Review on isoleucic acid in plants (and mammals): biosyntheses, functions, knowledge gaps, and future research

In their review "the branched-chain amino acid-related isoleucic acid: recent research advances" authors Mekonnen, Ghirardo, Zhang, and Schäffner review recent progress in the characterization of isoleucic acid (ILA) biosynthesis and function in plants and discuss current knowledge gaps and future directions in ILA research. ILA plays a positive role in plant signalling for defence responses against bacterial pathogens by increasing the abundance of salicylic acid aglycone through competitive inhibition of SA deactivation by glucosylation. ILA is also important for humans with maple syrup urine disease who are defective in the catabolism of branched-chain amino acids (BCAAs), that is, isoleucine, leucine, and valine and accumulate BCAA breakdown products like 2-keto acid derivatives. They also summarize the differences in ILA biosynthesis, regulation, and functional roles in plants vs. mammals.
Read whole paper open access in our scientific journal Plant Biology (2025) DOI: 10.1111/plb.13771