The damage caused by Cd toxicity to photosynthesis, cellular ultrastructure, antioxidant metabolism, and gene expression in young cacao plants are mitigated by high Mn doses in soil.

Manganese (Mn) is one of the essential mineral micronutrients most demanded by cacao. Cadmium (Cd) is highly toxic to plants and other living beings. There are indications that Mn can interact with Cd and mitigate its toxicity.

Soil flooding and its outcome on cadmium and nutrient uptake affect photosynthetic activity in Inga laurina plants.

Urban areas next to mangroves are subject to progressive heavy metal contamination. Treelets of Inga laurina were collected in this ecosystem and cultivated for 30 days in waterlogged conditions and closed pots (WC) and at field capacity (FC), while exposed to different Cd concentrations (0, 50 and 100 mg·kg). Soil water conditions did not affect total Cd in plants, with Cd accumulating in roots and WC inducing less leaf chlorophyll while increasing carotenoids and chlorophyll ratio.

Uranium transfer in grasses grown on mining waste and natural soil.

The transfer of radionuclides from soil to the food chain often begins with uptake by plant root system. The roots of most angiosperms showed symbiosis with arbuscular mycorrhizal fungi (AMF) and to understand the transfer process of these toxic elements it is important to consider different physical, chemical and biological factors in soils. In the present study, three grass species (Poaceae), Zea mays, Chrysopogon zizanioides and Aristida setifolia were cultivated with and without organic fertilization in experimental blocks on natural soils, at Fazenda Vargem Formosa (VF) with low uranium (U) contents in the soil, and in the leached ore deposit at the Uranium Concentrate Unit Mine (URA) in Caetité (Uraniferous Province of Lagoa Real - Brazil).

Mitigation of Cd toxicity by Mn in young plants of cacao, evaluated by the proteomic profiles of leaves and roots.

Cd is a non-essential metal and highly toxic to plants, animals and humans, even at very low concentrations. Cd has been found in cocoa beans and in their products, as in the case of chocolate. Mn plays an important role in photosynthetic and can interact with Cd and attenuate its toxic effects on plants.

Witches' broom resistant genotype CCN51 shows greater diversity of symbiont bacteria in its phylloplane than susceptible genotype catongo.

Background: Theobroma cacao L. (cacao) is a perennial tropical tree, endemic to rainforests of the Amazon Basin. Large populations of bacteria live on leaf surfaces and these phylloplane microorganisms can have important effects on plant health.

Mechanical stress caused by wind on leaves of Theobroma cacao: Photosynthetic, molecular, antioxidative and ultrastructural responses.

Theobroma cacao is cultivated in the shade, in a so-called 'Cabruca' system, in intercropped with Erithryna or other tree species of economic value, and in full sun as a monoculture in irrigated or chemically-irrigated systems. Since it is a species quite intolerant to wind, it is practically impossible to implant cacao crops under full exposure to the sun, or in areas of frequent winds, without the protection of windbreaks, using arboreal species around the area of culture in the form of box. Wind can cause mechanical stimuli in plants, affecting their growth and development.

Physiological, ultrastructural, biochemical and molecular responses of young cocoa plants to the toxicity of Cr (III) in soil.

The objective of this study was to evaluate Cr toxicity in young plants of the CCN 51 Theobroma cacao genotype at different concentrations of Cr in the soil (0, 100, 200, 400 and 600 mg kg) through physiological, ultrastructural, antioxidant and molecular changes. Doses of 400 and 600 mg Cr kg soil severely affected foliar gas exchange, promoted by damages in photosynthetic machinery evidenced by the decrease in CO fixation. Decreased expression of psbA and psbO genes, changes in enzymatic activity and lipid peroxidation also affected leaf gas exchange.

Photosynthetic, antioxidative, molecular and ultrastructural responses of young cacao plants to Cd toxicity in the soil.

Cadmium (Cd) is a highly toxic metal for plants, even at low concentrations in the soil. The annual production of world cocoa beans is approximately 4 million tons. Most of these fermented and dried beans are used in the manufacture of chocolate.

Morphology, ultrastructure, and element uptake in Calophyllum brasiliense Cambess. (Calophyllaceae J. Agardh) seedlings under cadmium exposure.

