Functional characterization of SvPRN1 and SvPRN2 genes in the grass model Setaria viridis and their implication in the regulation of lignin deposition

• Grant number: 24/21413-6
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: June 01, 2025
• End date: May 31, 2029
• Field of knowledge: Biological Sciences - Botany - Pant Physiology
• Principal Investigator: Igor Cesarino
• Grantee: Bianca Meeihua Sung
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 21/06142-8 - Steering the shikimate/phenylpropanoid pathway: from gene function discovery to green factories, AP.BIOEN.JP2

Abstract

Lignin is one of the most abundant biopolymers on Earth and has been extensively studied due to its ecological, physiological and economic importance. Over the past two decades, research on the mechanisms of regulation of lignin deposition has allowed the characterization of a complex transcriptional network. Recently, AtPRN2 from Arabidopsis thaliana, belonging to the PIRINs (PRNs) family, was characterized as a transcriptional (co)regulator of lignin deposition, acting upstream of the NAC-MYB network and regulating the chemical composition of xylem lignin in a cell-non-autonomous manner. However, there are no studies on the role of PRN genes in the regulation of lignin deposition in grasses. Previously, our research group characterized the PRN gene family in the model grass Setaria viridis and identified SvPRN1 and SvPRN2 as potential regulators of the lignification process. This project aims to perform the functional characterization of SvPRN1 and SvPRN2 in S. viridis, in order to confirm their role in the regulation of lignification. The tissue-specific expression patterns of SvPRN1 and SvPRN2 will be determined by in situ hybridization, while the function of these genes in planta will be assessed by phenotyping transgenic lines individually overexpressing each target gene. These lines will be characterized in terms of biomass production, secondary wall deposition and lignin composition. Furthermore, transcriptomic and metabolomic profiles will be analyzed to obtain a holistic view of the changes caused by genetic manipulation. Finally, saccharification assays will be performed to verify possible effects on biomass recalcitrance. The data generated in this project will contribute to a better understanding of phenolic metabolism in grasses and to validate possible biotechnological strategies focused on the use of plant biomass.