Related Experiment Video
Updated: Aug 6, 2026
11:56
A Rapid and Specific Microplate Assay for the Determination of Intra- and Extracellular Ascorbate in Cultured Cells
Published on: April 11, 2014
Ascorbic acid and melatonin synergistically maintain postharvest guava quality by regulating cell wall, antioxidant,
Junping Xu1,2, Shiqi Wen3, Yongmei Su4
1Life Science and Technology School, Lingnan Normal University, Zhanjiang, China. liluo@naver.com.
NPJ Science of Food
|July 18, 2026
Summary
Combined ascorbic acid (AsA) and melatonin (MT) treatment synergistically preserves guava quality by enhancing antioxidant defenses and regulating cell wall metabolism, reducing decay and extending shelf life.
Area of Science:
- Plant Physiology
- Postharvest Biology
- Food Science
Background:
- Guava (Psidium guajava) is highly perishable, suffering significant postharvest decay and senescence.
- Limited storage life and marketability are major challenges for tropical fruits like guava.
- Effective preservation strategies are crucial for reducing economic losses and ensuring fruit availability.
Purpose of the Study:
- To investigate the synergistic effects of combined ascorbic acid (AsA) and melatonin (MT) treatment on preserving 'Pearl' guava quality.
- To elucidate the underlying mechanisms of AsA + MT (AM) treatment on fruit storage quality, antioxidant activity, and cell wall metabolism.
- To identify key regulatory factors involved in AM-mediated fruit preservation.
Main Methods:
- Application of combined AsA + MT (AM) treatment to 'Pearl' guava.
- Assessment of fruit storage quality parameters (browning, weight loss, firmness, soluble solids, titratable acidity, vitamin C).
- Analysis of antioxidant enzyme activities (SOD, POD, APX, CAT), malondialdehyde (MDA) levels, and cell wall-degrading enzymes (PG, PME, CX, β-GAL).
- Transcriptomic and Weighted Gene Co-expression Network Analysis (WGCNA) to identify regulatory genes and transcription factors.
Main Results:
- AM treatment significantly reduced guava browning and weight loss while maintaining firmness, soluble solids, and vitamin C content.
- AM treatment slowed the decline in titratable acidity and alleviated oxidative damage by enhancing antioxidant enzyme activities and reducing MDA accumulation.
- AM suppressed the activity of cell wall-degrading enzymes, stabilizing protopectin and cellulose, thereby delaying fruit degradation.
- Transcriptomic and WGCNA analyses identified key genes and transcription factors (ERF, NAC, bHLH) involved in antioxidant defense and cell wall metabolism regulation.
Conclusions:
- Combined AsA + MT treatment offers a synergistic approach to effectively preserve guava quality during storage.
- AM treatment coordinates antioxidant defense and cell wall metabolism, providing a robust mechanism for delaying senescence and decay.
- This study provides a theoretical and practical foundation for sustainable preservation of tropical fruits.
Related Concept Videos
01:58Fruit Development, Structure, and Function
Fruits form from a mature flower ovary. As seeds develop from the ovules contained within, the ovary wall undergoes a series of complex changes to form fruit. In some fruits, such as soybeans, the ovary wall dries; in other fruits, such as grapes, it remains fleshy. In some cases, organs other than the ovary contribute to fruit formation; such fruits are called accessory fruits.
01:17Gene Regulation During Sporulation
Sporulation is a complex developmental process that allows certain Gram-positive bacteria, such as Bacillus subtilis and Clostridium species, to survive extreme environmental conditions. This process is tightly regulated by a series of signaling cascades and transcriptional controls, ensuring the formation of a highly resistant endospore.Sporulation is triggered by unfavorable conditions, such as nutrient depletion, and is governed by a phosphorelay system. One of the sensor kinases, such as...
01:05Bioavailability Enhancement: Drug Stability Enhancement and GI Retention
Improving a drug's stability in the gastrointestinal (GI) tract is paramount for enhancing its bioavailability and therapeutic effectiveness. Various strategies are employed to protect the drug from the harsh gastric milieu and to ensure its release and absorption at the desired site within the GI tract.Polymer coatings are one such method used to shield drugs from the stomach's acidic environment. By preventing premature drug release, these coatings improve the bioavailability of unstable...
02:50Transgenic Plants
Recombinant DNA technology called transgenesis is often used to add a foreign gene or remove a detrimental gene from an organism. Such genetically modified organisms are called transgenic organisms.
The first-ever transgenic plant was a tobacco plant developed in 1983 that showed resistance against the tobacco mosaic virus. Since then, many transgenic plants have been developed and commercialized for improving the agricultural, ornamental, and horticultural value of a crop plant. Transgenic...
The first-ever transgenic plant was a tobacco plant developed in 1983 that showed resistance against the tobacco mosaic virus. Since then, many transgenic plants have been developed and commercialized for improving the agricultural, ornamental, and horticultural value of a crop plant. Transgenic...
02:45Biological Clocks and Seasonal Responses
The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod.
02:04Regulation of Transpiration by Stomata
During photosynthesis, plants acquire the necessary carbon dioxide and release the produced oxygen back into the atmosphere. Openings in the epidermis of plant leaves is the site of this exchange of gasses. A single opening is called a stoma—derived from the Greek word for “mouth.” Stomata open and close in response to a variety of environmental cues.