RESUMEN
Fungicides are pesticides that are frequently used in agriculture because of their action against fungal diseases. However, the widespread application of pesticides around the world raises environmental and public health concerns, since these compounds are toxic and can pose risks to ecosystems and human health. The aim of this study was to evaluate the phytotoxic, cytogenotoxic, and biochemical effects of azoxystrobin and carbendazim on Lactuca sativa L. and their physiological effects on Phaseolus vulgaris L. by analyzing the cell cycle and chromosomal and nuclear alterations in L. sativa; the biochemical effects of azoxystrobin and carbendazim on Phaseolus vulgaris L. and their physiological effects on Phaseolus vulgaris L. by analyzing the cell cycle and chromosomal and nuclear alterations in L. sativa; the biochemical effects by analyzing the activity of antioxidant enzymes in L. sativa; and the physiological effects by analyzing chlorophyll content and chlorophyll a fluorescence in P. vulgaris. It was observed that both fungicides were phytotoxic and cytotoxic, reducing root growth and the mitotic index, cytogenotoxic, increasing the occurrence of chromosomal alterations, as well as inducing oxidative stress and an increase in chlorophyll fluorescence emission and altered energy absorption in the plants used as a test system. In view of this, studies such as the one presented here indicate that the use of pesticides, even in small quantities, can lead to damage to the metabolism of plant organisms.
Asunto(s)
Bencimidazoles , Carbamatos , Fungicidas Industriales , Lactuca , Phaseolus , Estrobilurinas , Phaseolus/efectos de los fármacos , Estrobilurinas/toxicidad , Bencimidazoles/toxicidad , Fungicidas Industriales/toxicidad , Carbamatos/toxicidad , Lactuca/efectos de los fármacos , Pirimidinas/toxicidad , Clorofila/metabolismoRESUMEN
The two stresses of weed competition and salt salinity lead to crop yield losses and decline in the productivity of agricultural land. These constraints threaten the future of food production because weeds are more salt stress tolerant than most crops. Climate change will lead to an increase of soil salinity worldwide, and possibly exacerbate the competition between weeds and crops. This aspect has been scarcely investigated in the context of weed-crop competition. Therefore, we conducted a field experiment on green beans (Phaseolus vulgaris ) to investigate the combined impact of weed competition and salt stress on key morpho-physiological traits, and crop yield. We demonstrated that soil salinity shifted weed composition toward salt tolerant weed species (Portulaca oleracea and Cynodon dactylon ), while it reduced the presence of lower tolerance species. Weed competition activated adaptation responses in green bean such as reduced leaf mass per area and biomass allocation to the stem, unchanged stomatal density and instantaneous water use efficiency, which diverge from those that are typically observed as a consequence of salt stress. The morpho-physiological modifications caused by weeds is attributed to the alterations of light intensity and/or quality, further confirming the pivotal role of the light in crop response to weeds. We concluded that higher yield loss caused by combined salt stress and weed competition is due to impaired morpho-physiological responses, which highlights the negative interaction between salt stress and weed competition. This phenomenon will likely be more frequent in the future, and potentially reduce the efficacy of current weed control methods.
Asunto(s)
Adaptación Fisiológica , Phaseolus , Malezas , Estrés Salino , Phaseolus/fisiología , Phaseolus/efectos de los fármacos , Malezas/efectos de los fármacos , Malezas/fisiología , Hojas de la Planta/fisiología , Hojas de la Planta/efectos de los fármacos , Productos Agrícolas/crecimiento & desarrollo , Salinidad , Suelo/química , BiomasaRESUMEN
Cricket Frass Fertilizer (CFF) was tested for its efficiency and potential as a fertilizer on the growth of green beans (Phaseolus vulgaris L.) in central Madagascar from April 2020 to October 2020. We grew green beans experimentally for 93 days with seven different fertilizer treatments: NPK 200 kg/ha (0.47 g of N/plant), GUANOMAD (guano from bat) 300 kg/ha (0.26 g of N/ plant), CFF 100 kg/ha (0.12 g of N/plant), CFF 200 kg/ha (0.24 g of N/plant), CFF 300 kg/ha (0.38 g of N/plant), CFF 400 kg/ha (0.52 g of N/plant), and no fertilizer (0 g of N/plant). Three plant traits were measured: survival proportion, vegetative biomass, and pod biomass. The survival proportion of plants treated with the highest dose of CFF (400 kg/ha, 88.1%), NPK (79.8%), and GUANOMAD (81.2%) were similar, but plants treated with the former yielded significantly higher vegetative (35.5 g/plant) and pod biomass (11 g/plant). These results suggest that fertilizing green beans with CFF at a 400 kg/ha dose is sufficient for plant survival and growth, and improves pod production. In Madagascar where soil quality is poor, dependence on imported chemical fertilizers (NPK) and other organic fertilizer (GUANOMAD) can be reduced. Cricket Frass Fertilizer can be used as an alternative sustainable fertilizer for beans.
