Integrated physiological, transcriptomic, and metabolomic analyses of drought stress alleviation in Ehretia macrophylla Wall. seedlings by SiO2 NPs (silica nanoparticles)

Minghui Chen; Si-Qian Jiao; Lihua Xie; Xining Geng; Shuaizheng Qi; Jianmin Fan; Shiping Cheng; Jiang Shi; Xibing Cao

doi:10.3389/fpls.2024.1260140

Integrated physiological, transcriptomic, and metabolomic analyses of drought stress alleviation in Ehretia macrophylla Wall. seedlings by SiO₂ NPs (silica nanoparticles)

Front Plant Sci. 2024 Feb 2:15:1260140. doi: 10.3389/fpls.2024.1260140. eCollection 2024.

Authors

Affiliations

¹ Pingdingshan University, Henan Province Key Laboratory of Germplasm Innovation and Utilization of Eco-economic Woody Plant, Pingdingshan, China.
² College of Agriculture, Henan University of Science and Technology, Luoyang, China.
³ College of Forestry, Henan Agricultural University, Zhengzhou, Henan, China.

^# Contributed equally.

Abstract

With environmental problems such as climate global warming, drought has become one of the major stress factors, because it severely affects the plant growth and development. Silicon dioxide nanoparticles (SiO₂ NPs) are crucial for mitigating abiotic stresses suffered by plants in unfavorable environmental conditions and further promoting plant growth, such as drought. This study aimed to investigate the effect of different concentrations of SiO₂ NPs on the growth of the Ehretia macrophylla Wall. seedlings under severe drought stress (water content in soil, 30-35%). The treatment was started by starting spraying different concentrations of SiO2 NPs on seedlings of Ehretia macrophyla, which were consistently under normal and severe drought conditions (soil moisture content 30-35%), respectively, at the seedling stage, followed by physiological and biochemical measurements, transcriptomics and metabolomics analyses. SiO₂ NPs (100 mg·L^-1) treatment reduced malondialdehyde and hydrogen peroxide content and enhanced the activity of antioxidant enzymes under drought stress. Transcriptomic analysis showed that 1451 differentially expressed genes (DEGs) in the leaves of E. macrophylla seedlings were regulated by SiO₂ NPs under drought stress, and these genes mainly participate in auxin signal transduction and mitogen-activated protein kinase signaling pathways. This study also found that the metabolism of fatty acids and α-linolenic acids may play a key role in the enhancement of drought tolerance in SiO₂ NP-treated E. macrophylla seedlings. Metabolomics studies indicated that the accumulation level of secondary metabolites related to drought tolerance was higher after SiO₂ NPs treatment. This study revealed insights into the physiological mechanisms induced by SiO₂ NPs for enhancing the drought tolerance of plants.

Keywords: Ehretia macrophylla Wall.; drought stress; metabolomic; silicon dioxide nanoparticles; transcriptomic.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This study was supported by the Foundation for the invigorating forestry through science and technology (YLK202216), Central Plain Scholar’s workstation of Henan province (ZYGZZ2021048), Major Science and Technology Projects in Henan Province (201300111400-7), Graduate Program Funding of Henan University of Science and Technology (2020YJG-020).