Nucleic Acids Res 1988, 16:4341–4352.PubMedCrossRef 30. Kieser T, Bibb MJ, Buttner MJ, Chater KF, Hopwood DA: Practical Streptomyces genetics John Innes Foundation, Norwich, United Kingdom 2000. 31. Strauch E, Takano E, Baylis HA, Bibb MJ: The stringent response in Streptomyces coelicolor A3(2). Mol Microbiol 1991, 5:289–298.PubMedCrossRef 32. Sambrook J, Fitsch EF, Maniatis T: Molecular Cloning: A Laboratory Manual Fulvestrant concentration Cold Spring Harbor, Cold Spring Harbor Press 1989. 33. Kuhstoss S, Rao RN: Analysis of the integration function of the streptomycete bacteriophage φC31. J Mol Biol 1991, 222:897–908.PubMedCrossRef 34. Okamoto S, Ochi K: An essential GTP-binding protein functions

as a regulator for differentiation in Streptomyces coelicolor. Mol Microbiol 1998, 30:107–119.PubMedCrossRef Authors’ contributions PFX conceived of the entire study, performed most of the experiments including gene (s) disruption, protein expression/purification, western blotting, microscopy, RT-PCR, and also drafted the manuscript. AZ performed disruption of genes in S. lividans ZX7. ZJQ was involved in project design, and prepared the manuscript.

All authors discussed the results and assisted with editing of the manuscript.”
“Background Moniliophthora perniciosa (Stahel) click here Aime and Phillip-Mora (2005) [1] is a hemibiotrophic basidiomycete that causes Witches’ Broom Disease (WBD) in cocoa (Theobroma cacao L). Currently, WBD occurs in South and Central America and can cause crop losses of up to 90% [2]. In Bahia (Brazil), M. perniciosa C-X-C chemokine receptor type 7 (CXCR-7) was identified in 1989 [3] and, as a consequence of its spreading, the annual production of cocoa beans dropped from 450,000 to 90,000 tons within 12 years, reducing export values from an all-time high of about US$ 1 billion to 110 million. During this period nearly 200,000 rural workers lost their jobs, resulting in an intensive migration from farms to urban areas [4]. The fungus infects young meristematic tissues inducing hypertrophy and hyperplasia, loss of apical dominance, and proliferation

of axillary shoots. The hypertrophic growth of the infected vegetative meristems (green broom) is the most characteristic symptom of WBD [5]. Basidiomata, in which basidiospores are produced, develop on dead but attached dry brooms of cacao trees in the field, after dry and wet periods. Basidiospores are spread by wind and depend on sufficient moisture for survival. They can only germinate on and infect susceptible cacao tissues (i.e. buds, young leaves, flower cushions, or young pods) if relative humidity levels are near 100%. Shortly after infection the pathogen establishes a biotrophic relationship with the host during which the fungus has an intercellular, biotrophic, monokaryotic growth phase, without clamp connections.