Morphophysiological and Proteomic Responses on Plants of Irradiation with Electromagnetic Waves

Fresh-cut watermelon: postharvest physiology, technology, and opportunities for quality improvement

Watermelon (Citrullus lanatus L.) fruit is widely consumed for its sweetness, flavor, nutrition and health-promoting properties. It is commonly commercialized in fresh-cut format, satisfying consumer demand for freshness and convenience, but its shelf-life is limited. Despite the potential for growth in fresh-cut watermelon sales, the industry faces the challenge of maintaining quality attributes during storage. Fresh-cut processing induces a series of physiological and biochemical events that lead to alterations in sensory, nutritional and microbiological quality. A signal transduction cascade involving increases in respiration and ethylene production rates and elevated activities of cell wall and membrane-degrading enzymes compromise cellular and tissue integrity. These responses contribute to the development of quality defects like juice leakage, firmness loss and water-soaked appearance. They also drive the loss of bioactive compounds like lycopene, affecting flesh color and reducing nutritional value, ultimately culminating in consumer rejection, food losses and waste. Although great research progress has been achieved in the past decades, knowledge gaps about the physiological, biochemical and molecular bases of quality loss persist. This review article summarizes the advances in the study of physicochemical, microbiological, nutritional, and sensory changes linked to the deterioration of watermelon after processing and during storage. Different technological approaches for quality improvement and shelf-life extension are summarized: pre- and postharvest, physical, and chemical. We also discuss the advantages, disadvantages and challenges of these interventions and propose alternative directions for future research aiming to reduce qualitative and quantitative fresh-cut watermelon losses.

The role of photobiomodulation in accelerating bone repair

Bone repair is faced with obstacles such as slow repair rates and limited bone regeneration capacity. Delayed healing even nonunion could occur in bone defects, influencing the life quality of patients severely. Photobiomodulation (PBM) utilizes different light sources to derive beneficial therapeutic effects with the advantage of being non-invasive and painless, providing a promising strategy for accelerating bone repair. In this review, we summarize the parameters, mechanisms, and effects of PBM regulating bone repair, and further conclude the current clinical application of PBM devices in bone repair. The wavelength of 635-980 nm, the output power of 40-100 mW, and the energy density of less than 100 J/cm2 are the most commonly used parameters. New technologies, including needle systems and biocompatible and implantable optical fibers, offer references to realize an efficient and safe strategy for bone repair. Further research is required to establish the reliability of outcomes from in vivo and in vitro studies and to standardize clinical trial protocols.

Membrane Proteomics to Understand Enhancement Effects of Millimeter-Wave Irradiation on Wheat Root under Flooding Stress

Millimeter-wave irradiation of wheat seeds enhances the growth of roots under flooding stress, but its mechanism is not clearly understood. To understand the role of millimeter-wave irradiation on root-growth enhancement, membrane proteomics was performed. Membrane fractions purified from wheat roots were evaluated for purity. H⁺-ATPase and calnexin, which are protein markers for membrane-purification efficiency, were enriched in a membrane fraction. A principal-component analysis of the proteomic results indicated that the millimeter-wave irradiation of seeds affects membrane proteins in grown roots. Proteins identified using proteomic analysis were confirmed using immunoblot or polymerase chain reaction analyses. The abundance of cellulose synthetase, which is a plasma-membrane protein, decreased under flooding stress; however, it increased with millimeter-wave irradiation. On the other hand, the abundance of calnexin and V-ATPase, which are proteins in the endoplasmic reticulum and vacuolar, increased under flooding stress; however, it decreased with millimeter-wave irradiation. Furthermore, NADH dehydrogenase, which is found in mitochondria membranes, was upregulated due to flooding stress but downregulated following millimeter-wave irradiation even under flooding stress. The ATP content showed a similar trend toward change in NADH dehydrogenase expression. These results suggest that millimeter-wave irradiation improves the root growth of wheat via the transitions of proteins in the plasma membrane, endoplasmic reticulum, vacuolar, and mitochondria.

Induction of Biosynthesis Antioxidant Molecules in Young Barley Plants by Trioxygen

Young barley plants are a good source of bioactive compounds. This paper presents the effects of gaseous O3 (trioxygen or ozone) on the biosynthesis of compounds, determining the antioxidant potential of young barley plants. The total content of polyphenols was determined along with their profile, as well as total antioxidant potential and vitamin C content. The highest contents of these compounds were identified in young barley plants exposed to gaseous O3. The main bioactive compound, representing polyphenols, determined in the examined raw materials was saponarin (isovitexin 7-O-glucoside). The induction of increased biosynthesis of these molecules was directly linked to the modification of the activity of selected enzymes. The increased polyphenol content resulted from the modified activities of polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL). On the other hand, the oxidative effect of ozone on barley plants was reduced, owing to the modified activities of catalases (CAT), glutathione peroxidases (SOD) and guaiacol peroxidase (GPOX). Analysis of the results showed that by applying gaseous O3 at a dose of 50 ppm for 10 min, the contents of bioactive compounds can be maximised in a residue-free way by activating oxidative stress defence mechanisms.

Proteomic and Biochemical Approaches Elucidate the Role of Millimeter-Wave Irradiation in Wheat Growth under Flooding Stress

Flooding impairs wheat growth and considerably affects yield productivity worldwide. On the other hand, irradiation with millimeter waves enhanced the growth of chickpea and soybean under flooding stress. In the current work, millimeter-wave irradiation notably enhanced wheat growth, even under flooding stress. To explore the protective mechanisms of millimeter-wave irradiation on wheat under flooding, quantitative proteomics was performed. According to functional categorization, proteins whose abundances were changed significantly with and without irradiation under flooding stress were correlated to glycolysis, reactive-oxygen species scavenging, cell organization, and hormonal metabolism. Immunoblot analysis confirmed that fructose-bisphosphate aldolase and β tubulin accumulated in root and leaf under flooding; however, even in such condition, their accumulations were recovered to the control level in irradiated wheat. The abundance of ascorbate peroxidase increased in leaf under flooding and recovered to the control level in irradiated wheat. Because the abundance of auxin-related proteins changed with millimeter-wave irradiation, auxin was applied to wheat under flooding, resulting in the application of auxin improving its growth, even in such condition. These results suggest that millimeter-wave irradiation on wheat seeds improves the recovery of plant growth from flooding via the regulation of glycolysis, reactive-oxygen species scavenging, and cell organization. Additionally, millimeter-wave irradiation could promote tolerance against flooding through the regulation of auxin contents in wheat.