title: Pscroph, a parasitic plant EST database enriched for parasite associated transcripts.
abstract: BACKGROUND
  Parasitic plants in the Orobanchaceae develop invasive root haustoria upon contact with host roots or root factors. The development of haustoria can be visually monitored and is rapid, highly synchronous, and strongly dependent on host factor exposure; therefore it provides a tractable system for studying chemical communications between roots of different plants.
  
  
  METHODS
  Triphysaria is a facultative parasitic plant that initiates haustorium development within minutes after contact with host plant roots, root exudates, or purified haustorium-inducing phenolics. In order to identify genes associated with host root identification and early haustorium development, we sequenced suppression subtractive libraries (SSH) enriched for transcripts regulated in Triphysaria roots within five hours of exposure to Arabidopsis roots or the purified haustorium-inducing factor 2,6 dimethoxybenzoquinone. The sequences of over nine thousand ESTs from three SSH libraries and their subsequent assemblies are available at the Pscroph database http://pscroph.ucdavis.edu. The web site also provides BLAST functions and allows keyword searches of functional annotations.
  
  
  CONCLUSIONS
  Libraries prepared from Triphysaria roots treated with host roots or haustorium inducing factors were enriched for transcripts predicted to function in stress responses, electron transport or protein metabolism. In addition to parasitic plant investigations, the Pscroph database provides a useful resource for investigations in rhizosphere interactions, chemical signaling between organisms, and plant development and evolution.
authors.affiliation: Department of Plant Sciences, University of California, Davis, CA 95616, USA. mjtorres@uga.edu
authors.forename: Manuel J
authors.initials: MJ
authors.lastname: Torres
authors.forename: Alexey A
authors.initials: AA
authors.lastname: Tomilov
authors.forename: Natalya
authors.initials: N
authors.lastname: Tomilova
authors.forename: Russell L
authors.initials: RL
authors.lastname: Reagan
authors.forename: John I
authors.initials: JI
authors.lastname: Yoder
mesh_terms: D017360:Arabidopsis / Q000033:anatomy & histology / Q000469:parasitology; D016227:Benzoquinones / Q000494:pharmacology; D019295:Computational Biology; D030561:Databases, Nucleic Acid; D020224:Expressed Sequence Tags; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D006790:Host-Parasite Interactions; D031670:Orobanchaceae / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D018517:Plant Roots / Q000033:anatomy & histology / Q000254:growth & development / Q000469:parasitology; D018749:RNA, Plant / Q000737:chemistry*
chemical_list: D016227:Benzoquinones; D018749:RNA, Plant