Transgenic Arabidopsis thaliana and Nicotiana tabacum overexpressing the Eucalyptus grandis Cellulose Synthase 3 and its expression pattern in different Eucalyptusspecies and tissues

Background In Brazil, the forest industry accounts for 4,5% from the Gross Domestic Product and the country is the biggest Eucalyptus cellulose exporter. That’s really good news because Eucalyptus forests are a competitive and efficient alternative to convert carbon from the atmosphere in cellulose, an important source for paper and bioenergy production. The cellulose biosynthesis happens through the Cellulose Synthase Complex activity. This complex is composed by different Cellulose Synthase genes (CesA) that work together in a non redundant way [1]. It is also known that some of these isoforms act in the primary cell wall synthesis while others, in the secondary cell wall. In this last group there is the gene Eucalyptus Cellulose Synthase 3 (EgCesA3), the most expressed CesA gene during xylogenesis [2]. Besides, knockout experiments proved that the AtCesA7 (EgCesA3 ortholog in Arabidopsis thaliana) activity is essential for the xylem formation and for plant vertical growth [3]. In front of these evidences, the EgCesA3 gene had it expression pattern evaluated in leaf and xylem tissues among the three most economic important Eucalyptus species in Brazil: E. grandis, E. globulus andE. urophyla. As demonstrated in this work, the expression experiment provided enough information about the EgCesA3 function, that’s why this gene was chosen to be overexpressed in model plants (Arabidopsis thaliana and Nicotiana tabacum). It’s expected increased cellulose content in the transgenic plants xylem.