11 research outputs found

    INVESTIGAÇÃO E TDIC NO ENSINO E NA APRENDIZAGEM DE CIÊNCIAS: RELATO DE UMA OFICINA ACERCA DA RELAÇÃO ENTRE VIDA, PIGMENTOS E DNA DE PLANTAS

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    The expository method is known to be prevalent in basic education in Brazil. However, there arealternatives to this approach, such as educational technologies known as active methodologies, ofwhich teaching by inquiry is an example. Faced with the global challenge of social distancingresulting from the Covid-19 pandemic, remote or hybrid teaching became a reality, on a contingentand emergency basis, which represented difficulties and opportunities to reflect, implement andevaluate research teaching in the context of application of digital information and communicationtechnologies (TDIC). This work is an account of a workshop inspired by this, held in remote format,in a Moodle environment and with the use of TDIC, with the application of the investigativemethod for teaching the theme Life: DNA and pigments, aimed at students in the last years ofthe Elementary School II and High School students. The workshop took place in the format of aDidactic Sequence with moments of exposition of problem situations, carrying out experimentsand reporting and discussion of results as systematization. In the end, it was observed that themethodology used provided effective learning about the relationship between life and DNA, inaddition to improvements in students’ abilities to collect, interpret, analyze and reframe data ininvestigative instructional processes.O método expositivo é sabidamente prevalente na educação básica no Brasil. Entretanto, há alternativas a essa abordagem, como as tecnologias da educação conhecidas como metodologias ativas, das quais o ensino por investigação é um exemplo. Diante do desafio mundial de distanciamento social consequente da pandemia de Covid-19, tornou-se realidade o ensino remoto ou híbrido, em caráter contingente e emergencial, o que representou dificuldades e oportunidades de refletir, implementar e avaliar o ensino por investigação no contexto da aplicação das tecnologias digitais de informação e comunicação (TDIC). Este trabalho é um relato de uma oficina assim inspirada, ocorrida no formato remoto, em ambiente Moodle e com o uso de TDIC, com a aplicação do método investigativo para o ensino do tema Vida: DNA e pigmentos, voltada para estudantes dos últimos anos do Ensino Fundamental II e estudantes de Ensino Médio. A oficina se deu no formato de uma Sequência Didática com momentos de exposição de situações problema, realização de experimentos e relato e discussão dos resultados como sistematização. Ao final, observou-se que a metodologia empregada proporcionou aprendizagens efetivas acerca da relação entre vida e DNA, além de melhorias nas habilidades dos estudantes em colher, interpretar, analisar e ressignificar dados em processos instrucionais investigativos

    Mécanismes moléculaires de la première étape de la réponse mediée par ABA chez Coffea ssp

