What did feruloylation ever do for us plants?

Abstract:
Ferulic acid is a phenolic compound that constitutes a distinct feature in cell walls of grasses. It is anchored via ester linkages at the arabinose O-5 position of the arabinoxylan side chains in the primary and secondary walls. The oxidative action of cell wall peroxidase/H2O2 triggers ferulic acid coupling and the formation of diferuloyl bridges between previously separated arabinoxylans (AX) molecules creating cross-links between AX backbones. The role of cell wall feruloylation are being elucidated but despite its importance, the identification of putative genes involved in ferulates incorporation to AX and elucidation of the precise mechanism have been challenging.

Here we will discuss evolving concepts and our findings on cell wall feruloylation and ferulate oxidative coupling processes in grasses, and the effects these have on a wide range of cell wall properties. Special emphasis will be given to the modification of cell wall feruloylation by heterologous expression of a fungal ferulic acid esterase, as this strategy has provided insights into the impact of feruloylation on the physicochemical properties of cell wall with consequent effects on various plant processes such as leaf growth, internode elongation, plant resistance to herbivores and cell wall saccharification. We will also highlight emerging candidate feruloyl transferase candidate genes that codify enzymes accounting for anchoring ferulates into grass arabinoxylans.

Grasses play an important role in human nutrition as cereal crops, in animal feeding as grazing (fresh forage) or as silage and hay (preserved forages) and in addition, grasses also constitute as an abundant and renewable source of polymers to produce biofuels. Understanding the process of cell wall feruloylation can lead to a more efficient utilization of grass cell walls in agriculture, food and biofuel industries.

About the Speaker:
- B.S. in Agronomic Engineering from Federal and Rural University of Pernambuco in Brazil
- Ph.D. in Plant Breeding and Genetics from Aberystwyth University/IBERS, Wales UK, under supervision Dr. Mike Hayward
- Post-doctoral at the Institute of Grassland and Environmental Research, Plas Gogerddan, Wales, UK. Working with Dr. Phillip Morris.
- Currently in Biology Department at Penn State University
- Teaches Plant Medicinal Chemistry (400 level BIOL undergraduate course)
- Research has focused on grass cell walls, with a special interest in understanding feruloylation. It is also part of the Buanafina's research to study the expression of fungal cell wall degrading enzymes in planta in order to test if their expression can assist the digestion of polysaccharides and improve the nutritional properties of grasses as a ruminant feed or as a bioenergy crop.

Contact

Cristina Rosa
czr2@psu.edu