Paulo César Magalhães

Brazilian Agricultural Research Corporation (EMBRAPA) | Embrapa

The hypothesis of this research was to verify the feasibility of using rhizobacteria in maize production, aiming to reduce the effect of water stress and the use of nitrogen fertilizers. Therefore, the objective of this study was to evaluate the morphophysiological responses and yield of maize plants inoculated with A. brasilense cultivated under t...

Current climate change scenarios require strategies that mitigate the effects of water deficits. Given that chitosan stimulates induced resistance responses, we tested the hypothesis that foliar application of this polysaccharide can have positive effects on the primary metabolite, antioxidant, and osmoregulatory metabolisms of sorghum, mitigating...

One of the largest accidents with mine tailings happened in Brazil in 2015, with the rupture of the Fundão dam, and the physical characteristics of these tailings make it difficult to recover degraded areas. Hymenaea courbaril is a tree species native to Brazil that has low nutritional and water requirements, besides its capacity for survival in co...

This work aimed to evaluate the effects of lower water levels on leaf intercellular spaces and to assess their relations with the gas exchange, anatomy, and growth of Sorghum bicolor. Experiments were conducted in a greenhouse, in which plants were subjected to three water conditions (ten replicates, n = 30): well-irrigated, decreased irrigation, a...

The objective of this study was to evaluate the physiological characteristics and rhizofiltration potential of Talinum paniculatum cuttings subjected to lead (Pb) and manganese (Mn) excess. The cuttings excised from T. paniculatum were transferred to a nutrient solution, to which different concentrations of Pb (0, 10, 50, 100, and 200 mg L⁻¹) and M...

Chitosan induces tolerance to abiotic stress agents in plants. However, studies on the different application forms of this biopolymer are limited. This study evaluated the effect of two forms of chitosan application on the morphophysiology of and metal accumulation by Talinum patens cuttings subjected to Cd to develop new cadmium (Cd) decontaminati...

Water stress is among the most severe abiotic stress factors for maize production. The application of chitosan causes various responses in plants, as a function of its structure and concentration. Therefore, chemical modifications were proposed in this study to enhance the biological effects on plants. Hybrid maize plants with drought-contrasting c...

The objective of this study was to evaluate the the ability of foliar application of potassium nitrate (KNO3) to induce water deficit tolerance in sorghum plants (Sorghum bicolor cv. P898012) subjected to water deficit at pre-flowering. The experiment was conducted under greenhouse conditions with 4 treatments: field capacity (FC), water deficit (W...

The present study aimed to evaluate root cortical aerenchyma formation in response to Cd‐driven hydrogen peroxide (H2O2) production and the role of nitric oxide (NO) in the alleviation of Cd oxidative stress in maize roots and its effects on aerenchyma development. Maize plants were subjected to continuous flooding for 30 days, and the following tr...

Silicon (Si) supplementation is related to the induction of different tolerance mechanisms, leading to higher farm crop yields. The objective of this study was to elucidate the Si action mechanisms as a beneficial element in primary, antioxidant, and osmoregulatory metabolism in sorghum plants cultivated in soil under two different water availabili...

Hitherto studies on the synthesis of trehalose derivatives and their effects on plants have not been explored. Therefore, the purpose of this study was to perform a foliar application of trehalose and its derivatives and assess their role in mitigating drought effects in maize plants. The experiment was conducted in a greenhouse, using BRS 1030, a...

Maize is an important crop, with genotype BRS-4154, 'Saracura', being tolerant to intermittent flooding. Cattail is an aquatic plant with known radial oxygen loss activity, being widely diffused around the world and highly invasive. We aimed to analyse the interaction of Maize and Cattail under waterlogging and field capacity. The experiment was co...

The objective of this study was to evaluate the gas exchange, root morphology and nutrient concentration in maize plants inoculated with A. brasilense under two water conditions. The experiments were carried out in a greenhouse, one under irrigation and the other under water deficit. The treatments consisted of four A. brasilense inoculants (contro...

PurposeThis study was conducted to assess the effects of silicon treatments on architecture and morphometry of root systems of sorghum plants grown at two different soil water levels and to elucidate whether physiological improvements caused by silicon were related to morphometric modifications of the root system.Methods Plants of the sorghum genot...

The collapse of the Fundão dam in Mariana, MG, in 2015 resulted in the overflow of more than 50 million m3 of mud containing mine tailings, leaving a path of destruction and immeasurable social and environmental consequences. Tailings’ chemical and physical assessments revealed the presence of some elements at levels higher than those allowed by Br...

