文献类型：期刊文献

英文题名：Monolignol Benzoates Incorporate into the Lignin of Transgenic Populus trichocarpa Depleted in C3H and C4H

作者：Kim, Hoon[1] Li, Quanzi[5] Karlen, Steven D.[1] Smith, Rebecca A.[1] Shi, Rui[6] Liu, Jie[3] Yang, Chenmin[3] Tunlaya-Anukit, Sermsawat[3] Wang, Jack P.[3] Chang, Hou-Min[7] Sederoff, Ronald R.[3] Ralph, John[1,2] Chiang, Vincent L.[3,4]

第一作者：Kim, Hoon

通信作者：Kim, H[1];Ralph, J[1];Ralph, J[2];Chiang, VL[3];Chiang, VL[4]

机构：[1]Great Lakes Bioenergy Res Ctr, Wisconsin Energy Inst, Dept Energy, Madison, WI 53726 USA;[2]Univ Wisconsin, Dept Biochem, Madison, WI 53706 USA;[3]North Carolina State Univ, Dept Forestry & Environm Resources, Forest Biotechnol Grp, Raleigh, NC 27695 USA;[4]Northeast Forestry Univ, State Key Lab Tree Genet & Breeding, Harbin 150040, Peoples R China;[5]Chinese Acad Forestry, State Key Lab Tree Genet & Breeding, Res Inst Forestry, Beijing 100091, Peoples R China;[6]North Carolina State Univ, Dept Crop & Soil Sci, Raleigh, NC 27695 USA;[7]North Carolina State Univ, Dept Forest Biomat, Raleigh, NC 27695 USA

年份：2020

卷号：8

期号：9

起止页码：3644-3654

外文期刊名：ACS SUSTAINABLE CHEMISTRY & ENGINEERING

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000519150200015)】；

基金：This work was supported by grants from the DOE Great Lakes Bioenergy Research Center (DOE BER Office of Science DE-SC0018409) and the National Science Foundation Plant Genome Research Program grant (DBI-0922391).

语种：英文

外文关键词：poplar; 2D NMR; HSQC; enzyme; p-hydroxybenzoate; biomass; cytochrome P450

摘要：Lignin, an abundant renewable aromatic biopolymer, is an essential macromolecule in terrestrial vascular plants. Genetic modifications affecting monolignol biosynthesis, which produces lignin monomers, alter the metabolic flux through the pathway and are becoming increasingly explored for improving the lignin and biomass quality and for producing high-value commodity chemical feedstocks. Benzoate (BA) conjugates are important metabolites in plants that have not been adequately characterized as components of the lignin structure, In addition to finding trace levels of BA conjugates in wild-type (WT) Populus trichocarpa, these become significantly augmented in strategic triple transgenics. Genes for three key cytochrome P450 enzymes, two 4-hydroxylases (PtrC4H1 and PtrC4H2), and one 3-hydroxylase (PtrC3H3), were downregulated to produce the transgenic plants in which monolignol benzoate (ML-BA) conjugates were incorporated into their lignin at a level some 16-fold higher than in WT. The co-downregulation of PtrC4H1/PtrC4H2/PtrC3H3 genes may cause a rerouting or modification of the pathway due to the interaction of the benzoate biosynthetic pathway with the conventional pathway for monolignol biosynthesis. The total lignin content in the transgenics was decreased by 50%, and the lignin H-unit level was elevated some 70-fold. The wood from the transgenic trees showed reduced recalcitrance toward enzymatic saccharification, which has value for the conversion of plant biomass to bioenergy.