Ethylene synthesis and photosynthetic responses in bean and maize plants exposed to auxins

As auxinas AIA (ácido indol-3-acético), 2,4-D (ácido 2,4-diclorofenoxiacético) e 2,4,5-T (ácido 2,4,5-triclorofenoxiacético) foram aplicadas em plantas de milho (Zea mays, monocotiledônea) e feijão (Phaseolus vulgaris, dicotiledônea), visando compreender os mecanismos que levam a respostas diferenciais das plantas de milho e feijão em relação ao metabolismo do etileno. Plantas de milho tratadas com as auxinas não produziram etileno, já o feijão produziu bastante após o tratamento. Após pulverização com as auxinas, o milho não exibiu produção do ácido 1-carboxílico-1-amino-ciclopropano (ACC), fato observado no feijoeiro O rendimento quântico máximo do fotossistema II (razão Fv/Fm) e os níveis dos pigmentos fotossintéticos não foram alterados em plantas de milho tratadas com as auxinas. As plantas de feijão mostraram quedas significativas em ambas variáveis após o tratamento com 2,4-D e 2,4,5-T, mas não com o AIA. A redução nos níveis das clorofilas em plantas de feijão tratadas com 2,4-D e 2,4,5-T relacionou-se com a clorose observada, uma vez que ocorreu uma degradação mais acentuada das clorofilas do que dos carotenoides. As xantofilas também tiveram uma degradação mais acentuada do que o alfa e beta caroteno em plantas de feijão tratadas com 2,4-D e 2,4,5-T. Quando aminoetoxivinilglicina (AVG) e Co2+ foram fornecidos às plantas de feijão, conjuntamente com as auxinas, não ocorreu queda na razão Fv/Fm e nem no nível dos pigmentos, com exceção do alfa caroteno.Auxins IAA (indole-3-acetic acid), 2,4-D (2,4-dichlorophenoxyacetic acid) and 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) were applied on maize (Zea mays, monocot) and bean (Phaseolus vulgaris, dicot) plants, with the goal to understand the mechanisms that lead to different responses in relation to the metabolism of ethylene. Maize plants treated with auxins did not produce ethylene, whereas beans produced a lot of it after the treatment. After being sprayed with auxins, maize did not produced any 1-Aminocyclopropane-1-carboxylic acid (ACC), which was observed on beans. The maximum quantum yield of the photosystem II (Fv/Fm ratio) and the levels of photosynthetic pigments were not altered in maize plants treated with auxins. Bean plants showed significant decreases in both variables after the treatment with 2,4-D and 2,4,5-T, but not with IAA. The reduction of chlorophyll levels in bean plants treated with 2,4-D and 2,4,5-T was related to the observed chlorosis, since there was a more accentuated degradation of chlorophylls than carotenoids. Xantophylls also had a more accentuated degradation than alpha and beta carotene in bean plants treated with 2,4-D and 2,4,5-T. When aminoethoxyvinylglycine (AVG) and Co2+ were provided to bean plants together with auxins, there was no fall in the Fv/Fm ratio and in the pigment levels, except for the alpha carotene

Severe complication by irregular use of industrial silicone in a transsexual patient: a case report

The use of industrial liquid silicone as a material for aesthetic modification of body contour is a practice that has been carried out clandestine for about 60 years. Currently, most reports come from countries in Asia and South America, and the victims are mainly women and transsexuals. Due to the large number of cases with complications, the use of industrial silicone for aesthetic purposes has never been approved. However, it continues to be applied alone or associated with other products, determining severe local and systemic complications. We report a case of death of a transsexual patient after injecting industrial silicone in the thighs and buttocks

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Germination of dormant seeds of Stylosanthes humilis H.B.K. as promoted by ethylene accumulation in closed environment