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    Abscisic acid (ABA) is a phytohormone universally conserved in land plants which coordinates several aspects of the plant response to water deficit such as root architecture, seed dormancy and regulation of stomatal closure. A mechanism of ABA signal transduction has been proposed, evolving intracellular ABA receptors (PYR/PYL/RCARs) interacting with PP2Cs phosphatases and SnRK2 protein kinases regulating this tripartite protein system. The goal of this study was to identify and characterize for the first time the orthologs genes of this tripartite system in Coffea. For this purpose, protein sequences from Arabidopsis, citrus, rice, grape, tomato and potato were chosen as query to search orthologous genes in the Coffee Genome Hub (http://coffee-genome.org/). Differential expression in tissues as leaves, seeds, roots and floral organs was checked through in silico analyses. In vivo gene expression analyses were also performed by RT-qPCR in leaves and roots of drought-tolerant (DT 14, 73 and 120) and drought-susceptible (DS 22) C. canephora Conilon clones submitted (or not) to drought. The expression profiles of the tripartite system CcPYL-PP2C-SnRK2 genes were also analyzed in leaves of C. arabica (Ca) and C. canephora (Cc) plants grown under hydroponic condition and submitted to exogenous ABA treatment (500 µM). This approach allowed the identification and characterization of 24 candidate genes (9 PYL/RCARs, 6 PP2Cs and 9 SnRK2s) in Cc genome. The protein motifs identified in the predict coffee sequences enabled characterize these genes as family’s members of PYL/RCARs receptors, PP2Cs phosphatases or SnRK2 kinases of the ABA-dependent response pathway. These families were functionally annotated in the Cc genome. In vivo analyses revealed that eight genes were up-regulated under drought conditions in both leaves and roots tissues. Among them, three genes coding phosphatases were expressed in all (DT and DS) clones therefore suggesting that they were activated as a general response to cope with drought stress. However, two other phosphatase coding genes were up-regulated only in the DT clones, suggesting that they constitute key-genes for drought tolerance in these clones. The DT clones also showed differential gene expression profiles for five other genes thus reinforcing the idea that multiple biological mechanisms are involved in drought tolerance in Cc. In response to exogenous ABA, 17 genes were expressed in leaves of Cc and Ca plants. Several genes were differentially expressed in the DT clone 14 either in control condition or after 24h with ABA treatment. Under control condition, five genes were higher expressed as in the Cc as in Ca DT plants. The kinase CcSnRK2.6 was highlighted as a gene specifically expressed in the Cc plants (DT and DS) after 72h of ABA treatment. Overall, it was observed that ABA signaling pathway is delayed in the DS C. arabica Rubi. Those molecular evidences corroborated with microscopies analyses which showed that the DT clone 14 was more efficient to control the stomatal closure than other coffee plants in response to ABA treatment. All these evidences will help us to identify the genetic determinism of drought tolerance through ABA pathway essential to obtain molecular markers that could be used in coffee breeding programsL'acide abscissique (ABA) est une phytohormone universellement conservée dans les plantes terrestres qui coordonne plusieurs aspects de la réponse des plantes au déficit hydrique telles que l'architecture de la racine, la dormance des graines et la régulation de la fermeture des stomates. Un mécanisme de transduction du signal de l'ABA a été proposé incluant des récepteurs intracellulaires (ABA PYR/PYL/RCARs) qui coopèrent avec les phosphatases PP2Cs et des protéines kinases SnRK2 régulant ce système tripartite. Le but de cette étude était d'identifier et de caractériser pour la première fois les gènes orthologues de ce système tripartite chez Coffea. Ainsi, les séquences de protéines d'Arabidopsis, de citrus, du riz, du raisin, de la tomate et de la pomme de terre ont été choisis pour la requête des gènes orthologues dans le Coffee Genome Hub (http://coffee-genome.org/). L'expression différentielle dans les tissus tels que les feuilles, les graines, les racines et les organes floraux a été vérifié par le biais des analyses in silico. L'expression des gènes in vivo a été également réalisée par RT-qPCR dans les feuilles et les racines des clones Conilon de C. canephora tolérant (DT 14, 73 et 120) et susceptibles soumis (ou non) à la sécheresse (DS 22). Les profils d'expression des genes du système tripartite CcPYL-PP2C-SnRK2 ont également été analysés dans des feuilles de C. arabica (Ca) et de C. canephora (Cc) cultivées dans des conditions hydroponiques et soumis à un traitement d´ABA exogène (500 uM). Cette approche a permis l'identification et la caractérisation de 24 gènes candidats (9 PYR/PYL/RCARs, 6 PP2Cs et 9 SnRK2s) dans le génome de Cc. Les motifs protéiques identifiés dans les séquences de café ont permis la caractérisation de ces gènes comme des membres de la famille des récepteurs PYL /RCARs, les phosphatases PP2Cs ou kinase SnRK2 de la voie de réponse dépendante d'ABA. Ces familles ont été fonctionnellement annotés dans le génome de Cc. Les analyses in vivo ont révélées que huit gènes étaient surexprimé en condition de sécheresse dans les feuilles et les racines. Parmi eux, trois gènes codant phosphatases se sont exprimés dans tous les clones (DT et DS), suggèrant qu'ils ont été activés comme une réponse générale face au stress de la sécheresse. Cependant, deux autres gènes de la phosphatase de codage n´ont été surexprimé que dans les clones DT, suggèrant qu'ils constituent les principaux gènes de tolérance à la sécheresse chez ces clones. Les clones DT ont également montré des profils d'expression génique différents pour les cinq autres gènes, renforçant ainsi l'idée que des multiples mécanismes biologiques sont impliqués dans la tolérance à la sécheresse en Cc. En réponse à l´ABA exogène, 17 gènes se sont exprimés dans les feuilles des plantes Cc et Ca. Plusieurs gènes se sont exprimés differament chez le clone DT 14, soit en traitement contrôle ou après 24h de traitement avec ABA. En condition contrôle, cinq gènes se sont surexprimés aussi bien chez le Cc que chez le Ca DT. La kinase CcSnRK2.6 a été soulignée comme un gène exprimé spécifiquement chez le Cc (DT et DS) après 72h de traitement avec ABA. En géneral, on a observé que la voie de signalisation de l'ABA est retardée chez le DS Ca Rubi. Ces preuves moléculaires sont confirmées par des analyses de microscopie montrant que le clone DT 14 était plus efficace dans le contrôle de la fermeture des stomates que d'autres plantes de café en réponse au traitement d´ABA. Tous ces évidences nous aideront à identifier le déterminisme génétique de la tolérance à la sécheresse par la voie de l´ABA, essentielle pour obtenir des marqueurs moléculaires qui pourraient être utiles dans les programmes de sélection du café

