Molecular cloning and characterization of FLOWERING LOCUS T (FT)gene from kinnow mandarin (Citrus reticulata)

Abstract

FLOWERING LOCUS T (FT) is considered as a crucial regulator involved in early flowering induction which functions by switching the vegetative phase into reproductive phase. The role of early flowering has been elucidated by many workers but till date, there has been no report on cloning of FT gene from Kinnow mandarin (Citrus reticulata Blanco). An experiment was conducted during 2022–23 at Punjab Agricultural University, Ludhiana, Punjab for molecular cloning and characterization of FT gene from Kinnow mandarin. During the study, FT gene was cloned into pGEM-T Easy vector and characterized using in silico analysis. Sequence analysis revealed that the FT gene is comprised of 822 nucleotides, including a 5’- untranslated region (UTR) of 137 bp, a coding sequence (CDS) of 534 bp, and a 3’-UTR region of 151 bp. The BLASTn results of CrFT CDS showed high similarity to FT-like genes of other citrus species including C. unshiu, C. sinensis, and C. clementina which were found homologous to Phosphatidylethanolamine binding protein (PEBP). The predicted molecular weight of protein was approximately 20 kDa and isoelectric point (pI) was 6.73 indicating slightly acidic nature of the protein. The instability, aliphatic and GRAVY (Grand Average of Hydropathy) indices of the protein were determined as 40.97, 73.16 and -0.491, respectively. This study would help to elucidate the molecular mechanism behind flowering in Kinnow mandarin and facilitate the molecular breeding studies targeted to obtain early flowering phenotypes.