A review on mycotoxins and mycotoxicoses in ruminants and Equidae in South America.

Of the mycotoxicoses caused by molds contaminating grains or their byproducts, leukoencephalomalacia of horses and less frequently aflatoxicosis in cattle have been reported in South America. However, the most important group of mycotoxins in the region are those caused by fungi that infect forages and other types of plants and have regional distribution. In this group, ergotism is important, both caused by Claviceps purpurea infecting grains or by Epichloë coenophiala infecting Schedonorus arundinaceus. Other important mycotoxicoses are those caused by indole-diterpenes produced by Clavicipitaceous fungi including Claviceps paspali in Paspalum spp., Claviceps cynodontes in Cynodon dactylon, and by Periglandula a seed transmitted symbiont associated with the tremorgenic plant Ipomoea asarifolia. The latter is an important poisoning in the northeastern and northern Brazil. Other important mycotoxicoses are those caused by swainsonine containing plants. It was demonstrated that swainsonine contained in Ipomoea carnea var. fistulosa is produced by an epibiotic fungus of the order Chaetothyriales whose mycelia develop on the adaxial surface of the leaves. Swainsonine is also produced by the symbiotic, endobiotic fungi Alternaria section Undifilum spp., which is associated with Astragalus spp. in the Argentinian Patagonia causing poisoning. Another form of mycotoxicosis occurs in poisoning by Baccharis spp., mainly B. coridifolia, a very important toxic plant in South America that contains macrocyclic trichothecenes probably produced by an endophytic fungus that has not yet been identified. Pithomycotoxicosis caused by Pithomyces chartarum used to be an important mycotoxicosis in the region, mainly in cattle grazing improved pastures of legumes and grasses. Slaframine poisoning, diplodiosis and poisoning by barley contaminated by Aspergillus clavatus has been rarely diagnosed in Brazil, Uruguay and Argentina.

Metabolic and physiological adaptations of microalgal growth-promoting bacterium Azospirillum brasilense growing under biogas atmosphere: a microarray-based transcriptome analysis.

Using microalgal growth-promoting bacteria (MGPB) to improve the cultured microalga metabolism during biotechnological processes is one of the most promising strategies to enhance their benefits. Nonetheless, the culture condition effect used during the biotechnological process on MGPB growth and metabolism is key to ensure the expected positive bacterium growth and metabolism of microalgae. In this sense, the present research study investigated the effect of the synthetic biogas atmosphere (75% CH4-25% CO2) on metabolic and physiological adaptations of the MGPB Azospirillum brasilense by a microarray-based transcriptome approach. A total of 394 A. brasilense differentially expressed genes (DEGs) were found: 201 DEGs (34 upregulated and 167 downregulated) at 24 h and 193 DEGs (140 upregulated and 53 downregulated) under the same conditions at 72 h. The results showed a series of A. brasilense genes regulating processes that could be essential for its adaptation to the early stressful condition generated by biogas. Evidence of energy production is shown by nitrate/nitrite reduction and activation of the hypothetical first steps of hydrogenotrophic methanogenesis; signal molecule modulation is observed: indole-3-acetic acid (IAA), riboflavin, and vitamin B6, activation of Type VI secretion system responding to IAA exposure, as well as polyhydroxybutyrate (PHB) biosynthesis and accumulation. Moreover, an overexpression of ipdC, ribB, and phaC genes, encoding the key enzymes for the production of the signal molecule IAA, vitamin riboflavin, and PHB production of 2, 1.5 and 11 folds, respectively, was observed at the first 24 h of incubation under biogas atmosphere Overall, the ability of A. brasilense to metabolically adapt to a biogas atmosphere is demonstrated, which allows its implementation for generating biogas with high calorific values and the use of renewable energies through microalga biotechnologies.

Primera evidencia de actividad enzimática nitrilasa en Xylaria sp., y su relación con la biosíntesis de ácido indol-3-acético / First evidence of nitrilase enzymatic activity of Xylaria sp. and its relationship with the biosynthesis of indole-3-acetic acid

Resumen Muchos de los hongos degradadores de madera están implicados en la síntesis de metabolitos bioactivos de naturaleza antimicrobiana y terapéutica, así como de compuestos de importancia biotecnológica, incluyendo derivados indólicos, entre otros. Estos hongos brindan ciertos beneficios ecológicos a las plantas, entre los que se destacan la protección contra fitopatógenos y la promoción del crecimiento radicular. Xylaria sp. es un hongo degradador de celulosa (lignocelulolítico) con potencial biotecnológico. El ácido indol-3-acético (AIA) desempeña un papel sumamente importante en las interacciones planta-microorganismo, ya que es esencial para la fisiología y el correcto desarrollo morfológico vegetal. Se sabe que las enzimas nitrilo-hidrolíticas (nitrilasas) están involucradas en la síntesis de compuestos indólicos en las plantas, no obstante, se dispone de poca información acerca de la naturaleza de estas enzimas en el reino de los hongos. A través de una aproximación bioquímica y de genética molecular, se demuestra por primera vez que Xylaria sp. posee actividad enzimática nitrilasa utilizando compuestos ricos en nitrógeno y carbono como sustrato. La cepa estudiada aumentó sus niveles de expresión génica relativa y mostró crecimiento micelial, ambos en presencia de compuestos químicos como cianobenceno y KCN. Los resultados de este trabajo sugieren que el microorganismo es capaz de degradar moléculas nitrogenadas complejas. Por otra parte, mediante biofertilización con extractos fúngicos, se observó que Xylaria sp. promueve el desarrollo del sistema radicular de plántulas de Arabidopsis thaliana, además de sintetizar AIA.