Asunto(s)
Fertilizantes , Phaseolus , Fertilizantes/análisis , Phaseolus/crecimiento & desarrollo , Phaseolus/efectos de los fármacos , Biomasa , Madagascar , Animales , Gryllidae/crecimiento & desarrolloRESUMEN
Globally, agricultural productivity is facing a serious problem due to soil salinity which often causes osmotic, ionic, and redox imbalances in plants. Applying halotolerant rhizobacterial inoculants having multifarious growth-regulating traits is thought to be an effective and advantageous approach to overcome salinity stress. Here, salt-tolerant (tolerating 300 mM NaCl), exopolysaccharide (EPS) producing Rhizobium azibense SR-26 (accession no. MG063740) was assessed for salt alleviation potential by inoculating Phaseolus vulgaris (L.) plants raised under varying NaCl regimes. The metabolically active cells of strain SR-26 produced a significant amount of phytohormones (indole-3-acetic acid, gibberellic acid, and cytokinin), ACC deaminase, ammonia, and siderophore under salt stress. Increasing NaCl concentration variably affected the EPS produced by SR-26. The P-solubilization activity of the SR-26 strain was positively impacted by NaCl, as demonstrated by OD shift in NaCl-treated/untreated NBRIP medium. The detrimental effect of NaCl on plants was lowered by inoculation of halotolerant strain SR-26. Following soil inoculation, R. azibense significantly (p ≤ 0.05) enhanced seed germination (10%), root (19%) shoot (23%) biomass, leaf area (18%), total chlorophyll (21%), and carotenoid content (32%) of P. vulgaris raised in soil added with 40 mM NaCl concentration. Furthermore, strain SR-26 modulated the relative leaf water content (RLWC), proline, total soluble protein (TSP), and sugar (TSS) of salt-exposed plants. Moreover, R. azibense inoculation lowered the concentrations of oxidative stress biomarkers; MDA (29%), H2O2 content (24%), electrolyte leakage (31%), membrane stability (36%) and Na+ ion uptake (28%) when applied to 40 mM NaCl-treated plants. Further, R. azibense increases the salt tolerance mechanism of P. vulgaris by upregulating the antioxidant defensive responses. Summarily, it is reasonable to propose that EPS-synthesizing halotolerant R. azibense SR-26 should be applied as the most cost-effective option for increasing the yields of legume crops specifically P. vulgaris in salinity-challenged soil systems.
Asunto(s)
Antioxidantes , Phaseolus , Reguladores del Crecimiento de las Plantas , Polisacáridos Bacterianos , Rhizobium , Tolerancia a la Sal , Phaseolus/efectos de los fármacos , Phaseolus/fisiología , Phaseolus/crecimiento & desarrollo , Rhizobium/fisiología , Polisacáridos Bacterianos/metabolismo , Antioxidantes/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Microbiología del Suelo , Homeostasis , Salinidad , Cloruro de Sodio/farmacología , IonesRESUMEN
Glyphosate applied at low doses can stimulate photosynthesis and yield. The objective of this study was to evaluate the application of low doses of glyphosate and sowing seasons in physiological characteristics and grain yield of common bean of early cycle. Two experiments were conducted in the field, the first in winter season and the second in wet season. The experimental design was a randomized complete block design, consisting of five and seven low doses of glyphosate and one period of application, with four replications. Glyphosate low dose of 108.0 g a.e. ha-1 impaired net CO2 assimilation rate, stomatal conductance, transpiration rate, instantaneous carboxylation efficiency, number of pods per plant, number of grains per plant and number of grains per pod. Glyphosate dose of 7.2 g a.e. ha-1 provided a 23% increase in grain yield in winter season, and the dose of 36.0 g a.e. ha-1 provided a 109% increase in grain yield in wet season. To our knowledge, this is the first report on effect of glyphosate at low doses and sowing season to obtain yield increases in common bean of early cycle.
