Ocorrência de ferrugem em Myrcianthes pungens (O. Berg) D. Legrand causada por Austropuccinia psidii no estado do Rio Grande do Sul

Guabiju tree (Myrcianthes pungens) belongs to the Myrtaceae family, with wide occurrence in Rio Grande do Sul (RS), southern Brazil, demonstrates great commercial potential regarding the consumption of its fresh fruit, which has a sweet taste and can be used in drinks, jellies and ice creams, in addition to its nutraceutical properties. As their main characteristic, rusts present the formation of orange pus- tules containing urediniospores of the pathogen on affected organs. The action of the pathogen causes deformation of stems, leaves, flowers and fruits, thus interfering with the physiological processes of the plant. Thus, the present work aimed at presenting information on the occurrence and confirmation of the causal agent of guabiju rust, in addition to reporting the accessions most susceptible and resistant to Austropuccinia in the guabiju working collection of Eldorado do Sul, RS, Brazil. The diagnosis of the disease was based on symptoms, observation of fungal structures by light microscopy and molecular analyses. From microscopy, ellipsoid to ovoid and slightly equinulate urediniospores were observed, characteristic of Austropuccinia sp. The sequence of the internal transcribed spacer (ITS) region of the isolate showed 99.06% similarity with sequences from the same region of A. psidii deposited on the nucleotide database - GenBank (NCBI). This is the first report of rust associated with guabiju in the state of Rio Grande do Sul, Brazil. From the diagrammatic scale developed, it was possible to identify different levels of susceptibility to A. psidii in guabiju accessions under study.Guabiju (Myrcianthes pungens), pertencente à família Myrtaceae, com ampla ocorrência no Rio Grande do Sul (RS), apresenta grande potencial para exploração de seus frutos no consumo in natura, com sabor adocicado, podendo compor bebidas, geleias e sorvetes, além de possuir propriedades nutracêuticas. As ferrugens, como característica principal, apresentam a formação de pústulas alaranjadas contendo urediniósporos do patógeno sobre os órgãos afetados. A ação do patógeno causa deformação dos órgãos: caules, folhas, flores e frutos, interferindo, assim, nos processos fisiológicos da planta. Assim, o pre- sente trabalho teve como objetivo apresentar informações sobre a ocorrência, confirmação do agente causal da ferrugem do guabijuzeiro, além de relatar os acessos mais suscetíveis e resistentes a Austropuccinia na coleção de trabalho de guabijuzeiros em Eldorado do Sul-RS. A diagnose da doença foi realizada com base nos sintomas, na observação das estruturas fúngicas por microscopia óptica e por análises moleculares. A partir da microscopia, observaram-se urediniósporos elipsoides a ovoides e levemente equinulados, característicos de Austropuccinia sp. A sequência da região internal transcribed spacer (ITS) do isolado apre- sentou 99,06% de similaridade com sequências da mesma região da espécie A. psidii depositadas no banco de dados nucleotídeos - GenBank (NCBI). Este é o primeiro relato de ferrugem associada a guabijuzeiros no Estado do Rio Grande do Sul, Brasil. A partir da escala diagramática desenvolvida, foi possível identificar diferentes níveis de suscetibilidade a A. psidii nos acessos de guabijuzeiros avaliados

Diferença entre isolados de lesões mancha de olho pardo e cercospora negra em cafeeiro

The objective of this work was to evaluate the difference between the isolates from two cercospora leaf spot symptoms (brown eye spot and black spot) in relation to conidial morphology, mycelial growth, cercosporin production, and reproduction of symptoms in coffee leaves collected in three municipalities in the state of Minas Gerais, Brazil. There was a difference between the isolates for the studied variables, but without any relation to the type of symptom. The differences found were not associated with the origin of the isolates. The symptoms characterized as black spot were associated with different host conditions during the infection process.O objetivo deste trabalho foi avaliar a diferença entre isolados de dois tipos de sintomas de cercosporiose do cafeeiro (mancha de olho pardo e cercospora negra) em relação à morfologia conidial, ao crescimento micelial,  à produção de cercosporina e à reprodutibilidade dos sintomas em folhas de cafeeiro coletadas em três municípios de Minas Gerais, Brasil. Observou-se diferença entre os isolados para as variáveis estudadas, mas sem relação com o tipo de sintoma. As diferença encontradas não foram associadas à origem do isolado. Os sintomas caracterizados como cercospora negra foram associados a diferentes condições do hospedeiro durante o processo de infecção