Abstract Endophytic fungi inhabit plant tissues internally and asymptomatically, and many of them are involved in the synthesis of bioactive metabolites of antifungal and therapeutic nature, as well as other compounds of biotechnological importance including indole derivatives, among many others. Ecologically, they provide some benefits to plants including protection against phy-topathogens and promotion of root growth. In this sense, Xylaria sp. is a cellulose-decomposing fungus with biotechnological potential. It is worth mentioning that indole-3-acetic acid (IAA) also plays an extremely important role in plant-micro-organism interactions, as it is essential for physiology and proper plant morphological development. It is known that nitrile-hydrolytic enzymes (nitrilases) are involved in the synthesis of plant indole compounds; however, relatively little information is available concerning the nature of these enzymes in the fungal kingdom. In view of the above, through a biochemical and molecular-genetic approach, it has been demon-strated for the first time that Xylaria sp. carries out nitrile-hydrolytic enzyme activity using nitrogen and carbonrich compounds as substrate. The studied strain increased its relative gene expression levels and showed mycelial growth, both in the presence of chemical compounds such as cyanobenzene and KCN. Thus, the results of this work suggest that the micro-organism is capable of degrading complex nitrogenous molecules. On the other hand, through fungal biofertilization, it was observed that Xylaria sp. promotes the development of the root system of Arabidopsis thaliana seedlings, in addition to synthesizing IAA.

[First evidence of nitrilase enzymatic activity of Xylaria sp. and its relationship with the biosynthesis of indole-3-acetic acid]. / Primera evidencia de actividad enzimática nitrilasa en Xylaria sp., y su relación con la biosíntesis de ácido indol-3-acético.

Endophytic fungi inhabit plant tissues internally and asymptomatically, and many of them are involved in the synthesis of bioactive metabolites of antifungal and therapeutic nature, as well as other compounds of biotechnological importance including indole derivatives, among many others. Ecologically, they provide some benefits to plants including protection against phytopathogens and promotion of root growth. In this sense, Xylaria sp. is a cellulose-decomposing fungus with biotechnological potential. It is worth mentioning that indole-3-acetic acid (IAA) also plays an extremely important role in plant-micro-organism interactions, as it is essential for physiology and proper plant morphological development. It is known that nitrile-hydrolytic enzymes (nitrilases) are involved in the synthesis of plant indole compounds; however, relatively little information is available concerning the nature of these enzymes in the fungal kingdom. In view of the above, through a biochemical and molecular-genetic approach, it has been demonstrated for the first time that Xylaria sp. carries out nitrile-hydrolytic enzyme activity using nitrogen and carbon-rich compounds as substrate. The studied strain increased its relative gene expression levels and showed mycelial growth, both in the presence of chemical compounds such as cyanobenzene and KCN. Thus, the results of this work suggest that the micro-organism is capable of degrading complex nitrogenous molecules. On the other hand, through fungal biofertilization, it was observed that Xylaria sp. promotes the development of the root system of Arabidopsis thaliana seedlings, in addition to synthesizing IAA.

Influence of Melatonin Treatment on Cellular Mechanisms of Redox Adaptation in K562 Erythroleukemic Cells.

Melatonin (MEL) presents well-documented pleiotropic actions against oxidative stress (OS), acting indirectly through activation of transcription factors, e.g., FoxO3 and Nrf2. Thus, this study aimed to investigate the possible modulating effects of MEL on the redox signaling pathways PI3K/AKT/FoxO3 and Keap1/Nrf2/ARE in K562 erythroleukemic cells subjected to OS induction. For this, the viability, and transcript levels of genes involved in redox adaptation were evaluated in K562 cells in different periods of erythroid differentiation: under OS induction by hydrogen peroxide (100 µM H2O2); treated with 1 nM (C1) and 1 mM (C2) MEL; and associated or not with stress induction. We observed a restoration of physiological levels of Nrf2 in both MEL concentrations under OS. The C1 was related to enhanced expression of antioxidant and proteasome genes through the Nrf2-ARE pathway, while C2 to the induction of FOXO3 expression, suggesting an involvement with apoptotic pathway, according to BIM transcript levels. The effects of MEL administration in these cells showed a period and dose-dependent pattern against induced-OS, with direct and indirect actions through different pathways of cellular adaptation, reinforcing the importance of this indolamine in the regulation of cellular homeostasis, being a promising therapeutic alternative for diseases that present an exacerbated OS.

In vitro bioprospecting of rhizospheric fungi associated to cactus (Opuntia cochenillifera) to plant growth promotion / Bioprospección in vitro de hongos rizosféricos asociados al cactus (Opuntia cochenillifera) para la promoción del crecimiento vegetal

Abstract This study aimed to evaluate in vitro the plant growth promotion capacity of rhizospheric fungi from Opuntia cochenillifera. The isolates were submitted to phosphate solubilization, acetic acid-3-indole (AIA) production, antagonism against phytopathogens, and growth under water activity. All test results were subjected to statistical analysis. The studied isolates were able to solubilize phosphate, being F04 (Aspergillus sp.) and F05 (Coprinellus radians) the ones that presented the highest solubilization indices. As to produce AIA, F02 (Penicillium sp.) and F07 (Aspergillus sp.) were the most promising. All isolates could inhibit the growth of Colletotrichum sp. and Fusarium sp. Water restriction provided mycelial growth for all isolates. Therefore, these characteristics confer characteristics as growth promoters in plants.

