ISSN 2169-3048
International Journal of Biochemistry and Biotechnology ISSN 2169-3048 Vol. 15 (2), pp. 001-008, February, 2026. Available online at www.internationalscholarsjournals.org © International Scholars Journals
Full Length Research Paper
Molecular Mechanism of Flowering Induction via DNA Methylation in Photoperiod-Sensitive Rice
Theerachai Thanananta1,2*, Pradit Pongtongkam2, Amara Thongpan2, Lilly Kaveeta3, Surin Peyachoknagul2
1Department of Biotechnology, Faculty of Science and Technology, Thammasat University, Pathum Thani 12121, Thailand.
2Department of Genetics, Faculty of Science, Kasetsart University, Bangkok 10903, Thailand.
3Department of Botany, Faculty of Science, Kasetsart University, Bangkok 10903, Thailand.
Accepted 23 November, 2025
Methylation-sensitive amplified polymorphism (MSAP) technique was adapted to screen a photoperiod- responsive gene of rice KDML105. Six out of thirty-two primer combinations gave twelve EcoRI/HpaII- generated MSAP markers from the genomic DNA of KDML105 after exposure to short-day (SD) photoperiod. These MSAP fragments were cloned and used as probes to hybridize to MSAP fingerprints. Positive fragments generating the signals correlated to the MSAP fingerprints were sequenced and aligned to the database. Ten out of twelve MSAP markers showed 93-100% homology to database sequences and the best homology fragment (F1) was chosen for complete gene cloning, sequencing, and alignment. This candidate gene fragment showed 98% homology to the sequences of rice genomic DNA gi|23237916 and rice cDNA gi|32986083. It also has an open reading frame (ORF) of 402 bp and deduced a polypeptide of 134 amino acid residues, while those of gi|23237916 and gi|32986083 have a deduced polypeptide of 137 amino acid residues resulting in the overall homology of 97%. In addition, RT-PCR products and the Southern blot hybridization of the genomic DNA of KDML105 digested with HpaII or MspI indicated that the expression of this candidate gene depends on DNA demethylation, which is induced by 10 days of SD photoperiod. It is speculated that this gene might belong to another class of regulatory gene for the flowering time or heading-time loci in rice or it is a downstream product of flower initiation.
Key words: DNA methylation, photoperiod, rice, Oryza sativa L., MSAP, methylation sensitive AFLP.