Figure 5

Silique amino acid composition of three dmr1 mutant alleles. Gas chromatography mass spectroscopy (GC-MS) was used to identify and quantify the amino acids present in dmr1-1, dmr1-2 and dmr1-3 compared to eds1-2 in the absence of Fusarium infection. Homoserine (a) was not detectable in eds1-2 siliques but was abundant in the siliques of the dmr1 mutants. Despite the absence of a functional homoserine kinase in the dmr1 mutants, levels of threonine (b) isoleucine (c) glycine (d) and methionine (e), downstream products of homoserine phosphorylation, were not reduced in the dmr1 mutants compared to eds1-2. The level of an uncharacterised amino acid (f) was also elevated in all three dmr1 mutants. Analysis was done on three independent biological silique samples per genotype. Bar = standard error.