Asunto(s)
Glicina/administración & dosificación , Herbicidas/administración & dosificación , Phaseolus/efectos de los fármacos , Grano Comestible/efectos de los fármacos , Glicina/análogos & derivados , Glicina/farmacología , Herbicidas/farmacología , Phaseolus/fisiología , Fotosíntesis/efectos de los fármacos , Estaciones del Año , GlifosatoRESUMEN
The leafminer Liriomyza trifolii is one of the major insects that affect Phaseolus vulgaris production worldwide. Novel and safe biobased stimulator compound (BSTC) with micronutrient-amino acid chelated compounds was developed from natural compounds and was used for foliar spray of P. vulgaris. Treated plants showed significantly increased in quality and productivity as well as significant reduction in leafminer infestation by close the tunnel end resulting in larvae suffocation and death. BSTC contains chemical composition that has important function in inducing immunity and resistance against insects, enhance plant growth and production. Also, HPLC showed that the assembled BSTC is rich in nucleobases than yeast extract (> 56 fold). Aminochelation zinc enhanced the rate of absorption of nutrient compounds and could participate in safe biofortification strategy. The expression of plant defense related genes under BSTC treatment revealed strong correlations between the transcription rates of defense related genes. Based on binding energies and interacting residues of six vital insect proteins, the best-docked complexes was obtained with disodium 5'-inosinate, delphinidin 3-glucoside and hyperoside. Obtained findings indicate that the foliar application of BSTC can enhance plant growth and productivity, uptake of important elements, expression of defense related genes and inhibit insect essential genes.
Asunto(s)
Productos Biológicos , Dípteros , Control de Plagas/métodos , Phaseolus , Defensa de la Planta contra la Herbivoria/efectos de los fármacos , Animales , Productos Biológicos/química , Productos Biológicos/farmacología , Dípteros/efectos de los fármacos , Dípteros/crecimiento & desarrollo , Insectos , Larva/efectos de los fármacos , Larva/crecimiento & desarrollo , Phaseolus/efectos de los fármacos , Phaseolus/crecimiento & desarrollo , Phaseolus/metabolismo , Fitoquímicos/química , Fitoquímicos/farmacología , Hojas de la Planta/metabolismo , PlantasRESUMEN
Two new bioactive trisubstituted furanones, named pinofuranoxins A and B (1 and 2), were isolated from Diplodia sapinea, a worldwide conifer pathogen causing severe disease. Pinofuranoxins A and B were characterized essentially by NMR and HRESIMS spectra, and their relative and absolute configurations were assigned by NOESY experiments and computational analyses of electronic circular dichroism spectra. They induced necrotic lesions on Hedera helix L., Phaseolus vulgaris L., and Quercus ilex L. Compound 1 completely inhibited the growth of Athelia rolfsii and Phytophthora cambivora, while 2 showed antioomycetes activity against P. cambivora. In the Artemia salina assay both toxins showed activity inducing larval mortality.
Asunto(s)
Ascomicetos/química , Furanos/farmacología , Enfermedades de las Plantas/microbiología , Animales , Artemia/efectos de los fármacos , Basidiomycota/efectos de los fármacos , Fungicidas Industriales/aislamiento & purificación , Fungicidas Industriales/farmacología , Furanos/aislamiento & purificación , Hedera/efectos de los fármacos , Estructura Molecular , Phaseolus/efectos de los fármacos , Phytophthora/efectos de los fármacos , Quercus/efectos de los fármacos , TúnezRESUMEN
Seeds of common bean (Phaseolus vulgaris L.), of the Etna variety, were treated with low-pressure oxygen plasma sustained by an inductively coupled radiofrequency discharge in the H-mode for a few seconds. The high-intensity treatment improved seed health in regard to fungal contamination. Additionally, it increased the wettability of the bean seeds by altering surface chemistry, as established by X-ray photoelectron spectroscopy, and increasing surface roughness, as seen with a scanning electron microscope. The water contact angle at the seed surface dropped to immeasurably low values after a second of plasma treatment. Hydrophobic recovery within a month returned those values to no more than half of the original water contact angle, even for beans treated for the shortest time (0.5 s). Increased wettability resulted in accelerated water uptake. The treatment increased the bean radicle length, which is useful for seedling establishment in the field. These findings confirm that even a brief plasma treatment is a useful technique for the disinfection and stimulation of radicle growth. The technique is scalable to large systems due to the short treatment times.
