The passion fruit liana (Passiflora edulis Sims, Passifloraceae) is tolerant to ozone

• Published in: The Science of the total environment 2019-03, Vol.656, p.1091-1101
• Main Authors: Fernandes, Francine Faia, Esposito, Marisia Pannia, da Silva Engela, Marcela Regina Gonçalves, Cardoso-Gustavson, Poliana, Furlan, Claudia Maria, Hoshika, Yasutomo, Carrari, Elisa, Magni, Giada, Domingos, Marisa, Paoletti, Elena
• Format: Article
• Language: English
• Subjects: Air Pollutants - adverse effects; Anatomical acclimatization; Antioxidant system; Dose-Response Relationship, Drug; Liana; Oxidative stress; Ozone - adverse effects; Passiflora - anatomy & histology; Passiflora - chemistry; Passiflora - drug effects; Passiflora - physiology; Plant Leaves - anatomy & histology; Plant Leaves - chemistry; Plant Leaves - drug effects; Plant Leaves - physiology; Polyphenols; Seedlings - anatomy & histology; Seedlings - chemistry; Seedlings - drug effects; Seedlings - physiology; Tropical environment; Vine species
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2018.11.425

Passiflora edulis Sims is a liana species of high economic interest and is an interesting model plant for understanding ozone action on disturbed vegetation. In this work we hypothesized that P. edulis has adaptive responses to oxidative stress that enable it to tolerate ozone damage based on its capacity to grow under a diversity of environmental conditions and to dominate disturbed areas. We exposed seedlings to three levels of ozone in a Free-Air Controlled Exposure (FACE) system (22, 41 and 58 ppb h AOT40 and 13.52, 17.24 and 20.62 mmol m−2 POD0, over 97 days) for identifying its tolerance mechanisms. Anatomical (leaf blade structure and fluorescence emission of chloroplast metabolites), physiological (leaf gas exchange, growth rate and biomass production) and biochemical (pigments, total sugars, starch, enzymatic and non-enzymatic antioxidant metabolites, reactive oxygen species and lipid peroxidation derivatives) responses were assessed. Ozone caused decreased total number of leaves, hyperplasia and hypertrophy of the mesophyll cells, and accelerated leaf senescence. However, O3 did not affect carbohydrates content, net photosynthetic rate, or total biomass production, indicating that the carboxylation efficiency and associated physiological processes were not affected. In addition, P. edulis showed higher leaf contents of ascorbic acid, glutathione (as well high ratio between their reduced and total forms), carotenoids, and flavonoids located in the chloroplast outer envelope membrane. Our results indicate that P. edulis is an O3-tolerant species due to morphological acclimation responses and an effective antioxidant defense system represented by non-enzymatic antioxidants, which maintained the cellular redox balance under ozone. [Display omitted] •Seedlings of Passiflora edulis were exposed to ozone in a FACE system.•Anatomical changes observed in leaf tissue may restrain damage progression.•A high level of O3 did not affect physiological processes.•Biochemical leaf traits enable P. edulis to tolerate oxidative stress.•P. edulis can be considered an O3-tolerant species.