Sementes dormentes escarificadas de estilosante (Stylosanthes humilis HBK), leguminosa tropical forrageira anual, germinaram em ambiente fechado devido ao acúmulo de etileno por elas produzido. O etileno acumulado fez aumentar a germinação e intensificou a sua produção. A adição de etileno à atmosfera interna dos frascos Erlenmeyers selados, às concentrações 0,5 mmol m -3 ou menores, promoveu um aumento na produção de etileno, em comparação ao etileno adicionado, caracterizando um efeito autocatalítico do regulador gasoso. A remoção do etileno da atmosfera dos frascos por solução de perclorato de mercúrio levou a diminuição da emanação do regulador gasoso pelas sementes dormentes e não- dormentes e também da germinação. Os inibidores da biossíntese do etileno, 2- aminoetoxivinilglicina mais Co(NO 3 ) 2 , bloquearam completamente a germinação das sementes dormentes, mas não das não-dormentes, possivelmente devido ao etileno residual produzido por estas. A combinação das duas técnicas, isto é, remoção do etileno da atmosfera dos frascos simultaneamente à embebição das sementes com a solução dos inibidores, promoveu uma inibição completa da produção de etileno por sementes dormentes e não-dormentes e da germinação. Com a Injeção de etileno na atmosfera dos frascos Erlenmeyer, a germinação das sementes não- dormentes foi estimulada sob concentrações bem menores do que as requeridas para a germinação das sementes dormentes, indicando que a sensibilidade ao regulador gasoso foi bem maior nas sementes não-dormentes.Scarified dormant seeds of Townsville stylo (Stylosanthes humilis HBK), an annual tropical forage legume, germinated in closed environments in response to ethylene accumulation. This accumulation, caused an increased germination and also in ethylene production. Injection of ethylene, at concentrations 0.5 mmol m -3 or less into sealed Erlenmeyer flasks promoted an ethylene increase in their internal atmospheres, as compared to ethylene injected, demonstrating an autocatalytic production. In an ethylene-free atmosphere obtained with a mercuric perchlorate solution, emanation of the gaseous regulator from dormant and non-dormant seeds was drastically decreased as was also total germination. Germination of dormant seeds, but not of non-dormant ones, was completely blocked by ethylene biosynthesis inhibitors 2-aminoethoxyvinylglycine (AVG) plus Co(NO 3 ) 2 , likely due to the residual ethylene produced by non-dormant seeds. When both techniques were used, e.g., by removing ethylene form the flask atmosphere and simultaneously imbibing seeds in AVG plus Co 2+ solution, neither germination of nor ethylene production by dormant and non-dormant seeds occurred. Ethylene injected into this system promoted germination of non-dormant seeds at much lower concentrations than those required for germination of dormant seeds, demonstrating that in non- dormant seeds sensitivity to the gaseous regulator was higher than in dormant seeds.Dissertação importada do Alexandri

Reavaliação do papel do óxido nítrico como um componente da rota de sinalização do ácido abscísico em células-guardas