Resumen El objetivo de este estudio fue evaluar in vitro la capacidad de los hongos rizosféricos aislados del cactus Opuntia cochenillifera para promover el crecimiento de las plantas. Los aislados fueron sometidos a pruebas de solubilización de fosfato, producción de ácido 3-indol acético (AIA), antagonismo contra fitopatógenos y crecimiento bajo actividad de agua. Todos los resultados de las pruebas se sometieron a análisis estadístico. Los aislados estudiados fueron capaces de solubilizar fosfato, siendo F04 (Aspergillus sp.) y F05 (Coprinellus radians) los que presentaron los mayores índices de solubilización. Sobre la producción de AIA, los que más produjeron fueron F02 (Penicillium sp.) y F07 (Aspergillus sp.). Todos los aislados pudieron inhibir el crecimiento de Colletotrichum sp. e Fusarium sp.. La restricción de agua proporcionó el crecimiento del micelio para todos los aislados. Por lo tanto, estes aspectos les confieren características como promotores del crecimiento en las plantas.

Isolation and Characterization of Plant Growth-Promotion Diazotrophic Endophytic Bacteria Associated to Sugarcane (Saccharum officinarum L.) Grown in Paraíba, Brazil

Abstract: Sugarcane is an important Brazilian commodity, being usually cultivated in soils with low natural fertility. This study aimed to isolate diazotrophic endophytes from sugarcane tissues and evaluate the morphological and physiological characteristics of their colonies as well as their plant growth-promoting (PGP) traits in select diazotrophic endophytic bacteria. Fifty-six bacterial isolates were identified in the sugarcane tissues, and these isolates presented distinct morphological and physiological traits. A total of thirty-five bacterial isolates were biochemically evaluated. Overall, Bacillus was the dominant genus. Isolates of Methylobacterium spp. and Brevibacillus agri were present only in leaves, while Herbaspirillum seropedicae occurred only in stems. Except to IPA-CF45A, all isolates were nitrogenase positive. All endophytes exhibit production of indol 3-acetic acid. Over 50% of endophytes solubilize phosphate, release N-acyl homoserine lactones, and present the activity of 1-aminocyclopropane-1-carboxylic acid deaminase, catalase, lipase and protease. The network analysis showed that isolates belonged to Burkholderia, Herbaspirillum, and Methylobacterium interact with Bacillus. Bacterial endophytes exhibited distinct morphological, physiological, and PGP traits that are useful for sustainable agriculture, highlighting the isolates IPA-CC33, IPA-CF65, IPA-CC9 and IPA-CF27. Further studies on the effects of these diazotrophic endophytes and their potential for providing microbial inoculants for improving sugarcane fields will provide valuable information to maintain the sustainability and environment quality.

IDENTIFICATION OF ENDOPHYTIC BACTERIA OF SEEDS FROM Cedrela odorata L. (Meliaceae) WITH BIOTECHNOLOGICAL CHARACTERISTICS / Identificación de bacterias endófitas de semillas de Cedrela odorata L. (Meliaceae) con características biotecnológicas

ABSTRACT In the present study, 62 endophytic bacterial strains of cedar seeds (Cedrela odorata L.), collected in the municipalities of Huehuetán, Motozintla, and Pijijiapan in the state of Chiapas, Mexico were isolated. The goal was to identify characteristics of biotechnological interest such as biocontrol, promotion ofplant growth, and growth in aromatic compounds. The strains were identified by the partial sequence of the 16S ribosomal gene as belonging to the Bacillus genus. The biocontrol capacity of phytopathogenic fungi, production of indoleacetic acid (IAA), solubilization of phosphate, and growth in xenobiotic compounds (phenanthrene, benzene, anthracene, or phenol) were detected in 26 strains of the 62 isolates. 21 % of the strains inhibited the mycelial growth of Alternaria solani and Fusarium sp., and 13 % of the Phytophthora capsici oomycete. IAA production was detected in 24 isolates, phosphate solubilizing activity was identified in 18 isolates, while the ability to grow in the presence of phenanthrene and benzene was found in 26 isolates; 24 isolates grew in the presence of anthracene and only two isolates grew in phenol as the only carbon sources. This is the first report of the isolation and identification of endophytic bacteria from cedar seeds, where biotechnological characteristics were detected for biological control, promotion of plant growth, and growth in the presence of xenobiotic compounds.

RESUMEN En el presente estudio se aislaron 62 cepas bacterianas endófitas de semillas de cedro (Cedrela odorata L.) colectadas en los municipios de Huehuetán, Motozintla y Pijijiapan en el estado de Chiapas, México, con el objetivo de identificar características de interés biotecnológicas como biocontrol, promoción del crecimiento vegetal y crecimiento en compuestos aromáticos. Las cepas se identificaron por la secuencia parcial del gen 16S ribosomal como pertenecientes al género Bacillus. En 26 cepas de las 62 aisladas se detectaron la capacidad de biocontrol de hongos fitopatógenos, la producción de ácido indolacético (AIA), la solubilización de fosfato y el crecimiento en compuestos xenobióticos (fenantreno, benceno, antraceno o fenol). El 21 % de las cepas inhibió el crecimiento miceliar de Alternaria solani y Fusarium sp., y el 13 % del oomiceto Phytophthora capsici. La producción de ácido indolacético se detectó en 24 aislados y la actividad solubilizadora de fosfato se encontró en 18 aislados, mientras que la capacidad de crecer en presencia de fenantreno y benceno se manifestó en 26 aislados (24 aislados crecieron en presencia de antraceno y solo dos aislados crecieron en fenol como únicas fuentes de carbono). Es importante mencionar que este es el primer reporte del aislamiento e identificación de bacterias endófitas de semillas de cedro, en el que se detectaron características biotecnológicas para el control biológico, la promoción del crecimiento vegetal y el crecimiento en presencia de compuestos xenobióticos.

Isolation and Antibacterial Activity of Indole Alkaloids from Pseudomonas aeruginosa UWI-1.

