Identification and validation of post-transcriptional regulatory modules involved in lignin metabolism in grasses

• Grant number: 24/01685-1
• Support Opportunities: Regular Research Grants
• Start date: August 01, 2024
• End date: July 31, 2026
• Field of knowledge: Biological Sciences - Botany - Pant Physiology
• Agreement: CNPq
• Principal Investigator: Igor Cesarino
• Grantee: Igor Cesarino
• 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
• Associated scholarship(s): 24/12357-5 - Identification and validation of post-transcriptional regulatory modules involved in lignin metabolism in grasses, BP.JD

Abstract

Lignocellulosic biomass is a sustainable alternative to the complex oil production chain, and it can be processed into simple sugars and aromatic compounds that can be converted into biofuels and other bioproducts in biorefineries. In this context, the aromatic polymer lignin, deposited in the secondary walls that make up plant biomass, is a major bottleneck as it hinders biomass processing and its subsequent conversion into bioproducts. Therefore, lignin metabolism has been intensely characterized, whose knowledge allows the development of bioengineering strategies for the generation of optimized biomass for the bioeconomy. Lignin metabolism includes regulation, biosynthesis of monomers, transport of monomers to the cell wall and polymerization. As lignin is an irrecoverable carbon investment for the plant, its deposition must be tightly regulated. This regulation occurs at the epigenetic, transcriptional, post-transcriptional and post-translational levels. However, little is known about the post-transcriptional control of lignification, especially in C4 grasses. Therefore, the objective of this project is to contribute to the elucidation of post-transcriptional mechanisms regulating lignification in C4 grasses, using Setaria viridis as a model. To identify potential post-transcriptional regulatory modules, an integrated micro-transcriptomic and degradomic analysis will initially be performed using 4 organs of S. viridis contrasting for lignin deposition. From the integration of these data with the prediction of miRNAs-targets interactions, potential regulatory modules between miRNAs and genes involved in different aspects of lignin metabolism will be selected. A total of 5 modules will be selected for validation in vivo using transient expression assays in tobacco leaves. This work will be linked to the Young Researcher Award Phase 2 (Processo Fapesp 2021/06142-8) and is fully aligned with its objectives of characterizing molecular mechanisms underlying lignification in C4 grasses. The results of this work will not only contribute to a deeper understanding of lignin metabolism in C4 grasses but may also assist in the development of biotechnological strategies for bioengineering of plant biomass for the bioeconomy. (AU)