Noncatalytic functions of ISOAMYLASE 1 and 2 affect the proportion of insoluble and soluble α-polyglucans in maize.

ABSTRACT: Starch arose in chloroplast-containing species from a combination of prokaryotic and eukaryotic genes involved in the metabolism of soluble branched α-polyglucan, i.e. glycogen. Nonmutant plants entirely lack such soluble polymers and instead contain amylopectin in insoluble starch granules. The transition between soluble and insoluble branched α-polyglucans during plant evolution is not well understood. This study generated maize (Zea mays L.) lines exhibiting a gradually varying distribution between soluble α-polyglucan and starch in the endosperm. These chemotypes were determined by complexes of conserved α-(1→6)-glucosidases of the isoamylase class (ISA). Four independent spontaneous missense substitutions in the ISA1 subunit of these complexes each cause a distinct soluble/insoluble α

SUBMITTER: Hennen-Bierwagen TA 

PROVIDER: S-EPMC12510319 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature