Vitor Resende Do Nascimento

This research was carried out with the aim of evaluating the attenuating effect of 24-epibrassinolide (EBL) on oxidative stress at emergence in paricá seedlings subjected to arsenic (As) toxicity. Paricá seeds (Schizolobium amazonicum Huber ex Ducke) were used in an experiment with a completely randomized experimental design (DIC) with factorial combinations between three concentrations of 24- epibrassinolide (0, 10 nM and 20nM) and four concentrations of sodium arsenite (NaAsO2 - 0.2 mg L-1, 4 mg L-1, 6 mg L-1). The EBL positively influenced the emergence percentage and shoot and root growth, mainly in the dosage of 20nM of EBL. However, the increase in arsenic concentration had a negative effect on these parameters, mainly at a dosage of 6 mg. L-1. Analysis of the antioxidant system showed that the level of SOD (Superoxide Dismutase) remained constant, the production of APX (Ascorbate Peroxidase) and G-POD (Guaiacol Peroxidase) is negatively modulated by EBL in the leaves. In the root, APX showed low levels and the concentration of G-POD increased with dosages of 20nM of EBL. In summary, doses of 20nM of EBL showed evidence of an attenuating effect on the percentage of emergence, shoot growth and stimulation of G-POD activity.

Objective: Due to this, this study aimed to evaluate the behavior of the normalized difference vegetation index (NDVI) correlating with leaf biochemical variables of Brazilian mahogany (Swietenia macrophylla) under the effect of increasing doses of nickel. Theoretical Framework: Multispectral analyses are a way to assess the early, efficient, unbiased, and, most importantly, non-destructive responses of plants subjected to stress. Method: The experimental design used was a randomized block design (RBD), with five treatments (0, 2, 4, 6 and 8 mg.L-1 of NiCl2.6H2O), with six replicates. The data set obtained was subjected to Pearson's correlation (1892) and multivariate analysis by principal components using the R-Studio-1.3.1093 software. Results and Discussion: The multispectral responses were quite distinct between control and stressed plants until the 30th day of exposure to nickel. The increase in chlorophylls was not accompanied by an increase in the production of photoassimilates, since although there was an increase in such pigments, they were possibly not at their potential operating capacity due to the nickel stress levels. Research Implications: In stress situations, mahogany plants tend to maintain NDVI with a relationship directly proportional to carbohydrates, on the other hand, variables such as leaf temperature, chlorophyll a, b and total tend to have an inversely proportional relationship. Originality/Value: Even though a considerable number of studies have demonstrated the toxicological effects and stress mechanisms caused by nickel in forest plants, there are still unknown parameters, such as the biochemical response related to vegetative index parameters. Therefore, there is a need to clarify many aspects addressed in this study.

The objective of this work was to evaluate the biometric parameters, photosynthetic pigments and the antioxidant system of Clitoria fairchildiana R.A Howard seedlings subjected to exogenous application of 5-aminolevulinic acid and different concentrations of cadmium (Cd). The experiment was conducted in a greenhouse from May to August 2023. Initially, seedlings were produced from straw seeds. After three months, they were transplanted into 3 kg pots containing previously corrected and fertilized black soil. Ten days after transplanting, the plants received exogenous application of 5-ALA, weekly for 5 weeks, totaling 5 applications. After three days of acclimatization, cadmium concentrations were applied in a single time (42nd DAT), in the form of Cadmium Chloride (CdCl2.H2O): 0 (Control), 15 and 30 mg/L-1. The experimental design was completely randomized blocks (CRB), in a 3x3 factorial scheme, specified as follows: three concentrations of Cd (0, 15 and 30 mg L-1 of CdCl2.H20); and three concentrations of 5-ALA (0, 50 and 100 mg L-1 5-ALA), with 9 replicates. The main biometric and photosynthetic pigment variables showed changes with the application of 5-ALA and little variation in the levels subjected to the presence of cadmium. For the antioxidant system, the activity of the enzymes guaiacol peroxidase (G-POD), ascorbate peroxidase (APX), superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) suffered oscillations in their levels due to the application of 5-ALA and Cd, varying according to the concentration of the metal and the part of the plant.

