Loss of the Galactosyl hydrolase GH43 Alters Ray Parenchyma Anatomy and Increases Wood Fibre Length in Hybrid Aspen
Pieter Nibbering (Sweden)1; Pratibha Kumari (Sweden)1; Tayebeh Abedi (Sweden)1; Katarzyna Sokołowska (Poland)2; Alicja Dolzblasz (Poland)2; Karol Sarnecki (Poland)3; Totte Niittylä (Sweden)1;
1 - Umeå Plant Science Centre, Swedish University of Agricultural Sciences, Umeå, Sweden; 2 - Department of Plant Developmental Biology, Faculty of Biological Sciences, University of Wrocław, Poland; 3 - Student Research Society of Botanists, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland.;
Keywords: GH43; Populus; Wood development;
Abstract Topics: Theme 4: Arabinogalactan Proteins
Type of Presentation: Poster

Abstract text: The glycoside hydrolase family 43 (GH43) encodes for Golgi-localized β-1,3-galactosidases. In Arabidopsis, the mutants exhibit defects in root cell elongation, associated with altered arabinogalactan protein (AGP) glycosylation. The goal of this work was to investigate the role of the GH43s in wood development in hybrid aspen (Populus tremula x tremuloides) by generating loss-of-function mutants using CRISPR–Cas9-mediated mutagenesis. The CRISPR-generated gh43 knockout lines showed no obvious growth phenotypes and only small changes in wood chemistry, with increased pectin and AGP quantities. Complementation of the Arabidopsis root cell expansion growth defect phenotype by a 35S-driven Populus GH43–cYFP construct indicates conserved gene function between Arabidopsis and Populus. Anatomical analysis of developing wood in the Populus mutants revealed altered morphology of ray parenchyma cells and increased fibre length. These phenotypes coincided with altered expression of genes involved in gibberellin biosynthesis, suggesting a link between gibberellins and AGP glycosylation during wood development.