Mixed-Linkage Glucan Is the Main Carbohydrate Source and Starch Is an Alternative Source during Brachypodium Grain Germination

ABSTRACT: Seeds of the model grass Brachypodium distachyon are unusual because they contain very little starch and high levels of mixed-linkage glucan (MLG) accumulated in thick cell walls. It was suggested that MLG might supplement starch as a storage carbohydrate and may be mobilised during germination. In this work, we observed massive degradation of MLG during germination in both endosperm and nucellar epidermis. The enzymes responsible for the MLG degradation were identified in germinated grains and characterized using heterologous expression. By using mutants targeting MLG biosynthesis genes, we showed that the expression level of genes coding for MLG and starch-degrading enzymes was modified in the germinated grains of knocked-out cslf6 mutants depleted in MLG but with higher starch content.

SUBMITTER: Francin-Allami M 

PROVIDER: S-EPMC10095428 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature