TITLE:
Cell Wall Characteristics of a Maize Mutant Selected for Decreased Ferulates
AUTHORS:
Ronald D. Hatfield, Hans Jung, Jane M. Marita, Hoon Kim
KEYWORDS:
Hydroxycinnamates, Ferulates, Ferulate Dimers, Cell Wall, Digestibility
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.9 No.3,
February
26,
2018
ABSTRACT: The cross-linked nature of plant cell walls provides
structural integrity for continued growth and development, but limits
degradation and utilization by ruminants. In grasses a major cross-linking
component is ferulic acid that is incorporated into cell walls as an ester
linked residue on arabinoxylans. Ferulates can become coupled to each other and
to lignin forming a highly cross-linked matrix of carbohydrates and lignin.
Seedling ferulate ester mutants (sfe) were produced in maize using the transposon system
and evaluated in feeding trials. The work described here was undertaken to
characterize changes in the ferulate cross-linked nature as well as other
components of the corn cell wall matrix in leaf, sheath and stem tissues. Total ferulates decreased modestly due to the mutation and were more apparent in leaf tissue (16% - 18%) compared to sheath (+5 to-6% change) and stem (8% - 9% decrease). The most significant changes were in
the ether linked ferulates to lignin, both monomer and dehydrodiferulates (14% to 38% decrease). Other characteristics of the cell
wall (lignin, neutral sugar composition) also showed modest changes. The change
in total ferulates was modest, but led to improved animal performance. These
findings suggest that relatively small changes can have a significant impact
upon how well plant materials can be broken down and utilized by ruminants such
as dairy cows.