Respostas fisiológicas e anatômicas de plantas jovens de eucalipto expostas ao cádmio

Marques, Teresa Cristina Lara Lanza de Sá e Melo; Soares, Ângela Maria; Gomes, Marcelo Pedrosa; Martins, Giordane

doi:10.1590/s0100-67622011000600005

Cited by 17 publications

(10 citation statements)

References 32 publications

(23 reference statements)

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“…Heavy metals influence the process of cell expansion by decreasing the cell size (GOMES et al, 2011a;GOMES et al, 2011b;MARQUES et al, 2011). Therefore, the observed increase in stomatal density in plants grown under contamination with heavy metals compensated for the smaller diameter stomata found in these conditions, confirming the data found in this study for B. arrecta cultivated under As contamination.…”

Section: Resultssupporting

confidence: 88%

“…This anatomical modification was attributed to the relatively smaller size of the mesophyll cells and to the collapse of the parenchyma cells (GOMES et al, 2011a). The same was observed by Gomes et al (2011b) in a study of Brachiaria decumbens exposed to cadmium (Cd) in soil and by Marques et al (2011) in a study of Eucalyptus camaldulensis exposed to Cd contamination in a nutrient solution. These studies suggest that the metal could have prompted the collapse of cells due to induction in the extensibility cell, indicating that the metal caused toxicity symptoms in these plants.…”

Section: Resultsmentioning

confidence: 62%

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Anatomical and physiological characteristics of tanner grass exposed to arsenic

Argenta

Oliveira

Castro

et al. 2013

RCA

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Phytoremediation is a biological process that stands out as an effective and economic alternative for the removal of toxic elements; however, its success depends on previous studies of plant species and the species' tolerance of certain pollutants. The aim was at evaluating the anatomy and physiology of Tanner grass (Brachiaria arrecta) to determine its anatomical and physiological plasticity characteristics that potentially enable arsenic tolerance. B. arrecta plants were cultivated in a greenhouse in a Hoagland-Arnon nutritive solution with the following As concentrations: 0.0, 0.25, 0.5, 1.0, 2.0 and 4.0 mg L-1. Gas exchange, anatomical characteristics, DNA quantification and arsenic absorption were evaluated at 18 and 21 days. An evaluation of plant growth was conducted to compare the selected plants at the beginning and after 21 days of the experiment. The plants absorbed the arsenic contained in the solution and showed an increase in the leaf stomatal density, mesophyll and leaf blade thickness and root endodermis and exodermis, and the anatomical modifications showed no evidence of stress in the plant structure. The gas exchange, growth and DNA content were not modified by arsenic in B. arrecta plants. The B. arrecta plants have anatomical and physiological characteristics that contribute to their survival in the presence of arsenic, possibly helped by the tolerance of this species of arsenic contamination from the nutrient solution and the lack of anatomical and physiological changes resulting in damage to this species. RESUMO: A fitorremediação é um processo biológico, que se destaca como alternativa eficaz e econômica à remoção de elementos tóxicos; porém, depende de estudos prévios de espécies vegetais e de suas características relacionadas à tolerância a esses poluentes. O objetivo deste trabalho foi avaliar a anatomia e a fisiologia de plantas de braquiária-dobrejo (Brachiaria arrecta), no intuito de detectar características de plasticidade anatômica e fisiológica, relacionadas à potencial tolerância dessa espécie ao arsênio. As plantas de B. arrecta foram cultivadas em casa de vegetação, em solução nutritiva de Hoagland-Arnon contendo as seguintes concentrações de arsênio: 0,0; 0,25; 0,5; 1,0; 2,0 e 4,0 mg L-1. Características de trocas gasosas, anatômicas, quantificação do DNA e absorção de arsênio foram avaliadas aos 18 e 21 dias. A avaliação do crescimento foi conduzida comparando-se plantas utilizadas no início do experimento e após 21 dias. As plantas absorveram o arsênio contido em solução e demonstraram aumento na densidade estomática, na espessura do mesofilo e no limbo foliar, sendo que as modificações anatômicas não indicaram evidências de estresse na estrutura das plantas. As trocas gasosas, o crescimento e o conteúdo de DNA não foram modificados pelo As nas plantas de B. arrecta. As plantas de B. arrecta apresentam características anatômicas e fisiológicas que contribuem para a sobrevivência da espécie, possivelmente por auxiliar na potencial tolerância dessas plantas à contaminação pelo...

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Section: Resultssupporting

confidence: 88%

Section: Resultsmentioning

confidence: 62%

Anatomical and physiological characteristics of tanner grass exposed to arsenic

Argenta

Oliveira

Castro

et al. 2013

RCA

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“…Reductions in the thickness of the epidermis and mesophyll are common responses by plants growing under conditions of heavy metal contamination. Marques et al (2011) reported similar results in Eucalyptus plants growing in soil contaminated with cadmium. The anatomical modifications of the leaves under conditions of heavy metal contamination could result from physiological modifications (SHI; CAI, 2009;SOUZA et al, 2009).…”

Section: Resultssupporting

confidence: 62%

Lead tolerance during germination and early growth of the Brazilian peppertree and the morpho-physiological modifications

Pereira¹,

Pereira²,

Correa³

et al. 2013

RCA

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Woody plants are important for phytoremediation systems, and few species of lead hyperaccumulators are known. We evaluated the lead (Pb) tolerance of Schinus molle L. plants and the resulting anatomical and physiological modifications during germination and early growth. Two experiments were conducted to evaluate the response of S. molle seeds and plants to exposure to five concentrations of Pb(NO 3 ) 2 (0.0, 0.5, 1.0, 2.0, and 5.0 mM). The seed germination and seedling growth were unaffected, and the accumulation of Pb was higher in the roots than in the shoots. The root and leaf anatomy was significantly modified, but the internal structure exhibited no evidence of toxicity. S. molle accumulated Pb to levels close to those of metal-tolerant plants, although the Pb translocation decreased proportionately as the Pb concentration of the solution increased. Thus, S. molle accumulated Pb to concentrations above toxic levels and showed only favorable modifications to the anatomical structure and growth, suggesting this species is Pb tolerant and has the potential for use in phytoremediation systems.RESUMO: Plantas lenhosas são muito importantes para sistemas de fitorremediação e poucas espécies hiperacumuladoras de chumbo são conhecidas. O objetivo deste trabalho foi avaliar a tolerância de Schinus molle L. ao chumbo (Pb), em função de modificações anatômicas e fisiológicas durante a germinação e o crescimento inicial. Dois experimentos foram montados para avaliar a exposição de sementes e plantas de S. molle a cinco concentrações de Pb(NO 3 ) 2 -0,0; 0,5; 1,0; 2,0 e 5,0 mM. Ocorreram modificações significativas na anatomia das raízes e folhas sob exposição ao Pb; contudo, a estrutura interna de S. molle não apresentou nenhuma evidência de toxicidade. A germinação das sementes e o crescimento das plantas não foram afetados pela exposição ao Pb. O acúmulo de Pb foi maior nas raízes, em comparação com a parte aérea. S. molle acumula teores de Pb próximos aos observados em plantas tolerantes a metais, sendo que a translocação de Pb foi reduzida com o aumento da concentração desse elemento na solução. Portanto, S. molle acumula Pb em concentrações acima das consideradas tóxicas e demonstra apenas modificações favoráveis na estrutura anatômica e no crescimento. Dessa forma, esta espécie apresenta tolerância ao Pb e pode ter potencial para ser utilizada em sistemas de fitorremediação.

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“…Other studies also found a Cd-induced decrease in chlorophyll content in plants of Eucalyptus camaldulensis (MARQUES et al, 2011), Pisum sativum L. (JANUŠKAITIEN, 2012) and Medicago sativa L. (MAHMOOD et al, 2014).…”

Section: Resultsmentioning

confidence: 86%

“…The reductions in pigment content were probably due to the affinity of Cd to sulfhydryl groups, forming associations that inactivate some enzymes, and can inhibit the synthesis of 5aminolevulinic acid (chlorophyll precursor molecule), besides inducing deficiencies of magnesium (Mg), iron (Fe) and manganese (Mn), which are necessary for the activity of enzymes involved in the biosynthesis of these pigments (MARQUES et al, 2011). Decreases in Fe, Mn and Mg contents have been attributed to competitive inhibition between Cd and these nutrients for absorption sites in the plasma membrane (HOSEINI; ZARGARI, 2013).…”