Selection of tolerant plants is essential to meet the challenges of food production. The objective of this study was to evaluate agronomic and physiological characteristics as indicators for the selection of water restriction-tolerant grain sorghum genotypes. The experiments were conducted in 2014, 2015 and 2016. Two trials were installed in each y...

The use of plant growth-promoting rhizobacteria (PGPR) is an important and promising tool for sustainable agriculture. The objective of this study was to evaluate the morphophysiological responses and nutrient uptake of maize plants inoculated with A. brasilense under two water conditions. The experiment was carried out in a greenhouse with ten tre...

Low water availability is characterized as an abiotic stressthat limits the agricultural production. Due to the physical and chemicalcharacteristics of the chitosan (CHT), this substance might stimulatephysiological responses on plants to tolerate the water deficit. In this sense,we submitted corn plants to water deficit and application of chitosan...

The Fundão dam was designed to store iron mine tailings in the region of Mariana, MG, Brazil. When it ruptured, the tailings overflowed. These tailings affected the soil due to the formation of a thick crust as a result of drying (compaction) and hindered the natural revegetation process. In this context, the use of organic fertilizers, including v...

This study tested a tosylated and azide trehalose derivative mixture for its ability to mitigate water deficit-induced stress in maize via photosynthetic efficiency analyses. The experiment was conducted in greenhouse pots, using a maize hybrid that is sensitive to drought. The mixture of derivatives (28 mM) was applied with a hand sprayer. Plants...

The use of plant growth-promoting rhizobacteria (PGPR) is an important and promising tool for sustainable agriculture. The objective of this study was to evaluate the morphophysiological responses and nutrient uptake of maize plants inoculated with A. brasilense under two water conditions. The experiment was carried out in a greenhouse with ten tre...

Low water availability is characterized as an abiotic stressthat limits the agricultural production. Due to the physical and chemicalcharacteristics of the chitosan (CHT), this substance might stimulatephysiological responses on plants to tolerate the water deficit. In this sense,we submitted corn plants to water deficit and application of chitosan...

Acidic soils with elevated aluminum (Al) saturations are worldwide distributed and harm the crop production in most of the tropical and subtropical regions. Under these conditions, root elongation may be impaired and thus disturbs water and nutrient uptake. Consequently, physiological responses of plants challenged with excess Al may resemble those...

The present research seeks to elucidate the feasibility of chitosan (CHT) in the induction of water deficit tolerance in different maize hybrids, contrasting tolerance to water restriction, tolerance and sensitivity. The maize plants were subjected to water deficit and foliar application of different chitosan doses (60, 100, 140, and 180 mg L-1) at...

It is a fact that the regions that cultivate the most maize crop do not have fully adequate technologies to measure productivity losses caused by irregularities in water availability. The objective of this study was to evaluate the physiological characteristics of maize hybrids tolerant (DKB 390) and sensitive (BRS 1030) to drought, at V5 growth st...

Research has shown that chitosan induces plant stress tolerance and protection, but few studies have explored chemical modifications of chitosan and their effects on plants under water stress. Chitosan and its derivatives were applied (isolated or in mixture) to maize hybrids sensitive to water deficit under greenhouse conditions through foliar spr...

Chitosan induces plant tolerance to various abiotic stresses, including water deficit. However, its use may be limited, due to its constitution and low solubility in water. Thus, chemical modifications were proposed in this study with the objective of potentializing its biological effects in maize plants. The derivatives were semi-synthesized (N-su...

The feasibility of thermography as a technique for plant screening aiming at drought-tolerance has been proven by its relationship with gas exchange, biomass, and yield. In this study, unlike most of the previous, thermography was applied for phenotyping contrasting maize genotypes whose classification for drought tolerance had already been establi...

Excess copper (Cu) in the soil causes physiological and morphological changes in plants. The objective of this research was to evaluate root morphology and photosynthetic responses in Peltophorum dubium plants exposed to excess Cu. Growth, leaf gas exchange, root morphology and bioaccumulated Cu in the different plant tissues were evaluated. Excess...

– This study associated data of performance, gas exchange and morphometric analysis of the root system using the WinRhizo software. The main objective was to verify how the modifications in the root system contribute to maintain the photosynthetic rates and productivity in sorghum hybrids divergent regarding tolerance to water deficit. The 1G 282 t...