In this study, we report the first isolation of three antibiotic indole alkaloid compounds from a Pseudomonad bacterium, Pseudomonas aeruginosa UWI-1. The bacterium was batch fermented in a modified Luria Broth medium and compounds were solvent extracted and isolated by bioassay-guided fractionation. The three compounds were identified as (1) tris(1H-indol-3-yl) methylium, (2) bis(indol-3-yl) phenylmethane, and (3) indolo (2, 1b) quinazoline-6, 12 dione. A combination of 1D and 2D NMR, high-resolution mass spectrometry data and comparison from related data from the literature was used to determine the chemical structures of the compounds. Compounds 1-3 were evaluated in vitro for their antimicrobial activities against a wide range of microorganisms using the broth microdilution technique. Compounds 1 and 2 displayed antibacterial activity against only Gram-positive pathogens, although 1 had significantly lower minimum inhibitory concentration (MIC) values than 2. Compound 3 displayed potent broad-spectrum antimicrobial activity against a range of Gram positive and negative bacteria. Several genes identified from the genome of P. aeruginosa UWI-1 were postulated to contribute to the biosynthesis of these compounds and we attempted to outline a possible route for bacterial synthesis. This study demonstrated the extended metabolic capability of Pseudomonas aeruginosa in synthesizing new chemotypes of bioactive compounds.

The Plasmodium falciparum eIK1 kinase (PfeIK1) is central for melatonin synchronization in the human malaria parasite. Melatotosil blocks melatonin action on parasite cell cycle.

Melatonin and its indoles derivatives are central in the synchronization of malaria parasites. In this research, we discovered that melatonin is unable to increase the parasitemia in the human malaria Plasmodium falciparum that lacks the kinase PfeIK1. The PfeIK1 knockout strain is a valuable tool in the screening of indol-related compound that blocks the melatonin effect in wild-type (WT) parasite development. The assays were performed by using flow cytometry with simultaneous labeling for mitochondria viability with MitoTracker Deep Red and nucleus staining with SYBR Green. We found that Melatotosil leads to an increase in parasitemia in P. falciparum and blocks melatonin effect in the WT parasite. Using microscopy imaging system, we found that Melatotosil at 500 nM is able to induce cytosolic calcium rise in transgenic PfGCaMP3 parasites. On the contrary, the compound Triptiofen blocks P. falciparum cell cycle with IC50 9.76 µM ± 0.6, inhibits melatonin action, and does not lead to a cytosolic calcium rise in PfGCaMP3 parasites. We also found that the synthetic indol-related compounds arrested parasite cycle for PfeIK1 knockout and (WT) P. falciparum (3D7) in 72 hours culture assays with the IC50 values slighting lower for the WT strain. We concluded that the kinase PfeIK1 is central for melatonin downstream signaling pathways involved in parasite cell cycle progression. More importantly, the indol-related compounds block its cycle as an upstream essential mechanism for parasite survival. Our data clearly show that this class of compounds emerge as an alternative for the problem of resistance with the classical antimalarials.

Growth and Development of Stevia Cuttings During Propagation with Hormones in Different Months of the Year.

Stevia is an important non-caloric sweetener that has health-beneficial properties. The objective is to evaluate growth, development, and rooting of stevia plants during different seasons of the year using growth hormones. Eight experiments were set up in Ciudad Guzman, Jalisco, Mexico, with three treatments (T): T1, indol-3 butyric acid (IBA) 7.4 mM; T2, alphanaphthylacetamide (ANA) 6.4 mM + IBA 0.3 mM; and T3, control. The variables evaluated were rooted plantlets, plant height, root length, number of leaves, stem diameter, leaf dry weight, stem dry weight, root dry weight, leaf area, shoot biomass, total biomass, as well as development and growth indexes. Four samplings were conducted in each experiment. The results show that the most appropriate months for propagating stevia cuttings are February, March, April, May, and July, when 96% to 99% of the cuttings rooted. The hormones had the best results related to production of root development. The control was outstanding only in variables related to production of shoot biomass and not to root development. It is concluded that stevia can be propagated vegetatively using cuttings treated with IBA 7.4 mM or ANA 6.4 mM + IBA 0.3 mM, preferable in the period from February to July, with the exception of June.

Growing broccoli under salinity: the influence of cultivar and season on glucosinolates content

The evaluation of factors that affect glucosinolates (GLS) concentrations in the roots, leaves, and inflorescence of broccoli plants is important in the improvement of the concentration of bioactive compounds and thus in the enhancement of the nutritional properties. In this work, the yield and the concentration of GLS of seven broccoli cultivars (Brassica oleracea var. italica) grown under salinity in field conditions were studied during three different seasons (autumn, winter, and spring). The results show that, generally, salinity did not alter significantly the inflorescence yield during any of the seasons, indicating a high tolerance of the cultivars tested. Yield was reduced only in cultivar Gea in autumn and in cultivar Parthenon in spring. The distribution of the GLS showed that their accumulation was greater in inflorescences and leaves, with higher concentrations in autumn and spring. The activation of GLS synthesis by salinity was restricted to several cultivars and depended on the season, with no reductions compared to control plants. In this study, we discuss the appearance of a Cinnamoyl-indol-GLS derivative in some of the cultivars and seasons with higher incidence in NaCl-treated plants.(AU)

Vegetative propagation of mate from shoot cuttings induced by coppicing of selected plants / Propagação vegetativa de erva-mate por estaquia de brotações de decepa de plantas selecionadas

