| Full text | |
| Author(s): |
Total Authors: 2
|
| Affiliation: | [1] Nucleo Pesquisa Anat, Inst Bot, BR-04045972 Sao Paulo, SP - Brazil
Total Affiliations: 1
|
| Document type: | Journal article |
| Source: | Environmental Science and Pollution Research; v. 22, n. 9, p. 6535-6545, MAY 2015. |
| Web of Science Citations: | 4 |
| Abstract | |
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 So Paulo highlighting the temporal dynamics of the cellular events. Leaves with and without necrosis were processed according to standard techniques for anatomical analyses. Leaves from the site with higher SUM00 presented thinner palisade parenchyma, fewer layers of spongy parenchyma, higher stomatal density, clusters of vessel elements in the midrib, erosion of cuticular waxes and stomatal damage. The sequence of microscopic events from the third day of exposure were condensation of the cytoplasm in parenchyma tissue, sinuosity of anticlinal walls, pectinaceous cell wall protrusions, chromatin condensation and changes in chlorophyll autofluorescence. On the 14th day of exposure, these events finally led to cell death in the palisade parenchyma and necrosis on the leaf. The markers observed indicated oxidative stress caused by ozone. (AU) | |