Functional characterization of sugarcane (Saccharum spp.) genes encoding ammonium transporters

• Grant number: 16/14669-8
• Support type: Regular Research Grants
• Duration: November 01, 2016 - April 30, 2019
• Field of knowledge: Biological Sciences - Genetics - Plant Genetics
• Principal Investigator: Antonio Vargas de Oliveira Figueira
• Grantee: Antonio Vargas de Oliveira Figueira
• Home Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Assoc. researchers: Joni Esrom Lima

Abstract

Crop yields rely heavily on nitrogen (N) fertilization, and the growing demand for food and biofuels has led to the indiscriminate increase in the use of nitrogen fertilizers in modern agriculture, causing a negative impact on the environment. Therefore, increasing plant N use efficiency (NUE) is essential for the development of sustainable agriculture. Plant NUE is a complex trait determined by uptake efficiency, defined as the ability to acquire inorganic N from soil, and utilization efficiency, which includes N translocation, assimilation, and remobilization. Although sugarcane (Saccharum spp.) is considered one of the largest sources for biofuel production, the inefficient use of N fertilizer by the commercial sugarcane cultivars in comparison to other grass cereal crops argues against its sustainability. Ammonium is a predominant inorganic N form in most soils and is preferentially absorbed by sugarcane roots upon field N-replete conditions. Ammonium acquisition and transport in plants is mediated by AMMONIUM TRANSPORTERs (AMTs), which are transmembrane proteins with essential roles in N nutrition in living organisms. Despite the increased knowledge generated about the signaling components controlling N metabolism, physiology and growth in model plants, the molecular basis of ammonium transport system remains to be elucidated in most crop species. Here, we aim to conduct the molecular and functional characterization of ammonium transporters genes in sugarcane. To gain insight into AMTs in sugarcane genome, we previously identified and selected clones from bacterial artificial chromosomes (BACs) harboring AMT1 and AMT2 sequences, homologue to the ones from other grasses. We propose the functional and molecular characterization of four sugarcane AMTs genes based on reverse genetics approaches using ammonium transport-defective yeast and Arabidopsis thaliana mutants to reveal the molecular features of these genes in control of ammonium homeostasis in sugarcane. (AU)