Biochemical screening of resveratrol and molecular characterization of chalcone synthase gene in tomato (Lycopersicon esculentum Mill.)

Date

4-2014

Degree

Bachelor of Science in Agricultural Biotechnology

College

College of Agriculture and Food Science (CAFS)

Adviser/Committee Chair

Antonio C. Laurena

Abstract

Trans-resveratrol was detected in the peeled skin of selected local tomato varieties as a bright-blue fluorescing band with an Rf value of 6 using thin layer chromatography (TLC). The tomato hybrid Maguilas had relatively higher levels of trans-resveratrol compared to other varieties such as Apollo, Atlas, Cherry and Improved Pope. Gene search by in silico methods in the recently completed 900 megabase (Mb) Heinz 1706 tomato genome and in the recently Kazusa Expressed Sequenced Tags (ESTs) database of Micro-Tom tomato with 57, 422 full-length cDNA failed to identify resveratrol synthase genes. Eight degenerate and specific primers also failed to generate amplicons by in silico PCR. DegRSF and DegRSR primer pairs were also used for actual PCR but did not produce resveratrol synthase DNA amplicons. The presence of resveratrol in tomato skin and the absence of resveratrol synthase genes indicated that tomato uses another enzyme, chalcone synthase. Resveratrol and chalcone synthases belong to the superfamily of Type III PKS condensing enzymes involved in polyketide biosynthesis. In silico gene search of the tomato genome identified two chalcone synthase genes in chromosome 5 and other one in Chromosome 9. Specific primers for chalcone synthase were designed and successfully amplified a 972-bp PCR amplicon from tomato cv Maguilas. BLAST search of the partial DNA sequence identified the amplicons as xviii Chalcone synthase at the nucleotide and protein level. This study is the first commited step towards full molecular characterization of the gene towards the elucidation of an alternate pathway to resveratrol biosynthesis in tomato.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2014 A127 S86

Document Type

Thesis

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