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.

Acanthopanax senticosus (A. senticosus) is a member of Acanthopanax Miq. and is used in traditional Chinese medicine, and it has been found that grafting technology can be used to alter plant metabolite composition and transcriptome characteristics. In this study, shoots of A. senticosus were grafted onto the rootstocks of the vigorous Acanthopanax sessiliflorus (A. sessiliflorus) to improve its varietal characteristics. In order to investigate the changes in metabolites and transcriptional patterns in grafted A. senticosus leaves (GSCL), fresh leaves were collected from 2-year-old grafted A. senticosus scions, while self-rooted seedling A. senticosus leaves (SCL) were used as controls to analyse the transcriptome and metabolome. Metabolic profiles and gene expression patterns were further identified and correlated in special metabolite target pathways. The content of chlorogenic acid and triterpenoids in the GSCL was higher than in the control, while the quercetin content was lower. All these metabolic changes were associated with changes in the expression pattern of transcripts. Our results revealed the transcriptome and metabolome characteristics of GSCL. This may help to improve leaf quality in A. senticosus cultivation, suggesting that it is feasible to improve the medicinal quality of GSCL through asexual propagation, but the long-term effects need further investigation. In conclusion, this dataset provides a useful resource for future studies on the effects of grafting on medicinal plants.

With the decrease in the number of natural populations of Actinidia arguta, there is an urgent need to collect A. arguta germplasm resources and explore their genetic diversity for better management and protection. In this study, 31 simple sequence repeat (SSR) markers were used to identify 148 wild A. arguta germplasms from six natural populations in Changbai Mountain, China, and the genetic diversity of their leaf quality traits was subsequently evaluated. SSR analysis revealed rich genetic diversity among different individuals and within populations of A. arguta. Molecular variance analysis determined that the genetic diversity of wild A. arguta mainly came from within the populations (95% variance component ratio), while only a small part originated from among populations (5% variance component ratio). Abundant genetic variations were observed in the leaf quality traits of the different A. arguta resources with a high genetic diversity index (0.13–1.23). Leaf quality trait clustering and the unweighted pair group method with arithmetic average (UPGMA) clustering analysis showed similar classification results. Population structure analysis divided 148 individuals into three subgroups. Our results indicate that the populations of A. arguta in Changbai Mountain have large genetic variation and high genetic diversity. This study broadens the genetic basis of the A. arguta breeding germplasm.