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Title: Cell Wall Ultrastructure of Stem Wood, Roots, and Needles of a Conifer Varies in Response to Moisture Availability

The composition, integrity, and architecture of the macromolecular matrix of cell walls, collectively referred to as cell wall ultrastructure, exhibits variation across species and organs and among cell types within organs. Indirect approaches have suggested that modifications to cell wall ultrastructure occur in response to abiotic stress; however, modifications have not been directly observed. Glycome profiling was used to study cell wall ultrastructure by examining variation in composition and extractability of non-cellulosic glycans in cell walls of stem wood, roots, and needles of loblolly pine saplings exposed to high and low soil moisture. Soil moisture influenced physiological processes and the overall composition and extractability of cell wall components differed as a function of soil moisture treatments. The strongest response of cell wall ultrastructure to soil moisture was increased extractability of pectic backbone epitopes in the low soil moisture treatment. The higher abundance of these pectic backbone epitopes in the oxalate extract indicate that the loosening of cell wall pectic components could be associated with the release of pectic signals as a stress response. The increased extractability of pectic backbone epitopes in response to low soil moisture availability was more pronounced in stem wood than in roots or needles. Additional responsesmore » to low soil moisture availability were observed in lignin associated carbohydrates released in chlorite extracts of stem wood, including an increased abundance of pectic arabinogalactan epitopes. Overall, these results indicate that cell walls of loblolly pine organs undergo changes in their ultrastructural composition and extractability as a response to soil moisture availability and that cell walls of the stem wood are more responsive to low soil moisture availability compared to cell walls of roots and needles. In conclusion, to our knowledge, this is the first direct evidence, delineated by glycomic analyses, that abiotic stress affects cell wall ultrastructure. This study is also unique in that glycome profiling of pine needles has never before been reported.« less
 [1] ;  [2] ;  [1] ;  [1] ;  [2] ;  [2] ;  [3]
  1. Univ. of Georgia, Athens, GA (United States). Complex Carbohydrate Research Center
  2. Univ. of Georgia, Athens, GA (United States). Daniel B. Warnell School of Forestry and Natural Resources
  3. Univ. of Georgia, Athens, GA (United States). Daniel B. Warnell School of Forestry and Natural Resources;Univ. of Georgia, Aiken, SC (United States). Savannah River Ecology Laboratory
Publication Date:
Grant/Contract Number:
AC05-00OR22725; 2011-67009-30065; 2013-67009-21405
Accepted Manuscript
Journal Name:
Frontiers in Plant Science
Additional Journal Information:
Journal Volume: 7; Journal ID: ISSN 1664-462X
Frontiers Research Foundation
Research Org:
Univ. of Georgia, Athens, GA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); National Science Foundation (NSF)
Country of Publication:
United States
59 BASIC BIOLOGICAL SCIENCES; 54 ENVIRONMENTAL SCIENCES; cell walls; glycome profiling; moisture stress; monoclonal antibodies; pectin; Pinus taeda; xylan; pine pinus-taeda; carbon-isotope discrimination; loblolly-pine; arabidopsis-thaliana; extracellular-matrix; vascular tissues; elastic-modulus; drought stress; abiotic stress; water-deficit
OSTI Identifier: