Maize Stem Tissues: Impact of Development on Cell Wall Degradability

Grass degradability declines as cell wall and lignin concentrations increase during maturation. The role of tissue development and lignification in decline of stem degradability was examined in maize (Zea mays L.) internodes sampled at 10 stages of growth from early elongation through plant physiological maturity. The fourth elongated internode above ground level was collected from three maize hybrids grown in a 2-yr, replicated field trial at St. Paul, MN. Internode cross-sections and ground samples were incubated in vitro for 24- and 96-h with rumen microbes. Tissue degradation was examined by light microscopy and degradability of cell wall polysaccharide components from ground internodes was determined. All tissues in elongating internodes were completely degradable except for protoxylem vessels, which was the only lignified tissue. After elongation, degradability of all tissues declined markedly except for phloem, which never lignified. Tissues with thick, lignified secondary walls (sclerenchyma and rindregion parenchyma) required longer incubation times for observable degradation. Cell wall polysaccharide components were highly degradable in immature internodes, but degradability declined after elongation and reached a minimum by Sampling Date 8, with glucose and xylose residues having the greatest reductions in degradability. Cell wall polysaccharide degradation was related to lignin concentration and ferulate cross-linking in a complex manner.

[1]  D. Buxton,et al.  Activity of two lignin biosynthesis enzymes during development of a maize internode , 1994 .

[2]  R. Andersson,et al.  Total dietary fiber determined as neutral sugar residues, uronic acid residues, and Klason lignin (the Uppsala method): collaborative study. , 1995, Journal of AOAC International.

[3]  D. Buxton,et al.  Forage Cell Wall Structure and Digestibility , 1993 .

[4]  F. M. Engels,et al.  Alfalfa Stem Tissues: Cell Wall Deposition, Composition, and Degradability , 2002 .

[5]  J. Wilson,et al.  Cell wall accessibility and cell structure limitations to microbial digestion of forage , 1995 .

[6]  J. Wilson.  Organization of Forage Plant Tissues , 1993 .

[7]  Ronald D. Hatfield,et al.  Identification and synthesis of new ferulic acid dehydrodimers present in grass cell walls , 1994 .

[8]  D. R. Buxton,et al.  Cell‐Wall Composition of Maize Internodes of Varying Maturity , 1998 .

[9]  Hansang Jung,et al.  Forage quality variation among maize inbreds: Relationships of cell‐wall composition and in‐vitro degradability for stem internodes , 1994 .

[10]  J. Labavitch,et al.  A SIMPLIFIED METHOD FOR ACCURATE DETERMINATION OF CELL WALL URONIDE CONTENT , 1978 .

[11]  Hansang Jung,et al.  Selection and evaluation of smooth bromegrass clones with divergent lignin or etherified ferulic acid concentration , 1999 .

[12]  J. Ralph,et al.  Diferulate cross-links impede the enzymatic degradation of non-lignified maize walls , 1998 .

[13]  Bruce A. Stone,et al.  Phenolic acid bridges between polysaccharides and lignin in wheat internodes , 1990 .

[14]  Hansang Jung,et al.  Maize stem tissues: ferulate deposition in developing internode cell walls. , 2003, Phytochemistry.

[15]  Ronald D. Hatfield,et al.  Lignin-ferulate cross-links in grasses: active incorporation of ferulate polysaccharide esters into ryegrass lignins , 1995 .

[16]  J. Gressel,et al.  Partial suppression of cellulase action by artificial lignification of cellulose , 1983 .

[17]  Ronald D. Hatfield,et al.  Ferulate cross-linking in cell walls isolated from maize cell suspensions , 1995 .

[18]  R. Helm,et al.  Lignin–feruloyl ester cross-links in grasses. Part 1. Incorporation of feruloyl esters into coniferyl alcohol dehydrogenation polymers , 1992 .

[19]  J. Ralph,et al.  Ferulate Cross-Links Limit the Enzymatic Degradation of Synthetically Lignified Primary Walls of Maize , 1998 .

[20]  E. Mcdougall.  Studies on ruminant saliva. 1. The composition and output of sheep's saliva. , 1948, The Biochemical journal.

[21]  Hansang Jung,et al.  Maize Stem Tissues , 2006 .

[22]  Michael D. Casler,et al.  Maize stem tissues: cell wall concentration and composition during development , 2006 .

[23]  D. Buxton,et al.  A Comparison of the Insoluble Residues Produced by the Klason Lignin and Acid Detergent Lignin Procedures , 1994 .

[24]  F. M. Engels.  Some Properties of Cell Wall layers Determining Ruminant Digestion , 1989 .

[25]  M. Galyean,et al.  Utilization of Forage Fiber by Ruminants , 1993 .