Asunto(s)
Germinación/efectos de los fármacos , Phaseolus/efectos de los fármacos , Phaseolus/crecimiento & desarrollo , Gases em Plasma/farmacología , Semillas/efectos de los fármacos , Semillas/crecimiento & desarrollo , Espectroscopía de Fotoelectrones , Desarrollo de la Planta/efectos de los fármacos , Semillas/ultraestructura , Propiedades de Superficie , Agua , HumectabilidadRESUMEN
Microbial endophytes organize symbiotic relationships with the host plant, and their excretions contain diverse plant beneficial matter such as phytohormones and bioactive compounds. In the present investigation, six bacterial and four fungal strains were isolated from the common bean (Phaseolus vulgaris L.) root plant, identified using molecular techniques, and their growth-promoting properties were reviewed. All microbial isolates showed varying activities to produce indole-3-acetic acid (IAA) and different hydrolytic enzymes such as amylase, cellulase, protease, pectinase, and xylanase. Six bacterial endophytic isolates displayed phosphate-solubilizing capacity and ammonia production. We conducted a field experiment to evaluate the promotion activity of the metabolites of the most potent endophytic bacterial (Bacillus thuringiensis PB2 and Brevibacillus agri PB5) and fungal (Alternaria sorghi PF2 and, Penicillium commune PF3) strains in comparison to two exogenously applied hormone, IAA, and benzyl adenine (BA), on the growth and biochemical characteristics of the P. vulgaris L. Interestingly, our investigations showed that bacterial and fungal endophytic metabolites surpassed the exogenously applied hormones in increasing the plant biomass, photosynthetic pigments, carbohydrate and protein contents, antioxidant enzyme activity, endogenous hormones and yield traits. Our findings illustrate that the endophyte Brevibacillus agri (PB5) provides high potential as a stimulator for the growth and productivity of common bean plants.
Asunto(s)
Producción de Cultivos/métodos , Endófitos/metabolismo , Phaseolus/efectos de los fármacos , Reguladores del Crecimiento de las Plantas/farmacología , Adenina/análogos & derivados , Adenina/farmacología , Biomasa , Brevibacillus/metabolismo , Ácidos Indolacéticos/farmacología , Phaseolus/crecimiento & desarrollo , Phaseolus/microbiología , FotosíntesisRESUMEN
We report the evaluation of chalcone derivatives as photosystem II (PSII) and plant growth inhibitors. Chalcone derivatives were evaluated as PSII inhibitors through Chl a fluorescence measurement. (E)-Chalcone (6a) and (E)-3-(4-bromophenyl)-1-(4-fluorophenyl)prop-2-en-1-one (6j) showed the best results, reducing the performance index on absorption basis parameter (PIabs ) by 70 %. Additionally, the decrease of TR0 /RC and ET0 /RC parameters indicates that the chalcone derivatives limited the number of active PSII reaction centers and the amount of trapped energy within them. Compounds 6a and 6j both act as post-emergent herbicides at 50â µM, reducing the root biomass of the Ipomoea grandifolia weed by 72 % and 83 %, respectively, corroborating the fluorescence results. The selectivity against weeds as compared to valuable crops by compounds 6a and 6j were evaluated employing Zea mays and Phaseolus vulgaris plants. In these, our newly synthesized compounds showed no effects on biomass accumulation of roots and aerial parts when compared to the control, providing valuable evidence for the role of these compounds as selective inhibitors of the growth of undesired weeds.
Asunto(s)
Chalconas/farmacología , Inhibidores de Crecimiento/farmacología , Herbicidas/farmacología , Complejo de Proteína del Fotosistema II/antagonistas & inhibidores , Biomasa , Chalconas/síntesis química , Chalconas/química , Inhibidores de Crecimiento/síntesis química , Inhibidores de Crecimiento/química , Herbicidas/síntesis química , Herbicidas/química , Ipomoea/efectos de los fármacos , Ipomoea/crecimiento & desarrollo , Estructura Molecular , Phaseolus/efectos de los fármacos , Phaseolus/crecimiento & desarrollo , Procesos Fotoquímicos , Complejo de Proteína del Fotosistema II/metabolismo , Análisis de Componente Principal , Zea mays/efectos de los fármacos , Zea mays/crecimiento & desarrolloRESUMEN
The voltage-dependent anion channel (VDAC) is the major pathway for metabolites and ions transport through the mitochondrial outer membrane. It can regulate the flow of solutes by switching to a low conductance state correlated with a selectivity reversal, or by a selectivity inversion of its open state. The later one was observed in non-plant VDACs and is poorly characterized. We aim at investigating the selectivity inversion of the open state using plant VDAC purified from Phaseolus coccineus (PcVDAC) to evaluate its physiological role. Our main findings are: (1) The VDAC selectivity inversion of the open state occurs in PcVDAC, (2) Ion concentration and stigmasterol affect the occurrence of the open state selectivity inversion and stigmasterol appears to interact directly with PcVDAC. Interestingly, electrophysiological data concerning the selectivity inversion of the PcVDAC open state suggests that the phenomenon probably does not have a significant physiological effect in vivo.
Asunto(s)
Phaseolus/metabolismo , Semillas/metabolismo , Estigmasterol/metabolismo , Canales Aniónicos Dependientes del Voltaje/metabolismo , Medición de Intercambio de Deuterio , Activación del Canal Iónico/efectos de los fármacos , Iones , Cinética , Liposomas , Concentración Osmolar , Phaseolus/efectos de los fármacos , Semillas/efectos de los fármacos , Estigmasterol/farmacologíaRESUMEN
Mineral (Fe/Zn) stress significantly affects fundamental metabolic and physiological responses in plants that results in reduction of plant growth and development. Deficiency of these micronutrients leads to inhibition of photosynthesis by having impact on various crucial biological processes like protein synthesis, primary and secondary metabolism and carbohydrate partitioning between source and sink tissues. In the present study, common bean variety Shalimar French Bean-1 (SFB-1) plants were used as an experimental material and were grown under in vitro condition on four different MGRL media i.e. normal MGRL medium (Control), MGRL without Fe (0-Fe), MGRL without Zinc (0-Zn) and MGRL with excess Zn (300-Zn) for 21 days under optimum conditions. Shoot and root tissues from all the treatments were harvested and further subjected to estimation of total chlorophyll, total sugar and extraction of total RNA for differential gene expression of sugar transporter 13 (STP13). We observed significant decrease in total chlorophyll content in samples harvested from mineral stress plants. However, the concentration of total sugar and fold expression of STP13 gene was significantly higher in shoots of Fe/Zn stressed and in roots of 300-Zn plants. We observed higher accumulation of sugar under stress condition that correlated with high expression of sugar transporter 13 (STP 13). Further, we observed decrease in the chlorophyll content under stress conditions. Based on these findings, we propose the role of sugar driven signaling in decreasing photosynthesis in case of common bean. The decrease in photosynthesis is confirmed by observing significant decrease in chlorophyll content in stressed plants.
Asunto(s)
Hierro/toxicidad , Phaseolus/fisiología , Fotosíntesis , Proteínas de Plantas/metabolismo , Transducción de Señal , Estrés Fisiológico , Azúcares/metabolismo , Zinc/toxicidad , Productos Agrícolas/efectos de los fármacos , Productos Agrícolas/fisiología , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Genes de Plantas , Phaseolus/efectos de los fármacos , Phaseolus/genética , Fotosíntesis/efectos de los fármacos , Fotosíntesis/genética , Proteínas de Plantas/genética , Transducción de Señal/efectos de los fármacos , Estrés Fisiológico/efectos de los fármacos , Estrés Fisiológico/genéticaRESUMEN
Grain legumes are important crops, but they are salt sensitive. This research dissected the responses of four (sub)tropical grain legumes to ionic components (Na+ and/or Cl-) of salt stress. Soybean, mungbean, cowpea, and common bean were subjected to NaCl, Na+ salts (without Cl-), Cl- salts (without Na+), and a "high cation" negative control for 57 days. Growth, leaf gas exchange, and tissue ion concentrations were assessed at different growing stages. For soybean, NaCl and Na+ salts impaired seed dry mass (30% of control), more so than Cl- salts (60% of control). All treatments impaired mungbean growth, with NaCl and Cl- salt treatments affecting seed dry mass the most (2% of control). For cowpea, NaCl had the greatest adverse impact on seed dry mass (20% of control), while Na+ salts and Cl- salts had similar intermediate effects (~45% of control). For common bean, NaCl had the greatest adverse effect on seed dry mass (4% of control), while Na+ salts and Cl- salts impaired seed dry mass to a lesser extent (~45% of control). NaCl and Na+ salts (without Cl-) affected the photosynthesis (Pn) of soybean more than Cl- salts (without Na+) (50% of control), while the reverse was true for mungbean. Na+ salts (without Cl-), Cl- salts (without Na+), and NaCl had similar adverse effects on Pn of cowpea and common bean (~70% of control). In conclusion, salt sensitivity is predominantly determined by Na+ toxicity in soybean, Cl- toxicity in mungbean, and both Na+ and Cl- toxicity in cowpea and common bean.