O paricá (Schizolobium parahyba var. amazonicum) é considerada uma das essências nativas mais utilizadas em reflorestamentos no país. O objetivo é avaliar os comportamentos fenológicos de mudas de paricá e identificar quais, que direta ou indiretamente, explicam a variabilidade do desenvolvimento das mudas; utilizando métodos da estatística multivariada. Foram utilizadas mudas de Paricá, que após o 16° DAS de aclimatação das mudas em solução nutritiva, deu-se início a aplicação das concentrações de cádmio, na forma de cloreto de cádmio monohidratado (CdCl2H2O), nas concentrações de 0 (controle) mg L-1; 10 mg L-1; 20 mg L-1; 30 mg L-1 e 40 mg L-1, no qual cada concentração correspondeu ao tratamento, considerado na análise de trilha como variável principal. A análise de trilha indicou que, nos primeiros 60 dias de exposição ao cádmio, as mudas cresceram em altura e diâmetro, clorofila A e carotenoides, de forma direta. Os atributos altura de mudas e número de folhas foram influenciados de forma primária, negativa pelo tratamento de cádmio aos 80 dias, indicando correlação inversa, ou seja, o aumento das dosagens de cádmio culminou em redução de altura e número de folhas nas mudas de Paricá. Análises secundárias e negativas da análise de trilha destacam que o número de folíolos na segunda avaliação, aos 80 dias, tem correlação indireta significativa com altura, diâmetro e número de folhas. Essa verificação é interessante, pois mostra que o aumento do teor de cádmio a longo prazo (80 dias) nas mudas de Paricá, reduz o número de folíolos em mudas que apresentaram desenvolvimento satisfatório em altura, diâmetro e número de folhas.

Environmental contamination by heavy metals represents a growing concern throughout the world, and the physiological potential of the seed allows estimating the theoretical capacity to manifest its vital functions in stressful situations. Due to this, this work aimed to evaluate the effect of increasing dosages of nickel on the physiological potential of Brazilian mahogany (Swietenia macrophylla) seeds and seedlings, seeking to indicate the potential use of this species in phytoremediation programs for use as technology clean. The seeds were grown in polyethylene pots containing sand and maintained at a constant temperature of 28°C, relative humidity (RH) of 90% and a 12-hour photoperiod for 43 days. The experimental design used was randomized blocks, with five treatments (0, 2, 4, 6 and 8 mg.L-1 de NiCl2.6H2O), with six replications. Data were subjected to analysis of variance (ANOVA) and means were tested for significant differences by Tukey test using R-Studio-1.3.1093 software at 5% significance. Changes in plant growth and biomass were observed under different nickel concentrations. In stressful situations, seedling emergence decreased to 28.6%, the average emergence time was postponed to 25 days and there was a longer interval between the first and last seedling emergence, impacting stand establishment. Despite the variations, the seed was capable of emerging, developing and surviving environments contaminated by nickel, indicating some resistance to metal stress.

Brazil is the world leader in the production of charcoal, however, this process generates byproducts that, if not managed correctly, cause adverse environmental impacts. One of these by-products is pyroligneous liquor, derived from the carbonization of wood, historically used for various purposes, such as treating diseases and dyeing fibers. Its chemical composition is influenced by several factors, including temperature and type of wood. This liquid has been applied in agriculture and is recognized for its sustainability and effectiveness in protecting and treating wood. Pyroligneous extract is considered an innovative and sustainable solution to environmental and fire safety issues in the wood industry. Furthermore, the use of biomass by-products as sustainable alternatives for oil-dependent industries is discussed. Pyrolysis is highlighted as an efficient technique to convert biomass into biochar, bio-oil and biogas, contributing to the production of green energy. Experiments were conducted to explore the potential of pyroligneous extract in organic fertilizers and in the cosmetic and sanitizing industry, opening new perspectives for its valorization as a renewable raw material.

