Torres Manuel J, Tomilov Alexey A, Tomilova Natalya, Reagan Russell L, Yoder John I
Department of Plant Sciences, University of California, Davis, CA 95616, USA.
BMC Plant Biol. 2005 Nov 16;5:24. doi: 10.1186/1471-2229-5-24.
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.
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.
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.
列当科寄生植物在与宿主根或根因子接触时会发育侵入性根吸器。吸器的发育可以通过视觉监测，且迅速、高度同步，并且强烈依赖于宿主因子暴露；因此，它为研究不同植物根系之间的化学通讯提供了一个易于处理的系统。
三齿列当属兼性寄生植物，在与宿主植物根、根分泌物或纯化的吸器诱导酚类物质接触后几分钟内就开始吸器发育。为了鉴定与宿主根识别和早期吸器发育相关的基因，我们对抑制性消减文库（SSH）进行了测序，这些文库富集了在三齿列当根中暴露于拟南芥根或纯化的吸器诱导因子2,6 - 二甲氧基苯醌后五小时内受调控的转录本。来自三个SSH文库的九千多个EST序列及其后续组装可在Pscroph数据库http://pscroph.ucdavis.edu上获取。该网站还提供BLAST功能，并允许对功能注释进行关键词搜索。
用宿主根或吸器诱导因子处理的三齿列当根制备的文库中，富集了预测在应激反应、电子传递或蛋白质代谢中起作用的转录本。除了寄生植物研究外，Pscroph数据库还为根际相互作用、生物体之间的化学信号传递以及植物发育与进化的研究提供了有用的资源。
