KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Settings

Subject: search.filters.subject.peroxidase

Search Results

Now showing 1 - 4 of 4
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Differential Biochemical Responses of Resistant and Susceptible Genotypes of Chili to Pepper Yellow Leaf Curl Thailand Virus
    (2025-09-01)
    Mueangkhong, Manthana
    ;
    Suwor, Patcharaporn
    ;
    Techawongstien, Suchila
    ;
    Teerarak, Montinee
    ;
    Tsai, Wen Shi
    Chili (Capsicum annuum L.) production is threatened by the pepper yellow leaf curl virus (PepLCV), transmitted by whiteflies, leading to reduced yields. This study investigated the biochemical changes in two chili genotypes, PEP6 (tolerant to PepLCV) and Homsuphan (susceptible to PepLCV), following inoculation with the Thailand strain of PepLCV (known as Pepper Yellow Leaf Curl Thailand Virus, PepYLCTHV). Inoculation was performed using whitefly transmission (WF) and graft transmission (GT) methods, and disease severity was evaluated using a standardized index. The level of total phenolic compounds and the activities of peroxidase (POD) and polyphenol oxidase (PPO) enzymes were analyzed in virus-infected plants and compared with those in uninoculated controls. Both chili genotypes exhibited a more rapid increase in disease severity when inoculated with WF than with GT. In PEP6, disease severity was lower than Homsuphan in both WF and GT inoculations. Disease severity in WT-inoculated PEP6 plants increased gradually, reaching 100% by day 36, whereas Homsuphan plants had a more rapid progression, attaining 100% by day 21. The GT method led to slower disease severity progression in both genotypes, reaching 80–85% by day 36. In PEP6 plants, total phenolic compound content increased significantly following WF, indicating an active defense response, whereas levels remained stable in GT plants. Phenolic content in the tolerant genotype Homsuphan remained stable across all conditions. Notably, peroxidase (POD) activity was elevated in GT plants of both genotypes, which correlated with reduced disease severity. Polyphenol oxidase (PPO) activity was lowest in control plants, but WT and GT increased the PPO level. Among the treatments, GT induced the highest PPO activity, which was associated with the lowest disease severity. These findings suggest that GT may enhance disease resistance by modulating phenolic compound accumulation and increasing POD and PPO activity.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Formulation and evaluation of nanoemulsions from Jasminum officinale essential oil for controlling postharvest browning and maintaining quality in jasmine (Jasminum sambac) flowers
    (2025-01-01)
    Yeamsuriyotai, Kittiya
    ;
    Pradabkun, Natthamon
    ;
    Manichart, Nutcha
    ;
    Yonsawad, Nipaporn
    ;
    Khamchatra, Na Monrug
    The jasmine (Jasminum sambac (L.) Aiton) flower has delicate petals, resulting in rapid browning after harvest. The aim of this study was to search for an innovative postharvest treatment for delaying browning of jasmine petals using plant essential oils. J. officinale L. f. var. grandiflorum (L.) essential oil was found to reduce peroxidase activity in jasmine flower by 44.21% in the in vitro condition. The antioxidant activities and chemical composition of J. officinale essential oil were subsequently characterized. The essential oil exhibited the ability to scavenge 2,2-diphenyl-1-picrylhydrazil (DPPH) radicals with a 50% inhibition (EC<inf>50</inf>) value of 6.72 ± 0.89 mg/mL, a chelating effect with EC<inf>50</inf> value of 7.42 ± 1.59 mg/mL, and reducing power with EC<inf>0.5</inf> value of 14.89 ± 0.73 mg/mL. GC-MS analysis detected 29 compounds in the oil, with benzyl alcohol (20.68%) and benzyl acetate (19.87%) predominating. As plant essential oils have restricted water solubility, an oil-in-water emulsion was formulated using a spontaneous emulsification method. The resulting J. officinale essential oil naonoemulsion (JEN) had an oil droplet size of 70.2 ± 0.39 nm and a narrow polydispersity index. In vivo testing confirmed the inhibitory effects of JEN on jasmine flower browning and relevant enzyme activities. Jasmine flowers