Mutations in Two Aphid-Regulated -1,3-Glucanase Genes by CRISPR/Cas9 Do Not Increase Barley Resistance to L.

Callose deposition is induced in plants by various stress factors such as when plants are attacked by herbivores and pathogens. In the case of aphids, callose plugging of aphid-damaged phloem sieve tubes is expected to reduce aphid access to the phloem sap, while aphid-induced upregulation of callose-degrading -1,3-glucanase genes in the host plant might counteract this negative effect on aphid performance. We have tested this hypothesis with barley mutants in which one or both of two -1,3-glucanase genes (1636 and 1639) have been mutated by CRISPR/Cas9 technique in cv.