Gossypium hirsutum (commercial cooton) is one of the most economically important fibers sources and a commodity crop highly affected by insect pests and pathogens. Several transgenic approaches have been developed to improve cotton resistance to insect pests, through the transgenic expression of different factors, including Cry toxins, proteinase inhibitors, and toxic peptides, among others. In the present study, we developed transgenic cotton plants by fertilized floral buds injection (through the pollen-tube pathway technique) using an DNA expression cassette harboring the cry1Ia12 gene, driven by CaMV35S promoter. The T0 transgenic cotton plants were initially selected with kanamycin and posteriorly characterized by PCR and Southern blot experiments to confirm the genetic transformation. Western blot and ELISA assays indicated the transgenic cotton plants with higher Cry1Ia12 protein expression levels to be further tested in the control of two major G. hirsutum insect pests. Bioassays with T1 plants revealed the Cry1Ia12 protein toxicity on Spodoptera frugiperda larvae, as evidenced by mortality up to 40% and a significant delay in the development of the target insects compared to untransformed controls (up to 30-fold). Also, an important reduction of Anthonomus grandis emerging adults (up to 60%) was observed when the insect larvae were fed on T1 floral buds. All the larvae and adult insect survivors on the transgenic lines were weaker and significantly smaller compared to the non-transformed plants. Therefore, this study provides GM cotton plant with simultaneous resistance against the Lepidopteran (S. frugiperda), and the Coleopteran (A. grandis) insect orders, and all data suggested that the Cry1Ia12 toxin could effectively enhance the cotton transgenic plants resistance to both insect pests.
Resumo: Introdução: As atuais Diretrizes Curriculares Nacionais (DCN) dos cursos de graduação em Medicina visam atualizar e transformar a escola médica brasileira incentivando currículos interdisciplinares e o uso de métodos ativos de ensino. O desafio de reduzir a adoção de aulas expositivas tende a impactar tanto discentes quanto docentes, que podem ser resistentes às mudanças quando estas não são apoiadas em pesquisas com a devida reflexão crítica. Desenvolvimento: Neste artigo, apresentamos um protocolo desenvolvido pela equipe do Núcleo de Apoio Pedagógico e Experiência Docente da Faculdade de Medicina da Universidade de Brasília em que se utilizam dois questionários para a realização de estudos quali-quantitativos que visem avaliar a motivação e a percepção de docentes e discentes em relação aos distintos métodos de ensino e aprendizagem. O protocolo foi criado para auxiliar a compreensão da dinâmica, dos desafios e das expectativas acerca do processo de ensino e aprendizagem. Conclusão: Coletar, analisar, descrever, interpretar e divulgar dados sobre a motivação e a percepção de docentes e discentes relacionadas aos distintos métodos é importante para fundamentar ações que visem promover a melhoria do ensino. O protocolo apresentado neste artigo pode ser aplicado em cenários diversos e poderá contribuir para o processo de desenvolvimento de um ensino médico mais alinhado às DCN.
This work was conducted to assess whether or not a natural occurring polysaccharide from Adenanthera pavonina seeds (PLSAp) and its chemically sulfated derivative galactomannan (SPLSAp), which did not act as fungicides, induce defense proteins and protect a susceptible cowpea (Vigna unguiculata) genotype (BR3-Tracuateua) against the phytopathogenic fungus Colletotrichum gloeosporioides. Twelve-day-old plants were sprayed to runoff with PLSAp or SPLSAp, both at 100 and 200 mg L-1 , dissolved in 0.01% Triton X-100, which served as control. The primary leaves were collected at 0, 6, 12, 24, and 48 h after the carbohydrate treatments and the activities of guaiacol peroxidase (POX), β-1,3-glucanase (βGLU), and chitinase (CHI) were determined to verify the ability of the studied galactomannans to induce alterations in their kinetics. In addition, the primary leaves of a plant group previously sprayed with SPLSAp and 6 h later inoculated with C. gloeosporioides were collected at 0, 6, 12, 24, and 48 h after the polysaccharide treatment, the enzyme activities measured, and the severity of the fungal disease evaluated. SPLSAp induced more prominently POX, βGLU, and CHI activity than PLSAp. Importantly, the combined treatment of SPLSAp and C. gloeosporioides was even more effective as enzyme inductor than SPLSAp alone, and the necrotic lesions of the anthracnose disease caused by the fungus were much less severe compared to control plants. The results indicate that SPLSAp induces plant defense proteins and increases the cowpea tolerance to C. gloeosporioides. These findings indicate that SPLSAp merits further investigation as a promising alternative or a supplemental environmentally friendly protector agent against anthracnose.
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