Assistant Professor University of Illinois at Urbana-Champaign Urbana, Illinois
Body of Abstract: Efforts to increase oil accumulation in the stems of highly productive crops such as sugarcane, energy cane, and sorghum have been hindered by pleiotropic effects associated with constitutive promoter usage. To overcome this challenge, we aimed to identify promoters that are specific to the stem parenchyma, enabling efficient utilization of stored photoassimilates. Through an integrative approach involving RNA-seq atlas analysis, in silico examination of the sugarcane genome, phylogenetic analysis, quantitative PCR, and RNA in situ hybridization, we identified two TST genes, pTST1 and pTST2b, encoding tonoplast sugar transporters highly expressed in cane stems. Moreover, we characterized the promoters of two alleles, TST2b-1A and TST2b-1C, from one of the TST genes. Promoter analysis demonstrated these two promoters were capable of driving GUS expression exclusively in the stem when tested in Arabidopsis. Our findings offer promising avenues for future research and the development of strategies to enhance oil accumulation in the stems of highly productive crops. This advancement could facilitate the large-scale production of biofuels, lubricants, and high-value lipid-based products. These stem parenchyma-specific promoters also hold potential for broader applications in biological studies associated with this critical plant tissue.