Species-specific dynamics of specialized metabolism in germinating cereal grain revealed by temporal and tissue-resolved transcriptomics and metabolomics

We analyzed the metabolism of the defense compound dhurrin during sorghum grain germination and early seedling development in detail. Dhurrin is a cyanogenic glucoside, which is catabolized into different bioactive compounds at other stages of plant development, but its fate and role during germination is unknown. We dissected sorghum grain into three different tissues and investigated dhurrin biosynthesis and catabolism at the transcriptomic, metabolomic and biochemical levels. We further analyzed transcriptional signature differences of cyanogenic glucoside metabolism between sorghum and barley, which produces similar specialized metabolites.