Ozone affects leaf physiology and causes injury to foliage of native tree species from the tropical Atlantic Forest of southern Brazil.

In southern Brazil, the recent increase in tropospheric ozone (O) concentrations poses an additional threat to the biodiverse but endangered and fragmented remnants of the Atlantic Forest. Given the mostly unknown sensitivity of tropical species to oxidative stress, the principal objective of this study was to determine whether the current O levels in the Metropolitan Region of Campinas (MRC), downwind of São Paulo, affect the native vegetation of forest remnants. Foliar responses to O of three tree species typical of the MRC forests were investigated using indoor chamber exposure experiments under controlled conditions and a field survey.

Tillandsia usneoides: A successful alternative for biomonitoring changes in air quality due to a new highway in São Paulo, Brazil.

Tillandsia usneoides is an aerial epiphytic bromeliad that absorbs water and nutrients directly from the atmosphere by scales covering its surface. We expanded the use of this species as a broader biomonitor based on chemical and structural markers to detect changes in air quality. The usefulness of such comprehensive approach was tested during the construction and opening of a highway (SP-21) in São Paulo State, Brazil.

Synergism between ozone and light stress: structural responses of polyphenols in a woody Brazilian species.

Microscopic studies on isolated ozone (O3) effects or on those in synergy with light stress commonly report the induction of polyphenols that exhibit different aspects within the vacuole of photosynthesizing cells. It has been assumed that these different aspects are randomly spread in the symptomatic (injured) regions of the leaf blade. Interestingly, secretory ducts that constitutively produce polyphenols also exhibit these same variations in their vacuolar aspect, in a spatial sequence related to the destiny of these cells (e.

Tillandsia usneoides: a successful alternative for biomonitoring changes in air quality due to a new highway in São Paulo, Brazil.

Tillandsia usneoides is an aerial epiphytic bromeliad that absorbs water and nutrients directly from the atmosphere by scales covering its surface. We expanded the use of this species as a broader biomonitor based on chemical and structural markers to detect changes in air quality. The usefulness of such comprehensive approach was tested during the construction and opening of a highway (SP-21) in São Paulo State, Brazil.

Searching for native tree species and respective potential biomarkers for future assessment of pollution effects on the highly diverse Atlantic Forest in SE-Brazil.

This study summarizes the first effort to search for bioindicator tree species and respective potential biomarkers for future assessment of potential mixed pollution effects on the highly diverse Atlantic Forest in SE-Brazil. Leaves of the three most abundant species inventoried in a phytosociological survey (Croton floribundus, Piptadenia gonoacantha and Astronium graveolens) were collected in four forest remnants during winter and summer (2012). Their potential bioindicator attributes were highlighted using a screening of morphological, chemical and biochemical markers.

Temporal dynamics of the cellular events in tobacco leaves exposed in São Paulo, Brazil, indicate oxidative stress by ozone.

Nicotiana tabacum 'Bel-W3' is widely used as an ozone bioindicator species, showing typical necrosis preceded by microscopic markers of oxidative stress. This study aimed to follow the development of symptoms in tobacco exposed in São Paulo highlighting the temporal dynamics of the cellular events. Leaves with and without necrosis were processed according to standard techniques for anatomical analyses.

Ozone-induced responses in Croton floribundus Spreng. (Euphorbiaceae): metabolic cross-talk between volatile organic compounds and calcium oxalate crystal formation.

Here, we proposed that volatile organic compounds (VOC), specifically methyl salicylate (MeSA), mediate the formation of calcium oxalate crystals (COC) in the defence against ozone (O3) oxidative damage. We performed experiments using Croton floribundus, a pioneer tree species that is tolerant to O3 and widely distributed in the Brazilian forest. This species constitutively produces COC.

Climatic factors influence leaf structure and thereby affect the ozone sensitivity of Ipomoea nil 'Scarlet O'Hara'.

Phenotypic plasticity of the leaves can interfere with the plant sensitivity to ozone (O3) toxic effect. This study aimed to assess whether the leaf structure of Ipomoea nil changes due to climatic variations and whether these changes affect the species' sensitivity. Field exposures, in different seasons (winter and spring) were made.

Ozone phytotoxic potential with regard to fragments of the Atlantic Semi-deciduous Forest downwind of Sao Paulo, Brazil.

In the Metropolitan Region of Campinas (MRC), Brazil, high levels of primary pollutants contribute to ozone (O3) formation. However, little is known regarding the O3 effects in the tropics. Objectives in this study were to characterize the present levels of O3 pollution and to evaluate the relevance of current concentration-based indices for assessing the phytotoxic potential of O3.

Response of Brazilian native trees to acute ozone dose.

Ozone (O3) is a toxic secondary pollutant able to cause an intense oxidative stress that induces visual symptoms on sensitive plant species. Controlled fumigation experiment was conducted with the aim to verify the O3 sensibility of three tropical species: Piptadenia gonoachanta (Mart.) Macbr.

The efficiency of tobacco Bel-W3 and native species for ozone biomonitoring in subtropical climate, as revealed by histo-cytochemical techniques.

We aimed to verify whether hydrogen peroxide (H(2)O(2)) accumulation and cell death are detected early in three bioindicators of ozone (O(3)), Nicotiana tabacum 'Bel-W3', Ipomoea nil 'Scarlet O'Hara' and Psidium guajava 'Paluma', and whether environmental factors also affect those microscopic markers. The three species were exposed to chronic levels of O(3) in a subtropical area and a histo-cytochemical technique that combines 3,3'-diaminobenzidine (DAB) with Evans blue staining was used in the assessments. The three species accumulated H(2)O(2), but a positive correlation with O(3) concentration was only observed in N.

Potential of the Trad-MCN assay applied with inflorescences of Tradescantia pallida 'Purpurea' for evaluating air contamination by naphthalene.

The aims of this study were to determine clastogenic responses of Tradescantia pallida cv. Purpurea to naphthalene (NAPH) by means of the bioassay Trad-MCN with inflorescences of T. pallida cv.