Maize Stem Tissues: Impact of Development on Cell Wall Degradability

Abstract

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 rind‐region 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.

Topochemical distribution of lignin and hydroxycinnamic acids in sugar-cane cell walls and its correlation with the enzymatic hydrolysis of polysaccharides

“…This is consistent with previous work showing that parenchyma cells from maize stems at various states of maturation were preferentially degraded by rumen biota [27]. Hansen et al .…”

Phylogeny in Defining Model Plants for Lignocellulosic Ethanol Production: A Comparative Study of Brachypodium distachyon, Wheat, Maize, and Miscanthus x giganteus Leaf and Stem Biomass

“…2A) resembled the value that was previously reported (21%) [43]. In that study, the lignin content was also determine by the acetyl bromide method whereas amounts of lignin were reported to be lower in those studies where Klason lignin was determined [44], [45]. This contributes to the observation that values for the lignin content deriving from different methods are not directly comparable [30].…”

“…This contributes to the observation that values for the lignin content deriving from different methods are not directly comparable [30]. In addition, the lignin content in Z. mays stem biomass was strongly dependent on the tested inbred line and growing conditions [44], [45]. Whereas we used biomass from the Z. mays inbred line A188 grown under greenhouse conditions, other studies mainly refer to biomass from different, field grown Z. maize cultivars.…”

Genotypic covariations of traits underlying sorghum stem biomass production and quality and their regulations by water availability: Insight from studies at organ and tissue levels

“…This will also help orienting the development of appropriate phenotyping facilities to support the development of varieties and innovative crop management practices (Cabrera-Bosquet et al, 2016;Legland, El-Hage, Mechin, & Reymond, 2017;M. Jung and Casler (2006) reported that lignin deposition in internode sclerenchyma and outer parenchyma was not synchronized with that in the internal zone of the internode. Jung and Casler (2006) reported that lignin deposition in internode sclerenchyma and outer parenchyma was not synchronized with that in the internal zone of the internode.…”