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Field and saccharification performances of poplars severely downregulated in CAD1
Author(s) -
De Meester Barbara,
Van Acker Rebecca,
Wouters Marlies,
Traversari Silvia,
Steenackers Marijke,
Neukermans Jenny,
Van Breusegem Frank,
Déjardin Annabelle,
Pilate Gilles,
Boerjan Wout
Publication year - 2022
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.18366
Subject(s) - cinnamyl alcohol dehydrogenase , monolignol , lignin , biomass (ecology) , hydrolysis , botany , cinnamyl alcohol , lignocellulosic biomass , biology , horticulture , chemistry , food science , agronomy , enzyme , biochemistry , biosynthesis , selectivity , catalysis
Summary Lignin is one of the main factors causing lignocellulosic biomass recalcitrance to enzymatic hydrolysis. Glasshouse‐grown poplars severely downregulated for CINNAMYL ALCOHOL DEHYDROGENASE 1 ( CAD1 ), the enzyme catalysing the last step in the monolignol‐specific branch of lignin biosynthesis, have increased saccharification yields and normal growth. Here, we assess the performance of these hpCAD poplars in the field under short rotation coppice culture for two consecutive rotations of 1 yr and 3 yr. While 1‐yr‐old hpCAD wood had 10% less lignin, 3‐yr‐old hpCAD wood had wild‐type lignin levels. Because of their altered cell wall composition, including elevated levels of cinnamaldehydes, both 1‐yr‐old and 3‐yr‐old hpCAD wood showed enhanced saccharification yields upon harsh alkaline pretreatments (up to +85% and +77%, respectively). In contrast with previous field trials with poplars less severely downregulated for CINNAMYL ALCOHOL DEHYDROGENASE (CAD) , the hpCAD poplars displayed leaning phenotypes, early bud set, early flowering and yield penalties. Moreover, hpCAD wood had enlarged vessels, decreased wood density and reduced relative and free water contents. Our data show that the phenotypes of CAD‐deficient poplars are strongly dependent on the environment and underpin the importance of field trials in translating basic research towards applications.