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Maize stem tissues: cell wall concentration and composition during development
Author(s) -
Jung H.G.,
Casler M.D.
Publication year - 2009
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2006.02.0086er
Subject(s) - plant stem , xylose , biology , arabinose , cell wall , botany , elongation , horticulture , biochemistry , fermentation , materials science , ultimate tensile strength , metallurgy
Grass maturation results in reduced cell wall degradability by ruminant livestock. Using a specific internode of maize (Zea mays L.) stems as a model, the pattern of grass stem tissue and cell wall de- velopment was characterized. The fourth elongated internode above ground level from three maize hybrids was sampled at 10 stages of development beginning when the internodewas about 10 mm in length through physiological maturity from a 2-yr, replicated field trial at St. Paul, MN. Tissue development was characterized by light microscopy. Cell wall concentration and composition (polysaccharide sugar res- idues, lignin, ferulates, and p-coumarates) were determined. Internode length and cross-sectional area increased from Sampling Date 1 until the interval between Sampling Dates 5 and 6. During elongation only protoxylem vessels stained positive for lignin. After elongation, paren- chyma, sclerenchyma, and metaxylem tissues lignified, but phloem did not. Cell wall concentration increased until shortly after elongation ended. Cell wall lignin concentration declined over the first four sam- ples, with an increase in glucose and xylose polysaccharide residues, before rising sharply until after elongation was complete. Ferulate cross-links of lignin to arabinoxylan increased 12-fold during elonga- tion. Our results indicated that post-elongation development of scle- renchyma and rind-region parenchyma accounted for the majority of cell wall accumulation and lignification in maize stems.