Type A glandular trichomes of the wild potato (Solanum berthaultii Hawkes) entrap insects by rapidly polymerizing the trichome contents after breakage by insect contact. Polymerization of trichome exudate appears to be driven by a soluble polyphenol oxidase (PPO). PPO constitutes up to 70% of the protein in individually collected trichomes and reaches a concentration approaching 200 mum in thes...

Alternate strategies for prevention of enzymatic browning of fruits and vegetables are required by food industries due to restrictions and several negative health attributes of sulphites, which are effective inhibitors of enzymatic browning reaction. These reactions result mostly from polyphenol oxidase (PPO). The present study was conducted to evaluate the antioxidant and PPO inhibitory potent...

Silicone and Glutathione application are including systemic acquired resistance or induced against plant diseases against. It is a successful means to control rot disease it leads fundamental effects on the physiology of host, as use in agent hostile Fusarium solani causal Broad bean root .The results this study appeared that have make less tot incidence severity plants increase resistance-Link...

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...

The expression of three polyphenol oxidase (PPO; EC 1.10.3.1) genes was investigated in hybrid poplar (Populus trichocarpa · P. deltoides). PtdPPO1 was previously isolated as a woundand herbivore-inducible PPO (Constabel et al. Plant Physiol 124: 285–295, 2000), whereas PtdPPO2 and PtdPPO3 are two novel hybrid poplar PPO genes isolated from stem and root tissue, respectively. Sequence analysis ...

The antioxidant potential of eight clingstone peach cultivars was investigated by determining phenolic compounds and inhibition of low-density lipoprotein (LDL) oxidation. Cultivars low in polyphenol oxidase (PPO) were also selected to minimize enzymatic browning. Inhibition of LDL oxidation varied from 17.0 to 37.1% in peach flesh extract, from 15.2 to 49.8% in whole peach extract, and from 18...

This study evaluated the effects of inhibitors on polyphenol oxidase (PPO) activity, the effect of the PPO inhibitor tropolone on noodle darkening, and the correlation of PPO activity with darkening of alkaline noodles. The PPO inhibitors tropolone and salicylhydroxamic acid (each at 1 microM) reduced kernel PPO activity by approximately 50% in three hexaploid wheat cultivars but did not inhibi...

Genetic variability of polyphenol oxidase (PPO) activity was evaluated in hexaploid, tetraploid, and aneuploid wheat (Triticum spp.). A DNA probe to kernel-specific PPO hybridized to PPO clones from an immature wheat kernel cDNA library but not to clones from a seedling cDNA library. Recombinant protein and antibody were developed from the kernel-specific PPO. PPO transcript and antigenic prote...

The effect of pre-heating fresh strawberries (hot break) and the use refrigerated temperatures prior to pasteurization on stability anthocyanins, vitamin C, color polyphenol oxidase (PPO) activity during storage (42 days at 35 °C) strawberry puree was studied. Hot break resulted in 20% residual PPO caused 10% anthocyanin degradation, whereas C unaffected. After mashing, purees were stored 4 °C ...

The enzyme polyphenol oxidase (PPO) catalyzes the oxidation of phenolic compounds into highly reactive quinones. Polymerization of PPO-derived quinones causes the postharvest browning of cut or bruised fruit, but the native physiological functions of PPOs in undamaged, intact plant cells are not well understood. Walnut (Juglans regia) produces a rich array of phenolic compounds and possesses a ...