Sugarcane is one of the most important crops in the world and Brazil is its principal producer. However, little is known about physiological and molecular mechanisms of acquisition and functionality of nutrients in Sugarcane. Potassium (K+) is the most absorbed macronutrient and corresponds up to 10% of plants dry mass. K+ transporters are important for acquisition of the ion from the soil, stomatal movements, stress tolerance and, mainly, participate on loading/unloading of photoassimilates to/from phloem. The relation between K+ transporters gene expression in different tissues and sink-source balance has never been approached. In Arabidopsis thaliana and Vicia faba some transporters have been studied, however there is no data about these proteins in agronomical important species such as Sugarcane. The main goal of this project is identify and characterize Sugarcane transporters using two strategies: (1) amplification of sugarcane orthologs sequences for Arabidopsis thaliana AKT2/3 gene using primers designed after AKT2 grasses sequences alignments and obtain sugarcane sequences fragments, something inexistent on public databases. With this fragment we will able to design specific primers and amplify its extremities using RACE technique and, clone the hole sequence for mutant yeast complementation test. (2) Construction of cDNA libraries from leaves and roots and cloning of those sequences in mutant yeast for complementation test and select those that were capable of restoring the yeast ability to gowth at low K+ concentration media. Positive clones will be sequenced and sequences annotated. Primers for qRT-PCR will be design and the expression pattern of sugarcane K+ transporters will be evaluated in different tissues (leaves and culms) under normal growth conditions. We also propose evaluate those genes expressions on plants with disturbed sink-source relation (shading experiments).
News published in Agência FAPESP Newsletter about the scholarship: