Sorbitol promotes the graft healing process in pears

Abstract

Pear propagation is primarily achieved through asexual reproduction via grafting. During the graft union healing process, there is metabolic exchange between the rootstock and the scion. However, a multi-omics systematic study on the role of sugar in the graft union healing process has not been reported. In this study, using micrografting techniques, we comparatively analyzed the metabolic changes during the healing process in homograft and heterograft of pear through metabolomics and transcriptomics. We found significant differences in sugar metabolism pathways after grafting. In the fructose and mannose metabolic pathways, sorbitol exhibited opposite trends in homograft and heterograft. Subsequent transcriptomics analysis confirmed that these metabolite changes were caused by differential expression of related synthetic and converting enzyme genes. Furthermore, spatial metabolomics identified sorbitol accumulation in the scion after homologous grafting. To further verify the role of sorbitol, exogenous sorbitol treatment was applied, revealing that it enhanced tissue adhesion, shortened the time required for callus growth, promoted high expression of xylem formation genes and cambium differentiation genes, and facilitated the reconnection of xylem and phloem, thereby playing a positive role in graft union healing. This study systematically analyzed changes in sugar metabolism during the grafting process and confirmed that sorbitol can promote graft union healing.

Acknowledgements

The author(s) declare that financial support was received for the research, authorship, and/or publication of this article. The earmarked fund for the Agricultural Variety Improvement Project of Shandong Province (2022LZGC011), CARS (CARS-28-07), the Qingdao Agricultural University Doctoral Start-Up Fund.

Author contributions

J.L., B.W., S.Z., and D.L. conceived and designed the experiments. C.L., M.L., W.L., and P.Y. performed the experiments. S.Z. and B.W. analyzed the data. J.L., S.Z., and C.L. wrote the paper. J.S., Y.Y., R.W., and D.L. interpreted the data and revised the manuscript.

Data availability

The raw sequence data of RNA-seq was deposited at National Center for Biotechnology Infommation (NCBI, https://www.ncbi.nlm.nih.gov/bioproject/) under accession number GSE190654. All data generated or analyzed during this study are included in the manuscript and supporting files (Figs S1-S7; Tables S1-S4).

Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Supplementary data

Supplementary data is available at Horticulture Research online.

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