Silício e indutores de resistência no controle da pinta bacteriana do tomateiro e na atividade de enzimas de defesa

A pinta bacteriana causada por Pseudomonas syringae pv. tomato (Pst) (Okabe) Young, Dye & Wilkie tem importância econômica para a cultura do tomateiro industrial no Brasil. O uso de agentes potencializadores e/ou indutores das defesas das plantas é uma alternativa que atende aos requisitos do manejo integrado de doenças. Este estudo avaliou o efeito do silício (Si) e de indutores químicos em alguns componentes de resistência do tomateiro à pinta bacteriana e na atividade de enzimas envolvidas na defesa das plantas. No primeiro estudo plantas de tomateiro foram cultivadas em: solo sem silicato de cálcio (controle) (T1), solo sem silicato de cálcio e plantas pulverizadas com Supa Sílica® (SS) (2 mL/L de SS) (T2) e solo com silicato de cálcio (0,38 g) (T3), sendo inoculadas por pulverização com suspensão do patógeno. Foram avaliados o período de incubação (PI), número de lesões (NL) por planta, severidade estimada pelo software QUANT 1.0 (SEQ) e concentração foliar de Si, bem como a atividade das enzimas peroxidases (POX), polifenoloxidases (PFO), β-1,3-glucanases (GLU), fenilalanina amônia-liases (FAL), lipoxigenases (LOX) e concentração de aldeído malônico (MDA). Também foi avaliado o efeito do SS no crescimento de Pst in vitro. Não houve diferença significativa entre os tratamentos para o PI e para a concentração foliar de Si. Não houve diferença significativa para o NL por planta e a SEQ entre o tratamento T3 e o controle. O tratamento T2 reduziu significativamente o NL 46,8 e 45,1% e a SEQ 61,5 e 56,2%, em relação ao controle e ao tratamento T3, respectivamente. Houve resposta linear negativa das doses de SS no crescimento da Pst in vitro. A atividade das POX, PFO e GLU foi significativamente maior nos tratamentos T2 e T3. A atividade das FAL e das LOX foi significativamente maior no T3. A concentração de MDA foi significativamente maior no tratamento T2 em relação ao controle, nas plantas não inoculadas com Pst e aos 7 dias após inoculação (d.a.i.); sendo significativamente menor aos 10 d.a.i. No segundo estudo, três experimentos foram realizados para avaliar o efeito dos indutores ácido jasmônico (AJ; 0,1 mM), ethephon (ET; 0,5 mM) e acibenzolar-S-metil (Bion®, ASM; 300 mg/L) pulverizados 48 h antes da inoculação da Pst, avaliando-se o PI e o NL por planta, além da atividade das enzimas POX, PFO, GLU e LOX. Também foi avaliado o efeito do AJ e do ET no crescimento da Pst in vitro. Apenas no experimento 3 o PI aumentou significativamente em 1 dia nas plantas pulverizadas com ASM em relação ao controle. O NL por planta foi significativamente reduzido pelos tratamentos AJ, ET e ASM em relação ao controle para todos os experimentos, atingindo valores de 38,9, 45,3 e 68,1%, respectivamente, no experimento 2. O crescimento da Pst in vitro não foi influenciado significativamente pelo AJ ou ET. Em determinadas épocas de avaliação, o AJ elevou significativamente a atividade das POX, PFO e GLU; ASM elevou a atividade das PFO, GLU e LOX e o ET elevou a atividade das GLU e LOX em relação ao controle. Os resultados desses estudos evidenciam que a pulverização com SS e com indutores AJ, ET e ASM afetaram alguns dos componentes de resistência do tomateiro à pinta bacteriana, além