Gene expression of Agave spp. for bioenergy: exploiting the potential of CAM plants

Abstract

Different species of Agave are commercially grown for the production of fibers or alcohol. Among the Agaves grown to obtain fiber, the most widely cultivated is Agave sisalana (Sisal). Brazil is currently the world's largest producer and exporter of sisal fiber, representing 70% of the exports and 58% of the global production. The commercially cultivated agave in Brazilian territory occupies a large area of nutrient-poor soils in the Northeast's semiarid region, where it often shows itself as the only growing crop alternative with satisfactory economic results. It's possible mainly due to the crassulacean acid metabolism (CAM), a more water-use efficient photosynthetic mechanism. In recent years it has been observed decline in sisal's culture due to two major factors: (i) the low rate plant utilization - only 4 % of harvested leaves are converted into commercial fiber product; (ii) low competitiveness when compared to synthetic fibers. This trend, coupled with these plant's adaptation mechanisms and new technologies for second generation ethanol production, provide a unique opportunity for renewable energy production in marginal lands. Additionally, projections regarding global warming suggest that there could be a gradual increase in the severity and frequency of extreme weather conditions, including higher temperatures and drought conditions. Agaves appear as a viable model to create agronomic solutions associated with climate change. Therefore, this project seeks to obtain the transcriptome of three Agave species and their glycome profile to understand the mechanisms regulating CAM and biomass production. (AU)