Sweet potato (Ipomoea batatas (L.) Lam.) is served as an important root crop worldwide due to its high yield, strong adaptability and nutrient richness. Sweet potato has played a significant role in ensuring food security and family income opportunities for local populations in China for years of experience. The storage roots, which provide abundant nutrition and health benefits to people, are the mainly harvested and consumed parts of sweet potato. However, after harvest, physiological disorders, such as sprouting, mechanical injury and infectious postharvest diseases, increase the magnitude of sweet potato root quality decline and nutritional compound losses. Ethylene and 1-methylcyclopropene (1-MCP) were considered to be effective commercial treatments in sweet potato postharvest. Exogenous ethylene and 1-MCP treatment could successfully inhibit root sprouts and reduce rot decay without affecting the storage quality of sweet potato. This review aims to summarize the latest available information on the effects of ethylene and 1-MCP with respect to enhancing or impairing sweet potato root quality. A better understanding of the influence of ethylene and 1-MCP on root quality parameters will be useful to further explore the role and mechanisms of action of ethylene in regulating the postharvest storage of sweet potato roots and contributions to technological development and innovation.

Trihelix transcription factors with helix–loop–helix–loop–helix characteristics are essential in plant growth, development, and response to adversity. Several potential functions of Trihelix have been studied in multiple plant species, but little is known about the features and functions of Trihelix genes in pineapple. In this study, 23 Trihelix members were identified and classified into 5 groups and were unevenly distributed in 17 chromosomes of pineapple. The results revealed that six fragment duplication events and one tandem duplication event were found through gene duplication analysis. Moreover, 4, 10, 21, and 23 homologous gene pairs were found between pineapple and Arabidopsis, grape, banana, and rice, respectively. The promoters of Trihelix have many cis-elements, especially in light and hormone response. The expression characteristics of AcTrihelix members showed obvious tissue specificities in different tissues. The expressions of AcTrihelix3, AcTrihelix8, AcTrihelix16, AcTrihelix19, AcTrihelix20, and AcTrihelix23 were maintained at high levels during the late stage of flower bud development. In floral organs, the expression of different members was very different. In conclusion, some AcTrihelix members may play important roles during the floral development of pineapple, and they provide resources for further studies of the function of Trihelix and the molecular mechanism during pineapple flower formation.

Soft rotting caused by Rhizopus stolonifer is one of the most important postharvest decays in Kokei No. 14 organic sweet potato roots. While various methods have been explored for controlling this pathogen, there remains a need for effective, safe, and applicable alternatives, particularly using essential oils (EOs). This study evaluated the efficacy of EOs, specifically carvacrol, thymol, and thyme oil, in controlling Rhizopus soft rot. We conducted both in vitro and in vivo tests to assess their effects on fungal mycelial growth, spore germination, and the incidence and severity of soft rot in sweet potatoes, along with quality evaluations of the roots. The results indicated that the vapor phase of carvacrol, thymol, and thyme oil was more effective than the contact phase in inhibiting fungal growth and spore germination. In vivo tests revealed that all three EOs significantly reduced the incidence and severity of soft rot, with thymol and thyme oil at 300 mg/L, and carvacrol at 500 mg/L being the most effective. Quality assessments showed minimal impact on properties such as firmness, weight loss, color, starch, carotenoids, and flavonoids, although residual odors increased. GC/MS analysis confirmed that thyme oil contained high levels of both thymol and carvacrol, along with other antimicrobial compounds, suggesting that the cumulative activity of these volatile compounds enhanced their bacteriostatic effects. Thyme oil demonstrated greater efficacy in reducing soft rot development compared to its individual components, making it a promising biofumigant for controlling postharvest diseases in Kokei No. 14 organic sweet potato roots. These findings emphasized the potential for using thyme oil as a safe and effective approach to managing postharvest decay.

