The CDNA Cloning And Expression Analysis Of Key Enzyme 4CL And CCR Gene In Lignin Synthesis Pathway Of Boehmeria Nivea

Boehmeria nivea is one of the most important fiber crop, its soil and water conservation, medicinal development, energy development and fodder were constantly developed and these function has great economic value. However, lignin in ramie brings about many unfavorable factors to fiber degumming, medicinal value and forage nutritive value of ramie. Regulation of lignin content and composition by transgenic technology has become a research hotspot, and has made certain achievements. Therefore, the research of key enzyme genes in lignin biosynthesis pathway of raime will provide theoretical basis for proving the function of key enzyme genes, control process and the composition principle of accumulation of lignin biosynthesis.Two cDNA sequence of cinnamoyl-coA reductase and two cDNA sequence of 4-coumarate coenzyme a ligase were cloned by RACE technology base on transcriptome sequencing data of Boehmeria nivea, and their bioinformatics were analyzed. Their expression levels in tissues of phloem and xylem were also tested respectively in rapid-growth stage, maturation stage and late maturity stage by quantitative Real-time PCR.The results showed that the Bn4CL2 was 1,869 bp in length and encoding 539 amino acids. The sequence of Bn4CL3 gene was 938 bp. The all cloned cDNA sequence of 4CL were confirmed as ramie 4-coumarate coenzyme a ligase genes by online BLAST and analysis of its conserved domains. Phylogenetic tree analysis showed that the the Bn4CL2 and Bn4CL3 on the two different branches.The results showed that the BnCCR1 was 1056 bp in length and encoding 277 amino acids. The coding sequence of BnCCR2 gene was 1291 bp, and could be translated into a 248 amino acids. The all cloned cDNA sequence of CCR were confirmed as ramie cinnamoyl-coA reductase genes by online BLAST and analysis of its conserved domains, its demonstrated that BnCCR1 and BnCCR2 were two CCR family or family members in ramie, and may participate lignin biosynthesis in Boehmeria nivea.The result of qRT-PCR indicated that Bn4CL2 and Bn4CL3 were both actively expressed differently in different periods and plant organization. We speculated that Bn4CL2 and Bn4CL3 have different functions in plant growth and development of phenylpropanoid metabolism, or 4CL gene family have function of equivalent or supplement in the different branches of the phenylpropanoid derivatives in Boehmeria nivea. The result of qRT-PCR indicated that the expression of both BnCCRI and BnCCR2 was different in different periods, while not in different tissues, but the levels of expression in different tissues showed significant differences. We speculated that BnCCRI and BnCCR2 are different CCR genes in lignin metabolism of Boehmeria nivea, and the result of this study provide a theoretical basis for further exploration of their function in the ramie lignin biosynthesis and regulation.