Abstract

Arabidopsis plants were transformed with a chimeric construct containing expression cassettes for GFP election marker and CaMV 35S promoter-driven At5g35220 cDNA, via Agro bacterium-mediated method. Two transformants produced pigmentation deficient phenotype. Analysis revealed the decrease of chlorophyll in all etiolated plants. RT-PCR showed that, total At5g35220 mRNA levels were greatly inhibited in co-suppression lines. PORA and PORB mRNA expression were influenced also in the mutants. It is found that, the At5g35220 gene is responsive to both inhibitor and some hormone with regard to MVP/MEP pathway in our study.

Key words: Etiolation, co-suppression, protochlorophyllide oxidoreductase gene (POR), light regulation.

Abbreviation

POR, Protochlorophyllide oxidoreductase gene; Pchlide,protochlorophyllide; MVA, mevalonate; MEP, 2-C-methyl-d-erythritol 4-phosphate;2,4-D, 2,4-dichlorophenoxyacetic acid; ABA, abscisic acid; IAA, indole-3-acetic acid;GA₃, gibberellic acid; PCR, polymerase chain reaction; RT-PCR, reverse transcriptase-mediated-PCR; GFP, green fluorescent protein; EGFP, enhanced green fluorescent protein; HMGR, 3-hydroxy-3-methylglutaryl coenzyme A reductase; DXP,deoxyxylulose 5-phosphate; PTGS, post-transcriptional gene silencing; SRE, sterol regulatory element; SREBPs, sterol regulatory element binding proteins; IPP,isoprenoids isopentenyl diphosphate; DMAPP, isomer dimethylallyl diphosphate.