Through transcriptomic analysis, researchers uncovered thousands of genes associated with hormone signaling, starch and sugar metabolism, and flavonoid biosynthesis that regulate the dormancy-to-sprouting transition.
Sweet potato (Ipomoea batatas [L.] Lam.), China’s fourth-largest food crop, is rich in nutrients but faces storage problems, particularly sprouting. Sprouting accelerates water loss, reduces commercial quality, and contributes to food waste. Ethylene, a plant hormone, and 1-MCP, an ethylene-action inhibitor, have been used in other crops to delay senescence and sprouting. However, their combined effect on sweet potato roots—and the molecular mechanisms involved—remain poorly understood. With rising demand for organic produce and year-round availability, understanding how to delay sprouting without compromising quality is essential. This study investigates the postharvest effects of ethylene and 1-MCP on the organic cultivar Kokei No.14 and explores their influence on root physiology and gene regulation.
A study (DOI: 10.48130/tp-0025-0015) published in Tropical Plants on 07 May 2025 by Jingjing Kou & Guopeng Zhu’s team, Hainan University, not only provides practical solutions for maintaining root freshness but also unravels the complex gene networks behind sprouting inhibition, paving the way for more sustainable postharvest management strategies.
In this study, researchers evaluated the effects of postharvest treatments—ethylene (ETH), 1-MCP, and their combination—on the storage quality and gene expression of the organic sweet potato cultivar Kokei No.14. Roots were stored under controlled conditions and assessed for weight loss, respiration rate, color, hardness, sprouting behavior, biochemical changes, sensory attributes, and transcriptomic profiles. Results showed that all three treatments significantly reduced weight loss and respiration, with the ETH + 1-MCP combination being the most effective. ETH-treated roots displayed the most vibrant color, while ETH + 1-MCP-treated roots retained the greatest firmness over 27 days. Sprouting was notably delayed across treatments, with the ETH + 1-MCP group showing the longest dormancy extension. Biochemical assays revealed that ETH + 1-MCP-treated roots maintained the highest levels of starch, sucrose, and flavonoids, correlating with superior freshness. Sensory evaluations found ETH-treated samples to have improved appearance and sweetness, although with some increase in off-odors. Transcriptome analysis identified thousands of differentially expressed genes (DEGs), enriched in pathways related to hormone signaling, sugar metabolism, and flavonoid biosynthesis. Weighted Gene Co-expression Network Analysis (WGCNA) linked specific gene modules to physiological traits such as sprout length, weight loss, and sugar accumulation. Transcription factor families AP2/ERF, MYB, WRKY, and bHLH were highly represented, suggesting their central roles in dormancy and sprouting regulation. Hormonal gene expression patterns indicated suppression of auxin signaling and enhancement of ethylene responses under treatment. Sugar metabolism-related genes were upregulated post-sprouting, especially under ETH and ETH + 1-MCP, supporting increased starch and sucrose accumulation. Flavonoid biosynthesis genes showed selective activation, with CYP73A notably increased under ETH treatments. Together, the physiological and transcriptomic results confirm that ETH and 1-MCP, particularly in combination, effectively maintain sweet potato storage quality by regulating multiple metabolic and genetic pathways.
The study shows ETH and 1-MCP treatments not only delay sprouting in sweet potato roots but also maintain visual and sensory quality. These methods are scalable for commercial storage and transportation, especially for high-value organic varieties like Kokei No.14. By reducing spoilage and maintaining nutritional quality, these treatments can minimize food waste, improve supply chain efficiency, and enhance consumer satisfaction. The identification of molecular markers linked to dormancy regulation also opens up new possibilities for breeding sweet potato varieties with superior storage traits. This dual approach represents a cost-effective and sustainable strategy for root crop preservation in global food systems.
###
References
DOI
10.48130/tp-0025-0015
Original Source URL
https://doi.org/10.48130/tp-0025-0015
Funding Information
This research was funded by the National Natural Science Foundation of China (32260443), Hainan Provincial Natural Science Foundation of China (322QN251 & 323RC411), the Project of Sanya Yazhou Bay Science and Technology City (SKJC-JYRC-2024-20), the Earmarked Fund for CARS-10-Sweetpotato, National Tropical Plants Germplasm Resource Center, Specific Research Fund of the Innovation Platform for Academicians of Hainan Province (YSPTZX202206) and the Scientific Research Start-up Fund Project of Hainan University (KYQD(ZR)22125).
About Tropical Plants
Tropical Plants (e-ISSN 2833-9851) is the official journal of Hainan University and published by Maximum Academic Press. Tropical Plants undergoes rigorous peer review and is published in open-access format to enable swift dissemination of research findings, facilitate exchange of academic knowledge and encourage academic discourse on innovative technologies and issues emerging in tropical plant research.