Different genetic strategies to generate high amylose starch mutants by engineering the starch biosynthetic pathways

Abstract

This review systematically documents the major different strategies of generating high-amylose (HAS) starch mutants aiming at providing high resistant starch, by engineering the starch biosynthesis metabolic pathways. We identify three main strategies based on a new representation of the starch structure: 'the building block backbone model': i) suppression of starch synthases for reduction of amylopectin (AP) side-chains; ii) suppression of starch branching enzymes (SBEs) for production of AM-like materials; and iii) suppression of debranching enzymes to restrain the transformation from over-branched pre-AP to more ordered AP. From a biosynthetic perspective, AM generated through the second strategy can be classified into two types: i) normal AM synthesized mainly by regular expression of granule-bound starch synthases, and ii) modified linear AP chains (AM-like material) synthesized by starch synthases due to the suppression of starch branching enzymes. The application of new breeding technologies, especially CRISPR, in the breeding of HAS crops is also reviewed.

Keywords

High-amylose starch; Biosynthesis; Amylose-like material; Starch branching enzyme; Backbone model

Published in

Carbohydrate Polymers
2022, volume: 287, article number: 119327
Publisher: ELSEVIER SCI LTD

SLU Authors

• Liu, Ying

  • Department of Plant Breeding, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Food Engineering

Publication identifier

• DOI: https://doi.org/10.1016/j.carbpol.2022.119327

Permanent link to this page (URI)

https://res.slu.se/id/publ/118357