    Expression of DREB-like genes in Coffea canephora and C. arabica subjected to various types of abiotic stress

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    The aim of this work was to study the regulation of coffee DREB-like genes in leaves of C. arabica subjected to cold, heat, low relative humidity, exogenous abscisic acid and high light stress, as well as in leaves and roots of drought-tolerant and drought-susceptible clones of Coffea canephora subjected to water limitation. In C. arabica, CaERF017 was the most expressed gene under low temperatures and relative humidity, while low humidity and high temperatures up-regulated the expression of CaERF053 and CaERF014, respectively. Under water limitation, CcDREB1B, CcRAP2.4, CcERF027, CcDREB1D and CcTINY were the most expressed genes mainly in leaves of drought-tolerant C. canephora. On the other hand, expression of the CcERF016, CcRAP2.4 and CcDREB2F genes was highly up-regulated under water limitation in the roots of drought-susceptible C. canephora clone 22. We previously reported fine-tuned regulation of CcDREB1D promoter haplotypes (HP15, HP16 and HP17) in transgenic C. arabica subjected to low humidity. Here, we investigated the regulation of these haplotypes under high light, cold, heat, and abscisic acid (ABA) stress. In apical buds and leaf guard cells, GUS-stained percentages were higher in pHP16L-transformed plants subjected to low humidity, high light and ABA stress than in pHP17L- and pHP15L-transformed plants. We also reported up-regulated expression of the endogenous CaDREB1D gene for both the cold and low humidity in leaves of pHP16L-transformed C. arabica suggesting a key role of this gene in controlling the responses of coffee plants to abiotic stress probably through an ABA-dependent pathway

    Transcriptome Profiling of the Resistance Response of <i>Musa acuminata</i> subsp. <i>burmannicoides</i>, var. Calcutta 4 to <i>Pseudocercospora musae</i>

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    Banana (Musa spp.), which is one of the world’s most popular and most traded fruits, is highly susceptible to pests and diseases. Pseudocercospora musae, responsible for Sigatoka leaf spot disease, is a principal fungal pathogen of Musa spp., resulting in serious economic damage to cultivars in the Cavendish subgroup. The aim of this study was to characterize genetic components of the early immune response to P. musae in Musa acuminata subsp. burmannicoides, var. Calcutta 4, a resistant wild diploid. Leaf RNA samples were extracted from Calcutta 4 three days after inoculation with fungal conidiospores, with paired-end sequencing conducted in inoculated and non-inoculated controls using lllumina HiSeq 4000 technology. Following mapping to the reference M. acuminata ssp. malaccensis var. Pahang genome, differentially expressed genes (DEGs) were identified and expression representation analyzed on the basis of gene ontology enrichment, Kyoto Encyclopedia of Genes and Genomes orthology and MapMan pathway analysis. Sequence data mapped to 29,757 gene transcript models in the reference Musa genome. A total of 1073 DEGs were identified in pathogen-inoculated cDNA libraries, in comparison to non-inoculated controls, with 32% overexpressed. GO enrichment analysis revealed common assignment to terms that included chitin binding, chitinase activity, pattern binding, oxidoreductase activity and transcription factor (TF) activity. Allocation to KEGG pathways revealed DEGs associated with environmental information processing, signaling, biosynthesis of secondary metabolites, and metabolism of terpenoids and polyketides. With 144 up-regulated DEGs potentially involved in biotic stress response pathways, including genes involved in cell wall reinforcement, PTI responses, TF regulation, phytohormone signaling and secondary metabolism, data demonstrated diverse early-stage defense responses to P. musae. With increased understanding of the defense responses occurring during the incompatible interaction in resistant Calcutta 4, these data are appropriate for the development of effective disease management approaches based on genetic improvement through introgression of candidate genes in superior cultivars
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