Unda, Faride Mottiar, Yaseen Mahon, Elizabeth L. Karlen, Steven D. Kim, Kwang Ho Loque, Dominique Eudes, Aymerick Ralph, John Mansfield, Shawn D. 2024-01-19T11:34:20Z 2024-01-19T11:34:20Z 2022-05-24 2022-07 0028-646X https://pubs.kist.re.kr/handle/201004/114926 Renewed interests in the development of bioenergy, biochemicals, and biomaterials have elicited new strategies for engineering the lignin of biomass feedstock plants. This study shows, for the first time, that 3,4-dihydroxybenzoate (DHB) is compatible with the radical coupling reactions that assemble polymeric lignin in plants. We introduced a bacterial 3-dehydroshikimate dehydratase into hybrid poplar (Populus alba x grandidentata) to divert carbon flux away from the shikimate pathway, which lies upstream of lignin biosynthesis. Transgenic poplar wood had up to 33% less lignin with p-hydroxyphenyl units comprising as much as 10% of the lignin. Mild alkaline hydrolysis of transgenic wood released fewer ester-linked p-hydroxybenzoate groups than control trees, and revealed the novel incorporation of cell-wall-bound DHB, as well as glycosides of 3,4-dihydroxybenzoic acid (DHBA). Two-dimensional nuclear magnetic resonance (2D-NMR) analysis uncovered DHBA-derived benzodioxane structures suggesting that DHB moieties were integrated into the lignin polymer backbone. In addition, up to 40% more glucose was released from transgenic wood following ionic liquid pretreatment and enzymatic hydrolysis. This work highlights the potential of diverting carbon flux from the shikimate pathway for lignin engineering and describes a new type of 'zip-lignin' derived from the incorporation of DHB into poplar lignin. English Blackwell Publishing Inc. A new approach to zip-lignin: 3,4-dihydroxybenzoate is compatible with lignification Article 10.1111/nph.18136 1 New Phytologist, v.235, no.1, pp.234 - 246 New Phytologist 235 1 234 246 Y scie scopus 000790377800001 Plant Sciences Plant Sciences Article P-HYDROXYBENZOATE DEFICIENT PLANTS DOWN-REGULATION REDUCES LIGNIN CAD-DEFICIENT POPLAR SACCHARIFICATION BIOSYNTHESIS ACID TRANSFERASE acylated monolignols biomass feedstock engineering lignin valorization poplar trees Populus alba x grandidentata zip-lignin