Transcriptomic analysis and co-expression network construction in model systems for identification of genes involved in secondary cell wall deposition and lignin metabolism in grasses

Abstract

The production of lignocellulosic biofuels still faces technical difficulties regarding the efficient degradation of plant biomass, which is known as recalcitrance. In order to develop biotechnological strategies to reduce biomass recalcitrance, it is essential to understand the molecular basis of Secondary Cell Wall (SCW) biosynthesis and deposition, since SCW is the main constituent of plant biomass. Although C4 grasses are the main bioenergy crops, most of the knowledge on SCW metabolism has been generated in dicotyledonous plants. These two groups of plants differ considerably in composition, structure and regulation of the cell wall, which hampers the translation from results obtained in dicots to grasses. Thus, the characterization of specific aspects of secondary cell wall metabolism in grasses requires systematic studies in this group of plants. Recently, we started a systems biology study based on metabolomics and transcriptomics in sorghum model systems at Prof. Igor Cesarino's (IB/USP) laboratory to correlate changes in secondary cell wall biochemical compositions with changes in gene expression (Project BIOEN Young Investigator, 2015/02527-1). In this context, the goal of this post-doc project is to analyze the transcriptome of the model systems and generate co-expression networks, in order to identify genes potentially involved in the deposition of secondary cell wall, with a special focus in lignin, and initiate the functional characterization of transcription factors previously chosen based on co-expression networks by transient expression assays. The knowledge generated will be important to develop biotechnological strategies to reduce the recalcitrance of biomass in bioenergy crops such as sugarcane. (AU)