Oryza sativa dating from 12,000–11,000 BP indicates that wild rice collection was part of the local means of subsistence. Changes in the morphology of Diaotonghuan phytoliths dating from 10,000–8,000 BP show that rice had by this time been domesticated. Analysis of Chinese rice residues from Pengtoushan, which were carbon 14 dated to 8200–7800 BC, show that rice had been domesticated by this time. In 1998, Crawford and Shen reported the earliest of 14 AMS or radiocarbon dates on rice from at least nine Early to Middle Neolithic sites are no older than 7000 BC, that rice from the Hemudu and Luojiajiao sites
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