Yong-Jie Liu: Beijing Engineering Research Center for Hybrid Wheat, The Municipal Key Laboratory of the Molecular Genetics of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
Shi-Qing Gao: Beijing Engineering Research Center for Hybrid Wheat, The Municipal Key Laboratory of the Molecular Genetics of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China. gaoshiqing@baafs.net.cn.
Yi-Miao Tang: Beijing Engineering Research Center for Hybrid Wheat, The Municipal Key Laboratory of the Molecular Genetics of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
Jie Gong: Beijing Engineering Research Center for Hybrid Wheat, The Municipal Key Laboratory of the Molecular Genetics of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
Xiao Zhang: Hebei Normal University, Shijiazhuang, 050024, China.
Yong-Bo Wang: Beijing Engineering Research Center for Hybrid Wheat, The Municipal Key Laboratory of the Molecular Genetics of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
Li-Ping Zhang: Beijing Engineering Research Center for Hybrid Wheat, The Municipal Key Laboratory of the Molecular Genetics of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
Ren-Wei Sun: Beijing Engineering Research Center for Hybrid Wheat, The Municipal Key Laboratory of the Molecular Genetics of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
Quan Zhang: Shandong Normal University, Jinan, 250014, China.
Zhao-Bo Chen: Beijing Engineering Research Center for Hybrid Wheat, The Municipal Key Laboratory of the Molecular Genetics of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
Sheng-Quan Zhang: Beijing Engineering Research Center for Hybrid Wheat, The Municipal Key Laboratory of the Molecular Genetics of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
Feng-Ting Zhang: Beijing Engineering Research Center for Hybrid Wheat, The Municipal Key Laboratory of the Molecular Genetics of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
Jian-Gang Gao: Beijing Engineering Research Center for Hybrid Wheat, The Municipal Key Laboratory of the Molecular Genetics of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
Hui Sun: Beijing Engineering Research Center for Hybrid Wheat, The Municipal Key Laboratory of the Molecular Genetics of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
Wei-Bing Yang: Beijing Engineering Research Center for Hybrid Wheat, The Municipal Key Laboratory of the Molecular Genetics of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
Wei-Wei Wang: Beijing Engineering Research Center for Hybrid Wheat, The Municipal Key Laboratory of the Molecular Genetics of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
Chang-Ping Zhao: Beijing Engineering Research Center for Hybrid Wheat, The Municipal Key Laboratory of the Molecular Genetics of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China. zhaochangping@baafs.net.cn.
MAIN CONCLUSION: Transcriptome analysis was carried out for wheat seedlings and spikes from hybrid Jingmai 8 and both inbred lines to unravel mechanisms underlying heterosis. Heterosis, known as one of the most successful strategies for increasing crop yield, has been widely exploited in plant breeding systems. Despite its great importance, the molecular mechanism underlying heterosis remains elusive. In the present study, RNA sequencing (RNA-seq) was performed on the seedling and spike tissues of the wheat (Triticum aestivum) hybrid Jingmai 8 (JM8) and its homozygous parents to unravel the underlying mechanisms of wheat heterosis. In total, 1686 and 2334 genes were identified as differentially expressed genes (DEGs) between the hybrid and the two inbred lines in seedling and spike tissues, respectively. Gene Ontology analysis revealed that DEGs from seedling tissues were significantly enriched in processes involved in photosynthesis and carbon fixation, and the majority of these DEGs expressed at a higher level in JM8 compared to both inbred lines. In addition, cell wall biogenesis and protein biosynthesis-related pathways were also significantly represented. These results confirmed that a combination of different pathways could contribute to heterosis. The DEGs between the hybrid and the two inbred progenitors from the spike tissues were significantly enriched in biological processes related to transcription, RNA biosynthesis and molecular function categories related to transcription factor activities. Furthermore, transcription factors such as NAC, ERF, and TIF-IIA were highly expressed in the hybrid JM8. These results may provide valuable insights into the molecular mechanisms underlying wheat heterosis.