O ácido abscísico (AAB), sintetizado em resposta ao défice hídrico, induz o fechamento dos estômatos via ativação de uma complexa cascata de sinalização. Tem-se demonstrado que o óxido nítrico (ON) é um componente chave na cadeia de sinalização que leva ao fechamento dos estômatos induzido pelo AAB em várias espécies, sob boa disponibilidade hídrico. Entretanto, a função do ON no fechamento dos estômatos induzido pelo AAB em resposta ao défice de água não está esclarecida. O AAB induz a formação de ON e a remoção do ON por um seqüestrador inibe o fechamento dos estômatos em folhas túrgidas, mas não nas desidratadas. A síntese de ON induzida pela redutase do nitrato (RN) parece necessária para o fechamento dos estômatos induzido por AAB em folhas túrgidas de Arabidopsis, mas não nas desidratadas. Além disso, as células-guardas de folhas túrgidas do duplo mutante da RN nia1 nia2 e do mutante simples da RN nia1::Ds não sintetizam ON e nem fecham os estômatos em resposta ao AAB ou nitrito, embora os estômatos desses mutantes se feche em resposta ao NPS (nitroprusado de sódio), composto liberador de ON. Entretanto, o fechamento dos estômatos do mutante nia1 nia2 e nia1::Ds foi induzido por AAB, mas não por nitrito ou NPS em folhas mantidas sob défice hídrico, indicando que o fechamento dos estômatos induzido por AAB ocorreu independentemente da síntese de ON mediada pela RN. Confirmando esses resultados, o AAB reduziu a perda de água nos mutantes nia1 nia2 e nia1::Ds, e também em plantas do tipo selvagem, mas NPS e nitrito não diminuíram a transpiração das folhas dos mutantes deficientes na RN e em folhas do tipo selvagem. O tratamento de folhas de mutantes insensíveis ao AAB, abi1-1 e abi2-1, com AAB ou NPS não promoveu qualquer alteração significativa na abertura dos estômatos em folhas tanto sob condições de défice hídrico como em folhas não estressadas, sugerindo que o ON foi incapaz em sobrepor-se à mutação abi1-1 e abi2-1. Assim, o ON não parece necessário para o fechamento dos estômatos induzido pelo AAB em folhas sob condições de défice de água.Conselho Nacional de Desenvolvimento Científico e TecnológicoThe plant hormone abscisic acid (ABA), synthesized in response to waterdeficit, induces stomatal closure via activation of a complex signalling cascade. It has been established that nitric oxide (NO) is a key signalling molecule mediating ABA-induced stomatal closure in several species under well watered condition. However, the function of NO in ABA-induced stomatal closure in response to water deficit has as yet been kept unresolved. The present study provides pharmacological, physiological and genetic evidences that responses of the tissues to NO differ between wilting and turgid conditions in Arabidopsis plants. ABA triggers NO generation, and sequestration of NO by its scavenger 2-phenyl-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide inhibits stomatal closure in turgid leaves and not in dehydrated leaves. Nitrate reductase (NR)-mediated NO synthesis is required for ABA-induced stomatal closure in turgid leaves but not in dehydrated ones. Moreover, in turgid leaves of the double mutant nia1 nia2 and nia1::Ds mutant both ABA and nitrite failed to induce stomatal closure, but stomatal closure was still induced by SNP (sodium nitroprusside), a NO donor, in these mutants. However, in water-stressed leaves of nia1 nia2 and nia1::Ds mutant stomatal closure was induced by ABA but not by nitrite or SNP, indicating that the ABA-induced stomatal closure was independent on NO synthesis via NR. In agreement with these results, ABA reduced the water loss in nia1 nia2 and nia1::Ds mutants and also in wild type plants, but SNP and nitrite failed in doing the same. In the ABA-insensitive abi1- 1 and abi2-1 mutants treated either with ABA or NO (applied as SNP) no significant changes in stomatal apertures occurred under both well watered and water stress conditions, suggesting that NO was not able to bypass the effects of abi1-1 and abi2-1 mutations. Together, these data indicate that NO is not required for ABA-induced stomatal closure during water stress

Germination of dormant seeds of Stylosanthes humilis as promoted by ethylene accumulation in closed environments

Germination of scarified dormant seeds of Townsville stylo (Stylosanthes humilis) is very low in Petri dishes, but may be appreciable in sealed Erlenmeyer flasks if ethylene accumulates in their atmospheres. When ethylene in the flask atmosphere was fixed by a mercuric perchlorate solution, emanation of the gaseous regulator and germination of dormant seeds were drastically decreased. On the other hand, ethylene produced by dormant seeds and accumulated in the flask atmosphere led to a further enhancement of ethylene accumulation and a corresponding increased seed germination. Germination of both dormant and non-dormant seeds did not occur when ethylene biosynthesis was completely blocked.A germinação de sementes dormentes escarificadas de estilosante (Stylosanthes humilis) é muito baixa em placas de Petri, mas pode ser considerável em frascos de Erlenmeyer selados devido a um acúmulo de etileno em sua atmosfera. Quando esse etileno foi adsorvido por solução de perclorato de mercúrio, a emanação do regulador gasoso das sementes dormentes e sua germinação foram drasticamente diminuídas. O etileno produzido pelas sementes dormentes, ao difundir-se na atmosfera dos frascos, promoveu maior acúmulo do próprio gás e um correspondente aumento da germinação. Sementes dormentes e não-dormentes não germinaram quando a biossíntese do regulador foi completamente bloqueada

