10 research outputs found
Cultura de tecidos em feijão caupi
O Brasil é o terceiro produtor de feijão-caupi (Vigna unguiculata (L.) Walp.) no mundo, sendo a região nordeste do país responsável pela maior área e produção. Uma vez que o feijão-caupi é uma planta de grande valor para a agricultura sustentável no Brasil, varias técnicas de cultura de tecidos in vitro tem sido aplicadas, com o objetivo de desenvolver protocolos para facilitar os programas de melhoramento e biotecnológicos. A regeneração eficiente dos tecidos vegetais através de organogênese a partir de células feijão-caupi é um pré-requisito para a engenharia genética, que pode ser posteriormente aplicado na agricultura. A disponibilidade de protocolos eficientes de cultura de tecidos de plantas de feijão-caupi permite a obtenção de plantas geneticamente modificadas, mais rapidamente, diminuindo assim o tempo para obter uma nova cultivar. Este documento descreve várias técnicas utilizadas para a cultura de tecidos feijão-caupi
Sugarcane apoplast fluid modulates the global transcriptional profile of the diazotrophic bacteria Paraburkholderia tropica strain Ppe8.
The stalk apoplast fluid of sugarcane contains different sugars, organic acids and amino acids that may supply the demand for carbohydrates by endophytic bacteria including diazotrophs P. tropica (syn. B. tropica) strain Ppe8, isolated from sugarcane, is part of the bacterial consortium recommended as inoculant to sugarcane. However, little information has been accumulated regarding this plant-bacterium interaction considering that it colonizes internal sugarcane tissues. Here, we made use of the RNA-Seq transcriptomic analysis to study the influence of sugarcane stalk apoplast fluid on Ppe8 gene expression. The bacterium was grown in JMV liquid medium (100 ml), divided equally and then supplemented with 50 ml of fresh JMV medium or 50 ml of apoplast fluid extracted from sugarcane variety RB867515. Total RNA was extracted 2 hours later, the rRNAs were depleted and mRNAs used to construct libraries to sequence the fragments using Ion Torrent technology. The mapping and statistical analysis were carried out with CLC Genomics Workbench software. The RNA-seq data was validated by RT-qPCR using the reference genes fliP1, paaF, and groL. The data analysis showed that 544 genes were repressed and 153 genes were induced in the presence of apoplast fluid. Genes that induce plant defense responses, genes related to chemotaxis and movements were repressed in the presence of apoplast fluid, indicating that strain Ppe8 recognizes the apoplast fluid as a plant component. The expression of genes involved in bacterial metabolism was regulated (up and down), suggesting that the metabolism of strain Ppe8 is modulated by the apoplast fluid. These results suggest that Ppe8 alters its gene expression pattern in the presence of apoplast fluid mainly in order to use compounds present in the fluid as well as to avoid the induction of plant defense mechanisms. This is a pioneer study showing the role played by the sugarcane apoplast fluid on the global modulation of genes in P. tropica strain Ppe8
Germinação de sementes inteiras e fracionadas de quinze matrizes de Eugenia pyriformis (uvaia)
Objetivou-se determinar a potencialidade da germinação de sementes de uvaia inteira e fracionadas (bipartida e tetrapartida) de 15 diferentes matrizes, em estufa tipo BOD com 25ºC, ausência de luz e umidade relativa a 40%, visando à seleção das matrizes para reprodução em escala comercial. Foram avaliados a germinação, índice de velocidade de germinação, tempo médio de germinação, velocidade média de germinação, plântulas normais e anormais. A germinação de sementes de uvaia ocorre em sementes inteiras (97%) e fracionadas bipartidas (73%) e tetrapartidas (62%), porém o percentual de germinação e de plântulas normais é superior nas sementes inteiras não justificando o fracionamento das sementes visando a sua otimização para produção de mudas. As melhores matrizes para a produção de mudas em escala comercial foram as de número 2, 16, 29, 39 e 42
Transcriptomic Response of the Diazotrophic Bacteria Gluconacetobacter diazotrophicus Strain PAL5 to Iron Limitation and Characterization of the fur Regulatory Network
Gluconacetobacter diazotrophicus has been the focus of several studies aiming to understand the mechanisms behind this endophytic diazotrophic bacterium. The present study is the first global analysis of the early transcriptional response of exponentially growing G. diazotrophicus to iron, an essential cofactor for many enzymes involved in various metabolic pathways. RNA-seq, targeted gene mutagenesis and computational motif discovery tools were used to define the G. diazotrophicusfur regulon. The data analysis showed that genes encoding functions related to iron homeostasis were significantly upregulated in response to iron limitations. Certain genes involved in secondary metabolism were overexpressed under iron-limited conditions. In contrast, it was observed that the expression of genes involved in Fe-S cluster biosynthesis, flagellar biosynthesis and type IV secretion systems were downregulated in an iron-depleted culture medium. Our results support a model that controls transcription in G. diazotrophicus by fur function. The G. diazotrophicusfur protein was able to complement an E. colifur mutant. These results provide new insights into the effects of iron on the metabolism of G. diazotrophicus, as well as demonstrate the essentiality of this micronutrient for the main characteristics of plant growth promotion by G. diazotrophicus
Multiomic Approaches Reveal Hormonal Modulation and Nitrogen Uptake and Assimilation in the Initial Growth of Maize Inoculated with <i>Herbaspirillum seropedicae</i>
