Journal of Applied Biosciences (J. Appl. Biosci.) [ISSN 1997 - 5902]
Volume 37: 2425 - 2433. Published January 10, 2011.
A novel method of measuring oxidative stress of pepper (Capsicum annuum var. Charlee) infected with tobacco mosaic virus
Murat Dikilitas, M. Ertugrul Guldur, Ahmet Deryaoglu, Ozcan Erel
11Harran University, Faculty of Agriculture, Department of Plant Protection, S.Urfa, Turkey
2Food and Agricultural Engineer-Trabzon, Turkey
3Ataturk Research and Educational Hospital, Ministry of Health, Ankara, Turkey
*Author for correspondence e-mail: m.dikilitas@gmail.com
ABSTRACT
Objective: To evaluate oxidative, antioxidative and the phenol status of pepper plants (Capsicum annuum var. Charlee) at an early stage of the growing period using a novel method.
Methodology and results: Tobacco mosaic virus (TMV) which was isolated from infected pepper plants growing in a greenhouse was inoculated to uninfected healthy pepper plants by mechanical inoculation method at an early stage of the growing period, 4 weeks. The infection of inoculated plants was confirmed by ELISA method. Fruits expressing the virus symptoms were collected and used for biochemical analyses. Total antioxidant status (TAS) and total oxidative status (TOS) of the fruits were determined colorimetrically. Total phenol (TP), free phenol (FP) and conjugated phenol (CP) amounts were measured as part of defense response. Vitamin C contents were also measured using ascorbate oxidase to determine the quality of fruits. The percent ratio of TOS to TAS was evaluated as oxidative stress index (OSI). TAS levels, vitamin C contents, and FP were found significantly lower in the infected peppers than those of healthy ones. In contrary, TOS, OSI, CP and TP levels were significantly higher in the infected peppers than those of the control plants. There were significant correlations among oxidative, antioxidative, and phenol parameters.
Actual or potential application of findings: This study showed that the production of low amounts of TAS and high amount of TOS negatively affected the quality of peppers under TMV stress. Quality of fruits and the condition of plants would be determined in advance of the stress development with the use of instant determination of TAS, TOS and OSI with this novel automated system.
Key Words: Antioxidant, Phenol, Tobacco Mosaic Virus, Total oxidative status, Total antioxidant status, Vitamin C.
Abbreviations: TMV, Tobacco Mosaic Virus; TAS, Total antioxidative status; TOS, Total oxidative stress; OSI, Oxidative stress index; TP, Total phenol; FP, Free phenol; CP, Conjugated phenol; ROS, Reactive oxygen species.
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