|Kim, Jonggeun -|
Submitted to: Plant Omics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 24, 2012
Publication Date: January 1, 2013
Citation: Kim, J., Natarajan, S.S. 2013. Expression analysis of kenaf cinnamate 4-hydroxylase (C4H) ortholog during developmental and stress responses. Plant Omics. 6(1):65-72. 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 “Cinnamate-4-hydroxylase (C4H)” during different developmental stages of the Kenaf plant as well as with different stress applications. We found that the C4H gene was expressed in all tissues, as well as in response to various stress treatments. This information will be useful for scientists to select suitable plant genotypes for biomass production.
Technical Abstract: This study was conducted to clone and analyze the expression pattern of a C4H gene encoding cinnamate 4-hydroxylase from kenaf (Hibiscus cannabinus L.). A full-length C4H ortholog was cloned using degenerate primers and the RACE (rapid amplification of cDNA ends) method. The full-length C4H ortholog contained a 1,518-bp open reading frame (ORF) encoding 505 amino acids. The deduced amino acid sequence showed that kenaf C4H had the highest similarity (95%) with that of Gossypium arboretum. We examined the expression patterns of the C4H ortholog in diverse tissues and at different developmental stages, as well as in response to abiotic stress conditions such as wounding, NaCl, cold, H2O2, ABA (abscisic acid) and SA (salicylic acid). Three-week-old stem tissues were used to examine the effects of abiotic stresses on C4H ortholog expression. While the highest transcript level of C4H ortholog was observed at an early stage in both stems and leaves, the transcripts were most abundant in the late stage flowers. In the cases of wounding and SA, an early induction of the C4H ortholog was observed. Conversely, H2O2 led to intermediate induction, while cold and ABA led to late induction. NaCl treatment showed different expression patterns such as complex biphasic expression. In summary, the C4H ortholog was expressed in all tissues and organs, as well as in response to various treatments.