|FANELLI, AMANDA - Universidad De Sao Paulo|
|RANCOUR, DAVID - Lytic Solutions, Llc|
|KARLEN, STEVEN - University Of Wisconsin|
|RALPH, JOHN - University Of Wisconsin|
|RIANO-PACHON, DIEGO - Universidad De Sao Paulo|
|VICENTINI, RENATO - Public University In Campinas|
|DE FRANK SILVA, TATIANE - Universidade De Sao Paulo|
|FERRAZ, ANDRE - Universidade De Sao Paulo|
|HATFIELD, RONALD - Retired ARS Employee|
|ROMANEL, ELISSON - Universidade De Sao Paulo|
Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/12/2021
Publication Date: 4/21/2021
Citation: Fanelli, A., Rancour, D.M., Sullivan, M.L., Karlen, S.D., Ralph, J., Riano-Pachon, D.M., Vicentini, R., De Frank Silva, T., Ferraz, A.L., Hatfield, R.D., Romanel, E. 2021. Overexpression of a sugarcane BAHD acyltransferase alters hydroxycinnamate content in maize cell wall. Frontiers in Plant Science. 11:626168. https://doi.org/10.3389/fpls.2021.626168.
Interpretive Summary: The plant cell wall components lignin and xylan are often modified with the hydroxycinnamic acids p-coumaric acid and ferulic acid. Attachment of these can affect digestibility of cell walls in ruminant animal and bioengergy production systems. In bioengery production systems, pretreatment of the biomass can liberate ferulic acid and p-coumaric acids as potential valuable co-products. Using existing genomic data, this study identified genes from sugarcane for enzymes potentially involved in attachment of hydroxycinnamic acids to cell wall components. One of the identified genes, ScAt10, was further characterized by overexpressing it in transgenic maize. In the transgenic plants, the ratio of p-coumaric acid to ferulic acid in cell walls was changed up to ten-fold, indicating the gene is involved in hydroxycinnamic acid modification of plant cell wall components. This finding further suggests ScAt10, and related enzymes, could be used to alter digestibility of plant cell walls for animal and bioengery production, and could also favorably alter cell wall composition to enhance production of valuable co-products.
Technical Abstract: The purification of hydroxycinnamic acids [p-coumaric acid (pCA) and ferulic acid (FA)] from grass cell walls requires high-cost processes. Feedstocks with increased levels of one hydroxycinnamate in preference to the other are therefore highly desirable. We identified and conducted expression analysis for nine BAHD acyltransferase ScAts genes from sugarcane. The high conservation of AT10 proteins, together with their similar gene expression patterns, supported a similar role in distinct grasses. Overexpression of ScAT10 in maize resulted in up to 75% increase in total pCA content. Mild hydrolysis and derivatization followed by reductive cleavage (DFRC) analysis showed that pCA increase was restricted to the hemicellulosic portion of the cell wall. Furthermore, total FA content was reduced up to 88%, resulting in a 10-fold increase in the pCA/FA ratio. Thus, we functionally characterized a sugarcane gene involved in pCA content on hemicelluloses and generated a C4 plant that is promising for valorizing pCA production in biorefineries.