Mate (Ilex paraguariensis A. St.-Hil) is an arboreal species of great economic and socio-environmental importance, which presents difficulties in the adventitious rooting process. The rhizogenic competence of vegetative propagules of mate can be attained by coppicing, but the factors that influence the success of this technique have not yet been elucidated. Therefore, the aim of this study was to evaluate the effects of the stock plant, time of shoot collection, treatment with indolebutyric acid (IBA) and diameter of vegetative propagules in the adventitious rooting of cuttings from shoots induced by coppicing of selected adult plants of mate. Shoots produced from coppiced 13SM01 and 13SM05 stock plants were collected at different times of the year to prepare single-bud cuttings. The cuttings were measured as their diameter in the central portion and treated with 0 and 3000 mg L-¹ of IBA. After 60 days, cuttings were evaluated to determine survival and rooting percentages, number of roots, and length of the three largest roots. A completely randomized design was used in a 4 × 2 × 2 × 13 (collection times x stock plants x IBA treatment x diameter classes) factorial scheme with 15 replications. Competence for adventitious rooting was highest for stock plant 13SM05. Cuttings collected in November and February had the highest rooting percentages, without the need of IBA treatment. Cuttings from 13SM01 and 13SM05 with diameters smaller than 0.636 cm (classes 1 to 6) and smaller than 0.712 cm (classes 1 to 7), respectively, had the highest rooting percentages and differed significantly from cuttings with larger diameters. Thus, the results of the present study indicate that stock plants, time of shoot collection, and diameter of vegetative propagules influence adventitious rooting competence of mate cuttings from coppicing adult plants. Rooting of mate cuttings with lower rhizogenic competence is influenced by the application of 3000 mg L-¹ of IBA.(AU)

A erva-mate (Ilex paraguariensis A. St.-Hil) é uma espécie arbórea de grande importância econômicae socioambiental, que apresenta dificuldades no processo de enraizamento adventício. A competência rizogênica dos propágulos vegetativos de erva-mate pode ser obtida pelo decepa, mas os fatores que influenciam no sucesso dessa técnica ainda não foram elucidados. Assim sendo, o presente estudo objetivou avaliar a influência das características genéticas das plantas matrizes, das épocas de coleta, do tratamento com ácido indol-butírico (AIB) e do diâmetro de propágulos vegetativos no enraizamento adventício de estacas de brotações provenientes da decepa de plantas adultas selecionadas de erva-mate. Brotações produzidas a partir da decepa das plantas matrizes 13SM01 e 13SM05 foram coletadas em diferentes épocas e seccionadas em estacas de gema única. As estacas tiveram os diâmetros medidos na porção central e foram tratadas com 0 e 3000 mg L-1 de AIB. Aos 60 dias de cultivo, as estacas foram avaliadas quanto às porcentagens de sobrevivência e enraizamento, número de raízes e comprimento médio das três maiores raízes. O experimento foi um fatorial 4 × 2 × 2 × 13 (época de coleta x planta matriz x tratamento com AIB x classe de diâmetro das estacas) no delineamento inteiramente casualizado, com 15 repetições. A competência ao enraizamento adventício foi maior nas estacas coletadas da planta matriz 13SM05. As estacas coletadas em novembro e fevereiro apresentaram as maiores porcentagens de enraizamento, sem a necessidade de tratamento com AIB. Estacas oriundas de 13SM01 e 13SM05 com diâmetros menores que 0,636 cm (classes 1 a 6) e 0,712 cm (classes 1 a 7),respectivamente, apresentaram os maiores percentuais de enraizamento e diferiram significativamente das estacas com maiores diâmetros. Assim, os resultados do presente estudo indicam que as plantas matrizes, a época de coleta das brotações e o diâmetro dos propágulos vegetativos [...].(AU)

Growing broccoli under salinity: the influence of cultivar and season on glucosinolates content

The evaluation of factors that affect glucosinolates (GLS) concentrations in the roots, leaves, and inflorescence of broccoli plants is important in the improvement of the concentration of bioactive compounds and thus in the enhancement of the nutritional properties. In this work, the yield and the concentration of GLS of seven broccoli cultivars (Brassica oleracea var. italica) grown under salinity in field conditions were studied during three different seasons (autumn, winter, and spring). The results show that, generally, salinity did not alter significantly the inflorescence yield during any of the seasons, indicating a high tolerance of the cultivars tested. Yield was reduced only in cultivar Gea in autumn and in cultivar Parthenon in spring. The distribution of the GLS showed that their accumulation was greater in inflorescences and leaves, with higher concentrations in autumn and spring. The activation of GLS synthesis by salinity was restricted to several cultivars and depended on the season, with no reductions compared to control plants. In this study, we discuss the appearance of a Cinnamoyl-indol-GLS derivative in some of the cultivars and seasons with higher incidence in NaCl-treated plants.

Vegetative propagation of mate from shoot cuttings induced by coppicing of selected plants / Propagação vegetativa de erva-mate por estaquia de brotações de decepa de plantas selecionadas

