Antioxidant activity and expression analysis of APX and CAT Genes in Solanum melongena L. grown under moisture stress conditions

Date

7-2016

Degree

Bachelor of Science in Agricultural Biotechnology

College

College of Agriculture and Food Science (CAFS)

Adviser/Committee Chair

Eureka Teresa M. Ocampo

Abstract

Eggplant (Solanum melongena L.) is a nutritional and economical crop in the Philippines that is highly affected by drought. This study determined the antioxidant activity (% scavenging activity) of four drought tolerant varieties of eggplant- PHL1602, PHL 2789, PHL 4841 and PHL5764, grown under progressive moisture stress conditions using DPPH assay. The eggplant variety that has the highest antioxidant activity based on the result of DPPH assay was PHL1602. Among the antioxidant enzymes, ascorbate peroxidase and catalase have the crucial role to detoxify H2O2 and protect plants from oxidative damage. Capacity of plant to scavenge ROS depends on the activity of scavenger enzymes or expression of its genes thereby the production of corresponding proteins. Semi-quantitative expression of CAT and APX genes in leaf samples of PHL1602 seedlings grown under progressive drought were determined. Total RNA was extracted from stressed and non-stressed PHL1602 plants and then cDNA was synthesized from it after which it was amplified using PCR. Lastly, the expressions, in terms of number of pixels, of APX and CAT genes were assessed using Image J (1.50i) freeware. Increasing expression of CAT gene of the drought plants was observed from Day 0 to Day 6 of drought while APX gene also increased its expression from Day 2 to Day 8. However, decreased expression was then observed to CAT gene at Day 8 to Day 10 and also to APX gene at Day 10 of drought. Increased expression of both genes was attributed to the amount of H2O2 present in the plant system that they need to scavenge as drought stress increases. However, the decrease in expression of these genes indicated that prolonged exposure to drought stress increases the formation of ROS, exceeding then the capacity of the antioxidant enzyme thus resulting to oxidative damage and cell death. The antioxidant activity and expression of CAT and APX were correlated based on the results, therefore in accordance with similar studies.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2016 A127 /P37

Notes

Major in Crop Biotechnology

Document Type

Thesis

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