Transcriptomic (RNA-seq) analysis of genes  responsive to cadmium stress  in Theobroma cacao
Dietary exposure to the heavy metal Cadmium (Cd) can lead to several human health problems. Cd has been detected in cacao beans (T. Cacao) grown in South American countries, including Colombia at significant levels. Despite this, the mechanisms involved in uptake, transport, and accumulation of Cd in cacao are not known. To investigate this, cacao plants were grown in a hydroponic platform and exposed to 10 ppm Cd in the hydroponic media. Accumulation levels in leaves were measured as well as the effect on gene expression using transcriptome sequencing. The highest and lowest uptake was identified in genotypes PA-122 and TSH-660, respectively. Roots and leaves were sampled at 0 hours (moments before 10 ppm Cd exposure), leaves were sampled 24 hours and leaves and roots 48 hours after treatment. We identify genes involved in signal transduction, ROS signaling, and metal ion transport that were significantly up and down-regulated.