Effects of Heavy Metals and Arbuscular Mycorrhiza on the Leaf Proteome of a Selected Poplar Clone: A Time Course Analysis

Arbuscular mycorrhizal (AM) fungi establish a mutualistic symbiosis with the roots of most plant species. While receiving photosynthates, they improve the mineral nutrition of the plant and can also increase its tolerance towards some pollutants, like heavy metals. Although the fungal symbionts exclusively colonize the plant roots, some plant responses can be systemic. Therefore, in this work a clone of Populus alba L., previously selected for its tolerance to copper and zinc, was used to investigate the effects of the symbiosis with the AM fungus Glomus intraradices on the leaf protein expression. Poplar leaf samples were collected from plants maintained in a glasshouse on polluted (copper and zinc contaminated) or unpolluted soil, after four, six and sixteen months of growth. For each harvest, about 450 proteins were reproducibly separated on 2DE maps. At the first harvest the most relevant effect on protein modulation was exerted by the AM fungi, at the second one by the metals, and at the last one by both treatments. This work demonstrates how importantly the time of sampling affects the proteome responses in perennial plants. In addition, it underlines the ability of a proteomic approach, targeted on protein identification, to depict changes in a specific pattern of protein expression, while being still far from elucidating the biological function of each protein

Soft Law as a New Mode of Governance: A Legal Perspective

After a brief review of the history and typology of soft law in public international law, we approach the concept deductively. We reject the binary view and subscribe to the continuum view. Building on the idea of graduated normativity and on the prototype theory of concepts, we submit that soft law is in the penumbra of law. It can be distinguished from purely political documents more or less readily, depending on its closeness to the prototype of law. Insights gained by the study of public international soft law are relevant to EC and EU soft law despite some differences between those legal orders. European soft law is created by institutions, Member States, and private actors. The legal effects of soft law acts can be clustered according to their relation to hard law. Both practical and normative considerations motivate reliance on soft law. An examination of the soft legal consequences of a disregard of soft law shows that compliance control mechanisms for hard and soft international law are converging. Moreover, some factors of compliance are independent of the theoretical hardness or softness of a given norm. In a legal policy perspective, the proliferation of soft law carries both dangers and benefits. Especially soft acts with a lawplus function do not weaken the respective regimes, but perfect them