|Natarajan, Savithiry - Savi|
Submitted to: The Scientific World
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/16/2013
Publication Date: 9/24/2013
Citation: Kim, J., Choi, B., Cho, B., Lim, H., Kimjoon Bum, Natarajan, S.S., Bae, H. 2013. Molecular characterization of ferulate 5-hydroxylase gene from kenaf (Hibiscus cannabinus L.). The Scientific World. doi:10.1155/2013/421578. Interpretive Summary: Kenaf (Hisbiscus cannabinus) is an annual fast growing plant and is used for making rope, cordage, canvas, sacking, carpet backing, nets, table cloths, etc. Recently, it has gained more attention as a possible source for the production of biomass fuels. For producing biofuels from plants, major technical problems occur in biological conversion due to higher interactions between lignin and polysaccharides. To address this problem, the study of the regulation of genes involved in the metabolic pathways leading to lignin production is important. We examined the changes in gene activity associated with one of the pathway genes called “ferulate 5-hydroxylase (F5H)” during different developmental stages of the Kenaf plant. We found that the F5H gene was expressed differentially in flower and stem tissues and in most abiotic stress treatments. This information will be useful for scientists to select suitable plant genotypes for biomass production.
Technical Abstract: The purpose of this research was to clone and characterize the expression pattern of a kenaf (Hibiscus cannabinus L.) F5H gene that encodes ferulate 5-hydroxylase in the phenylpropanoid pathway. Kenaf is well known as a fast growing dicotyledonous plant, which makes it a valuable biomass plant. The F5H is a cytochrome P450-dependent monooxygenase (CYP84) and is a key enzyme for S lignin biosynthesis. A full-length F5H ortholog was cloned and characterized using the RACE (rapid amplification of cDNA ends) method. The full-length of the F5H ortholog consists of a 1,557-bp open reading frame (ORF) encoding 518 amino acids (GenBank accession No. JX524278). The deduced amino acid sequence showed the highest similarity (78%) with that of Populus trichocarpa. Transcriptional analysis of kenaf F5H was conducted using quantitative real-time PCR (QPCR) during developmental stages in various tissues and in response to different abiotic stresses [wounding, NaCl, cold, ABA (abscisic acid), MeJA (methyl jasmonate) and drought]. Stem tissues (3-week old) were used to analyze the effects of abiotic stresses on the expression of F5H ortholog. The highest transcriptional level of the F5H ortholog was detected in immature flower tissues (5.61% relative to ACTIN) and in early stage (4-week-old) stem tissues (4.54% relative to ACTIN), while certain levels of expression were observed in all tissues tested. The highest transcript levels of the F5H ortholog were observed at late time points in most abiotic stress treatments: wound (24 h), NaCl (48 h), cold (24 h), ABA (24 h) and MeJA (24h).