Liu Jianlong, Wang Baoyi, Zhang Siying, Liu Min, Liu Wankun, Yang Ping, Liang Chenglin, Song Jiankun, Yang Yingjie, Wang Ran, Li Dingli
Qingdao Key Lab of Genetic Improvement and Breeding of Horticultural Plants, College of Horticulture, Qingdao Agricultural University, No. 700, Changcheng Road, Chengyang District, Qingdao City, Shandong Province 266109, China.
Haidu College, Qingdao Agricultural University, No. 11, Wenhua Road, Laiyang City, Shandong Province, 265200, China.
Hortic Res. 2025 Jun 25;12(9):uhaf168. doi: 10.1093/hr/uhaf168. eCollection 2025 Sep.
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.
梨的繁殖主要通过嫁接进行无性繁殖。在嫁接愈合过程中，砧木和接穗之间存在代谢交换。然而，尚未有关于糖在嫁接愈合过程中作用的多组学系统研究报道。在本研究中，我们利用微嫁接技术，通过代谢组学和转录组学对梨同种嫁接和异种嫁接愈合过程中的代谢变化进行了比较分析。我们发现嫁接后糖代谢途径存在显著差异。在果糖和甘露糖代谢途径中，山梨醇在同种嫁接和异种嫁接中呈现相反的趋势。随后的转录组学分析证实，这些代谢物变化是由相关合成和转化酶基因的差异表达引起的。此外，空间代谢组学确定了同种嫁接后接穗中山梨醇的积累。为了进一步验证山梨醇的作用，我们进行了外源山梨醇处理，结果表明它增强了组织粘附力，缩短了愈伤组织生长所需的时间，促进了木质部形成基因和形成层分化基因的高表达，并促进了木质部和韧皮部的重新连接，从而在嫁接愈合中发挥了积极作用。本研究系统分析了嫁接过程中糖代谢的变化，并证实山梨醇可促进嫁接愈合。