Mate (Ilex paraguariensis A. St.-Hil) is an arboreal species of great economic and socio-environmental importance, which presents difficulties in the adventitious rooting process. The rhizogenic competence of vegetative propagules of mate can be attained by coppicing, but the factors that influence the success of this technique have not yet been elucidated. Therefore, the aim of this study was to evaluate the effects of the stock plant, time of shoot collection, treatment with indolebutyric acid (IBA) and diameter of vegetative propagules in the adventitious rooting of cuttings from shoots induced by coppicing of selected adult plants of mate. Shoots produced from coppiced 13SM01 and 13SM05 stock plants were collected at different times of the year to prepare single-bud cuttings. The cuttings were measured as their diameter in the central portion and treated with 0 and 3000 mg L-¹ of IBA. After 60 days, cuttings were evaluated to determine survival and rooting percentages, number of roots, and length of the three largest roots. A completely randomized design was used in a 4 × 2 × 2 × 13 (collection times x stock plants x IBA treatment x diameter classes) factorial scheme with 15 replications. Competence for adventitious rooting was highest for stock plant 13SM05. Cuttings collected in November and February had the highest rooting percentages, without the need of IBA treatment. Cuttings from 13SM01 and 13SM05 with diameters smaller than 0.636 cm (classes 1 to 6) and smaller than 0.712 cm (classes 1 to 7), respectively, had the highest rooting percentages and differed significantly from cuttings with larger diameters. Thus, the results of the present study indicate that stock plants, time of shoot collection, and diameter of vegetative propagules influence adventitious rooting competence of mate cuttings from coppicing adult plants. Rooting of mate cuttings with lower rhizogenic competence is influenced by the application of 3000 mg L-¹ of IBA.

A erva-mate (Ilex paraguariensis A. St.-Hil) é uma espécie arbórea de grande importância econômicae socioambiental, que apresenta dificuldades no processo de enraizamento adventício. A competência rizogênica dos propágulos vegetativos de erva-mate pode ser obtida pelo decepa, mas os fatores que influenciam no sucesso dessa técnica ainda não foram elucidados. Assim sendo, o presente estudo objetivou avaliar a influência das características genéticas das plantas matrizes, das épocas de coleta, do tratamento com ácido indol-butírico (AIB) e do diâmetro de propágulos vegetativos no enraizamento adventício de estacas de brotações provenientes da decepa de plantas adultas selecionadas de erva-mate. Brotações produzidas a partir da decepa das plantas matrizes 13SM01 e 13SM05 foram coletadas em diferentes épocas e seccionadas em estacas de gema única. As estacas tiveram os diâmetros medidos na porção central e foram tratadas com 0 e 3000 mg L-1 de AIB. Aos 60 dias de cultivo, as estacas foram avaliadas quanto às porcentagens de sobrevivência e enraizamento, número de raízes e comprimento médio das três maiores raízes. O experimento foi um fatorial 4 × 2 × 2 × 13 (época de coleta x planta matriz x tratamento com AIB x classe de diâmetro das estacas) no delineamento inteiramente casualizado, com 15 repetições. A competência ao enraizamento adventício foi maior nas estacas coletadas da planta matriz 13SM05. As estacas coletadas em novembro e fevereiro apresentaram as maiores porcentagens de enraizamento, sem a necessidade de tratamento com AIB. Estacas oriundas de 13SM01 e 13SM05 com diâmetros menores que 0,636 cm (classes 1 a 6) e 0,712 cm (classes 1 a 7),respectivamente, apresentaram os maiores percentuais de enraizamento e diferiram significativamente das estacas com maiores diâmetros. Assim, os resultados do presente estudo indicam que as plantas matrizes, a época de coleta das brotações e o diâmetro dos propágulos vegetativos [...].

Plant growth promoting rhizobacteria and their potential as bioinoculants on Pennisetum clandestinum (Poaceae)

Introduction: The sustainable production of pastures has become a fundamental challenge for the livestock sector where research with plant growth-promoting rhizobacteria as a viable solution, has nearly not been reported. Objective: In this study, we aimed to examine the potential to stimulate growth in Pennisetum clandestinum grass using four isolated bacterial strains from soils obtained from a Colombian tropical silvopastoral system. Methods: We previously identified genetically the strains and characterized two plant growth promoting activities. In addition, we evaluated the growth-promoting effect of the strains in Kikuyo grass under greenhouse conditions. Results: We found that the four bacterial strains were phylogenetically associated with Klebsiella sp. (strains 28P and 35P), Beijerinka sp. (37L) and Achromobacter xylosoxidans (E37), based on partial 16S rRNA gene sequencing. Moreover, the in vitro biochemical assays demonstrated that the strains exhibited some plant growth promoting mechanisms such as 1-aminocyclopropane-1-carboxylic acid deaminase activity and indole compound synthesis. Notably, bacterial inoculation under greenhouse conditions showed a positive influence on P. clandestinum growth. We found a significant (P < 0.05) effect on root and shoot length and shoot dry weight. Shoot length increased by 52 % and 30 % with 37L and 35P compared to those without inoculation treatment. Similarly, the use of 37L and 28P raised shoot dry weight values by 170 % and 131 %, respectively. In root development, inoculation with strains 37L and E37 increased root length by 134 % and 100 %, respectively. Conclusion: Beijerinckia sp. 37L was the most effective of the four strains at increasing P. clandestinum biomass and length.

Introducción: La producción sostenible de pastos se ha convertido en un desafío fundamental para el sector ganadero, donde investigaciones con bacterias promotoras de crecimiento vegetal, como una solución viable, han sido poco reportadas. Objetivo: El objetivo de este estudio fue examinar el potencial para estimular el crecimiento del pasto Pennisetum clandestinum utilizando cuatro cepas bacterianas aisladas de suelos obtenidos de un sistema silvopastoril tropical colombiano. Métodos: Anteriormente identificamos genéticamente las cepas y caracterizamos dos actividades que promueven el crecimiento de las plantas. Además, evaluamos el efecto promotor del crecimiento de las cepas en el pasto Kikuyo en condiciones de invernadero. Resultados: Encontramos que las cuatro cepas bacterianas se asociaron filogenéticamente con Klebsiella sp. (cepas 28P y 35P), Beijerinka sp. (37L) y Achromobacter xylosoxidans (E37), basados en la secuenciación parcial del gen 16S rRNA. Además, los ensayos bioquímicos in vitro demostraron que las cepas exhibían algunos mecanismos que promueven el crecimiento de las plantas tales como la actividad de la enzima desaminasa del ácido 1-aminociclopropano-1- carboxílico, y la síntesis del compuesto indol. En particular, la inoculación bacteriana bajo condiciones de invernadero mostró una influencia positiva en el crecimiento de P. clandestinum. Encontramos un efecto significativo (P < 0.05) en la longitud de la raíz y el tallo, y el peso seco del tallo. La longitud del tallo aumentó en un 52 % y 30 % con 37L y 35P, respectivamente, en comparación con aquellos sin tratamiento de inoculación. Igualmente, el uso de las cepas 37L y 28P aumentó los valores de peso seco del tallo en un 170 y un 131 %, respectivamente. En el desarrollo de la raíz, la inoculación con las cepas 37L y E37 aumentó la longitud de la raíz en 134 y 100 %, respectivamente. Conclusión: Beijerinckia sp. 37L fue la más efectiva de las cuatro cepas al aumentar la biomasa y la longitud de P. clandestinum.