Cowpea is a leguminous plant belonging to the fabaceae family cultivated in the North and Northeast regions of Brazil, with productive potential. Among the abiotic factors, water deficiency is one of the main environmental limitations that influence agricultural production in the world. The objective was to evaluate changes in carbon and nitrogen metabolism in cowpea plants exposed to water deficit. The experiment was conducted in a greenhouse at the Universidade Federal Rural da Amazônia (UFRA, Belém, PA), cowpea plants BR-17 Gurguéia Vigna unguiculata (L.) Walp were used. The experimental design was completely randomized (DIC) in a 2 x 2 factorial scheme, two water conditions (control and water deficit) and two times of stress (four and six days of water suspension), with 7 replications, totaling 28 experimental units. Changes in the metabolism of cowpea plants were evident, with alterations in the activity of the nitrate reductase enzyme, concentrations of total soluble proteins, soluble amino acids, free ammonium and nitrate in the leaf tissue and roots.

O mogno africano (Khaya grandifoliola) é uma espécie arbórea que vem ganhando espaço no mercado florestal, apresentando utilidade nas mais diversas utilizações, principalmente em território brasileiro, onde é o principal substituto da madeira do mogno brasileiro. O objetivo deste trabalho foi realizar uma análise de trilha entre a resposta da solução nutritiva ao tratamento com cádmio e as demais variáveis e atributos estudados: aminoácido, nitrato, proteína, amônio, redutase, IDM, cádmio. O experimento foi conduzido em casa de vegetação. A princípio, as mudas foram habituadas para posteriormente serem levadas ao tratamento, onde a aplicabilidade se deu pelo cloreto de cádmio monohidratado (CdCl 2.H2O) de acordo com a solução nutritiva. O delineamento experimental foi inteiramente casualizado (DIC), misturado em cinco concentrações (0; 10; 20; 30 e 40 mg L-1) com sete repetições, totalizando 35 unidades experimentais. Para realizar o exame comparativo, os dados foram submetidos à análise de variância, seguida de análise de regressão. A análise de trilha permitiu verificar diretamente que doses crescentes de tratamento com Cádmio (CAR) refletiram em correlação negativa com o teor de aminoácidos (TAA) nas raízes das plantas de mogno. O estresse abiótico, que foi a exposição a um produto químico tóxico (cádmio), diminuiu, neste caso, a capacidade das plantas de sintetizar aminoácidos. O aumento das doses de tratamento com cádmio (CAL) refletiu em correlação negativa com o teor de proteína na folha (PRL) das plantas de mogno. Evidentemente, quanto maior a concentração de cádmio, maiores serão os danos aos sistemas metabólicos do mogno. Com este estudo, evidenciamos que excesso de cádmio no solo afeta o desenvolvimento de mudas de espécies florestais como o mogno.

Anthropogenic activities such as industrial and mining activities have caused biotic and abiotic stress in plants through contamination by heavy metals deposited in the environment. Some of these are toxic to the plant in any concentration. Phytoremediation and its techniques then emerged as a measure capable of reducing heavy metal contamination. In addition to phytoremediation techniques, research shows the use of growth regulators to act as attenuators and mitigators of stress caused by heavy metals in plants. Thus, the objective of this bibliography was to gather information on contamination by heavy metals in Amazonian forest species, and to outline possible pathways and mechanisms capable of reducing this problem, enabling the use of specific species that can carry out phytoremediation of the soil, making contaminated and unproductive areas into productive ones and capable of being used in forest restoration programs and recovery of degraded areas. Understanding and studies on phytoremediation and its techniques have been deepened. However, it is necessary to increasingly understand the behavior of different species in the presence of heavy metals in the soil.

Anthropic activities such as industries, agriculture and mining has generated public concern for its numerous irregular disposals of its waste, the incorrect deposition of heavy metals such as nickel (Ni) has caused the degradation and contamination of groundwater and water. Studies that point out cheap and efficient solutions have been an obstacle to the advancement of solutions for degraded area recovery programs. For this, a vegetable home experiment was developed, with an entirely randomized design with 5 treatments being a control (no metal) and 4 nickel concentrations (200 μM/L; 400 μM/L; 600 μM/L and 800 μM/L) with 6 repetitions. The variables analyzed were growth and biochemical activity. Plant height and diameter were not affected by increasing nickel concentrations and this response was due to the low leaf and leaflet production capacity of the species under these conditions, consequently reducing biomass production. Metabolic parameters such as sucrose, carbohydrates, proline and glycine increase under stressful conditions, which does not occur for nutritional configurations that decrease with increasing nickel stress.