Hugo Permingeat - Academia.edu (original) (raw)

Papers by Hugo Permingeat

Agrociencia Uruguay, 2021

Monilinia fructicola is a fungal pathogen responsible for fruit brown rot in many species of the ... more Monilinia fructicola is a fungal pathogen responsible for fruit brown rot in many species of the Prunus genus. The use of abiotic elicitors as phosphites is being studied for the induction of fruit resistance as an alternative to the use of synthetic fungicides. The aim of this work was to evaluate the effect of phosphites on the content of total phenols, chlorogenic acid and changes in susceptibility to M. fructicola in peach fruits. Peach fruits of the cultivars Flordaking and Elegant Lady were treated with potassium- and calcium-phosphites, and harvested at three development stages: green fruit (GF), pit hardening (PH) and harvest time (HT). After harvesting, half of them were inoculated with a conidia suspension of M. fructicola under laboratory conditions. Total phenols and chlorogenic acid content were assayed on the skin of the fruits. Results showed different behaviors according to the cultivar. In Flordaking, the phosphite treatment allowed an increase in the content of tot...

Current Research in Biotechnology

Mycologia, Jul 12, 2021

C4 grasses are common species in rangelands around the world and represent an attractive option f... more C4 grasses are common species in rangelands around the world and represent an attractive option for second-generation biofuels production. Although they display a high polysaccharide content and reach great levels of biomass accumulation, there is a major technical issue to be solved before they can be considered as biofuels feedstock: lignin removal. Concerning this, Pycnoporus and Ganoderma fungal genera have been highlighted due to their ability to hydrolyze lignocellulose. The goals here were to evaluate the pretreatment efficiency using P. sanguineus and G. applanatum secretomes harvested from a glucose-free inductive medium and to identify the fungal enzymatic activities responsible for the lignin degradation and glucose release. The findings show that P. sanguineus secretome exhibits a higher activity of lignocellulolytic enzymes compared to the one from G. applanatum. Interestingly, zymograms in presence of glucose suggest that a β-glucosidase isoform from P. sanguineus could be glucosetolerant. The proteomic approach carried out allowed to identify 73 and 180 different proteins for G. applanatum and P. sanguineus secretomes, respectively, which were functionally classified in five main categories, and a miscellaneous group. Many uncharacterized proteins were found in both secretomes, reflecting that greater research is still needed for a better comprehension of lignocellulose degradation.

Revista de Investigaciones de la Facultad de Ciencias Agrarias - UNR, Oct 25, 2012

En trabajos previos, nuestro grupo identifico 65 genes diferencialmente expresados en genotipos s... more En trabajos previos, nuestro grupo identifico 65 genes diferencialmente expresados en genotipos sexuales y apomicticos de Paspalum notatum. Uno de estos genes (codigo experimental N46) resulto homologo a MAP3Ks. Fue aislado del genotipo sexual y su secuencia mapeo in silico en el genoma de arroz en una region sintenica con la region genomica que controla la aposporia en P. notatum. El objetivo de nuestro trabajo fue caracterizar la secuencia y la expresion del gen candidato N46 y desarrollar una plataforma de transformacion para modificar su expresion en organos reproductivos de plantas apomicticas y sexuales. Se utilizo la tecnica de RACE para aislar la secuencia codificante completa (1390 nucleotidos), que en los analisis de Blastx arrojo la mayor similitud con un gen de maiz con anotacion MAP3K (E-value: 0.0 % ID: 96%). Los experimentos de hibridizacion in situ de tejidos reproductivos indicaron que la hebra sentido del transcripto se expresa en ovulos inmaduros de la planta apomictica, y la antisentido en planta sexual. Los experimentos de PCR en tiempo real confirmaron una expresion diferencial en plantas apomicticas y sexuales en estadio meiotico. Para iniciar los experimentos de transformacion, se desarrollo un sistema de cultivo de tejidos sobre el genotipo Q4117 (tetraploide apomictico), ensayando tres tipos de explantos: embriones maduros, meristemas de vastagos y semillas maduras. Los porcentajes de regeneracion obtenidos fueron similares en los tres casos (~45%), por lo que se eligio trabajar con semillas maduras. Los experimentos de transformacion transiente fueron realizados utilizando un acelerador de particulas de tungsteno, presiones de helio comprimido de 600, 800 y 1100 psi, y vectores de transformacion con genes de la via de antocianinas o EGFP (green fluorescent protein), clonados bajo el promotor constitutivo act1 de arroz. Se establecieron curvas de seleccion con el herbicida glufosinato de amonio y el antibiotico kanamicina. Los experimentos de transformacion estable se realizaron utilizando una mezcla de dos plasmidos en cantidades equimolares, uno de ellos con una construccion en horquilla del gen N46 (MAP3K) bajo el protomor act1 de arroz, junto con el selector bar (tolerancia a glufosinato de amonio), y el otro con GFP clonado bajo el promotor act1. El porcentaje de regeneracion obtenido fue de 71 plantas regenerantes/600 callos bombardeados. La introduccion de los transgenes fue analizada por PCR, obteniendose los siguientes resultados: 23.3% gfp, 3,3% bar, 30% co-transformacion (bar + gfp) y 26.7% escapes. Actualmente se estan realizando experimentos de Southern Blot para confirmar la integracion de los transgenes al genoma. Ademas los fenotipos de las inflorescencias de las plantas transgenicas estan siendo analizadas y se encontro expresion de gfp en polen de plantas reportadas como gfp positivas segun los experimentos de PCR.

