Full Length Research Paper

Isolation and characterization of LHY homolog gene expressed in flowering tissues of Tectona grandis (teak)

B. Norlia¹*, M. Norwati¹, A. Norwati¹, H. Mohd Rosli¹ and M. S. Norihan²

¹Genetic Unit, Forest Research Institute Malaysia (FRIM), 52109 Kepong, Selangor, Malaysia, Forest Biotechnology Division, Forest Research Institute Malaysia (FRIM), 52109 Kepong, Selangor, Malaysia.

²Cell and Molecular Biology Department, Faculty of Biotechnology and Biomolecular Science, Universiti Putra Malaysia (UPM), 43400 Serdang, Selangor, Malaysia.

*Corresponding author. E-mail: norlia@frim.gov.my. Tel: 603-62797148. Fax: 603-62804614.

Abbreviations: LHY, Late Elongated Hypocotyl; Tg-LHY, Tectona grandis Late Elongated Hypocotyl; TFS3, teak flowering stage 3; and RACE PCR, rapid amplification of cDNA end PCR.

Accepted 3 March, 2008

Floral initiation of teak through molecular biology approach is being studied for better understanding of teak flower development. Through PCR subtractive hybridization method, LHY homolog gene has been isolated from teak flowering tissues. The full-length cDNA of the gene was 2948 base pair (bp) and potentially encoded for 768 amino acids. It was named Tectona grandis LHY (Tg-LHY), as the gene was similar to the LHY gene of some species. Amino acid sequence alignment revealed that Tg-LHY was similar to LHY of Castanea sativa, LHY of Phaseolus vulgaris and LHY of Arabidopsis thaliana. The highly conserved region found in Tg-LHY was the MYB protein, which is the DNA-binding protein responsible in negative feedback loop reaction of central oscillator in plant circadian clock system. The level of gene expression was found to be high four hours after dawn in flowering shoots and flower. This paper reported the isolation and characterization of the gene.   

Key words: LHY gene, circadian clock, floral gene, Tectona grandis.