Copper (Cu) is a micronutrient essential for plant development. However, in excess, it is toxic to plants and may cause various physiological and morphological changes. The study of the growth of plants exposed to excess Cu is important for the development of phytoremediation programs and for understanding the mechanisms involved in the tolerance o...

Root cortical aerenchyma (RCA) is suggested to reduce metabolic cost for root growth, but it might lower water uptake by plants. The objective of this work was to evaluate the effects of drought and phosphorus on the RCA development along the root axis and to elucidate its role in water stress tolerance of two maize genotypes. Plants of drought-tol...

Root cortical aerenchyma (RCA) is suggested to reduce metabolic cost for root growth, but it might lower water uptake by plants. The objective of this work was to evaluate the effects of drought and phosphorus on the RCA development along the root axis and to elucidate its role in water stress tolerance of two maize genotypes. Plants of drought-tol...

The objectives of this study were to perform the physicochemical characterization of chitosan, to evaluate its effects on germination, early growth, root anatomy and on the cell cycle of two maize hybrids. The hybrids DKB 390 and DKB 390 VTPRO (transgenic) were used. DKB390 VTPRO is from Monsanto, and the event number is 89034, which expresses the...

Contamination with trace elements is characterized by an abiotic stress that represents a limiting factor in agricultural production. As cadmium (Cd) and Zinc (Zn) are physically and chemically similar, they can interact with the environment, causing antagonistic or synergistic effects. In this sense, physiological mechanisms to exclude detoxify or...

– Drought is considered the primary limitation to agriculture and, can reduce grain yield by up to 60%when occurs at pre-flowering in maize. In this context this research, aimed to understand the maize genotypes behaviorto drought management and carbon partitioning between grain production and structures to maintain hydration whensubmitted to droug...

– Drought is considered the primary limitation to agriculture and, can reduce grain yield by up to 60%when occurs at pre-flowering in maize. In this context this research, aimed to understand the maize genotypes behaviorto drought management and carbon partitioning between grain production and structures to maintain hydration whensubmitted to droug...

Background Photosynthesis can be roughly separated into biochemical and photochemical processes. Both are affected by drought and can be assessed by non-invasive standard methods. Gas exchange, which mainly assesses the first process, has well-defined protocols. It is considered a standard method for evaluation of plant responses to drought. Under...

The objective of this work was to characterize the morphoanatomy of roots and the yield traits of two corn hybrids contrasting for drought tolerance (DKB 390, tolerant; and BRS 1030, sensitive), at different stages of development. Water deficit was imposed for ten days, in a greenhouse, at three growth stages: V5, VT, and R3. These treatments were...

In order to understand possible relationships among the features of plant organs located above and below soil, their correlation and how it might affect strategies for drought adaptation, two sorghum lines contrasting in drought tolerance (BR007-sensitive and 99100-tolerant) were cultivated under different soil water levels during pre-flowering sta...

The present study combined evaluations of agronomic parameters such as roots morphometry (using the WinRhizo program) and leaf gas exchange, in order to detect features in the root system which allow the maintenance of photosynthetic rates and productivity in four maize genotypes contrasting for tolerance to water deficit (WD), two tolerant (DKB 39...

Resumo:O objetivo deste trabalho foi avaliar o papel do etileno e do peróxido de hidrogênio (H2O2) na formação do aerênquima em ciclos de seleção genética da cultivar de milho BRS 4154, sob alagamento. Plantas dos ciclos C1 e C18 foram submetidas a alagamento por 7 dias, com coleta das raízes aos 0 (controle, sem alagamento), 1 e 7 dias. Foram anal...

Plants may respond to drought by altering biomass allocation to shoots and roots or by changing the metabolic activities in these organs. To determine how drought changes the partitioning of carbon allocated to growth and secondary metabolism in maize roots and how it affects photosynthesis (A) and productivity in maize, we evaluated leaf gas excha...

In the northern region of the state of Minas Gerais, lack of rainfall limits crop production in the field, which is possible only with irrigation. Agricultural and physiological practices have been intensively searched to overcome drought effects and consequently increase production. In this context, the objective of this study was to characterize...

Garcinia brasiliensis (Mart.) is a native Amazonian tree cultivated throughout Brazil. This plant can tolerate flooding or submergence for several days, during certain periods of the year. The morphophysiological changes of G. brasiliensis (Mart.) seedlings were assessed that may favor their survival in flooded environments. Seedlings with six full...