How the redox state of tobacco 'Bel-W3' is modified in response to ozone and other environmental factors in a sub-tropical area?

► Nicotiana tabacum 'Bel-W3' is potentially a bioindicator of O3 in the sub-tropics. ► However, it is unknown if its redox state would affect its bioindicator performance under sub-tropical environmental conditions. ► This study revealed that the redox state of tobacco decreases few days after their placement in the sub-tropical environment, causing them to become susceptible to oxidative stress imposed by chronic doses of O3. ► Therefore, its bioindicator efficiency would not be diminished in such levels of atmospheric contamination. ► However, the bioindicator efficiency N. tabacum 'Bel-W3' for biomonitoring O3 should be regionally modeled in the sub-tropics, based on both its redox state and on the flux of O3 through stomata, in response to the varying micro-meteorological conditions that govern both physiological processes.