Section: Resultsmentioning

confidence: 99%

Photosynthetic Parameters as Physiological Indicators of Tolerance to Cadmium Stress in Sunflower Genotypes

et al. 2018

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The objective of the present study was to evaluate the tolerance to cadmium (Cd) of sunflower genotypes grown in greenhouse conditions, and the effectiveness of using photosynthetic parameters as physiological indicators of this tolerance. Seeds of two sunflower genotypes previously identified as tolerant (H358) and Cd-sensitive (AG960) to Cd were used. The seeds were germinated in plastic cups containing plant substrate; after 9 days, the seedlings were transplanted to plastic basins containing a nutrient solution with 0 or 10 µM of Cd, where they remained for 16 days. Samples of the plants were harvested every 5 days. The experiment was carried out in a randomized complete design, using a 4×2×2 factorial arrangement (4 days of grown in a nutrient solution with Cd, 2 sunflower genotypes, and 2 Cd levels) with four replications. Cd stress decreased CO 2 net assimilation, stomatal conductance, carboxylation efficiency, photosynthetic pigment contents, potential quantum yield (F v /F m ) , and effective quantum yield of plants of the two evaluated genotypes. The decrease in photosynthetic rates of these plants was caused by both stomatal and non-stomatal limitations. Plants of the AG960 genotype showed more pronounced deleterious effects due to Cd stress than those of the H358 genotype. Thus, CO 2 net assimilation rate, stomatal conductance, and chloroplast pigment content are good physiological indicators of sunflower tolerance to Cd and can at least in part, explain the greater tolerance of the H358 genotype to Cd stress when compared to the AG960 genotype. EFICÁCIA DOS PARÂMETROS FOTOSSINTÉTICOS COMO INDICADORES FISIOLÓGICOS DA TOLERÂNCIA AO CÁDMIO EM GIRASSOLRESUMO -O presente estudo foi conduzido em casa de vegetação objetivando-se demonstrar a tolerância ao cádmio (Cd) em genótipos de girassol e avaliar a eficácia dos parâmetros fotossintéticos como indicadores fisiológicos dessa tolerância. Para isto, foram utilizadas sementes de dois genótipos de girassol previamente identificados como tolerante (H358) e sensível (AG960) ao Cd.As sementes foram germinadas em copos plásticos contendo substrato vegetal e, após 9 dias, as plântulas foram transferidas para bacias plásticas com solução nutritiva contendo 0 ou 10 µM de Cd , onde permaneceram por 16 dias. As plantas foram coletadas a cada 5 dias. O delineamento experimental foi o inteiramente casualizado, em um arranjo fatorial 4 (dias de exposição) × 2 (genótipos) × 2 (níveis de Cd), com quatro repetições. A exposição ao Cd reduziu a taxa de assimilação líquida do CO 2 , a condutância estomática e a eficiência de carboxilação, bem como os teores de todos os pigmentos fotossintéticos, a razão F v /F m e o Y II das plantas de ambos os genótipos estudados. Demonstrando que a redução na taxa fotossintética dessas plantas foi ocasionada tanto por limitações estomáticas como não-estomáticas. Os efeitos deletérios do Cd foram mais pronunciados no genótipo AG960 em comparação com o H358. Assim, as variáveis A, gs e os teores de pigmentos mostraram-se bons indicadores fis...

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Respostas fisiológicas e anatômicas de plantas jovens de eucalipto expostas ao cádmio

Cited by 17 publications

References 32 publications

Anatomical and physiological characteristics of tanner grass exposed to arsenic

Anatomical and physiological characteristics of tanner grass exposed to arsenic

Lead tolerance during germination and early growth of the Brazilian peppertree and the morpho-physiological modifications

Photosynthetic Parameters as Physiological Indicators of Tolerance to Cadmium Stress in Sunflower Genotypes

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