were soaked in various concentrations of JEN for 5 min, packed in polyethylene plastic bags, and stored in a refrigerator at 10 ± 3°C with relative humidity 66 ± 5%. Flowers treated with 1 and 2 mg/mL JEN showed effective delay of petal browning and maintained good quality with minimum flower opening index, high freshness score, and high color retention index. JEN treatment also reduced phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), and peroxidase (POD) activities, indicating postponement of the browning process. In addition, scanning electron microscopy micrographs of treated flower epidermis cells revealed delayed cell wall collapse, indicating retention of intact cells. Taken together, these results support JEN as a potential preventative of enzymatic browning and hence petal browning in jasmine flower.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Grafting Compatibility, Scion Growth, and Fusarium Wilt Disease Incidence of Intraspecific Grafted Tomato
    (2022-12-01)
    Saman, Prakob
    ;
    Kawicha, Praphat
    ;
    Sangdee, Aphidech
    ;
    Wongpakdee, Somporn
    ;
    Rattanapolsan, Ladawan
    The tomato (Solanum lycopersicum L.) is one of the most important vegetables grown globally. However, the production of tomatoes is restricted by Fusarium oxysporum f. sp. lycopersici (Fol). This study aims to investigate the ability of Fol-resistant tomato genotypes to be a rootstock for the susceptible cultivar. In this study, a tomato cultivar was grafted on rootstocks of the same species (intraspecific), and grafting compatibility, peroxidase gene expression, and fusarium wilt disease incidence of tomato scion was evaluated. A Fol-susceptible tomato 'Sidathip 3' (SDT3) was grafted onto four different Fol-resistant tomato genotypes and compared with self-grafted cultivar/cultivar and rootstock/rootstock. The survival rate of all grafted plants was 100% at 20 days after grafting (DAG) without significant differences in incompatibility evaluated at 42 days after grafting. The expression of the peroxidase gene (Solyc02g084800.2) using the qPCR technique was compared in self-grafted rootstock LE472/LE472 and SDT3/LE472. The expression level was three times higher in heterografted plants than in self-grafted ones at 15 DAG, indicating graft incompatibility. The rootstocks did not affect the height of the plant, the number of branches, the size of the fruit, or the yield of SDT3 scion. All intraspecific heterografted plants significantly controlled Fol when evaluated 60 days after inoculation. These results showed the usefulness of intraspecific grafting by using the proper rootstock genotypes to increase pathogen resistance in addition to stimulating growth and fruit yield.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Effects of methyl jasmonate on physicochemical qualities and internal browning of ‘queen’ pineapple fruit during cold storage
    (2017-10-01)
    Boonyaritthongchai, Panida
    ;
    Supapvanich, Suriyan
    The effects of methyl jasmonate (MeJA) as a protectant against chilling injury on physicochemical qualities of ‘Trad-see-thong’ pineapple (‘Queen’ group) fruit was investigated. The pineapple fruit were immersed in 1 mM MeJA for 5 min and then stored at 10 ± 1°C for 20 days. MeJA had no effect on respiratory rate and pulp colour, but suppressed ethylene production during cold storage. Weight loss, ion leakage (IL), internal browning (IB), and loss of pulp firmness were inhibited by MeJA. The MeJA treatment also suppressed the reduction of lightness (L*) and yellowness (b*) and the increase of total phenols (TP) that commonly occurs during cold storage, and increased the polyphenol oxidase (PPO) activity of pulp adjacent to the core (PAC) tissue. Certain bioactive compounds, such as ascorbic acid (AsA) and superoxide dismutase (SOD) in PAC tissues were enhanced by MeJA. No significant difference in peroxidase (POD) activity in both pulp and PAC tissues were detected between the treated and control fruits. These results suggest that immersion in MeJA is an effective means to maintain quality, alleviate IB symptoms, and enhance certain bioactive compounds in ‘Queen’ pineapple fruit cv. Trad-see-thong during cold storage.