Effects of gibberellic acid on Tifton 85 bermudagrass (Cynodon spp.) in constructed wetland systems

This study aimed to evaluate 1) the influence of gibberellic acid (GA3) in the development of Tifton 85 bermudagrass grown in constructed wetland systems (CWs) and 2) the plant's capacity to remove nutrients and sodium from synthetic municipal wastewater (SMW). The experiment was carried out in Viçosa, Minas Gerais, Brazil, and consisted of foliar applications of GA3 set in randomized blocks design, with four replicates and 6 treatments as following: NC (control with plants); 0 μM GA3; N1: 5 μM GA3; N2: 25 μM GA3; N3: 50 and N4: 100 μM GA3 per CWs, NC* (control with no plants): 0 μM GA3. The study was conducted over two crop cycles in the spring 2016. The parameters used to evaluate the performance of the Tifton 85 bermudagrass were its plant height, productivity, chlorophyll measurement, number of internodes, nutrients and Na removals. Chemical analyses of the effluents were conducted. In response to the application of GA3, the increase in height of Tifton 85 bermudagrass in the first crop cycle was higher than the increase in height in the second crop cycle. The decrease in plant growth in response to GA3 in the second crop cycle may be linked to the age of the plant tissue and climatic conditions. The greater growth of the plants cultivated in the CWs allows a more efficient removal of pollutants, using simple management and low cost. The results suggest that applying 50 μM of GA3 to the development of Tifton 85 bermudagrass provides higher dry matter yield and removal of nitrogen, phosphorus, and sodium for the first crop cycle in CWs. However, in the second crop cycle, the application of GA3 had no effect on dry matter production and nutrient removal by Tifton 85 bermudagrass in CWs

Effect of the seed coat on dormancy and germination in Stylosanthes humilis H. B. K. Seeds

Abstract: Seed of Townsville stylo (Stylosanthes humilis H.B.K.) is known to exhibit a hard seed coat and when freshly harvested also show a physiological dormancy, however, the nature of the co-actions between seed coat and embryo growth that determine dormancy is poorly understood. In this study, physical dormancy of Townsville stylo seeds was not reduced during natural ageing at room temperature, in contrast to the physiological dormancy, which is gradually overcome during after-ripening. Furthermore, the permeability of seed coat was affected by scarification treatments as well as by low-pH solutions. Together, these data indicate that physical dormancy overcome of seed is prerequisite for radicle protrusion and physiological dormancy of Townsville stylo seeds contribute to its timing

Effect of the seed coat on dormancy and germination in Stylosanthes humilis H. B. K. Seeds

<div><p>Abstract: Seed of Townsville stylo (Stylosanthes humilis H.B.K.) is known to exhibit a hard seed coat and when freshly harvested also show a physiological dormancy, however, the nature of the co-actions between seed coat and embryo growth that determine dormancy is poorly understood. In this study, physical dormancy of Townsville stylo seeds was not reduced during natural ageing at room temperature, in contrast to the physiological dormancy, which is gradually overcome during after-ripening. Furthermore, the permeability of seed coat was affected by scarification treatments as well as by low-pH solutions. Together, these data indicate that physical dormancy overcome of seed is prerequisite for radicle protrusion and physiological dormancy of Townsville stylo seeds contribute to its timing.</p></div