DEFECTIVE KERNEL1 regulates cellulose synthesis and affects primary cell wall mechanics

Lazar Novaković; Gleb E Yakubov; Yingxuan Ma; Antony Bacic; Kerstin G Blank; Arun Sampathkumar; Kim L Johnson

doi:10.3389/fpls.2023.1150202

DEFECTIVE KERNEL1 regulates cellulose synthesis and affects primary cell wall mechanics

Front Plant Sci. 2023 Mar 14:14:1150202. doi: 10.3389/fpls.2023.1150202. eCollection 2023.

Authors

Lazar Novaković^{1

2}, Gleb E Yakubov³, Yingxuan Ma^{1

4}, Antony Bacic⁴, Kerstin G Blank^{5

6}, Arun Sampathkumar², Kim L Johnson⁴

Affiliations

¹ School of BioSciences, University of Melbourne, Parkville, VIC, Australia.
² School of Biosciences, Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany.
³ Faculty of Science, University of Nottingham, Leicestershire, United Kingdom.
⁴ La Trobe Institute for Sustainable Agriculture and Food, La Trobe University, Bundoora, VIC, Australia.
⁵ Mechano(bio)chemistry Department, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany.
⁶ Institute of Experimental Physics, Johannes Kepler University, Linz, Austria.

Abstract

The cell wall is one of the defining features of plants, controlling cell shape, regulating growth dynamics and hydraulic conductivity, as well as mediating plants interactions with both the external and internal environments. Here we report that a putative mechanosensitive Cys-protease DEFECTIVE KERNEL1 (DEK1) influences the mechanical properties of primary cell walls and regulation of cellulose synthesis. Our results indicate that DEK1 is an important regulator of cellulose synthesis in epidermal tissue of Arabidopsis thaliana cotyledons during early post-embryonic development. DEK1 is involved in regulation of cellulose synthase complexes (CSCs) by modifying their biosynthetic properties, possibly through interactions with various cellulose synthase regulatory proteins. Mechanical properties of the primary cell wall are altered in DEK1 modulated lines with DEK1 affecting both cell wall stiffness and the thickness of the cellulose microfibril bundles in epidermal cell walls of cotyledons.

Keywords: DEFECTIVE KERNEL1; cell wall; cellulose; cellulose synthase complex; mechanical properties.

Grants and funding

LN was funded by University of Melbourne Research Scholarship, Max Planck Society, Norma Hilda Schuster neé Swift Scholarship and Albert Shimmins Postgraduate Writing-up Award. YM acknowledges the support of a University of Melbourne Research Scholarship. KJ and AB would like to acknowledge the support of funds from the ARC Centre of Excellence in Plant Cell Walls (CE1101007) and start-up funds from La Trobe University.