Antioxidants and Phytohormones Act in Coordination to Regulate Sage Response to Long Term Ozone Exposure

Alessandra Marchica; Lorenzo Cotrozzi; Giacomo Lorenzini; Cristina Nali; Elisa Pellegrini

doi:10.3390/plants11070904

Antioxidants and Phytohormones Act in Coordination to Regulate Sage Response to Long Term Ozone Exposure

Plants (Basel). 2022 Mar 28;11(7):904. doi: 10.3390/plants11070904.

Authors

Alessandra Marchica¹, Lorenzo Cotrozzi^{1

2

3}, Giacomo Lorenzini^{1

2

3}, Cristina Nali^{1

2

3}, Elisa Pellegrini^{1

2

3}

Affiliations

¹ Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy.
² CIRSEC, Centre for Climate Change Impact, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy.
³ Nutrafood Research Center, University of Pisa, Via del Borghetto 50, 56124 Pisa, Italy.

Abstract

Antioxidants and phytohormones are hallmarks of abiotic stress responses in plants. Although it is known that they can offer cell protection or accelerate programmed cell death (PCD) depending on the level of stress, the involvement of these metabolites in stress acclimation is still not fully elucidated. Here, we showed the role of antioxidants and phytohormones in Salvia officinalis tolerance to long-term ozone (O₃) exposure (120 ppb for 36 days, 5 h day^-1). Salicylic acid (SA) content was increased under O₃ throughout the whole experiment (+150%, as average compared with control), being required to maintain the cellular redox state and potentiate defense responses. This accumulation was induced before the production of ethylene (ET), suggesting that ET was controlled by SA during O₃ exposure to modulate the magnitude of chlorosis formation and the cell redox balance (by regulating ascorbate and glutathione levels). The synthesis and/or regeneration of these antioxidants did not protect membranes from lipid peroxidation, as demonstrated by the accumulation of malondialdehyde (+23% as average). However, these processes of lipid oxidation did not include the synthesis of the membrane breakdown products, as confirmed by the unchanged values of jasmonic acid, thus indicating that this compound was not involved in the regulation of PCD strategies.

Keywords: Salvia officinalis; abscisic acid; aromatic herb; ascorbate-glutathione cycle; jasmonic acid; lipoic acid; oxidative stress; salicylic acid.