Divergent selection for ester-linked diferulates in maize pith stalk tissues. Effects on cell wall composition and...

Area of Science:

• Plant Biology
• Agricultural Science
• Biochemistry

Background:

• Diferulates (DFAs) are crucial cross-linking compounds in grass cell walls, influencing their properties.
• Genetic modification of DFA concentration in grasses has not been previously reported.
• Understanding DFA's role is key to improving cell wall characteristics and biomass degradability.

Purpose of the Study:

• To investigate the effects of direct genetic selection on ester-linked DFA concentration in maize stalk pith.
• To analyze associated changes in cell wall composition and biodegradability.
• To explore the heritability and breeding potential of DFA deposition in maize.

Main Methods:

• Divergent selection for total DFA (DFAT) concentration over two cycles in maize populations.
• Analysis of cell wall composition, including glucose and total cell wall content.
• Assessment of rumen cell wall degradability and identification of predictive DFA regioisomers.

Main Results:

• Maize populations selected for higher DFAT content (CHs) showed a 16% increase in DFAT concentration compared to lower DFAT populations (CLs).
• CHs exhibited 13% less glucose and 10% lower total cell wall concentration, indicating cell wall matrix repacking.
• CLs demonstrated 12% higher 24-h polysaccharide degradability, with 8-8-coupled DFAs negatively predicting degradability.

Conclusions:

• DFA concentration in maize pith is a highly heritable trait amenable to conventional breeding.
• Increased DFA cross-linking leads to altered cell wall structure and reduced biodegradability.
• Specific DFA regioisomers, particularly 8-8-coupled DFAs, significantly influence cell wall degradability, warranting further investigation.