Cadmium (Cd) is a metal known for its genotoxicity and cytotoxicity, much concerned for its potential environmental and human health impacts. This study evaluates the toxic effect of Cd in Calophyllum brasiliense plants. The plants were cultivated for 30 days in full nutrient solution in order to adapt, and for 15 days in nutrient solution without Cd or with 4, 8, 16, and 32 μmol Cd L.

Different salt concentrations induce alterations both in photosynthetic parameters and salt gland activity in leaves of the mangrove Avicennia schaueriana.

Mangrove sites are constantly under tidal regimes, where there is variation of dissolved oxygen and saline content in water. This study evaluated the effects of varying salinity in Avicennia schaueriana, an abundant species in the sea-mangrove-river interface. Seedlings of A.

Morphophysiological, ultrastructural, and nutritional changes induced by Cu toxicity in young Erythrina fusca plants.

Erythrina fusca is an important legume used for shade cover in cacao plantations in Brazil. Cacao plantations receive large quantities of copper (Cu)-containing agrochemicals, mainly for control of diseases. Therefore, Cu toxicity was investigated in seedlings grown in hydroponics with increasing concentrations of Cu (0.

Molecular, Biochemical and Ultrastructural Changes Induced by Pb Toxicity in Seedlings of Theobroma cacao L.

Pb is a metal which is highly toxic to plants and animals, including humans. High concentrations of Pb have been observed in beans of T. cacao, as well as in its products.

Morphological, biochemical, molecular and ultrastructural changes induced by Cd toxicity in seedlings of Theobroma cacao L.

Seeds from Theobroma cacao progenies derived from the self-pollination of 'Catongo'×'Catongo' and the crossing between CCN-10×SCA-6 were immersed for 24h in different Cd solutions (2; 4; 8; 16 and 32 mgL(-1)) along with the control treatment (without Cd). Shortly after, the seeds were sown in plastic tubes containing organic substrate and were grown in a greenhouse for 60 days. The treatment with Cd was observed to cause morphological, biochemical, molecular and ultrastructural changes in both progenies of T.

Effects of lead on anatomy, ultrastructure and concentration of nutrients in plants Oxycaryum cubense (Poep. & Kunth) Palla: a species with phytoremediator potential in contaminated watersheds.

Lead (Pb) has been highlighted as a major pollutant of both terrestrial and aquatic ecosystems, causing negative impacts to these environments. The concentration of Pb in plants has increased in recent decades, mainly due to anthropogenic activities. This study has as a hypothesis that the species Oxycaryum cubense (Poep.

Altered physiology, cell structure, and gene expression of Theobroma cacao seedlings subjected to Cu toxicity.

Seedlings of Theobroma cacao CCN 51 genotype were grown under greenhouse conditions and exposed to increasing concentrations of Cu (0.005, 1, 2, 4, 8, 16, and 32 mg Cu L(-1)) in nutrient solution. When doses were equal or higher than 8 mg Cu L(-1), after 24 h of treatment application, leaf gas exchange was highly affected and changes in chloroplasts thylakoids of leaf mesophyll cells and plasmolysis of cells from the root cortical region were observed.

Morphophysiological responses and programmed cell death induced by cadmium in Genipa americana L. (Rubiaceae).

Cadmium (Cd) originating from atmospheric deposits, from industrial residues and from the application of phosphate fertilizers may accumulate in high concentrations in soil, water and food, thus becoming highly toxic to plants, animals and human beings. Once accumulated in an organism, Cd discharges and sets off a sequence of biochemical reactions and morphophysiological changes which may cause cell death in several tissues and organs. In order to test the hypothesis that Cd interferes in the metabolism of G.

Histological changes in rat duodenum mucosa after whole-body gamma irradiation.

In order to understand the mechanisms of intestinal injuries due to ionizing radiation, various groups of rats have been whole-body irradiated by gamma-rays at two dose rates (1 Gy/min and 1 Gy/hr), three doses (1, 2 and 4 Gy) and two post-irradiation times (24 and 48 hr). Duodenum samples of the animals were prepared for light microscopy, according to classical methods for histology and TUNEL reaction. A small number of morphological differences were observed within the mucosa between the two dose rates used.