Isolation and Characterization of Encoded Formaldehyde Responsive Gene from the Plant Dieffenbachia compacta Anuar Ithnin*, Mira Azilah Ibrahim*, Che Radziah Md. Zain** and Azhar Abdul Halim**j *Environmental Health and Industrial Safety Program, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300, Kuala Lumpur, Malaysia **School of Environment & Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia jCorresponding Author: Azhar Abdul Halim ABSTRACT Plants have several defence mechanisms to survive in a stressful environment. Formaldehyde is one of the indoor air pollutants that can cause cancer. Ornamental plant Dieffenbachia compacta can be used as biological control for pollutants in the indoor air environment. This study was conducted to isolate the genes that response for detoxifying formaldehyde in Dieffenbachia compacta. Methods used to isolate the gene is by using reverse transcription PCR (RT-PCR). A total of 735 base pairs was isolated using a primer from Epipremnum aureum FALDH genes. Nucleotide sequence analysis showed that the sequence similarities of 85% and 84% to the FALDH mRNA for Epipremnum aureum and Populus trichocarpa respectively. While for amino acid 92% similarities were found against Epipremnum aureum and Populus trichocarpa. A total of 87 amino acids that were encoded from 261 base pairs using the Open Reading Frame Finder. Our finding showed that the isolated Dieffenbachia compacta gene is the gene for glutathione-dependent formaldehyde dehydrogenase (FALDH). As a conclusion, formaldehyde metabolism in plants is regulated by the enzyme glutathione-dependent formaldehyde dehydrogenase (FALDH). The activity of FALDH indicates that this enzyme might be part of the universal metabolism pathway shared by a variety of organisms. Nat. Env. & Poll. Tech. Website: www.neptjournal.com Received: 22-8-2014 Accepted: 16-10-2014 Key Words: Glutathione-dependent formaldehyde dehydrogenase (FALDH) Dieffenbachia compacta Formaldehyde responsive gene 2015 pp. 435-438 Vol. 14 ISSN: 0972-6268 No. 2 Nature Environment and Pollution Technology An International Quarterly Scientific Journal Original Research Paper INTRODUCTION According to the International Agency for Research on Can- cer (IARC), formaldehyde is classified as a human carcino- gen. Humans are exposed to formaldehyde in the indoor environment from wood-based products, rubber, paints, lu- bricants, cosmetics, electrical appliances and construction materials. Reduction of formaldehyde is important to im- prove indoor air quality and reduce public health risks. Ornamental plants can be used as biological control for pollutants in indoor environments. Dieffenbachia compacta can reduce formaldehyde contamination (Aydogan & Montoya 2011). Due to the increasing air pollution in envi- ronment, plants also need to have a variety of resistance to environmental pollutants. The plants produce various de- fence mechanisms against environmental stress and the ear- liest change that can be observed is in the gene (Tamoaki et al. 2004). The main enzyme that reacts to the stimulus of formal- dehyde on the eukaryotic cell is gluthatione-dependent for- maldehyde dehydrogenase (FALDH) (Tada et al. 2010). According to a study conducted on golden pothos (Epipremnum aureum), a class II chitinase gene responds to the stimulus from formaldehyde (Tada et al. 2010). This study was conducted to identify the genes that respond to formaldehyde in Dieffenbachia compacta. MATERIALS AND METHODS Formaldehyde treatment: For formaldehyde treatment, Dieffenbachia compacta was put into (30×30×30 cm) static environment airtight chamber containing 5µL of a 37% for- maldehyde solution placed in a Petri dish. The leaves were sampled at time 3 hours and 24 hours after exposing to the formaldehyde. Dieffenbachia compacta without formalde- hyde treatment was used as a control. mRNA extraction and RT-PCR: Green leaves of Dieffenbachia compacta treated and untreated with formal- dehyde were harvested and rapidly ground in nitrogen liq- uid. Total RNA was isolated using the RNeasy Plant Mini kit (QIAGEN, Tokyo Japan). Total RNA isolated was used for synthesis of first-strand cDNA. cDNA was synthesized using a QuantiTech Reverse Transcription kit (QIAGEN, Tokyo Japan) according to the protocol supplied. Reverse transcription was carried out by the incubation technique at 42°C in a final volume of 20µL. The RT-PCR was performed using PCR reagent (PROMEGA) in final volume 25µL. Re- action contained 1.5µL of cDNA, 5µL 10 × PCR buffer, 3µL