Harmful Elements in Estuarine and Coastal Systems

Estuaries and coastal zones are dynamic transitional systems which provide many economic and ecological benefits to humans, but also are an ideal habitat for other organisms as well. These areas are becoming contaminated by various anthropogenic activities due to a quick economic growth and urbanization. This chapter explores the sources, chemical speciation, sediment accumulation and removal mechanisms of the harmful elements in estuarine and coastal seawaters. It also describes the effects of toxic elements on aquatic flora and fauna. Finally, the toxic element pollution of the Venice Lagoon, a transitional water body located in the northeastern part of Italy, is discussed as a case study, by presenting the procedures adopted to measure the extent of the pollution, the impacts on organisms and the restoration activities

Features on the surface of the tobacco rattle tobravirus particle that are antigenic and sensitive to proteolytic digestion

The particle proteins of tobraviruses and tobamoviruses share six sequence motifs, two of which are also present in furoviruses and hordeiviruses. Analyses of four different polyclonal antisera to tobacco rattle tobravirus by Pepscan revealed that the C-terminal region of the particle protein was immunodominant. The N-terminal region and a central region (residues 110-121) were more weakly immunogenic. These results suggest that these regions are exposed externally on the assembled virus particle. Papain digestion showed that the C terminus can be removed without apparent structural damage to the particle. The external location of the C-terminal region along the sides of the particle could explain some transmission properties of the rod-shaped viruses.</p

Antigenic analysis of nematode-transmissible and non-transmissible isolates of tobacco rattle tobravirus using monoclonal antibodies

Murine monoclonal antibodies (MAbs) were produced against a nematode non-transmissible isolate of tobacco rattle tobravirus (TRV-PLB). Two of the MAbs (SCR 80 and 81) did not react with the serologically closely related isolate TRV-PPK20 (both isolates belong to the PRN serotype), which is readily transmissible by nematodes. When further isolates of the PRN serotype were tested, all the non-transmissible ones reacted with these two MAbs, but so also did some of those that are readily transmissible. SCR 80 and 81 were able to trap TRV-PLB particles onto electron microscope grids and reacted with metatopes located near the C terminus of the particle protein. The epitope recognized by SCR 81 was discontinuous. The MAbs that reacted with both TRV-PLB and TRV-PPK20 recognized either continuous cryptotopes (SCR 78) or discontinuous neotopes (SCR 79 and 82).</p

Revisiting esca symptoms in the vineyard: results of a four-year survey

International audienc

Characterization of potato potyvirus Y (PVY) isolates from seed potato batches. Situation of the NTN, Wilga and Z isolates

A collection of 38 PVY isolates from seed potato batches, originating from several Western European countries, was characterized by using current biological, serological and molecular tools differentiating PVY strains and groups. The correlation between the three kinds of tests was good but not absolute. No single serological or PCR method was able to discriminate among the five isolate groups found. Twenty-nine isolates belonged to the PVY(N) strain and six to the PVY(O) strain. No PVY(C) was found. Two other isolates reacted serologically like PVY(O), but were unable to elicit a hypersensitive response from the Ny(tbr) gene and probably represent the PVY(Z) group. At the molecular level, these two isolates showed a combination of both PVY(O) and PVY(N) and could be recombinants of these strains. Another isolate reacted serologically like PVY(O), but induced vein necrosis in tobacco, like PVY(N)-Wilga. Some PVY(N) isolates caused tuber ring necrosis in glasshouse conditions. These might belong to the PVY(NTN) group. The PVY(NTN), PVY(N)-Wilga and PVY(Z) groups probably represent pathotypes within strains PVY(N) and PVY(O), respectively. The present study also confirms previous reports showing a high genetic variation at the 5' end within the PVY(N) strain