Integrated Anatomical and Transcriptomic Analysis Revealed the Molecular Mechanism of the Healing Process in Homografted and Heterografted Seedlings of Acanthopanax senticosus

Abstract

Grafting is a widely used technique, and graft compatibility between the rootstock and scion is a prerequisite for grafting. To date, the underlying reasons for the success of healing after heterografting remain largely unknown. Here, using Acanthopanax senticosus (A. senticosus) grafted onto more vigorously grown Acanthopanax sessiliflorus (A. sessiliflorus) rootstocks, and self-grafting A. senticosus as controls, anatomical analysis was used to conduct studies on the healing process of grafted plants and transcriptome analysis was also performed on the healing union at 16 days after grafting (DAGs). In total, 10,215 significantly differentially expressed genes were detected between the transcriptomes of heterografts and homografts at 16 DAGs. Go and KEGG analyses showed that a number of metabolic, physiological and hormonal responses are involved in the healing process of heterografted seedlings, including metabolic processes, cellular processes, responses to stimulus, plant hormone signal transduction, the plant–pathogen interaction, the MAPK signaling pathway of the plant, transcription factors and defense responses. This study advances our understanding of the molecular mechanism of the grafting healing process in heterografts and provides a useful reference for elucidating the molecular mechanism of the healing process in homografted and heterografted systems and the candidate genes for functional analysis.