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Isolates of cell types from sorghum stems: Digestion, cell wall and anatomical characteristics
Author(s) -
Wilson John R.,
Mertens David R.,
Hatfield Ronald D.
Publication year - 1993
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740630406
Subject(s) - digestion (alchemy) , cell wall , biology , sorghum , botany , cell , agronomy , chemistry , biochemistry , chromatography
Cell types were separated from internode 5 of sorghum stems to study the interrelationship between digestion characteristics and cell wall composition. Isolates of epidermis (EPI), sclerenchyma (SCL), vascular bundle zone (VBZ), inner vascular bundles (IVB) and pith parenchyma cells (PITH) were freeze‐dried and ground for analysis. The cell fractions were digested in rumen fluid for times between 0 and 96 h, and wall composition measured using detergent extraction procedures. In‐vitro dry matter digestibility (g kg −1 after 48 h) of cell fractions was in the order of PITH (849‐906) > IVB (794‐816) > SCL (692‐701) > VBZ (641‐679) > EPI (608‐628). Total cell wall content (CWC), indigestible CWC, and lignin content followed the inverse order. Lignin concentration on a dry matter or cell wall basis was highly correlated with indigestible wall residue after 96 h. The proportion of cell wall digested after 96 h was higher for SCL and VBZ cells (61·8‐68·2%) than for PITH cells (48·4‐56·1 %), despite the former having lignin content three to five times higher than that of PITH cells. Clearly, there were differences between the cell types in wall composition or chemical linkages between wall components that lead to the observed differences in wall digestion.