de potencializar as enzimas POX, PFO, GLU, FAL e LOX, relacionadas com a defesa das plantas em resposta à Pst.The bacterial speck caused by Pseudomonas syringae pv. tomato (Pst) (Okabe) Young, Dye & Wilkie has economic relevance to the tomato for industry in Brazil. The use of products that potentiate and/or induce plant defenses is an alternative that meets the requirements of integrated disease management. This study aimed to evaluate the effect of silicon (Si) and chemical inducers in some components of tomato resistance to bacterial speck and activity of enzymes involved in plant defense. In the first study, tomato plants were grown in: soil without calcium silicate (control) (T1), soil without calcium silicate and plants sprayed with Supa Silica® (SS) (2 mL/L SS) (T2) and soil with calcium silicate (0.38 g) (T3), being inoculated by spraying with a suspension of the pathogen. Our research evaluated the incubation period (IP), number of lesions (NL) per plant, severity estimated by the software QUANT 1.0 (SEQ) and leaf concentration of Si, as well as the activity of enzymes peroxidases (POX), polyphenoloxidases (PPO) β-1,3-glucanases (GLU), phenylalanine ammonia lyases (PAL), lipoxygenases (LOX) and concentration of malondialdehyde (MDA). It was assessed the effect of SS in the Pst growth in vitro. There was no significant difference between treatments for the IP and the foliar concentration of Si. No significant differences were found for the NL per plant and SEQ between T3 and control. T2 significantly reduced NL in 46.8 and 45.1% and SEQ in 61.5 and 56.2% when compared with control and T3, respectively. There was negative linear response of SS doses on the Pst growth in vitro. The activity of POX, PPO and GLU was significantly higher in T2 and T3. The activity of FAL and LOX was significantly higher in T3. The MDA concentration was significantly higher in T2 compared to control, in non-inoculated plants and at 7 days after inoculation (d.a.i.), being significantly lower at 10 d.a.i. In the second study, three experiments were conducted to evaluate the effect of jasmonic acid (JA; 0.1 mM), ethephon (ET, 0.5 mM) and acibenzolar-S-methyl (Bion®, ASM; 300 mg/L) sprayed 48 h before inoculation with Pst, evaluating the IP and NL per plant, and the activity of enzymes POX, PPO, GLU and LOX. It was also assessed the effect of JA and ET in the growth of Pst in vitro. Only in experiment 3 incubation period increased significantly by one day in the plants sprayed with ASM compared with control. In all experiments, NL per plant was significantly reduced by JA, ET e ASM in relation to the control reaching values of 38.9, 45.3 and 68.1%, respectively, in experiment 2. The growth of Pst in vitro was not significantly influenced. In some evaluation times JA has significantly raised the activity of POX, PPO and GLU; ASM has elevated the activity of PPO, GLU and LOX, while ET only significantly raised the activity of GLU and LOX compared to the control. The results of these studies suggest that spraying tomato plants with SS and the inducers JA, ET and ASM affected some components of tomato resistance to bacterial speck, and activated the enzymes POX, PPO, GLU, PAL and LOX, involved in defense responses of tomato plants to Pst.Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNP

