RESEARCH ARTICLE Global transcriptome anal a

ial cells under fungal attack, where they accumulate in cyto- of isoquinoline alkaloids. Cytochrome P450s are diversi-Mizuno et al. BMC Plant Biology 2012, 12:121 http://www.biomedcentral.com/1471-2229/12/121[2,8]. These are structurally similar to anthocyaninsCenter, 1-2, Kannondai 2-chome, Tsukuba, Ibaraki 305-8602, JapanFull list of author information is available at the end of the articleplasmic inclusion bodies. The inclusions migrate to the site of attempted penetration, become pigmented, and ultimately release phytoalexins to kill the fungus [2]. Phytoalexins are produced mainly from aromatic amino acids (phenylalanine (Phe), tyrosine (Tyr)) by the action of many enzymes that sequentially catalyze biochemical reactions. Phenylalanine ammonia lyase (PAL) catalyzes fied to make various phytoalexins and participants in metabolic networks, such as anthocyanins, tannins, fla-vones, and isoflavonoid [6,7]. For phytoalexin synthesis, proper enzyme activity is required not only to synthesize the products needed, but also to avoid the accumulation of toxic metabolites. Sorghum (Sorghum bicolor L. Moench) is the fifth most commonly grown cereal in the world and is a rich source of sorghum-specific natural products. In response to pathogen infection, sorghum synthesizes a unique class of flavonoid phytoalexins, namely 3-deoxyanthocyanidins * Correspondence