SUGARCANE REGULATORY NETWORKS

 

 

This project aims to study gene expression regulation and to generate tools that will allow us to employ a Systems Biology approach in sugarcane to identify regulatory networks. As a starting point we intend to characterize two agronomical traits of interest in sugarcane: drought and brix. We will study gene categories with a well known regulatory role (Transcription Factors, Protein Kinases and Phosphatases), continue studies of the Transcriptome, produce transgenics e develop databases and computacional tools to integrate the several levels of information. We will identify TF targets using ChIP-HTS and clone gene promoters. The results will have multiple direct consequences on breeding programs which frequently select for CREs and TF changes in search for genotypes better adapted to the environment and with increased agronomical performance. PKs activate signaling cascades in response to environmental stimuli and our studies point to a predominant role of PKs in the regulation of sucrose content and drought responses. To identify new genes associated to brix and drought we will characterize the transcriptome of genotypes and cultivars that contrast for brix and drought tolerance using olinonucleotide arrays. Genes of interest will be functionally evaluated by generating transgenics altered for their expression. To integrate the immense amount of public data and that generated by this project a robust computational infra-structure and database will be developed. The SUCEST-FUN database will integrate the SUCEST sequences, promoters, CREs, expression data, agronomical, physiological and biochemical characterization of sugarcane cultivars. In parallel, we will also participate in the development of the GRASSIUS database to establish sugarcane, rice, maize and sorghum regulatory networks.

Plant Growth

 

 

Coordinator: Adriana S. Hemerly

IDENTIFICATION OF REGULATORY NETWORKS THAT CONTROL PLANT GROWTH


The strategy used by plants during their post-germination growth– where the plant body is constructed in a modular and indeterminate manner, through the function of the meristems – results in a development mode that is regulated during the plant life cycle by internal (e.g. mechanisms of cell division control) and external signals in response to the environment (e.g. association with beneficial microorganisms that promote plant growth). Because plant growth consists mainly of cell division events, followed by cell elongation and differentiation, a promising strategy for increasing the yield of economically interesting crops is the increase of biomass through the manipulation of regulatory networks that control the plant growth. Two distinct approaches have been taken by our research group to unravel the mechanisms that control plant growth: (a) the study of a regulatory network in grasses that controls the basic machinery of DNA replication, and therefore the cell division. Specifically, this part of the project involves the functional study of a new regulator of the G1/S transition in plants, ABAP1, focusing in unraveling the regulatory network which ABAP1 take part, and the processes of plant development in which ABAP1 acts; (b) the characterization of plant growth in grasses promoted by the association with beneficial endophytic bacteria that fix nitrogen and produce phytohormones, such as Gluconacetobacter diazotrophicus and Herbaspirillum spp. This part of the project involves the isolation, characterization and functional study of sugarcane and rice genes that are involved in the interaction with endophytic diazotrophic bacteria and promotion of plant growth.