<abstract xmlns="http://www.w3.org/1999/xhtml"><p>At the plants’ exposal to abiotic stress, organic acids, including citric acid, are exuded through their roots. Previous studies have suggested that the exogenous application of citric acid increases antioxidant activity within the plant. Thus, we postulated that organic acids released into the surroundings during times of environmental stress may function as signaling molecules to increase antioxidant enzyme activity. To gain further insight into this phenomenon, we identified individual organic acids exuded from the roots of leafy vegetables under drought stress. We then analyzed enzyme activity and the root/shoot lengths of seedlings after treatment with the types of organic acids found to be exuded from the studied leafy vegetables, including acetic, citric, lactic, and tartaric acids. There was a significant increase in catalase and ascorbate peroxidase enzyme activity in Napa cabbage (<italic>Brassica rapa</italic> var. <italic>pekinensis</italic>) after exogenous citric acid application. Root lengths of cabbage (<italic>Brassica oleracea</italic> var. <italic>capitata</italic>) and Napa cabbage seedlings were significantly longer in citric and lactic acids pretreated seedlings compared to those of the control. The above results support the conclusion that exogenous application of citric acid alleviates drought stress. However, there is insufficient evidence to prove that organic acids act as signaling molecules to prime neighboring plants for upcoming stress.</p></abstract>

At the plants’ exposal to abiotic stress, organic acids, including citric acid, are exuded through their roots. Previous studies have suggested that the exogenous application of citric acid increases antioxidant activity within the plant. Thus, we postulated that organic acids released into the surroundings during times of environmental stress may function as signaling molecules to increase antioxidant enzyme activity. To gain further insight into this phenomenon, we identified individual organic acids exuded from the roots of leafy vegetables under drought stress. We then analyzed enzyme activity and the root/shoot lengths of seedlings after treatment with the types of organic acids found to be exuded from the studied leafy vegetables, including acetic, citric, lactic, and tartaric acids. There was a significant increase in catalase and ascorbate peroxidase enzyme activity in Napa cabbage (Brassica rapa var. pekinensis) after exogenous citric acid application. Root lengths of cabbage (Brassica oleracea var. capitata) and Napa cabbage seedlings were significantly longer in citric and lactic acids pretreated seedlings compared to those of the control. The above results support the conclusion that exogenous application of citric acid alleviates drought stress. However, there is insufficient evidence to prove that organic acids act as signaling molecules to prime neighboring plants for upcoming stress.

Examining Organic Acid Root Exudate Content and Function for Leafy Vegetables Under Water-Stressed Conditions

Journal of Horticultural Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

At the plants’ exposal to abiotic stress, organic acids, including citric acid, are exuded through their roots. Previous studies have suggested that the...

Examining Organic Acid Root Exudate Content and Function for Leafy Vegetables Under Water-Stressed Conditions

Article Category: Short communication

Published Online: Nov 18, 2020

Page range: 83 - 90

Received: Jun 01, 2020

Accepted: Oct 01, 2020

DOI: https://doi.org/10.2478/johr-2020-0022

Keywords
antioxidant enzyme activity, cabbage, drought stress, Napa cabbage, organic acid, root exudate

© 2020 Naho Kasukawa et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Examining Organic Acid Root Exudate Content and Function for Leafy Vegetables Under Water-Stressed Conditions

Article Category: Short communication

Published Online: Nov 18, 2020

Page range: 83 - 90

Received: Jun 01, 2020

Accepted: Oct 01, 2020

DOI: https://doi.org/10.2478/johr-2020-0022

Keywordsantioxidant enzyme activity, cabbage, drought stress, Napa cabbage, organic acid, root exudate

© 2020 Naho Kasukawa et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
antioxidant enzyme activity, cabbage, drought stress, Napa cabbage, organic acid, root exudate