Changhe Wei1, Ming Li1,2, Jia Qin1, Yunfan Xu1, Yizheng Zhang1, Haiyan Wang3. 1. Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, College of Life Sciences, Sichuan University, Chengdu, 610064, China. 2. Institute of Biotechnology and Nuclear Technology, Sichuan Academy of Agricultural Sciences, Chengdu, 610061, China. 3. Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, College of Life Sciences, Sichuan University, Chengdu, 610064, China. hayawang@scu.edu.cn.
Abstract
BACKGROUND: Sweetpotato (Ipomoea batatas) is a hexaploid plant and generally most genotypes do not flower at all in sub-tropics. Heterografting was carried out between sweetpotato cultivar 'Xushu 18' and Japanese morning glory (Ipomoea nil). With sweetpotato as 'scion' and I. nil as 'rootstock', sweetpotato was induced flowering in the autumn. However, little is known about the molecular mechanisms underlying sweetpotato responses to grafting, especially during the full blooming stages. OBJECTIVES: To investigate the poorly understood molecular responses underlying the grafting-induced phenotypic processes in sweetpotato at full anthesis. METHODS: In this study, to explore the transcriptome diversity and complexity of sweetpotato, PacBio Iso-Seq and Illumina RNA-seq analysis were combined to obtain full-length transcripts and to profile the changes in gene expression of five tissues: scion flowers (SF), scion leaves (SL), scion stems (SS), own-rooted leaves (OL) and own-rooted stems (OS). RESULTS: A total of 138,151 transcripts were generated with an average length of 2255 bp, and more than 72% (100,396) of the transcripts were full-length. During full blooming, to examine the difference in gene expression of sweetpotato under grafting and natural growth conditions, 7905, 7795 and 15,707 differentially expressed genes were detected in pairwise comparisons of OS versus SS, OL versus SL and SL versus SF, respectively. Moreover, differential transcription of genes associated with anthocyanin biosynthesis, light pathway and photosynthesis, ethylene signal transduction pathway was observed in scion responses to grafting. CONCLUSION: Our study is useful in understanding the molecular basis of grafting-induced flowering in grafted sweetpotatoes, and will lay a foundation for further research on sweetpotato breeding in the future.
BACKGROUND: Sweetpotato (Ipomoea batatas) is a hexaploid plant and generally most genotypes do not flower at all in sub-tropics. Heterografting was carried out between sweetpotato cultivar 'Xushu 18' and Japanese morning glory (Ipomoea nil). With sweetpotato as 'scion' and I. nil as 'rootstock', sweetpotato was induced flowering in the autumn. However, little is known about the molecular mechanisms underlying sweetpotato responses to grafting, especially during the full blooming stages. OBJECTIVES: To investigate the poorly understood molecular responses underlying the grafting-induced phenotypic processes in sweetpotato at full anthesis. METHODS: In this study, to explore the transcriptome diversity and complexity of sweetpotato, PacBio Iso-Seq and Illumina RNA-seq analysis were combined to obtain full-length transcripts and to profile the changes in gene expression of five tissues: scion flowers (SF), scion leaves (SL), scion stems (SS), own-rooted leaves (OL) and own-rooted stems (OS). RESULTS: A total of 138,151 transcripts were generated with an average length of 2255 bp, and more than 72% (100,396) of the transcripts were full-length. During full blooming, to examine the difference in gene expression of sweetpotato under grafting and natural growth conditions, 7905, 7795 and 15,707 differentially expressed genes were detected in pairwise comparisons of OS versus SS, OL versus SL and SL versus SF, respectively. Moreover, differential transcription of genes associated with anthocyanin biosynthesis, light pathway and photosynthesis, ethylene signal transduction pathway was observed in scion responses to grafting. CONCLUSION: Our study is useful in understanding the molecular basis of grafting-induced flowering in grafted sweetpotatoes, and will lay a foundation for further research on sweetpotato breeding in the future.
Authors: Walter Chitarra; Irene Perrone; Carla G Avanzato; Andrea Minio; Paolo Boccacci; Deborah Santini; Giovanna Gilardi; Ilenia Siciliano; Maria L Gullino; Massimo Delledonne; Franco Mannini; Giorgio Gambino Journal: Front Plant Sci Date: 2017-04-27 Impact factor: 5.753