Plastidial starch phosphorylase regulates maltodextrin turnover during starch granule initiation in Arabidopsis leaves.

ABSTRACT: PLASTIDIAL STARCH PHOSPHORYLASE 1 (PHS1) is considered integral to starch synthesis, yet its role in transient starch synthesis in photosynthetic tissues remains unclear, as mutation of PHS1 in Arabidopsis (Arabidopsis thaliana) does not affect the metabolic profile of leaves. PHS1 activity is elevated in the starch branching enzyme sbe2.1 sbe2.2 double mutant, which lacks starch granules but retains intact genes encoding granule initiation proteins, making it an ideal plant material for exploring PHS1 function. We generated a triple mutant, sbe2.1 sbe2.2 phs1-1, which showed additional accumulation of soluble maltodextrins, a loss of insoluble linear α-glucans in the leaves, and substantially retarded plant growth, compared to the sbe2.1 sbe2.2 double mutant. STARCH SYNTHASE 3 (SS3) and S

SUBMITTER: Wang L 

PROVIDER: S-EPMC12203538 | biostudies-literature | 2025 May

REPOSITORIES: biostudies-literature