AUTHOR=Shafiei Reza , Hooper Matthew , McClellan Christopher , Oakey Helena , Stephens Jennifer , Lapierre Catherine , Tsuji Yukiko , Goeminne Geert , Vanholme Ruben , Boerjan Wout , Ralph John , Halpin Claire TITLE=Downregulation of barley ferulate 5-hydroxylase dramatically alters straw lignin structure without impact on mechanical properties JOURNAL=Frontiers in Plant Science VOLUME=13 YEAR=2023 URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1125003 DOI=10.3389/fpls.2022.1125003 ISSN=1664-462X ABSTRACT=
Barley is a major cereal crop for temperate climates, and a diploid genetic model for polyploid wheat. Cereal straw biomass is an attractive source of feedstock for green technologies but lignin, a key determinant of feedstock recalcitrance, complicates bio-conversion processes. However, manipulating lignin content to improve the conversion process could negatively affect agronomic traits. An alternative approach is to manipulate lignin composition which influences the physical and chemical properties of straw. This study validates the function of a barley ferulate 5-hydroxylase gene and demonstrates that its downregulation using the RNA-interference approach substantially impacts lignin composition. We identified five barley genes having putative ferulate 5-hydroxylase activity. Downregulation of