Raceme and glumes arranged in two opposite rows along the spikelet. Examples occur on rice (species "Oryza sativa") and wheat (genus "Triticum"), both grasses. An ament or catkin is very similar to a spike or raceme, "but with subtending bracts so conspicuous as to conceal the flowers until pollination, as in the pussy–willow, alder, [and] birch...". These are sometimes called amentaceous plants. A spadix is a form of spike in which the florets are densely crowded along a fleshy axis, and enclosed by one or more large, brightly–colored bracts called spathes. Usually the female flowers grow at the base, and male
Arogenate dehydratase hybrida", "Sorghum bicolor"", "and "Oryza sativa"", "which are all considered higher-order plants. "Erwinia herbicola"" and Pseudomonas aeruginosa"" "are known to" "have homologues for cyclohexadienyl dehydratase. Of the plants with ADT homologues, both "Arabidopsis thaliana "and "Petunia hybrida "are known to have paralogues for the gene (six and three, respectively). Arogenate dehydratase Arogenate dehydratase (ADT) (EC 4.2.1.91) is an enzyme that catalyzes the chemical reaction Hence, this enzyme has one substrate, L-arogenate, but 3 products:L-phenylalanine, HO, and CO. Certain forms of the protein have the potential to catalyze a second reaction, L-prephenate → L-phenylpyruvate + HO + CO This enzyme participates