Search Results

You are looking at 1 - 7 of 7 items for :

  • "AsA-GSH cycle" x
Clear All
Restricted access

Ying Qu, Xue Bai, Yajun Zhu, Rui Qi, Geng Tian, Yang Wang, Yonghua Li and Kaiming Zhang

–F ) and the changes in the levels of AsA-GSH cycle components ( Table 1 ); anthocyanins were eventually biosynthesized in B. semperflorens under LT conditions ( Fig. 2G–H ). To further verify the function of LT-mediated ROS accumulation in anthocyanin

Free access

Carolina A. Torres, Omar Hernandez, Maria A. Moya-León, Ivan Razmilic and David R. Rudell

A distinct type of postharvest skin browning on apple (Malus domestica Borkh.) fruit called “stain” is a frequent disorder in ‘Fuji’ grown under high light and elevated temperatures. Symptoms typically develop only on sun-exposed sections of the fruit regardless of the presence of sunburn symptoms, and sometimes only in the margins of this area. The role of different antioxidant systems in tissue exposed to different levels of sunlight and having different degrees of sun injury were investigated during cold storage [1 °C, >90% (relative humidity) RH]. Ascorbic acid (AsA) and glutathione (GSH) concentrations, AsA–GSH recycling enzyme activities and gene expression, and flavonoids and carotenoid concentrations were determined every 30 days. “Stain” incidence increased with sun exposure and sunburn level. Both shaded and exposed fruit peel without sunburn symptoms had the highest AsA content. The AsA–GSH recycling enzyme activities and gene expression levels had no clear relationship with sun exposure during cold storage. Chlorophyll a (chl a) and chlorophyll b (chl b) levels diminished over time and were higher in tissue without any type of sun injury. In contrast, carotenoid levels increased as sun injury incidence increased and remained relatively stable during storage. Total phenolics and quercetin glycoside levels changed coincidently during storage. Results indicate that the AsA–GSH cycle does not have a clear role in “stain” development. Nevertheless, reduced ascorbate levels may reduce the capacity to prevent oxidative stress–provoked damage which may, in turn, result in oxidation of quercetin glycosides, which would then lead to skin browning.

Free access

An Qin, Xiaosan Huang, Huping Zhang, Juyou Wu, Jie Yang and Shaoling Zhang

reported that an AsA-GSH pathway exists in cytosol, chloroplasts, mitochondria, and peroxisomes, and represents an important antioxidant defense system against H 2 O 2 ( Davey et al., 2000 ; Potters et al., 2000 ). In the AsA-GSH cycle, antioxidant

Free access

Lixin Xu, Liebao Han and Bingru Huang

et al., 1999 ) and has also been reported in cytosolic, mitochondrial, and peroxisomal fractions ( Arora et al., 2002 ). Catalase, peroxidases, and the ascorbate–glutathione cycle (AsA-GSH cycle), which involves four enzymes including ascorbate

Free access

Shu Hsien Hung, Chun Chi Wang, Sergei Veselinov Ivanov, Vera Alexieva and Chih Wen Yu

and Hirt, 2004 ; Scandalios, 1993 ). Among the antioxidant mechanisms, the ascorbic acid (AsA)–GSH cycle is a key component for elimination of ROS, especially H 2 O 2 ( Kingston-Smith and Foyer, 2000 ; Noctor et al., 2002 ). In the AsA–GSH cycle

Free access

Dawei Shi, Xiaodong Wei, Guoxiang Chen and Yanli Xu

cell compartments, and there are some reports about the increase of POD activity and the decrease of APX and CAT activities during leaf senescence ( Hodges and Forney, 2001 ; Kar and Mishra, 1976 ; Veljovic-Jovanovic et al., 2006 ). The ASA–GSH cycle

Free access

Sheng Xu, Mingmin Jiang, Jiangyan Fu, Lijian Liang, Bing Xia and Ren Wang

( Foyer and Noctor, 2005 ). Several studies have provided evidence of an effective protector role of the POD–CAT–SOD system against oxidative stress in diverse plant species ( Miller et al., 2010 ). APX is one of the components of the AsA–GSH cycle, which