The study demonstrates that soaking peanut seeds in a 0.2 mM ethylene solution optimally promotes germination by regulating hormone balance and fatty acid degradation. This research provides new insights into seed dormancy and germination, with significant implications for improving crop yields and agricultural practices, especially in peanuts and similar crops.
Peanuts (Arachis hypogaea L.), native to South America, are widely grown for their edible seeds and oil-rich content. As one of the most valuable oilseed crops globally, they contribute to both human nutrition and crop rotation due to their nitrogen-fixing properties. The success of peanut cultivation relies heavily on efficient seed germination, which is influenced by various factors including genetic, environmental, and hormonal regulation. Ethylene, known for its role in promoting germination in several plants, has been applied to break dormancy in peanut seeds, but the molecular mechanisms remain largely unexplored.
A study (DOI: 10.48130/seedbio-0025-0005) published in Seed Biology on 09 April 2025 by Xiaoqin Liu’s team, Peking University Institute of Advanced Agricultural Sciences, opens the door to more effective dormancy-breaking techniques.
The study investigated the effect of ethylene on peanut seed germination, employing different concentrations and treatment methods to assess its impact. Four concentrations of ethylene (0.5, 1.0, 2.0, and 5.0 mM) were tested using two methods: continuous soaking in ethylene for 7 days or soaking in ethylene for 12 hours followed by water soaking. The results indicated that high ethylene concentrations (5.0 mM) inhibited germination, regardless of the treatment method. In contrast, 0.5 mM ethylene resulted in a higher germination rate and a higher germination index, particularly on the 2nd, 3rd, and 7th days, though the differences were not statistically significant. The 0.2 mM ethylene treatment significantly enhanced germination, especially when applied for 12 hours followed by water soaking, showing improved germination rates and faster radicle growth compared to the control. This treatment also resulted in a significantly higher germination index, indicating a faster and more uniform germination process. Additionally, ethylene treatment increased the levels of gibberellins (GA), specifically GA3 and GA4, while reducing abscisic acid (ABA) levels. These hormonal changes support the role of ethylene in breaking seed dormancy and promoting germination. Gene expression analysis revealed that ethylene upregulated genes involved in ethylene synthesis and signaling, such as ACO and ETR1, and cell wall loosening genes like EXP and PEC. Moreover, ethylene treatment suppressed the expression of the ABA-insensitive gene ABI5, enhancing germination. The study also found that ethylene treatment accelerated fatty acid degradation in the seeds, particularly through the upregulation of key enzymes involved in beta-oxidation. These findings suggest that ethylene promotes peanut seed germination through complex hormonal modulation and metabolic adjustments.
In conclusion, the study demonstrates that ethylene significantly enhances peanut seed germination by regulating hormonal pathways, including the upregulation of gibberellins and the downregulation of abscisic acid. Ethylene also promotes fatty acid degradation, contributing to the energy required for seedling growth. These discoveries provide valuable insights that could improve agricultural practices, particularly in enhancing germination rates and crop yields.
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References
DOI
10.48130/seedbio-0025-0005
Original Source URL
https://doi.org/10.48130/seedbio-0025-0005
Funding information
This work was supported by the Taishan Scholars Program of Shandong Province (tsqn202103161), the Key R&D Program of Shandong Province, China (2024LZGC035), the Weifang Science and technology development plan (2024JZ001), and the Natural Science Foundation of Shandong Province (ZR202103010405) to Xiaoqin Liu. It was also founded by the Taishan Scholar Project Funding, China Agriculture Research System (Project No. CARS-13) to Xiaoyuan Chi.
About Seed Biology
Seed Biology (e-ISSN 2834-5495) is published by Maximum Academic Press in partnership with Yazhou Bay Seed Laboratory. Seed Biology is an open access, online-only journal focusing on research related to all aspects of the biology of seeds, including but not limited to: evolution of seeds; developmental processes including sporogenesis and gametogenesis, pollination and fertilization; apomixis and artificial seed technologies; regulation and manipulation of seed yield; nutrition and health-related quality of the endosperm, cotyledons, and the seed coat; seed dormancy and germination; seed interactions with the biotic and abiotic environment; and roles of seeds in fruit development. Seed biology publishes a wide range of research approaches, such as omics, genetics, biotechnology, genome editing, cellular and molecular biology, physiology, and environmental biology. Seed Biology publishes high-quality original research, reviews, perspectives, and opinions in open access mode, promoting fast submission, review, and dissemination freely to the global research community.