Genomic and transcriptomic inventory of membrane transporters in coffee: Exploring molecular mechanisms of metabolite accumulation

The genus Coffea (Rubiaceae)encompasses a group of perennial plant species, including a commodity crop from which seeds are roasted, ground, and infused to make one of the most appreciated beverages in the world. As an important tropical crop restricted to specific regions of the world, coffee production is highly susceptible to the effects of environmental instabilities (i.e., local year-to-year weather fluctuations and global climate change)and threatening pest pressures, not to mention an increasing quality rigor by consumers in industrialized countries. Specialized metabolites are substances that largely affect plant-environment interactions as well as how consumers experience agricultural products. Membrane transporters are key targets, albeit understudied, for understanding and tailoring the spatiotemporal distribution of specialized metabolites as they mediate and control molecular trafficking and substance accumulation. Therefore, we analyzed the transportome of C. canephora encoded within the 25,574 protein-coding genes annotated in the genome of this species and identified 1847 putative membrane transporters. Following, we mined 152 transcriptional profiles of C. canephora and C. arabica and performed a comprehensive co-expression analysis to identify transporters potentially involved in the accumulation of specialized metabolites associated with beverage quality and bioactivity attributes. In toto, this report points to an avenue of possibilities on Coffea genomic and transcriptomic data mining for genetic breeding strategies, which can lead to the development of new, resilient varieties for more sustainable coffee production systems.