The activities of antioxidant enzymes and levels of antioxidants involved in oxygen detoxification were studied in seedlings of three indica rice (Oryza sativa L.) cultivars, namely Panikekoa and T 1471 that show good capacity for anaerobic seedling establishment (tolerant reaction) and IR 42 which has a poor anaerobic seedling establishment capacity (susceptible reaction). The activities of th...

Anthocyanin content and the activities of polyphenol oxidase (PPO), peroxidase (POD) and phenylalanine ammonia-lyase (PAL) and their relationships were determined in the leaves of six lettuce (Lactuca sativa L.) cultivars, exposed for 6 weeks to alternating three different day/night temperatures. Anthocyanin content was found to be highest at 20/13°C, followed by 25/20°C and 30/25°C, showing ac...

introduction plant responses to environmental stress have a central role in agricultural production. responses results from events occurring at all levels of the organization, from biochemical reactions in cells to whole plant physiology. many plants are injured when exposed to low non-freezing temperatures. however, data on the effects of night temperatures are scarce. on the other hand, nitri...

In order to study the effect of melon powdery mildew on physiological indexes different varieties, high resistant variety ‘16-6’, medium ‘04-38’, and highly susceptible ‘15B-42’ were used as materials. The activities antioxidant defense system enzymes, contents of malondialdehyde (MDA), soluble protein chlorophyll, photosynthetic indicators in leave...

There are high levels of damage imposed on persimmon fruit postharvest, especially after storing it in cold storage, which causes chilling injury (CI). To reduce this stress the fruit, conventional way is to use chemical treatments. Since there a limitation materials, necessary apply non-harmful treatments decrease and maintain quality storage. The aim study investigate effects chitosan-loaded ...

Effect of sublethal heavy metal stress as plant biotic elicitor for triggering innate immunity in tomato plant was investigated. Copper in in vivo condition induced accumulation of defense enzymes like peroxidase (PO), polyphenol oxidase (PPO), phenylalanine ammonia-lyase (PAL), and β-1,3 glucanase along with higher accumulation of total phenol, antioxidative enzymes (catalase and ascorbate per...

objective: polyphenol oxidase or ppo (ec 1.14.18.1) is considered the enzyme responsible for quality deterioration and browning in different fruits during postharvest period. the objective of this study was to evaluate the antibrowning (inhibition of polyphenol oxidase activity) effect of cysteine, ascorbic acid, citric acid, kojic acid and glycine at two different ph (6 and 7) in  hawthorn. me...

Esculetin has been described as an inhibitor of tyrosinase and polyphenol oxidase and, therefore, of melanogenesis. In this work, we demonstrate that esculetin is not an inhibitor but a substrate of mushroom polyphenol oxidase (PPO) and horseradish peroxidase (POD), enzymes which oxidize esculetin, generating its o-quinone. Since o-quinones are very unstable, the usual way of determining the en...

The biological control agent Pseudomonas fluorescens was used against the bacterial wilt causing Ralstonia solanacearum. The present investigation focuses on the role of defense related enzymes in imparting resistance in tomato against R. solanacearum. A total of ten rhizobacterial isolates were screened against R. solanacearum, of which three isolates (Pf3, Pf5 & Pf8) showed a maximum inhibiti...