A defesa vegetal contra fitopatógenos

Com o crescente desenvolvimento de tecnologias voltadas para a agricultura, são evidentes os incrementos na utilização de insumos, em especial de pesticidas. O uso de agroquímicos vem contribuindo para o aumento da produtividade agrícola, mas também tem sido responsável por efeitos adversos sobre o meio ambiente e a saúde humana. Atualmente, com o avanço da agricultura de base agroecológica, novas medidas de proteção de plantas vêm apresentando destaque, como a indução de resistência, que é ativação  de mecanismos de defesa vegetal para o controle de pragas e doenças. Um enorme volume de pesquisas dentro da fitopatologia se concentra no fenômeno da especificidade entre o patógeno e o hospedeiro, fenômeno de reconhecimento, do papel das fitotoxinas e enzimas microbianas extracelulares na patogênese e dos fatores bioquímicos de resistência, como compostos fenólicos, fitoalexinas e proteínas relacionadas a patogênese. As plantas medicinais possuem compostos secundários que tanto podem ter ação fungitóxica (ação antimicrobiana direta) como elicitora, ativando mecanismos de defesa nas plantas (ação indireta).  O uso de medicamentos homeopáticos também usados como métodos de controle alternativo tem demonstrado capacidade para induzir a produção de metabólitos  secundários como às proteínas relacionadas à patogênese.  Esta revisão contém informações sobre trabalhos com extratos de plantas medicinais e homeopatia em modelos vegetais, onde o uso destes tem sido buscado como principal objetivo o controle de fitopatógenos, sua potencialidade e perspectivas de avanço visando uma agricultura de baixo impacto

Ten practical realities for institutional animal care and use committees when evaluating protocols dealing with fish in the field

Institutional Animal Care and Use Committee’s (IACUCs) serve an important role in ensuring that ethical practices are used by researchers working with vertebrate taxa including fish. With a growing number of researchers working on fish in the field and expanding mandates of IACUCs to regulate field work, there is potential for interactions between aquatic biologists and IACUCs to result in unexpected challenges and misunderstandings. Here we raise a number of issues often encountered by researchers and suggest that they should be taken into consideration by IACUCs when dealing with projects that entail the examination of fish in their natural environment or other field settings. We present these perspectives as ten practical realities along with their implications for establishing IACUC protocols. The ten realities are: (1) fish are diverse; (2) scientific collection permit regulations may conflict with IACUC policies; (3) stakeholder credibility and engagement may constrain what is possible; (4) more (sample size) is sometimes better; (5) anesthesia is not always needed or possible; (6) drugs such as analgesics and antibiotics should be prescribed with care; (7) field work is inherently dynamic; (8) wild fish are wild; (9) individuals are different, and (10) fish capture, handling, and retention are often constrained by logistics. These realities do not imply ignorance on the part of IACUCs, but simply different training and experiences that make it difficult for one to understand what happens outside of the lab where fish are captured and not ordered/purchased/reared, where there are engaged stakeholders, and where there is immense diversity (in size, morphology, behaviour, life-history, physiological tolerances) such that development of rigid protocols or extrapolation from one species (or life-stage, sex, size class, etc.) to another is difficult. We recognize that underlying these issues is a need for greater collaboration between IACUC members (including veterinary professionals) and field researchers which would provide more reasoned, rational and useful guidance to improve or maintain the welfare status of fishes used in field research while enabling researchers to pursue fundamental and applied questions related to the biology of fish in the field. As such, we hope that these considerations will be widely shared with the IACUCs of concerned researchers