Elucidating the roles of three β-glucuronosyltransferases (GLCATs) acting on arabinogalactan-proteins using a CRISPR-Cas9 multiplexing approach in Arabidopsis

• DOI: 10.1186/s12870-020-02420-5
• Publication Date: 2020-05-18T19:03:43Z
• Authors: Yuan Zhang; Michael A. Held; Allan M. Showalter
• Keywords: Arabinogalactan

Abstract Background Arabinogalactan-proteins (AGPs) are one of the most complex protein families in plant kingdom and present cell walls all land plants. AGPs implicated diverse biological processes such as growth, development, reproduction, stress responses. extensively glycosylated by addition type II arabinogalactan (AG) polysaccharides to hydroxyproline residues their cores. Glucuronic acid (GlcA) is only negatively charged sugar added functions GlcA on remain be elucidated. Results Three members CAZy GT14 family (GLCAT14A-At5g39990, GLCAT14B-At5g15050, GLCAT14C-At2g37585), which responsible for transferring glucuronic AGPs, were functionally characterized using a CRISPR/Cas9 gene editing approach Arabidopsis. RNA seq qRT-PCR data showed three GLCAT genes broadly expressed different tissues, with GLCAT14A GLCAT14B showing particularly high expression micropylar endosperm. Biochemical analysis from knock-out mutants various glcat single, double, triple revealed that double generally had small increases Ara Gal concomitant reductions GlcA, glcat14a glcat14b glcat14c mutants. Moreover, isolated displayed significant calcium binding compared WT. Further phenotypic analyses found exhibited delays seed germination, root hair length, trichome branching, accumulation defective pollen grains. Additionally, both significantly shorter siliques reduced set. Finally, higher-order adherent coat mucilage. Conclusions This research provides genetic evidence GLCAT14A-C function transfer turn play role variety biochemical physiological phenotypes including silique set, mucilage accumulation.