Ocorrência de Thekopsora minima causando ferrugem em pomares de mirtilo em Santa Catarina

The possible occurrence of Thekopsora minima causing rust on blueberry plants was observed in three orchards in Santa Catarina. Morphological and molecular observations, as well as pathogenicity tests were consistent in showing that T. minima is the causal agent of rust in blueberry orchards. In view of the confirmation of T. minima in the blueberry, fruit growers will have a great challenge to manage the rust in Santa Catarina orchards, due to the appropriate environmental conditions for the disease and the predominance of cultivars susceptible to the pathogen.A possível ocorrência de Thekopsora minima causando ferrugem em mirtilileiro foi observada em três pomares em Santa Catarina. Observações morfológicas e moleculares, bem como teste de patogenicidade, foram consistentes em mostrar que T. minima é o agente causal da ferrugem nos pomares de mirtilo. Diante da confirmação de T. minima no mirtileiro, fruticultores terão um grande desafio para manejar a ferrugem nos pomares catarinenses devido às condições ambientais adequadas à doença e a predominância de cultivares suscetíveis ao patógeno

Rhizobacteria induces resistance against Fusarium wilt of tomato by increasing the activity of defense enzymes

Fusarium wilt, caused by Fusarium oxysporum f.sp. lycopersici (Fol), is one of the most important diseases that affect tomato yield worldwide. This study investigated the potential of three antagonists, Streptomyces setonii (UFV 618), Bacillus cereus (UFV 592) and Serratia marcescens (UFV 252), and as positive control the hormone jasmonic acid (JA), to reduce Fusarium wilt symptoms and to potentiate the defense enzymes in the stem tissues of tomato plants infected by Fol. The seeds were microbiolized with each antagonist, and the soil was also drenched with them. The plants were sprayed with JA 48 h before Fol inoculation. The area under the Fusarium wilt index progress curve was reduced by 54, 48, 47 and 45% for the UFV 618, JA, UFV 592 and UFV 252 treatments, respectively. The three antagonists, and even the JA spray, efficiently reduced the Fusarium wilt symptoms on the tomato plant stems, which can be explained by the lower malondialdehyde concentration (an indication of oxidative damage to lipids in the plasma membranes) and the greater activities of peroxidases, polyphenoloxidases, glucanases, chitinases, phenylalanine ammonia-lyases and lipoxygenases, which are commonly involved in host resistance against fungal diseases. These results present a novel alternative that can be used in the integrated management of Fusarium wilt on tomatoes

Iron oxide polyaniline-coated nanoparticles modulate tumor microenvironment in breast cancer: an in vitro study on the reprogramming of tumor-associated macrophages

Abstract Background Breast cancer is the neoplastic disease with the highest incidence and mortality in the female population worldwide. Treatment remains challenging due to various factors. Therefore, it is of great importance to develop new therapeutic strategies that promote the safe destruction of neoplastic cells without compromising patients' quality of life. Among advances in the treatment of breast cancer, immunotherapy stands out as a promising trend. Recent studies have demonstrated the potential of iron oxide nanoparticles in promoting the reprogramming of M2 macrophages (pro-tumor phenotype) into M1 macrophages (anti-tumor phenotype) within the tumor microenvironment, resulting in potent antitumor effects. In this study, the effect of polyaniline-coated iron oxide nanoparticles (Pani/y-Fe2O3) on macrophage polarization and breast cancer cell death was investigated. Methods The non-cytotoxic concentration of nanoparticles was determined using the MTT assay. For in vitro co-culture experiments, breast cancer cell lines MCF -7 and MDA-MB -231 and macrophages THP-1 were co-cultured in a Transwell system and then the effects of Pani/y-Fe2O3 on cell viability, gene expression, cytokine profile, and oxidative stress markers were investigated. Results The results showed that Pani/y-Fe2O3 nanoparticles induced M2-to-M1 macrophage polarization in both cell lines through different pathways. In MCF -7 and THP-1 macrophage co-culture, the study showed a decrease in cytokine levels IL -1β, upregulation of M1-associated genes (IL-12, TNF-α) in macrophages, resulting in increased MCF -7 cell death by apoptosis (caspase 3/7+). In MDA-MB -231 co-cultures, increases in cytokines IL -6, IL -1β, and oxidative stress markers were observed, as well as upregulation of the inducible nitric oxide synthase (iNOS) gene in macrophages, leading to tumor cell death via apoptosis-independent pathways (Sytox+). Conclusions These findings highlight the potential of Pani/y-Fe2O3 as a promising therapeutic approach in the context of breast cancer treatment by effectively reprogramming M2 macrophages into an anti-tumor M1 phenotype, Pani/y-Fe2O3 nanoparticles demonstrated the ability to elicit antitumor effects in both MCF-7 and MDA-MB-231 breast cancer cell lines

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved