide insights on the regulation and biochemistry of soybean germination.