Exogenous methyl jasmonate promotes the graft union healing process of melon grafted onto squash and enhances low-temperature tolerance of grafted melon seedlings by activating the transcription factors CmWRKY23 and CmWRKY6
Abstract
The involvement of plant hormones in the graft union healing process is significant; yet, how exogenous MeJA affects graft union healing and stress tolerance in cucurbit seedlings remains poorly understood at the molecular level. Exogenous MeJA treatment significantly accelerated the healing process of oriental melon grafted onto squash rootstocks. This treatment led to increased expression of CmWRKY23, CmWRKY69, and the cell adhesion-related gene CmGH9B3 at the graft union, providing evidence for the participation of the CmWRKY23/CmWRKY69-CmGH9B3 module in the MeJA-facilitated graft union-healing process. Furthermore, CmWRKY23 and CmWRKY69 function as transcriptional activators by directly binding to the promoter of CmAOC2, a key jasmonic acid (JA) biosynthesis gene, thereby upregulating CmAOC2 expression. Knockout mutants of CmWRKY23 or CmWRKY69 significantly decreased the low-temperature tolerance of grafted oriental melon seedlings, accompanied by decreased antioxidant enzyme (SOD, POD, CAT) activity, downregulated CmAOC2 expression, and reduced endogenous JA levels. These findings further supported the role of this transcriptional module in regulating low-temperature tolerance through the JA signaling pathway. Overall, our work established that exogenous MeJA promoted graft union healing and enhanced the low-temperature tolerance in grafted oriental melon seedlings. This coordination was achieved via the CmWRKY23/CmWRKY69-CmGH9B3 module for graft union healing and a CmWRKY23/CmWRKY69-CmAOC2 positive feedback loop for low-temperature adaptation. This study revealed a dual regulatory mechanism by which MeJA coordinated both graft union healing and low-temperature resistance, providing new theoretical foundations and practical targets for improving the quality and environmental adaptability of grafted oriental melon seedlings.
Related
- Effects of different concentrations of exogenous methyl jasmonate on tuber metabolism and rhizosphere bacterial community dynamics in Polygonatum cyrtonema Hua
- Jasmonate-responsive group IX AP2/ERF transcription factors control the biosynthesis of benzylisoquinoline alkaloids
- Comparative Physiological and Biochemical Responses of Lettuce (Lactuca sativa L. var. romana) to Foliar Methyl Jasmonate, Nano-Kaolin, and Melatonin Under a Progressive High-Temperature Regime
- TBC-2, a Rab GTPase activating protein, regulates the localization of the HLH-30/TFEB and PQM-1 transcription factors in the C. elegans intestine.
- Exogenous melatonin enhances drought tolerance and secondary-metabolite accumulation in Paeonia ostii 'Fengdan' in association with improved PSI-PSII photochemical coordination.
BibTeX
@article{zhu2026exogenous,
title = {{Exogenous methyl jasmonate promotes the graft union healing process of melon grafted onto squash and enhances low-temperature tolerance of grafted melon seedlings by activating the transcription factors CmWRKY23 and CmWRKY6}},
author = {Yulei Zhu and Hongxi Wu and Jingwei Liu and Yinuo Liang and Xinzhuo Miao and Hongai Liu and Chuanqiang Xu and Tianlai Li},
journal = {Horticulture research},
year = {2026},
month = jun,
doi = {10.1093/hr/uhag220},
url = {https://europepmc.org/article/PMC/PMC13722867},
note = {CC BY},
}
RIS
TY - JOUR
TI - Exogenous methyl jasmonate promotes the graft union healing process of melon grafted onto squash and enhances low-temperature tolerance of grafted melon seedlings by activating the transcription factors CmWRKY23 and CmWRKY6
AU - Yulei Zhu
AU - Hongxi Wu
AU - Jingwei Liu
AU - Yinuo Liang
AU - Xinzhuo Miao
AU - Hongai Liu
AU - Chuanqiang Xu
AU - Tianlai Li
PY - 2026
DA - 2026/06/03
JO - Horticulture research
DO - 10.1093/hr/uhag220
UR - https://europepmc.org/article/PMC/PMC13722867
AB - The involvement of plant hormones in the graft union healing process is significant; yet, how exogenous MeJA affects graft union healing and stress tolerance in cucurbit seedlings remains poorly understood at the molecular level. Exogenous MeJA treatment significantly accelerated the healing process of oriental melon grafted onto squash rootstocks. This treatment led to increased expression of CmWRKY23, CmWRKY69, and the cell adhesion-related gene CmGH9B3 at the graft union, providing evidence for the participation of the CmWRKY23/CmWRKY69-CmGH9B3 module in the MeJA-facilitated graft union-healing process. Furthermore, CmWRKY23 and CmWRKY69 function as transcriptional activators by directly binding to the promoter of CmAOC2, a key jasmonic acid (JA) biosynthesis gene, thereby upregulating CmAOC2 expression. Knockout mutants of CmWRKY23 or CmWRKY69 significantly decreased the low-temperature tolerance of grafted oriental melon seedlings, accompanied by decreased antioxidant enzyme (SOD, POD, CAT) activity, downregulated CmAOC2 expression, and reduced endogenous JA levels. These findings further supported the role of this transcriptional module in regulating low-temperature tolerance through the JA signaling pathway. Overall, our work established that exogenous MeJA promoted graft union healing and enhanced the low-temperature tolerance in grafted oriental melon seedlings. This coordination was achieved via the CmWRKY23/CmWRKY69-CmGH9B3 module for graft union healing and a CmWRKY23/CmWRKY69-CmAOC2 positive feedback loop for low-temperature adaptation. This study revealed a dual regulatory mechanism by which MeJA coordinated both graft union healing and low-temperature resistance, providing new theoretical foundations and practical targets for improving the quality and environmental adaptability of grafted oriental melon seedlings.
SN - 2662-6810
SN - 2052-7276
ER -