Expression of starch-binding factor CBM20 in barley plastids controls the number of starch granules and the level of CO2 fixation.

ABSTRACT: The biosynthesis of starch granules in plant plastids is coordinated by the orchestrated action of transferases, hydrolases, and dikinases. These enzymes either contain starch-binding domain(s) themselves, or are dependent on direct interactions with co-factors containing starch-binding domains. As a means to competitively interfere with existing starch-protein interactions, we expressed the protein module Carbohydrate-Binding Motif 20 (CBM20), which has a very high affinity for starch, ectopically in barley plastids. This interference resulted in an increase in the number of starch granules in chloroplasts and in formation of compound starch granules in grain amyloplasts, which is unusual for barley. More importantly, we observed a photosystem-independent inhibition of CO2 fixation, with

SUBMITTER: Zhong Y 

PROVIDER: S-EPMC6913705 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature