Journal Article

Molecular mechanisms driving the success of grafting impacted by walnut rootstock

Zhang, Wen’E, Chen, Shengqun, Chen, Youliang, Pan, Xuejun, Cen, Xianchao, Hou, Na, Shen, Lianwen

2026

Overview

Background The foundation for ensuring walnuts of high yield and quality is excellent rootstock. Numerous studies have shown that the walnut rootstock has a major impact on the grafted varieties’ quality, yield, stress resistance, growth, and development. Elucidating the mechanism of grafting affinity in walnuts is crucial, as it paves the way for selecting premium rootstocks to achieve increased production and efficiency. In this study, a combined analysis of the transcriptome, miRNA, and metabolome was conducted to elucidate the molecular mechanisms underlying graft compatibility between different walnut rootstocks ( Juglans sigillata cv. ‘Qianhe 7’ and ‘Panzhou’). Results A total of 44, 41, 50, and 28 differential miRNAs were identified between ‘Qianhe 7’ vs ‘Panzhou’ at 1st d, 11th d, 17th d, and 30th d after grafting, respectively. These miRNAs target genes associated with plant hormone signaling pathways, particularly those related to IAA, SA, and ABA, such as ARF, SAUR, and RAS1-like genes. The most dominant metabolites in both J. sigillata rootstocks (cv. ‘Qianhe 7’ and ‘Panzhou’) at 1st d after grafting were salicylic acid (SA) and Indole-3-acetic acid (IAA). The concentration of SA increased with the extension of time in ‘Qianhe 7’, while IAA decreased significantly on the 30th d. The IAA and abscisic acid (ABA) contents of ‘Qianhe 7’ were markedly higher than those observed in ‘Panzhou’ at 11th d and 30th d post-grafting, respectively. But the concentration of jasmonic acid (JA) in the ‘Panzhou’ was significantly higher than that observed in the ‘Qianhe 7’ at 17th d post-grafting. Conclusions These results indicated that SA, ABA, and IAA may play a pivotal role in the adaptability of grafted J. sigillata (‘Qianhe 7’ and ‘Panzhou’), which provides a foundation for understanding walnut graft affinity. A deeper exploration of the synergistic regulatory network between the identified miRNAs and plant hormones is warranted to clarify the underlying mechanisms, thereby informing hormone-based breeding strategies for walnut rootstocks and facilitating the sustainable advancement of the walnut industry.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Abscisic acid / Acetic acid / Affinity / Analysis / Animal Genetics and Genomics / Binomial distribution / Biomedical and Life Sciences / Chromatography / Food quality / Fruits / Gene expression / Genes / Genetic aspects / Genetic engineering / Genetic research / Graft compatibility / Grafting / Heterogeneous rootstock / Hormones / Horticulture / Indoleacetic acid / Jasmonic acid / Juglans sigillata / Life Sciences / Metabolites / Metabolome / Microarrays / Microbial Genetics and Genomics / MicroRNAs / miRNA / Molecular modelling / Physiological aspects / Physiology / Phytohormones / Plant genetics / Plant Genetics and Genomics / Plant hormones / Proteomics / Rootstocks / Salicylic acid / Self-rooted rootstock / Signal transduction / Software / Transcriptome / Transcriptomes / Walnut