The cut flowers of the Oncidium hybridum cultivar ‘Honey Angle’ are highly regarded for their vibrant floral display, excellent flower quality, and broad commercial applications. However, its postharvest vase life is significantly challenged by wilting, water loss, and color fading, primarily due to ethylene exposure. To clarify the underlying mechanism, we performed treatments with ethylene and ethylene action inhibitor 1-Methylcyclopropene (1-MCP). The petal changes, vase life, and transcriptomic analysis after treatments were investigated. The results revealed that the 1-MCP treatment significantly extended the vase life by upregulating the genes involved in carotenoid synthesis, suppressing the genes related to cell wall degradation and the ethylene signaling pathways. In contrast, the ethylene treatment accelerated senescence by activating the senescence-related genes and increasing ethylene production. Transcriptome analysis identified 960 transcription factors, predominantly from the NAC, WRKY, ERF, bHLH, and MYB families, which were crucial in regulating quality changes during the vase life. A total of 5203 differentially expressed genes (DEGs) were assigned to 19 KEGG pathways including carbohydrate and energy metabolism as well as plant hormone signal transduction. Weighted gene co-expression network analysis (WGCNA) indicated that these DEGs were primarily associated with weight loss, flowering ratio, lightness, maximum petal diameter, and respiration intensity. This research provided valuable insights into the molecular mechanisms of floral senescence and practical guidance for extending the vase life of ‘Honey Angle’ cut flowers.

The organic sweet potato cultivar Kokei No.14 is recognized for its high quality, nutritional benefits, and favorable growth performance in Hainan province (China). However, postharvest sprouting of Kokei No.14 presents a significant challenge during storage. To clarify sprouting mechanism, we performed several treatments including continuous air (Air), 1-MCP (30 μL·L⁻¹), ethylene (200 μL·L⁻¹), and combined ethylene and 1-MCP. The sprouting rates, quality changes, and transcriptomic analysis after treatment were investigated. The results indicated that ethylene, 1-MCP, and their combined treatment significantly inhibited germination and respiration rates, reduced weight loss, and extended the root shelf life. The combination of ethylene and 1-MCP was more effective in reducing sprouting than the individual application of either compound. Meanwhile, ethylene treatment enhanced the color vibrancy and flavor of the roots. Transcriptome analysis identified 2,069 transcription factors, predominantly AP2/ERF, MYB, bHLH, and WRKY, which were crucial in regulating root sprouting and quality changes during germination. A total of 360 differentially expressed genes (DEGs) were assigned to 19 KEGG pathways including starch and sucrose metabolism, plant hormone signal transduction, and the flavonoid pathway by comparative transcriptome. Weighted Gene Co-Expression Network Analysis (WGCNA) indicated that these DEGs were primarily associated with physiological indicators such as sprout number, sprout length, weight loss, respiration rate, color, starch, and sucrose content. DEGs in these pathways played a crucial role in regulating sweet potato sprouting after ethylene and 1-MCP treatment. This research provided a theoretical basis and practical guidance in germination inhibition and quality improvement of organic Kokei No.14 sweet potato roots.

It has been well established that exogenous melatonin (MT) improves storage quality of many agricultural products. However, contrasting results have been reported in the regulation of MT with respect to several postharvest parameters, e.g., germination/sprouting and lignification, indicating that roles of MT may vary with plant species or storage environment. Previous studies mainly focus on above-ground organs including fruits, leaves, seedlings and flowers without addressing underground organs such as the storage root (SR) of sweetpotato (Ipomoea batatas). This study showed that spraying 0.5 mM MT solution improved postharvest quality of sweetpotato SRs during 40 d of storage at 15 °C. First, MT treatment inhibited SR sprouting by differentially regulating the content of germination-related hormones, i.e., increasing the content of ABA and JA but decreasing GA content. Second, MT reduced weight loss and lignification by inhibiting respiration as reflected by decreased respiration rate and hexose kinase activity. Third, MT treatment increased soluble sugar content by elevating the activity and expression of sucrose synthase (Sus) since the activities and expressions of invertases (CWIN, CIN and VIN) were inhibited by MT. Simultaneously, inhibited respiration by MT also contributed to increased content of soluble sugar by reducing their expenditure via glycolysis. Additionally, MT increased starch content by inhibiting β-amylase activity and possibly also by increasing Sus activity, which provides a substrate for starch biosynthesis. Finally, MT upregulated the activities of SOD, POD and CAT, which may improve storage quality of SRs by inhibiting senescence and lignification. This study provides an alternative option to maintain the storage quality of sweetpotato.