Steering the shikimate/phenylpropanoid pathway: from gene function discovery to green factories

• Grant number: 21/06142-8
• Support type: Research Grants - Young Investigators Grants - Phase 2
• Duration: June 01, 2022 - May 31, 2027
• Field of knowledge: Biological Sciences - Botany - Pant Physiology
• Principal researcher: Igor Cesarino
• Grantee: Igor Cesarino
• Home Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Assoc. researchers: Aymerick Eudes ; Carla Cristina Polo ; José Carlos del Río Andrade ; Wagner Rodrigo de Souza
• Associated research grant: 15/02527-1 - Development of model systems in sorghum and a systems biology approach to unravel the molecular mechanisms controlling lignin metabolism in grasses, AP.BIOEN.JP

Abstract

Plant lignocellulosic biomass constitutes a sustainable alternative to replace the complex carbon chemistries of petroleum as it can be deconstructed into simple sugars and aromatics that are further converted into biofuels and bioproducts. In this context, the shikimate/phenylpropanoid pathway is a major biotechnological target, as it is the source of not only the aromatic polymer lignin (a major bottleneck to biomass processing in biorefineries) but also of metabolites eligible as important bio-replacements for commonly fossil fuel-derived aromatics. This project aims to contribute both basic (novel knowledge) and applied (novel products) research regarding the shikimate/phenylpropanoid pathway in C4 grasses. The first objective is to perform the functional characterization of five candidate genes potentially involved in lignin metabolism using the model C4 grass Setaria viridis. These candidate genes were previously selected during JP1 Fapesp (2015/02527-1), in which large-scale transcriptomics followed by co-expression analyses were applied to model tools developed to facilitate the study of lignin metabolism in C4 grasses. The genes were selected to cover broad aspects of lignin metabolism, including transcriptional regulation, monolignol biosynthesis, monolignol transport and monolignol glycosylation. The second objective is to boost the status of sugarcane plants as multipurpose crops via bioengineering of the shikimate/phenylpropanoid pathway. Three strategies were selected, based on target metabolites that represent high-value compounds and whose metabolic engineering approach would potentially affect lignin deposition and, consequently, enhance biomass processability. Considering both parts of the project, target genes will be misregulated and the corresponding transgenic lines will be characterized by multiple-level phenotyping, including anatomical/structural analyses, wet-chemistry, large-scale transcriptomics, metabolic profiling and saccharification efficiency. This project has the potential to not only generate novel basic knowledge on lignin metabolism in C4 grasses but also to explore novel strategies for steering the shikimate/phenylpropanoid pathway for industrial purposes. (AU)