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Title: Identifying the ionically bound cell wall and intracellular glycoside hydrolases in late growth stage Arabidopsis stems: Implications for the genetic engineering of bioenergy crops

Identifying the cell wall-ionically bound glycoside hydrolases (GHs) in Arabidopsis stems is important for understanding the regulation of cell wall integrity. For cell wall proteomics studies, the preparation of clean cell wall fractions is a challenge since cell walls constitute an open compartment, which is more likely to contain a mixture of intracellular and extracellular proteins due to cell leakage at the late growth stage. Here, for this study, we utilize a CaCl 2-extraction procedure to isolate non-structural proteins from Arabidopsis whole stems, followed by the in-solution and in-gel digestion methods coupled with Nano-LC-MS/MS, bioinformatics and literature analyses. This has led to the identification of 75 proteins identified using the in-solution method and 236 proteins identified by the in-gel method, among which about 10% of proteins predicted to be secreted. Together, eight cell wall proteins, namely AT1G75040, AT5G26000, AT3G57260, AT4G21650, AT3G52960, AT3G49120, AT5G49360, and AT3G14067, were identified by the in-solution method; among them, three were the GHs (AT5G26000, myrosinase 1, GH1; AT3G57260, β-1,3-glucanase 2, GH17; AT5G49360, bifunctional XYL 1/α-L-arabinofuranosidase, GH3). Moreover, four more GHs: AT4G30270 (xyloglucan endotransferase, GH16), AT1G68560 (bifunctional α-l-arabinofuranosidase/XYL, GH31), AT1G12240 (invertase, GH32) and AT2G28470 (β-galactosidase 8, GH35), were identified by the in-gel solution method only. Notably, moremore » than half of above identified GHs are xylan- or hemicellulose-modifying enzymes, and will likely have an impact on cellulose accessibility, which is a critical factor for downstream enzymatic hydrolysis of plant tissues for biofuels production. Finally, the implications of these cell wall proteins identified at the late growth stage for the genetic engineering of bioenergy crops are discussed.« less
 [1] ;  [1] ;  [1] ;  [2] ;  [1] ;  [3] ;  [3] ;  [1]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States). Biosciences Center
  2. National Renewable Energy Lab. (NREL), Golden, CO (United States). Biosciences Center; Michigan State Univ., East Lansing, MI (United States). Dept. of Plant Biology
  3. National Renewable Energy Lab. (NREL), Golden, CO (United States). National Bioenergy Center
Publication Date:
Report Number(s):
Journal ID: ISSN 1664-462X
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Frontiers in Plant Science
Additional Journal Information:
Journal Volume: 6; Journal ID: ISSN 1664-462X
Frontiers Research Foundation
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Science (SC); National Renewable Energy Lab. (NREL), Golden, CO (United States)
Country of Publication:
United States
59 BASIC BIOLOGICAL SCIENCES; 09 BIOMASS FUELS; cell wall proteins; glycoside hydrolase; xylan-modifying enzyme; pectin-modifying enzyme; plant late growth stage; plant senescence; biomass recalcitrance; feedstock engineering
OSTI Identifier: