A systemic view of phenolic and lignin metabolism in the model grass Setaria viridis

• Grant number: 22/09003-1
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Effective date (Start): December 01, 2022
• Effective date (End): December 31, 2025
• Field of knowledge: Biological Sciences - Botany - Pant Physiology
• Principal Investigator: Igor Cesarino
• Grantee: Leydson Gabriel Alves de Lima
• 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

Plant biomass is mainly composed of secondary cell walls enriched in polysaccharides and constitutes a promising source of fermentable sugars for the production of biofuels and biomaterials. However, biomass processing is hampered by the complex structure and composition of secondary walls, a fact known as biomass recalcitrance. The main recalcitrance factor is the presence of the phenolic polymer lignin. Therefore, the elucidation of the molecular mechanisms involved in phenolic and lignin metabolism is essential to leverage the use of plant biomass as feedstock in the bioeconomy. In this context, C4 grasses are considered promising crops due to their high yield in biomass production. The objective of this project is to use Setaria viridis to deepen the knowledge on phenolic/lignin metabolism in C4 grasses. To this end, we propose a systems biology project divided into two main objectives. First, a metabolic map focused on phenylpropanoids and an expression atlas of different tissues of S. viridis will be generated. Metabolomics and transcriptomics data will be correlated to allow the identification of genes potentially involved in different aspects of phenolic metabolism. The second objective is the functional characterization of a transcription factor of the MYB family selected in a previous project of our group and potentially involved in tricin metabolism in S. viridis. Transgenic plants overexpressing and silencing this gene will be characterized for biomass parameters, metabolic profile, lignin deposition, global gene expression and saccharification yield. The proposed strategies will allow the elucidation of new aspects of phenolic and lignin metabolism in C4 grasses, as well as to validating potential biotechnological strategies to reduce biomass recalcitrance. (AU)