Gene expression analysis of TcNPR1 in cacao. A. Expression of TcNPR1 in various cacao tissues. Total RNA samples were collected from open flowers, unopened flowers, roots, seeds, exocarp and three different leaf developmental stages from youngest to oldest (A, C and E) from cacao genotype Scavina6 (SCA6). Semi- quantitative RT-PCR was performed and cacao actin (TcActin) was used as cDNA loading control. B. Expression of TcNPR1 in cacao leaf tissue after salicylic acid (SA) treatment. Semi-quantitative RT-PCR was performed with cDNA from stage C leaves of two different cacao genotypes ICS1 (left panel) and SCA6 (right panel), sampled 24 hrs after SA treatment in three different concentrations (1 mM, 2 mM and 4 mM). Water-treated samples served as a control and TcActin was used as cDNA normalization control. C. Calculated average relative gene expression levels from B. Gel images were quantified by ImageQuant and expression of TcNPR1 was normalized to TcActin. Expression levels are presented as the means ± standard errors of three biological replicates.