bioRxiv (Cold Spring Harbor Laboratory), Sep 23, 2020

Biofuels, Jun 18, 2018

Second-generation bioethanol derived from native perennial grasses offers a promising alternative... more Second-generation bioethanol derived from native perennial grasses offers a promising alternative for biofuel, especially when the biomass avoids land-use competition for crop production. Panicum prionitis Ness is a native perennial C4 grass predominant in soils of the Delta del Paran a River, Argentina. Its forage quality (palatability and digestibility) for livestock is low because of its substantial lignin content. In this work, we evaluated different pretreatments (phosphoric acid, ligninolytic enzymes and fungal secretomes) aimed to degrade lignin and improve cellulose hydrolysis efficiency. Results show that 2-day pretreatments with fungal secretomes highly improve release of fermentable sugars compared with conventional pretreatments. Although Pycnoporus sanguineus displayed a greater contribution than Ganoderma applanatum to the pretreatment, the latter triggered the highest final yield, achieving a hydrolysis of 47.5% of cellulose when added to green tissue. These results strengthen the feasibility of using Panicum prionitis biomass in a low-polluting bioethanol production process.

Plant Molecular Biology Reporter, Nov 20, 2018

Amaranthus hybridus L. is one of the most problematic weeds in summer crops in Argentina. However... more Amaranthus hybridus L. is one of the most problematic weeds in summer crops in Argentina. However, 20 years after the detection of the first case of resistance to ALS-inhibiting herbicides in this country, no extensive reports of the molecular mechanisms endowing resistance were published. In this work, we sequenced the acetolactate synthase gene of resistant plants belonging to five different populations of A. hybridus from Santa Fe and Cordoba provinces. We found that every population presented at least one of the previously documented substitutions W574L and D376E in ALS amino acid sequence. These results explain the cross-resistance to ALS-inhibiting herbicides and should alert about the usage of herbicides with a different site of action after an ineffective control of this species. This is the first report of these target-site mechanisms endowing resistance to ALS-inhibiting herbicides in A. hybridus populations from Argentina.

Plant Science, 2020

Genetic basis of the most relevant resistance mechanisms to herbicides are discussed here  Sever... more Genetic basis of the most relevant resistance mechanisms to herbicides are discussed here  Several under-exploited strategies should be considered for weed management programs  Climate change may contribute to the selection of herbicide resistant weeds  Gene drive and RNAi technologies offer new tools to defeat HR weed selection

Frontiers in Plant Science, Oct 24, 2018

Bioresource Technology, Oct 1, 2015

Second generation bioethanol obtained from native perennial grasses offers a promising alternativ... more Second generation bioethanol obtained from native perennial grasses offers a promising alternative for biofuel production, avoiding land use competition for crops production. Spartina argentinensis is a native perennial C4 grass with high photosynthetic rates, well adapted to halo-hydromorphic soils, though its forage quality (palatability and digestibility) for livestock is quite low due to its high lignin content. Hence, cattle raisers burn these grasslands frequently in order to stimulate the emergence of new leaves with higher digestibility for cattle feeding. Lignin is the main barrier to overcome in order to efficiently hydrolyze the cellulose for bioethanol production. In this work, we evaluate different pretreatments (phosphoric acid, ligninolytic enzymes and fungal supernatants) aimed to remove lignin and improving cellulose hydrolysis efficiency. Results show that pretreatment with Pycnoporus sanguineus supernatant improves fermentable carbohydrates availability, compared with a conventional chemical pretreatment, and that 56.84% of cellulose can be hydrolyzed using this pretreatment.

Pest Management Science, Feb 13, 2019

BACKGROUND: The evolution of herbicide-resistant weeds is one of the most important concerns of t... more BACKGROUND: The evolution of herbicide-resistant weeds is one of the most important concerns of the global agriculture. Amaranthus hybridus L. is a competitive weed for summer crops in South America. In this article, we intend to unravel the molecular mechanisms by which an A. hybridus population from Argentina has become resistant to extraordinarily high levels of glyphosate. RESULTS: The glyphosate resistant population ("A") exhibited particularly high parameters of resistance (GR 50 = 20900 g ai ha-1 , Rf= 314), with all plants completing a normal life cycle even after 32X dose application. No shikimic acid accumulation was detected in the resistant plants at any of the glyphosate concentrations tested. Molecular and genetic analyses revealed a novel triple substitution (TAP-IVS: T102I, A103V, and P106S) in the EPSPS enzyme of population "A" and an incipient increase on the epsps relative copy number but without effects on the epsps transcription levels. The novel mechanism was prevalent, with 48% and 52% of the individuals being homozygous and heterozygous for the triple substitution, respectively. In silico conformational studies revealed that TAP-IVS triple substitution would generate an EPSPS with a functional active site but with an increased restriction to the glyphosate binding. CONCLUSION: The prevalence of the TAP-IVS triple substitution as the solely mechanism detected in the highly glyphosate resistant population suggest the evolution of a new GR mechanism arising in A. hybridus. This is the first report of a naturally-occurring EPSPS triple substitution and the first glyphosate TSR mechanism described in A. hybridus.