Miniestaquia de mamoeiro hermafrodita ‘Golden com indutor auxínico, em sistema semi-hidropônico / Mini-cutting of hermaphrodite papaya 'Golden' with auxin inductor in semi-hydroponic system

O mamoeiro tradicionalmente é propagado por sementes. A propagação assexuada é uma alternativa para a produção de plantas hermafroditas com o padrão de frutos exigidos pelo mercado consumidor. Sendo assim, objetivou-se estudar a propagação vegetativa em mamoeiro hermafrodita ‘Golden, testando o ácido indol-3-butírico (AIB) no enraizamento de miniestacas, em sistema semi-hidropônico. O delineamento experimental utilizado foi o inteiramente casualizado. Os tratamentos consistiram de cinco concentrações de AIB (0, 3, 6, 9 e 12 mg L-1 ), com quatro repetições de seis miniestacas retiradas de plantas hermafroditas em cada parcela. Após 60 dias do cultivo, as miniestacas foram analisadas quanto à porcentagem de enraizamento, porcentagem de sobrevivência, comprimento da maior raiz, e número de folhas. A concentração em torno de 9 mg L-1 de AIB propiciou uma melhor indução ao enraizamento das miniestacas, bem como maior sobrevivência das mudas, formação de folhas e qualidade de suas raízes. Recomenda-se o uso de 9 mg L-1 de AIB no sistema semi-hidropônico de produção de mudas usando miniestacas de mamoeiro ‘Golden hermafrodita.(AU)

Papaya is traditionally propagated by seeds. Asexual propagation is an alternative for the production of hermaphrodite plants, with the fruit pattern required by the consumer market. The objective of this study was to study the vegetative propagation in 'Golden' hermaphrodite papaya, by testing the indole-3-butyric acid (IBA) in the rooting of mini-cuttings in a semi-hydroponic system. The experimental design was completely randomized. The treatments consisted of five concentrations of IBA (0, 3, 6, 9, and 12 mg L-1 ), with four replicates of six mini-cuttings taken from hermaphrodite plants in each plot. After 60 days of cultivation, the mini-cuttings were analyzed for rooting percentage, survival percentage, length of the largest root, and the number of leaves. The concentration around 9 mg L -1 of IBA provided a better induction to the rooting of mini-cuttings, as well as greater seedling survival, leaf formation, and root quality. The use of 9 mg L-1 of IBA in the semi-hydroponic system of seedling production is recommended using 'Golden' hermaphrodite papaya mini-cuttings.(AU)

Enraizamento de estacas caulinares de Passiflora actinia Hook: concentrações de IBA e formas de aplicação / Rooting of Passiflora actinia Hook stem cuttings: IBA concentrations and application forms

O maracujá-do-mato (Passiflora actinia Hook) é utilizado como porta-enxerto para diferentes espécies de maracujá devido à sua tolerância à baixas temperaturas. Objetivou-se neste trabalho avaliar a eficiência da técnica de estaquia caulinar na propagação vegetativa de P. actinia em função de concentrações de ácido indol butírico (IBA) e método de aplicação. O experimento foi conduzido em casa de vegetação da Universidade Federal do Paraná, no período de agosto a outubro de 2016. Estacas semilenhosas com 10 cm de comprimento foram tratadas com 0, 1.500 e 3.000 mg Kg-1/mg L-1 de IBA na forma de talco e em solução, plantadas em tubetes, o substrato foi vermiculita. Após 60 dias, foram avaliadas a porcentagem de enraizamento, presença de calos, sobrevivência, brotações novas, número de raízes/estacas e comprimento médio da maior raiz. A maior porcentagem de enraizamento (85,94%) e número de raízes/estaca foram encontradas nos tratamentos com IBA na forma de talco, nas concentrações de 3.000 mg kg-1 e 1.500 mg Kg-1, respectivamente. A estaquia de P. actinia é um método de propagação eficiente. O uso de IBA, em ambas as formas de aplicação, promoveu de forma eficiente o enraizamento da espécie, sendo recomendada a aplicação na concentração de 1.500 mg Kg-1 ou mg L-1.(AU)

The Caatinga passion fruit (Passiflora actinia Hook) is used as rootstock for different passion fruit species due to its tolerance to low temperatures. This study aimed to evaluate the efficiency of the stem cutting technique in the vegetative propagation of P. actinia according to different concentrations of indole butyric acid (IBA) and application methods. The experiment was conducted in the greenhouse of Federal University of Parana, between August and October 2016. Semi-woody stem cuttings measuring 10 cm long were treated with 0, 1500, and 3000 mg Kg-1/mg L-1 IBA in talc and solution, and then planted in plastic tubes with vermiculite as substrate. After 60 days, the stem cuttings were evaluated for rooting percentage, presence of callus, survival, new shoots, number of roots per cuttings and average length of the longest root. The best rooting percentage (85.94%) and number of roots/cuttings were found in cuttings treated with IBA in talc at 3.000 mg Kg-1 and 1.500 mg Kg-1, respectively. P. actinia propagation by stem cuttings is an efficient method. IBA, in both application forms, efficiently promoted the rooting of the species and can be recommended at the concentration of 1.500 mg Kg-1 or mg L-1.(AU)

Enraizamento de estacas caulinares de Passiflora actinia Hook: concentrações de IBA e formas de aplicação / Rooting of Passiflora actinia Hook stem cuttings: IBA concentrations and application forms

O maracujá-do-mato (Passiflora actinia Hook) é utilizado como porta-enxerto para diferentes espécies de maracujá devido à sua tolerância à baixas temperaturas. Objetivou-se neste trabalho avaliar a eficiência da técnica de estaquia caulinar na propagação vegetativa de P. actinia em função de concentrações de ácido indol butírico (IBA) e método de aplicação. O experimento foi conduzido em casa de vegetação da Universidade Federal do Paraná, no período de agosto a outubro de 2016. Estacas semilenhosas com 10 cm de comprimento foram tratadas com 0, 1.500 e 3.000 mg Kg-1/mg L-1 de IBA na forma de talco e em solução, plantadas em tubetes, o substrato foi vermiculita. Após 60 dias, foram avaliadas a porcentagem de enraizamento, presença de calos, sobrevivência, brotações novas, número de raízes/estacas e comprimento médio da maior raiz. A maior porcentagem de enraizamento (85,94%) e número de raízes/estaca foram encontradas nos tratamentos com IBA na forma de talco, nas concentrações de 3.000 mg kg-1 e 1.500 mg Kg-1, respectivamente. A estaquia de P. actinia é um método de propagação eficiente. O uso de IBA, em ambas as formas de aplicação, promoveu de forma eficiente o enraizamento da espécie, sendo recomendada a aplicação na concentração de 1.500 mg Kg-1 ou mg L-1.

The Caatinga passion fruit (Passiflora actinia Hook) is used as rootstock for different passion fruit species due to its tolerance to low temperatures. This study aimed to evaluate the efficiency of the stem cutting technique in the vegetative propagation of P. actinia according to different concentrations of indole butyric acid (IBA) and application methods. The experiment was conducted in the greenhouse of Federal University of Parana, between August and October 2016. Semi-woody stem cuttings measuring 10 cm long were treated with 0, 1500, and 3000 mg Kg-1/mg L-1 IBA in talc and solution, and then planted in plastic tubes with vermiculite as substrate. After 60 days, the stem cuttings were evaluated for rooting percentage, presence of callus, survival, new shoots, number of roots per cuttings and average length of the longest root. The best rooting percentage (85.94%) and number of roots/cuttings were found in cuttings treated with IBA in talc at 3.000 mg Kg-1 and 1.500 mg Kg-1, respectively. P. actinia propagation by stem cuttings is an efficient method. IBA, in both application forms, efficiently promoted the rooting of the species and can be recommended at the concentration of 1.500 mg Kg-1 or mg L-1.

Miniestaquia de mamoeiro hermafrodita ‘Golden’ com indutor auxínico, em sistema semi-hidropônico / Mini-cutting of hermaphrodite papaya 'Golden' with auxin inductor in semi-hydroponic system

O mamoeiro tradicionalmente é propagado por sementes. A propagação assexuada é uma alternativa para a produção de plantas hermafroditas com o padrão de frutos exigidos pelo mercado consumidor. Sendo assim, objetivou-se estudar a propagação vegetativa em mamoeiro hermafrodita ‘Golden’, testando o ácido indol-3-butírico (AIB) no enraizamento de miniestacas, em sistema semi-hidropônico. O delineamento experimental utilizado foi o inteiramente casualizado. Os tratamentos consistiram de cinco concentrações de AIB (0, 3, 6, 9 e 12 mg L-1 ), com quatro repetições de seis miniestacas retiradas de plantas hermafroditas em cada parcela. Após 60 dias do cultivo, as miniestacas foram analisadas quanto à porcentagem de enraizamento, porcentagem de sobrevivência, comprimento da maior raiz, e número de folhas. A concentração em torno de 9 mg L-1 de AIB propiciou uma melhor indução ao enraizamento das miniestacas, bem como maior sobrevivência das mudas, formação de folhas e qualidade de suas raízes. Recomenda-se o uso de 9 mg L-1 de AIB no sistema semi-hidropônico de produção de mudas usando miniestacas de mamoeiro ‘Golden’ hermafrodita.

Papaya is traditionally propagated by seeds. Asexual propagation is an alternative for the production of hermaphrodite plants, with the fruit pattern required by the consumer market. The objective of this study was to study the vegetative propagation in 'Golden' hermaphrodite papaya, by testing the indole-3-butyric acid (IBA) in the rooting of mini-cuttings in a semi-hydroponic system. The experimental design was completely randomized. The treatments consisted of five concentrations of IBA (0, 3, 6, 9, and 12 mg L-1 ), with four replicates of six mini-cuttings taken from hermaphrodite plants in each plot. After 60 days of cultivation, the mini-cuttings were analyzed for rooting percentage, survival percentage, length of the largest root, and the number of leaves. The concentration around 9 mg L -1 of IBA provided a better induction to the rooting of mini-cuttings, as well as greater seedling survival, leaf formation, and root quality. The use of 9 mg L-1 of IBA in the semi-hydroponic system of seedling production is recommended using 'Golden' hermaphrodite papaya mini-cuttings.