Effect of different durations of moderate ozone exposure on secondary metabolites of Brassica campestris L. ssp. chinensis

ABSTRACT

Tropospheric ozone is an important ambient atmospheric pollutant component in urban areas. Determining plant reactions to ozone in plant growth and biochemical quality contents plays an important role in understanding plant metabolism. This study aimed to provide an understanding of the effect of ozone on early vegetative growth stage Pak-Choi (Brassica campestris L. ssp. chinensis). An experiment was conducted within an airtight bio-chamber for six consecutive days under 60 ppb ozone concentration. Different exposure duration conditions were 0 h/day, 1 h/day, and 4 h/day. The results showed no reaction of plant growth, but ozone exposure led to significant impacts in biochemical quality. The content of photopigments was not significantly impacted at 1 h/day, but significantly increased at the 4 h/day exposure condition. There was a significant decrease in the total glucosinolate (GLS) and total aliphatic GLS after the 4 h/day exposure condition; however, 4-Methylthiobutyl-GLS, total indole, and aromatic GLS were significantly increased. It appears that biochemical systems are more sensitive than the systems controlling plant growth, and this needs to be taken into account when implementing urban production sites for vegetables.

KEYWORDS:

• Glucosinolates
• ozone stress
• photopigments
• plant growth
• plant stress compensation

Acknowledgments

The authors wish to thank Susanne Meier, and our colleagues at the department of Urban Plant Ecophysiology, Humboldt-Universität zu Berlin. YJH was funded by the Korea Meteorological Administration Research and Development Program “Advanced Research on Biometeorology” under Grant (KMA2018-00620).

Author contribution statement

YJH conceived the original screening and research plans and performed all of the experiments, AG and WB assisted substantially with writing the manuscript, IM and NF provided technical assistance, CU conceived and supervised the research, YJH wrote and edited the manuscript with contributions of all the authors.

Compliance with ethical standards

Disclosure statement

The authors declare that they have no conflict of interest.

Statement of human and animal rights

This article does not contain any studies with human participants or animals performed by any of the authors.

Supplementary material

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Additional information

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.