Marine Phytophthora species can hamper conservation and restoration of vegetated coastal ecosystems

Phytophthora species are potent pathogens that can devastate terrestrial plants, causing billions of dollars of damage yearly to agricultural crops and harming fragile ecosystems worldwide. Yet, virtually nothing is known about the distribution and pathogenicity of their marine relatives. This is surprising, as marine plants form vital habitats in coastal zones worldwide (i.e. mangrove forests, salt marshes, seagrass beds), and disease may be an important bottleneck for the conservation and restoration of these rapidly declining ecosystems. We are the first to report on widespread infection of Phytophthora and Halophytophthora species on a common seagrass species, Zostera marina (eelgrass), across the northern Atlantic and Mediterranean. In addition, we tested the effects of Halophytophthora sp. Zostera and Phytophthora gemini on Z. marina seed germination in a full-factorial laboratory experiment under various environmental conditions. Results suggest that Phytophthora species are widespread as we found these oomycetes in eelgrass beds in six countries across the North Atlantic and Mediterranean. Infection by Halophytophthora sp. Zostera, P. gemini, or both, strongly affected sexual reproduction by reducing seed germination sixfold. Our findings have important implications for seagrass ecology, because these putative pathogens probably negatively affect ecosystem functioning, as well as current restoration and conservation efforts

Transplacental transfer of melamine

Objective: To characterize transplacental transfer of melamine and related mechanisms as well as toxicity using human placental perfusion and cultured cells. Methods: Transfer and toxicity were analyzed in 4-h perfusions with 10 μM or 1 mM melamine, or 10 μM melamine with 10 nM cyanuric acid (CYA). Efflux transporters were studied in accumulation assay and toxicity in BeWo cells by MTT assay. Results: Of added melamine 34-45% was transferred to fetal circulation and CYA made no difference. Histology, hCG production, and PLAP activity indicated functionality of placental tissue with no grave toxicity. Highest concentration of melamine used (2 mM) with CYA and long treatment time decreased viability of BeWo cells. Inhibitors of ABCB1, ABCG2, ABCC2 did not affect the accumulation of melamine in cells. Conclusion: Melamine goes through human term placenta with no contribution of efflux transporters. Toxicity of melamine is low in placental tissue and BeWo cells. © 2011 Elsevier Ltd. All rights reserved.link_to_subscribed_fulltex