DataSheet_3_Integrated physiological, transcriptomic, and metabolomic analyses of drought stress alleviation in Ehretia macrophylla Wall. seedlings by SiO2 NPs (silica nanoparticles).pdf

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.

随着全球气候变暖等环境问题日益凸显，干旱已成为主要逆境胁迫因子之一，严重制约植物的生长与发育。二氧化硅纳米颗粒（Silicon dioxide nanoparticles, SiO₂ NPs）可有效缓解植物在不良环境下遭受的非生物胁迫，并进一步促进植物生长。本研究旨在探究不同浓度的二氧化硅纳米颗粒（SiO₂ NPs）在重度干旱胁迫（土壤含水量30%~35%）下对厚壳树（Ehretia macrophylla Wall.）幼苗生长的影响。实验于幼苗期分别对处于正常生长及重度干旱胁迫（土壤含水量30%~35%）条件下的厚壳树幼苗喷施不同浓度的二氧化硅纳米颗粒，随后开展生理生化指标测定、转录组及代谢组分析。100 mg·L⁻¹的二氧化硅纳米颗粒处理可降低干旱胁迫下厚壳树幼苗体内丙二醛与过氧化氢的含量，并提升抗氧化酶活性。转录组分析结果显示，干旱胁迫下，二氧化硅纳米颗粒调控了厚壳树幼苗叶片中的1451个差异表达基因（differentially expressed genes, DEGs），这些基因主要参与生长素信号转导及丝裂原活化蛋白激酶信号通路。本研究同时发现，脂肪酸与α-亚麻酸的代谢过程在二氧化硅纳米颗粒提升厚壳树幼苗抗旱性的过程中发挥关键作用。代谢组学研究表明，经二氧化硅纳米颗粒处理后，与抗旱性相关的次生代谢物的积累水平显著升高。本研究揭示了二氧化硅纳米颗粒提升植物抗旱性的潜在生理机制。