Herbaspirillum seropedicae is an endophytic bacterium that can fix nitrogen and synthesize phytohormones, which can lead to a plant growth-promoting effect when used as a microbial inoculant. Studies focused on mechanisms of action are crucial for a better understanding of the bacteria-plant interaction and optimization of plant growth-promoting response. This work aims to understand the underlined mechanisms responsible for the early stimulatory growth effects of H. seropedicae inoculation in maize. To perform these studies, we combined transcriptomic and proteomic approaches with physiological analysis. The results obtained eight days after inoculation (d.a.i) showed increased root biomass (233 and 253%) and shoot biomass (249 and 264%), respectively, for the fresh and dry mass of maize-inoculated seedlings and increased green content and development. Omics data analysis, before a positive biostimulation phenotype (5 d.a.i.) revealed that inoculation increases N-uptake and N-assimilation machinery through differentially expressed nitrate transporters and amino acid pathways, as well carbon/nitrogen metabolism integration by the tricarboxylic acid cycle and the polyamine pathway. Additionally, phytohormone levels of root and shoot tissues increased in bacterium-inoculated-maize plants, leading to feedback regulation by the ubiquitin-proteasome system. The early biostimulatory effect of H. seropedicae partially results from hormonal modulation coupled with efficient nutrient uptake-assimilation and a boost in primary anabolic metabolism of carbon–nitrogen integrative pathways
VIII Congresso Estadual Paulista sobre Formação de Educadores
O tema proposto para discussão durante o VIII Congresso Estadual Paulista sobre a Formação de Educadores – Modos de ser Educador: Artes e Técnicas – Ciências e Políticas envolve a busca de integração entre as diferentes dimensões que compõem a formação do profissional da educação. O trabalho e o sentido da intervenção social desse profissional se constituem em objeto em torno do qual as análises e interpretações vão recolher os fundamentos de debate sobre cultura como totalidade, incluindo: Artes e Técnicas – Ciências e Políticas. A dinâmica que caracteriza a formação de educadores requer a interpretaçãodesses fundamentos para o constante redimensionamento e definição dos objetivos visando aperfeiçoar o papel do profissional educador na sociedade. Por meio de discussões entrediferentes setores ligados à educação é que podem ser avaliados, preservados ou transformados os móveis que norteiam a formação do educador dentro de contextos culturais/sociais específicos, nos diversos campos, artes, técnicas, ciências e políticas. A disponibilidade de um espaço como o VIII Congresso Estadual Paulista sobre a Formação de Educadores para que estudiosos do tema - Educação - se congreguem e debatam a produção de conhecimento sob diversos ângulos, insere e qualifica esse evento como um processo de contribuição para o aprofundamento de estudos na área educacional. Os Congressos Estaduais Paulistas sobre a Formação de Educadores (CEPFE) vêm acontecendo desde 1990 e têm dedicado ênfase especial à formação de profissionais da educação, nos níveis de ensino fundamental, médio e universitário. Tal conformação do Congresso procura extrapolar questões próprias do padrão formal, para a abordagem de formação do profissional da educação embasada na crítica constante, capaz de dinamizar processos e resultados. Essa pretensão ressalta a importância do envolvimento de diferentes áreas do saber numa discussão sobre significados da produção de conhecimento. Daí poderão provir os resultados esperados a partir das atividades programadas para o VIII Congresso dentre os quais está esse caderno de resumos que ora apresentamos.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
Neotropical ornithology: Reckoning with historical assumptions, removing systemic barriers, and reimagining the future
A major barrier to advancing ornithology is the systemic exclusion of professionals from the Global South. A recent special feature, Advances in Neotropical Ornithology, and a shortfalls analysis therein, unintentionally followed a long-standing pattern of highlighting individuals, knowledge, and views from the Global North, while largely omitting the perspectives of people based within the Neotropics. Here, we review current strengths and opportunities in the practice of Neotropical ornithology. Further, we discuss problems with assessing the state of Neotropical ornithology through a northern lens, including discovery narratives, incomplete (and biased) understanding of history and advances, and the promotion of agendas that, while currently popular in the north, may not fit the needs and realities of Neotropical research. We argue that future advances in Neotropical ornithology will critically depend on identifying and addressing the systemic barriers that hold back ornithologists who live and work in the Neotropics: unreliable and limited funding, exclusion from international research leadership, restricted dissemination of knowledge (e.g., through language hegemony and citation bias), and logistical barriers. Moving forward, we must examine and acknowledge the colonial roots of our discipline, and explicitly promote anti-colonial agendas for research, training, and conservation. We invite our colleagues within and beyond the Neotropics to join us in creating new models of governance that establish research priorities with vigorous participation of ornithologists and communities within the Neotropical region. To include a diversity of perspectives, we must systemically address discrimination and bias rooted in the socioeconomic class system, anti-Blackness, anti-Brownness, anti-Indigeneity, misogyny, homophobia, tokenism, and ableism. Instead of seeking individual excellence and rewarding top-down leadership, institutions in the North and South can promote collective leadership. In adopting these approaches, we, ornithologists, will join a community of researchers across academia building new paradigms that can reconcile our relationships and transform science. Spanish and Portuguese translations are available in the Supplementary Material.• Research conducted by ornithologists living and working in Latin America and the Caribbean has been historically and systemically excluded from global scientific paradigms, ultimately holding back ornithology as a discipline.• To avoid replicating systems of exclusion in ornithology, authors, editors, reviewers, journals, scientific societies, and research institutions need to interrupt long-held assumptions, improve research practices, and change policies around funding and publication.• To advance Neotropical ornithology and conserve birds across the Americas, institutions should invest directly in basic field biology research, reward collective leadership, and strengthen funding and professional development opportunities for people affected by current research policies.Peer reviewe
Brazilian Flora 2020: Leveraging the power of a collaborative scientific network
International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora