Insights into the control of metabolism and biomass accumulation in a staple C4 grass

Abstract

The shikimate pathway is key to the synthesis of aromatic amino acids and many secondary metabolites in plants. Chen et al. (2020) identified the biomass yield 1 (by1) mutant in Sorghum using an ethylmethane sulfonate (EMS) mutagenesis screen. The mutation mapped to an amino acid substitution in the sequence of d-arabinoheptulosonate- 7-phosphate synthase (DAHPS)-the enzyme catalysing the first committed step of the shikimate pathway. Reduced DAHPS activity in by1 mutants resulted in severe defects in growth and development, such as reduced height, narrow leaves and stem, and abnormal floral organs, which ultimately led to less biomass and yield production. The by1 mutant reveals novel information regarding the integration of primary and secondary metabolism and how this influences growth and development.