In the present study the effect of rare earth element Praseodymium (Pr) on flavonoids production and its biosynthesis key enzymes including Peroxidase (POD; EC 1.11.1.7), Polyphenol oxidase (PPO; EC 1.10.3.1) and Phenylanlanine ammonialyase (PAL; EC 4.3.1.5) in hairy roots of Scutellaria viscidula was investigated. After 7 days of suspension culture, activity of POD, PPO and PAL and total flavo...

Considering the economic importance of the tomato and its nutritional benefits to human health, a study was made of how two different environmental factors (temperature and overall solar radiation) influence the nutritional quality of cherry tomatoes during the plant full production cycle. Solanum lycopersicum L. cv. Naomi plants were grown in an experimental greenhouse. Three fruit samples wer...

Polyphenol oxidase (PPO) from tomatoes was extracted and partially purified through  (NH4)2SO4 precipitation, dialysis and ion exchange chromatography. The activity of polyphenol oxidase was investigated in solanum lycopersicum. Spectrophotometric method was used to assay the enzyme activity and the kinetic constants - maximum enzyme velocity (Vmax) and Michealis - Menten constant (Km). Of the ...

In terms of the quality of minimally processed fruit, flesh browning is fundamentally important in the development of an aesthetically unpleasant appearance, with consequent off-flavours. The development of browning depends on the enzymatic action of the polyphenol oxidase (PPO). In the 'Golden Delicious' apple genome ten PPO genes were initially identified and located on three main chromosomes...

Polyphenol oxidase (PPO) (E.C. 1.14.18.1) also known as phenolase, catechol oxidase, catecholase, monophenol oxidase, o-diphenol oxidase and orthophenolase based on their substrate specificity, is widely distributed in plants and fungi (Mayer, 2006; Kaur et al., 2010; Asha et al., 2011; Pawar and Ingle, 2014). PPOs have been purified and characterized from a wide range of plant species and a va...

Ascorbate peroxidase (APX) is a crucial, haeme-containing enzyme of the ascorbate glutathione cycle that detoxifies reactive oxygen species in plants by catalyzing the conversion of hydrogen peroxide to water using ascorbate as a specific electron donor. Different APX isoforms are present in discrete subcellular compartments in rice and their expression is stress regulated. We revealed the homo...

Tomato Lycopersicon esculentum Mill. is one of the most cultivated and widely consumed vegetables in world. However, it very susceptible to infection initiated by Fusariumoxysporum fruit rot, which shortens post-harvest life thus reduces market value. This disease can be regulated appropriately application synthetic fungicides. chemical fungicides constitute a serious health risk, have harmful ...

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...

The aim of this study was to evaluate the impact ultrasound (US) at different frequencies (20, 370, and 583 kHz) power levels (35 48 W) on residual activity (RA) peroxidase (POD) polyphenol oxidase (PPO) in strawberry puree. Total anthocyanin content (TAC), total phenolic (TPC), ferric ion reducing antioxidant (FRAP) trolox equivalent capacity (TEAC) were also assessed. Results compared with un...

Heavy metals are the cause of major abiotic stresses in plants and a principal contributor to environmental pollution in recent decades. This study investigated the effects of exogenous hydrogen sulfide on the ascorbate-glutathione cycle in the leaves of coriander seedlings under copper stress. Results showed that copper stress not only reduced APX and GR activities but also decreased leaf AsA,...