Open AccessConstitutive expression of a fungal glucuronoyl esterase in Arabidopsis reveals altered cell wall composition and structure
Author(s) -
Tsai Alex Y.L.,
Canam Thomas,
Gorzsás András,
Mellerowicz Ewa J.,
Campbell Malcolm M.,
Master Emma R.
Publication year - 2012
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/j.1467-7652.2012.00735.x
Subject(s) - lignin , arabidopsis , biology , cell wall , esterase , arabidopsis thaliana , xylose , cellulose , biochemistry , xylan , botany , transgene , enzyme , gene , mutant , fermentation
Summary A family 15 carbohydrate esterase (CE15) from the white‐rot basidiomycete, Phanerochaete carnosa (PcGCE), was transformed into Arabidopsis thaliana Col‐0 and was expressed from the constitutive cauliflower mosaic virus 35S promoter. Like other CE15 enzymes, PcGCE hydrolyzed methyl‐4‐ O ‐methyl‐ d ‐glucopyranuronate and could target ester linkages that contribute to lignin–carbohydrate complexes that form in plant cell walls. Three independently transformed Arabidopsis lines were evaluated in terms of nine morphometric parameters, total sugar and lignin composition, cell wall anatomy, enzymatic saccharification and xylan extractability. The transgenic lines consistently displayed a leaf‐yellowing phenotype, as well as reduced glucose and xylose content by as much as 30% and 35%, respectively. Histological analysis revealed 50% reduction in cell wall thickness in the interfascicular fibres of transgenic plants, and FT‐IR microspectroscopy of interfascicular fibre walls indicated reduction in lignin cross‐linking in plants overexpressing PcGCE. Notably, these characteristics could be correlated with improved xylose recovery in transgenic plants, up to 15%. The current analysis represents the first example whereby a fungal glucuronoyl esterase is expressed in Arabidopsis and shows that the promotion of glucuronoyl esterase activity in plants can alter the extent of intermolecular cross‐linking within plant cell walls.