Ozone-Induced Biochemical and Molecular Changes in Leaves and Responses to Infections.

To investigate how plants cope with multi-stress conditions, we analyzed the biochemical and molecular changes of leaves subjected to single or sequential double stresses (infection by () and ozone (O, 100 ppb for 3 h) treatment). In Bc/O leaves, the hydrogen peroxide (HO) induction (observed at 12 and 24 h from the end of treatment (FET)) triggered a production of ethylene (Et; +35% compared with Bc/O leaves), which was preceded by an increase of salicylic acid (SA; +45%). This result confirms a crosstalk between SA- and Et-related signaling pathways in lesion spread.

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

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 tolerance to long-term ozone (O) exposure (120 ppb for 36 days, 5 h day).

Season-long exposure of bilberry plants to realistic and future ozone pollution improves the nutraceutical quality of fruits.

Ozone (O) is a phytotoxic air pollutant capable of limiting plant yield and growth, and altering the quality of edible plant products. This study aimed to investigate the effects of long-term O exposure at realistic and future concentrations (applied during fruit development) not only on morphological, physiological, and biochemical plant/leaf traits of Vaccinium myrtillus but also on its fruit yield and quality. Three-year-old saplings were grown from May to July under three levels of O concentration [1.

The Biosynthesis of Phenolic Compounds is an Integrated Defence Mechanism to Prevent Ozone Injury in .

Specialized metabolites constitute a major antioxidant system involved in plant defence against environmental constraints, such as tropospheric ozone (O). The objective of this experiment was to give a thorough description of the effects of an O pulse (120 ppb, 5 h) on the phenylpropanoid metabolism of sage, at both biochemical and molecular levels. Variable O-induced changes were observed over time among the detected phenylpropanoid compounds (mostly identified as phenolic acids and flavonoids), likely because of their extraordinary functional diversity.

Early Detection of Sage ( L.) Responses to Ozone Using Reflectance Spectroscopy.

Advancements in techniques to rapidly and non-destructively detect the impact of tropospheric ozone (O) on crops are required. This study demonstrates the capability of full-range (350-2500 nm) reflectance spectroscopy to characterize responses of asymptomatic sage leaves under an acute O exposure (200 ppb for 5 h). Using partial least squares regression, spectral models were developed for the estimation of several traits related to photosynthesis, the oxidative pressure induced by O, and the antioxidant mechanisms adopted by plants to cope with the pollutant.

Effects of chlorogenic acid, epicatechin gallate, and quercetin on mucin expression and secretion in the Caco-2/HT29-MTX cell model.

Mucins are a family of large glycoproteins that represent the major structural components of the mucus and are encoded by 20 different mucin genes. Mucin expression can be modulated by different stimuli. In this study, we analyzed four mucins (MUC2, MUC3, MUC13, and MUC17) in coculture of Caco-2/HT29-MTX cells to demonstrate the variation in gene expression in the presence of antioxidant compounds like chlorogenic acid, epicatechin gallate, and quercetin (apple, tea, and coffee polyphenols, respectively).

Signalling molecules responsive to ozone-induced oxidative stress in Salvia officinalis.

Tropospheric ozone (O) is the most important gaseous pollutant and induces a mass of negative impacts on vegetation at functional and genic levels. The aim of the present study was to investigate the role of reactive oxygen species and signalling molecules in sage plants exposed to O (200 ppb, 5 h). Ozone exposure induced only a transient oxidative burst, as confirmed by the rapid peak of anion superoxide during the first hours of exposure (+16% compared to controls).