Asunto(s)
Cloruros/toxicidad , Glycine max/efectos de los fármacos , Phaseolus/efectos de los fármacos , Cloruro de Sodio/toxicidad , Sodio/toxicidad , Vigna/efectos de los fármacos , Biomasa , Phaseolus/crecimiento & desarrollo , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/metabolismo , Tolerancia a la Sal/efectos de los fármacos , Glycine max/crecimiento & desarrollo , Especificidad de la Especie , Vigna/clasificación , Vigna/crecimiento & desarrolloRESUMEN
Plant growth can be stimulated by low doses of glyphosate. The objective of this work was to evaluate the effect of low doses of glyphosate and sowing season on the growth of the early cycle common bean. Two experiments were conducted in the field, the first in the winter and the second in the wet season, with the early cycle common bean cultivar IAC Imperador. The experimental design was a randomized complete block design, consisting of low doses of glyphosate applied on phenological stage V4, with four replications. Environmental conditions, such as air temperature, interfered in the early cycle common bean response to low doses of glyphosate. In the winter season, a dose of 36 g a.e. ha-1 promoted growth in the common bean, and a dose of 7.2 g a.e. ha-1 improved the harvest index. In the wet season, there was no growth stimulus, and the harvest index increased with a dose of 36 g a.e. ha-1. The harvest index was the only characteristic improved in both seasons, but with different doses. Our study indicates that growth characteristics of early cycle common bean are stimulated by low doses of glyphosate, but this response is dependent on the growing environment.
Asunto(s)
Glicina/análogos & derivados , Herbicidas/administración & dosificación , Hormesis , Phaseolus/crecimiento & desarrollo , Relación Dosis-Respuesta a Droga , Glicina/administración & dosificación , Phaseolus/efectos de los fármacos , Estaciones del Año , GlifosatoRESUMEN
The common-bean (Phaseolus vulgaris), a widely consumed legume, originated in Mesoamerica and expanded to South America, resulting in the development of two geographically distinct gene pools. Poor soil condition, including metal toxicity, are often constraints to common-bean crop production. Several P. vulgaris miRNAs, including miR1511, respond to metal toxicity. The MIR1511 gene sequence from the two P. vulgaris model sequenced genotypes revealed that, as opposed to BAT93 (Mesoamerican), the G19833 (Andean) accession displays a 58-bp deletion, comprising the mature and star miR1511 sequences. Genotyping-By-Sequencing data analysis from 87 non-admixed Phaseolus genotypes, comprising different Phaseolus species and P. vulgaris populations, revealed that all the P. vulgaris Andean genotypes and part of the Mesoamerican (MW1) genotypes analyzed displayed a truncated MIR1511 gene. The geographic origin of genotypes with a complete versus truncated MIR1511 showed a distinct distribution. The P. vulgaris ALS3 (Aluminum Sensitive Protein 3) gene, known to be important for aluminum detoxification in several plants, was experimentally validated as the miR1511 target. Roots from BAT93 plants showed decreased miR1511 and increased ALS3 transcript levels at early stages under aluminum toxicity (AlT), while G19833 plants, lacking mature miR1511, showed higher and earlier ALS3 response. Root architecture analyses evidenced higher tolerance of G19833 plants to AlT. However, G19833 plants engineered for miR1511 overexpression showed lower ALS3 transcript level and increased sensitivity to AlT. Absence of miR1511 in Andean genotypes, resulting in a diminished ALS3 transcript degradation, appears to be an evolutionary advantage to high Al levels in soils with increased drought conditions.
Asunto(s)
Aluminio/toxicidad , MicroARNs/genética , Phaseolus/genética , ARN de Planta/genética , Eliminación de Gen , Variación Genética , MicroARNs/metabolismo , Phaseolus/efectos de los fármacos , Phaseolus/metabolismo , Raíces de Plantas/crecimiento & desarrollo , ARN de Planta/metabolismo , Estrés FisiológicoRESUMEN
The present study was conducted to uncover underlying possible effect mechanisms of flavonoid naringenin (Nar, 0.1-0.4 mM) in nitrogen assimilation, antioxidant response, redox status and the expression of NLP7 and DREB2A, on salt (100 mM NaCl) and osmotic-stressed (10% Polyethylene glycol, -0.54 MPa) Phaseolus vulgaris cv. Yunus 90). Nar ameliorated salt/osmotic stresses-induced growth inhibition and improved the accumulation of proline, glycine betaine and choline. In response to stress, Nar increased endogenous content of nitrate (NO3-) and nitrite (NO2-) by regulating of nitrate reductase and nitrite reductase. Stress-triggered NH4+ was eliminated with Nar through increases in glutamine synthetase and glutamate synthase. After NaCl or NaCl + PEG exposure, Nar utilized the aminating activity of glutamate dehydrogenase in the conversion of NH4+. The stress-inducible expression levels of DREB2A were increased further by Nar, which might have affected stress tolerance of bean. Nar induced effectively the relative expression of NLP7 in the presence of the combination or alone of stress. Also, the impaired redox state by stress was modulated by Nar and hydrogen peroxide (H2O2) and TBARS decreased. Nar regulated the different pathways for scavenging of H2O2 under NaCl and/or PEG treatments. When Nar + NaCl exposure, the damage was removed by superoxide dismutase (SOD), catalase (CAT), POX (only at 0.1 mM Nar + NaCl) and AsA-GSH cycle. Under osmotic stress plus Nar, the protection was manifested by activated CAT and, glutathione S-transferase and the regeneration of ascorbate. 0.1 mM Nar could protect bean plant against salt/osmotic stresses, likely by regulating nitrogen assimilation pathways, improving expression levels of genes associated with tolerance mechanisms and modulating the antioxidant capacity and AsA-GSH redox-based systems.
Asunto(s)
Flavanonas/farmacología , Nitrógeno/metabolismo , Presión Osmótica , Phaseolus/fisiología , Especies Reactivas de Oxígeno/metabolismo , Salinidad , Estrés Fisiológico , Antioxidantes/metabolismo , Catalasa/metabolismo , Glutatión/metabolismo , Peróxido de Hidrógeno , Oxidación-Reducción , Phaseolus/efectos de los fármacos , Cloruro de Sodio/farmacología , Superóxido Dismutasa/metabolismoRESUMEN
Two microcystins, MC-LR and [D-Leu1]MC-LR, present in La Plata Basin blooms, are differentiated by substitution of D-Alanine for D-Leucine at position 1. Our objective was to evaluate acute toxicity of [D-Leu1]MC-LR and MC-LR in mice (N:NIH Swiss) and beans (Phaseolus vulgaris). We observed variations in [D-Leu1]MC-LR lethal doses with respect to those reported for MC-LR (100 µg/kg), with an increased liver/body weight ratio and intrahepatic hemorrhages in mice exposed to 50-200 µg [D-Leu1]MC-LR/kg and slight steatosis after a single 25 µg [D-Leu1]MC-LR/kg i.p. dose. Our study in the plant model showed alterations in germination, development, morphology and TBARs levels after a single contact with the toxins during imbibition (3.5 and 15 µg/mL), those treated with [D-Leu1]MC-LR being more affected than those treated with the same concentration of MC-LR. Protein phosphatase 1 (PP1) IC50 values were 40.6 nM and 5.3 nM for [D-Leu1]MC-LR and MC-LR, respectively. However, the total phosphatase activity test in root homogenate showed 60% inhibition for [D-Leu1]MC-LR and 12% for MC-LR. In mouse liver homogenate, 50% inhibition was observed for [D-Leu1]MC-LR and 40% for MC-LR. Our findings indicate the need for further research into [D-Leu1]MC-LR toxicity since together with oxidative stress, the possible inhibition of other phosphatases could explain the differences detected in the potency of the two toxins.
Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Inhibidores Enzimáticos/toxicidad , Hígado/efectos de los fármacos , Toxinas Marinas/toxicidad , Microcistinas/toxicidad , Phaseolus/efectos de los fármacos , Proteínas de Plantas/antagonistas & inhibidores , Proteína Fosfatasa 1/antagonistas & inhibidores , Animales , Enfermedad Hepática Inducida por Sustancias y Drogas/enzimología , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Relación Dosis-Respuesta a Droga , Hígado/enzimología , Hígado/patología , Masculino , Ratones , Phaseolus/enzimología , Proteínas de Plantas/metabolismo , Proteína Fosfatasa 1/metabolismoRESUMEN
[D-Leu1]MC-LR and MC-LR, two microcystins differing in one amino acid, constitute a sanitary and environmental problem owing to their frequent and concomitant presence in water bodies of the Americas and their association with human intoxication during recreational exposure to cyanobacterial bloom. Present in reservoirs used for irrigation as well, they can generate problems in the development of crops such as Phaseolus vulgaris, of nutritional and economic interest to the region. Although numerous works address the toxic effects of MC-LR, information on the toxicity of [D-Leu1]MC-LR is limited. Our objective was to study the toxic effects of [D-Leu1]MC-LR and MC-LR (3.5 µg/ml) on P. vulgaris after a single contact at the imbibition stage. Our findings indicate that 10 days post treatment, [D-Leu1]MC-LR generates morphological and physiological alterations more pronounced than those caused by MC-LR. In addition to the alterations produced by [D-Leu1]MC-LR in the development of seedlings and the structure of the leaves, roots and stems, we also found alterations in leaf stomatal density and conductivity, a longer delay in the phototropic response and a decrease in the maximum curvature angles achieved with respect to that observed for MC-LR. Our findings indicate that these alterations are linked to the greater inhibition of phosphatase activity generated by [D-Leu1]MC-LR, rather than to oxidative damage. We observed that 30 days after treatment with MC-LR, plants presented better development and recovery than those treated with [D-Leu1]MC-LR. Further studies are required on [D-Leu1]MC-LR and MC-LR toxicity and their underlying mechanisms of action.
Asunto(s)
Toxinas Marinas/toxicidad , Microcistinas/toxicidad , Phaseolus/efectos de los fármacos , Procesos Fototróficos/efectos de los fármacos , Desarrollo de la Planta/efectos de los fármacos , Peroxidación de Lípido/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Phaseolus/enzimología , Phaseolus/crecimiento & desarrollo , Fosfoproteínas Fosfatasas/antagonistas & inhibidores , Fosfoproteínas Fosfatasas/metabolismo , Proteínas de Plantas/antagonistas & inhibidores , Proteínas de Plantas/metabolismo , Factores de TiempoRESUMEN
In plants, pathogen triggered programmed cell death (PCD) is frequently mediated by polar lipid molecules referred as long chain bases (LCBs) or ceramides. PCD interceded by LCBs is a well-organized process where several cell organelles play important roles. In fact, light-dependent reactions in the chloroplast have been proposed as major players during PCD, however, the functional aspects of the chloroplast during PCD are largely unknown. For this reason, we investigated events that lead to disassembly of the chloroplast during PCD mediated by LCBs. To do so, LCB elevation was induced with Pseudomonas syringae pv. tomato (a non-host pathogen) or Fumonisin B1 in Phaseolus vulgaris. Then, we performed biochemical tests to detect PCD triggering events (phytosphingosine rises, MPK activation and H2O2 generation) followed by chloroplast structural and functional tests. Observations of the chloroplast, via optical phenotyping methods combined with microscopy, indicated that the loss of photosynthetic linear electron transport coincides with the organized ultrastructure disassembly. In addition, structural changes occurred in parallel with accumulation of H2O2 inside the chloroplast. These features revealed the collapse of chloroplast integrity and function as a mechanism leading to the irreversible execution of the PCD promoted by LCBs.