Bunyaatichart, Kanokpon

Loading...
Thumbnail Image
Preferred name
Bunyaatichart, Kanokpon
Alternative Name
Bunya-Atichart, Kanokpon
Bunya-atichart, Kanokpon
Bunya-Atichart, K.
Bunya-Atichart, Kanokporn
Bunya-Athichart, Kanokpon
Main Affiliation
Email
kanokpon.bu@kmitl.ac.th

Settings

Now showing 1 - 2 of 2
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Ethylene induction of chlorophyll degradation in melinjo (Gnetum gnemon L.) leaves: Lack of correlation with chlorophyllase, chlorophyll peroxidase and chlorophyll oxidase activities
    (2014-09-01)
    Bunya-Atichart, Kanokpon
    ;
    Ketsa, Saichol
    Melinjo (Gnetum gnemon L.), a leafy vegetable native to Southeast Asia, maintains a long shelf life when sprayed with water and stored in polyethylene bags. Also, during senescence of melinjo, the onset of leaf yellowing occurs much later than that of other vegetables. Postharvest crop management of green leafy vegetables could benefit from a better understanding of the factors that affect leaf yellowing in melinjo. This study investigated changes in chlorophyll concentrations and the roles of chlorophyll-degrading enzymes in melinjo leaf yellowing under exogenous ethylene and 1-methylcyclopropene (1-MCP) treatment. We recorded shelf life, total chlorophyll, chlorophyll a and b contents, activities of chlorophyllase, chlorophyll peroxidase and chlorophyll oxidase and found no significant difference between treated and untreated leaves. Untreated leaves turned yellow after 35 d. Leaves became yellow within 2 d of the ethylene treatment, whereby the chlorophyll concentrations decreased dramatically. Previous research suggested an alternative (oxidative) pathway of chlorophyll degradation involving chlorophyll peroxidase and chlorophyll oxidase in other green vegetables. Our results indicated that chlorophyll degradation involves enzymes other than the ones measured and that the pathway of chlorophyll degradation by oxidizing activities (peroxidase and oxidase) does not take place in harvested melinjo leaves.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Ethylene-sensitive and ethylene-insensitive abscission in Dendrobium: Correlation with polygalacturonase activity
    (2011-04-01)
    Bunya-atichart, Kanokpon
    ;
    Ketsa, Saichol
    ;
    van Doorn, Wouter G.
    We previously showed that the abscission of floral buds of the orchid Dendrobium cv. Miss Teen was absent in controls but highly promoted by ethylene, whilst open flowers also did not abscise without ethylene but were not responsive to ethylene. Here, we determined the activities of three enzymes in the abscission zone (AZ): polygalacturonase (PG), β-1,4-glucanase (cellulase), and pectin methylesterase (PME). In the AZ of floral buds an increase in PG activity coincided with the ethylene-induced abscission. A small increase was found in the AZ β-1,4-glucanase (cellulase) activity, shortly after the end of ethylene treatment of the flower buds and a few days before the onset of abscission. The activity of pectin methylesterase (PME) in the AZ of floral buds was not affected by ethylene. In the AZ of flowers that had just opened no increase in enzyme activity was observed after ethylene treatment. The data indicate a role of PG, and possibly of β-1,4-glucanase, in abscission. The data also suggest that the reason for the decrease in ethylene sensitivity of the abscission zone, during flower opening, lies upstream from the induction of enzyme activity in the AZ. © 2010 Elsevier B.V.