Title: Biochemical and physiological flexibility accompanies reduced cellulose biosynthesis in Brachypodium cesa1^S830N

Abstract

Here, we present a study into the mechanisms of primary cell wall cellulose formation in grasses, using the model cereal grass Brachypodium distachyon. The exon found adjacent to the BdCESA1 glycosyltransferase QXXRW motif was targeted using Targeting Induced Local Lesions in Genomes (TILLING) and sequencing candidate amplicons in multiple parallel reactions (SCAMPRing) leading to the identification of the Bdcesa1^S830N allele. Plants carrying this missense mutation exhibited a significant reduction in crystalline cellulose content in tissues that rely on the primary cell wall for biomechanical support. However, Bdcesa1^S830N plants failed to exhibit the predicted reduction in plant height. In a mechanism unavailable to eudicotyledons, B. distachyon plants homozygous for the Bdcesa1^S830N allele appear to overcome the loss of internode expansion anatomically by increasing the number of nodes along the stem. Stem biomechanics were resultantly compromised in Bdcesa1^S830N. The Bdcesa1^S830N missense mutation did not interfere with BdCESA1 gene expression. However, molecular dynamic simulations of the CELLULOSE SYNTHASE A (CESA) structure with modelled membrane interactions illustrated that Bdcesa1^S830N exhibited structural changes in the translated gene product responsible for reduced cellulose biosynthesis. Molecular dynamic simulations showed that substituting S830N resulted in a stabilizing shift in the flexibility of the class specific region arm ofmore » the core catalytic domain of CESA, revealing the importance of this motion to protein function.« less

Authors:

Brabham, Chad ^[1]; Singh, Abhishek ^[2]; Stork, Jozsef ^[1]; Rong, Ying ^[3]; Kumar, Indrajit ^[4]; Kikuchi, Kazuhiro ^[5]; Yingling, Yaroslava G. ^[2]; Brutnell, Thomas P. ^[4]; Rose, Jocelyn K. C. ^[6]; Debolt, Seth ^[1]; Jameson, ed., Paula

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+ Show Author Affiliations

1. Department of Horticulture, University of Kentucky, Lexington, KY, USA
2. Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, USA
3. Donald Danforth Plant Science Center, St. Louis, MO, USA, KWS Gateway Research Center, St. Louis, MO, USA
4. Donald Danforth Plant Science Center, St. Louis, MO, USA
5. Donald Danforth Plant Science Center, St. Louis, MO, USA, Syngenta Japan K.K., Chuo-ku, Tokyo, Japan
6. Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA

Publication Date:

Sat Jul 13 00:00:00 EDT 2019

Research Org.:

Energy Frontier Research Centers (EFRC) (United States). Center for Lignocellulose Structure and Formation (CLSF); Pennsylvania State Univ., University Park, PA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF); USDA

OSTI Identifier:

1570542

Alternate Identifier(s):

OSTI ID: 1767733; OSTI ID: 1873743

Grant/Contract Number:  

SC0001090

Resource Type:

Published Article

Journal Name:

AoB Plants

Additional Journal Information:

Journal Name: AoB Plants Journal Volume: 11 Journal Issue: 5; Journal ID: ISSN 2041-2851

Publisher:

Oxford University Press; Annals of Botany Company

Country of Publication:

United Kingdom

Language:

English

Subject:

59 BASIC BIOLOGICAL SCIENCES; biofuels (including algae and biomass); bio-inspired; membrane; carbon sequestration; materials and chemistry by design; synthesis (self-assembly); biomechanics; cellular expansion; cellulose; CESA; class-specific region; molecular dynamics