Diurnal Rhythms in Plant Defense Metabolites Figure 5. Diurnal rhythms and OS elicitation of Phe and Tyr and their related genes in different tissues. (A) Schematic overview of Phenylalanine (Phe) and Tyrosine (Tyr) metabolism. CM, chorismate mutase; ADT, arogenate dehydratase; PAL, phenylalanine ammonia lyase; C4H, cinnamate 4-hydroxylase; 4CL, 4-coumarate-coa ligase; TyrA, arogenate dehydrogenase; THT, tyramine N-hydroxycinnamoyltransferase; SAMDC, S- adenosylmethionine decarboxylase; SPDS, spemidine synthase. (B) Diurnal expression of genes encoding Phe or Tyr metabolism enzymes in source leaves. Gray box depicts the dark period. Ratio to average: Ratio of transcript abundance at the time point shown, to the mean abundance of the same transcript across all time points. Mean (6SE) levels of normalized intensity of Phe (C; m/z 164.07 at 192 s, C9H10NO22) and Tyr (G; m/z 180.07 at 144 s, C9H10NO32) in treated leaves, untreated leaves and roots at each harvest time for two days (gray dashed lines) in control plants. After W+W PLoS ONE | www.plosone.org 7 October 2011 | Volume 6 | Issue 10 | e26214