Open Access

ARTICLE

Nanosilver-Promoted Lateral Root Development in Rice is Mediated through Hydrogen Peroxide

by Yu-Jyun Chen, Xian-Hao Yang, Yun-Yang Chao^*

Department of Plant Industry, National Pingtung University of Science and Technology, Pingtung, 912301, Taiwan

* Corresponding Author: Yun-Yang Chao. Email:

(This article belongs to the Special Issue: High-Yield Rice Physiology & Genetics)

Phyton-International Journal of Experimental Botany 2021, 90(5), 1477-1489. https://doi.org/10.32604/phyton.2021.015719

Received 17 January 2021; Accepted 29 March 2021; Issue published 27 May 2021

Abstract

Nanosilver (10⁻⁹ m) refers to particles comprising 20–15,000 silver atoms, exhibiting high stability and specific surface area. At present, nanosilver has been used in agricultural cultivation and production. This study examined the effects of nanosilver on growth and development of rice root systems. Study results showed that fresh weight of rice belowground organs and root length both increased significantly by 5% and 25%, respectively, after rice radicles were treated with 2 ppm of nanosilver for three days. However, the H₂O₂ level reached its peak at 2 days from treatment, but the activities of the antioxidant enzymes CAT, APX, and GR were inhibited by 2 ppm of nanosilver treatment. The results showed that nanosilver treatment inhibited the antioxidant enzyme activity of rice roots. The treatment of rice radicles with 5 μM H₂O₂ promoted root development and the same was observed when nanosilver was used for treatment. Moreover, ascorbic acid (AsA) is a H₂O₂ scavenger and therefore rice root development was inhibited when AsA was added to rice radicles together with either treatment of nanosilver or H₂O₂. In summary, nanosilver treatment of rice radicles promoted root growth and development via the regulation of H₂O₂ and not the O₂^•− pathway.

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