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Microspectrophotometry of bermudagrass ( Cynodon dactylon ) cell walls in relation to lignification and wall biodegradability
Author(s) -
Hartley Roy D,
Akin Danny E,
Himmelsbach David S,
Beach Daniel C
Publication year - 1990
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.2740500206
Subject(s) - cynodon dactylon , lignin , phloroglucinol , plant stem , cell wall , rumen , ferulic acid , chemistry , absorbance , botany , pith , biology , food science , chromatography , fermentation
The walls of the major plant cell types, sclerenchyma and parenchyma, of the second (upper) and fifth (lower) internodes from the apex of bermudagrass ( Cynodon dactylon L) stem have been examined by ultraviolet absorption microspectrophotometry and the results related to wall digestibility (measured in vitro with rumen liquor) and to histochemical reactions for ‘lignin’ and phenolics. Sclerenchyma walls from the lower internode gave high values of absorbance in the ultraviolet region of the spectrum equivalent to 109 mg trans ‐ferulic acid g −1 dry walls; similar walls from the upper internode also gave high values but these were lower than values from the lower internode. Histochemical examination showed that the sclerenchyma walls, which were indigestible to rumen microorganisms, gave positive tests with acid phloroglucinol reagent for lignin. Parenchyma walls, which were either digested or partially digested, gave much lower absorbance values in the ultraviolet region and negative tests with acid phloroglucinol but positive tests with diazotised sulphanilic acid (upper and lower internodes) and chlorine‐sulphite (lower internode) reagents. Ultraviolet absorption microspectrophotometry is a useful technique for examining phenolics within individual cell walls that vary in biodegradability.