Distinct effects of PTST2b and MRC on starch granule morphogenesis in potato tubers.

ABSTRACT: The molecular mechanisms underpinning the formation of the large, ellipsoidal starch granules of potato tuber are poorly understood. Here, we demonstrate the distinct effects of PROTEIN TARGETING TO STARCH2b (PTST2b) and MYOSIN RESEMBLING CHLOROPLAST PROTEIN (MRC) on tuber starch granule morphology. A gene duplication event in the Solanaceae resulted in two PTST2 paralogs (PTST2a and PTST2b). PTST2b is expressed in potato tubers, and unlike PTST2a, it had no detectable interaction with STARCH SYNTHASE 4. MRC expression was detectable in leaves, but not in tubers. Using transgenic potato lines in the variety Clearwater Russet, we demonstrate that MRC overexpression leads to the formation of granules with aberrant shapes, many of which arise from multiple initiation points. Silencing PTST2b

SUBMITTER: Hochmuth A 

PROVIDER: S-EPMC11772324 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature