ORIGINAL RESEARCH article
Front. Plant Sci.
Sec. Functional and Applied Plant Genomics
Volume 16 - 2025 | doi: 10.3389/fpls.2025.1664465
This article is part of the Research TopicAnalysis of Genetic Basis of Crop Stress Resistance and Variety ImprovementView all 7 articles
MsDAD1 acts as a heat-induced "senescence brake" in alfalfa
Provisionally accepted
- School of Life Sciences, Qufu Normal University, Qufu, China
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Heat stress severely limits the productivity of alfalfa (Medicago sativa L.). In this study, the defender against apoptotic death 1 (DAD1) gene, MsDAD1, was identified and functionally characterized as a key positive regulator of heat tolerance. The expression of MsDAD1 was specifically and strongly induced by heat stress, and phylogenetic analysis confirmed its high conservation across plant species. Ectopic overexpression of MsDAD1 in transgenic alfalfa significantly enhanced tolerance to heat stress. Compared to wild-type plants, MsDAD1-overexpressing lines (MsDAD1-OE) exhibited reduced leaf chlorosis and abscission, higher relative water content, lower electrolyte leakage, greater chlorophyll retention, and diminished accumulation of reactive oxygen species (H₂O₂, O₂⁻) and malondialdehyde (MDA), suggesting improved membrane integrity and reduced oxidative damage. Transcriptome (RNA-seq) analysis and subsequent physiological validation indicated that MsDAD1 suppresses heat-induced accumulation of jasmonic acid (JA) and abscisic acid (ABA) by downregulating key biosynthetic genes, LOX1 and NCED1. As a result, MsDAD1-OE plants displayed attenuated JA-and ABA-mediated leaf senescence under heat stress. Furthermore, MsDAD1 overexpression delayed heat-induced flowering, correlating with the repression of flowering-promoting genes such as FT and ELF4. Collectively, these findings demonstrate that MsDAD1 enhances alfalfa heat tolerance by mitigating oxidative stress, modulating JA and ABA biosynthesis to delay senescence, and altering flowering time under high-temperature conditions. MsDAD1 represents a promising genetic target for improving heat resilience in alfalfa.
Keywords: MsDAD1, Heat stress, senescence, flowering, Medicago sativa
Received: 12 Jul 2025; Accepted: 11 Aug 2025.
Copyright: © 2025 Song, Guo, Wang, Zheng, Li and Dong. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Yuguang Song, School of Life Sciences, Qufu Normal University, Qufu, China
Wei Dong, School of Life Sciences, Qufu Normal University, Qufu, China
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