Acta Scientiarum-agronomy, Dec 21, 2021

Amaranthus palmeri S. Waston is currently one of the most problematic weeds worldwide. Biotypes w... more Amaranthus palmeri S. Waston is currently one of the most problematic weeds worldwide. Biotypes with resistance to herbicides such as glyphosate and ALS inhibitors are now present in almost all Argentinian cultivable areas. In this work, we studied glyphosate resistance in three different populations, some of them previously characterized as resistant to ALS inhibitors. Dose-response curves were conducted in order to assess the effect of glyphosate on the survival and dry biomass of the populations. Subsequently, the presence of target-site resistance (TSR) was studied. Results confirmed the glyphosate resistance in the three populations, showing different levels of resistance, being R2 and R3 significantly more resistant than r1 population. A high prevalence of the P106S substitution was detected in the three resistant populations, while none increase in the relative EPSPS copy number was noticed. Some surviving plants without any of the TSR mechanisms for glyphosate were detected in R3 population, suggesting the presence of non-targetsite resistance (NTSR).

Pest Management Science, Nov 9, 2021

BACKGROUND Amaranthus palmeri S. Watson is a problematic weed infesting summer crops in Argentina... more BACKGROUND Amaranthus palmeri S. Watson is a problematic weed infesting summer crops in Argentina and has developed multiple herbicide resistance. Resistance to acetolactate synthase (ALS)-inhibiting herbicides is particularly common, with high-level resistance mostly caused by different mutations in the ALS enzyme. Six versions of the enzyme were identified from a resistant A. palmeri population, carrying the substitutions D376E, A205V, A122S, A282D, W574L and S653N. This work aims to provide a comparative analysis of these mutants and the wild-type (WT) enzyme for fully understanding the herbicide resistance. Thus, all the versions of the ALS gene from A. palmeri were heterologously expressed and purified to evaluate their kinetics and inhibitory response against imazethapyr, diclosulam, chlorimuron-ethyl, flucarbazone-sodium and bispyribac-sodium. RESULTS A decrease in the catalytic efficiency was detected in the A205V, A122S-A282D, W574L and S653N ApALS enzymes, while only A205V and W574L substitutions also produced a decrease in the substrate affinity. In vitro ALS inhibition assays confirmed the cross-resistance to almost all herbicides tested, with the exception of A282D ApALS, which was equality susceptible as WT ApALS. Moreover, the results confirmed that the novel substitution A122S provides cross-resistance to at least one herbicide within each of the five families of ALS inhibitors, and this property could be explained by a lower number of hydrophobic interactions between the herbicides and the mutant enzyme. CONCLUSION This is the first report to compare various mutations in vitro from Amaranthus palmeri ALS. Our data contribute to understanding the herbicide-resistance impacts in this species.

Uso sustentable de pastizales naturales como fuente de bioenergíaFil: Feldman, Susana. Universida... more Uso sustentable de pastizales naturales como fuente de bioenergíaFil: Feldman, Susana. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentin

Ecología austral, Aug 1, 2013

Journal of Agricultural and Food Chemistry, 2002

Food Research International, 2006

Different foodstuffs for humans and monogastric animals were analysed to detect CryIA(b)gene and ... more Different foodstuffs for humans and monogastric animals were analysed to detect CryIA(b)gene and quantify the CryIA(b) protein present in the transgenic maize used as an ingredient. Eight out of 32 foods obtained from the market showed to have been elaborated with transgenic Bt maize. Specific primers used to identify the transgenic event revealed that Mon810 was predominantly present in the foodstuffs. A commercial ELISA test allowed the quantification of the CryIA(b) protein in low processed foods, and found that 0.1 ppm was the highest value per gram of food. A Western blot carried out with immuno-purified polyclonal antibodies was capable of detecting both the intact or degraded CryIA(b) protein depending on the food assayed.

Electronic Journal of Biotechnology, 2008

Plant Molecular Biology, 2003

Transgenic wheat plants without the selectable marker gene were obtained either in the presence o... more Transgenic wheat plants without the selectable marker gene were obtained either in the presence or in the absence of selective pressure during the transformation protocol. When using hygromycin as selective agent in a co-transformation experiment involving a mixture of plasmids pGL2, containing the hpt gene, and pAI1Gus, containing the uidA gene, 3 out of 19 transgenic wheat plants had the uidA gene alone as shown by Southern blots. The gene was transmitted to the progeny following Mendelian rules. Segregation and loss of the selectable marker gene was also found in three out of six events from other experiments where high-molecular-weight glutenin genes were expressed or over-expressed. On the other hand, in 7 experiments where no selective pressure was applied and that involved 1016 bombarded explants, 23 transgenic wheat plants were obtained. The uidA gene was stably integrated as suggested by its transmission to the progeny.