Drought is a major abiotic stress that negatively impacts plant growth and crop production. Among various techniques used to alleviate drought stress in plants, nanoparticle application is considered to be effective and promising. In this study, the responses of plants treated with iron, copper, cobalt, and zinc oxide nanoparticles (NPs) were analyzed in soybean under drought-induced conditions. The obtained results indicated that these metal-based NPs supported the drought tolerance of NP-treated plants. The desired physiological traits, viz., relative water content, drought tolerance index, and biomass reduction rate, were significantly improved, especially in iron NP-treated plants. At the molecular level, quantitative PCR analysis of several drought-responsive genes revealed a gene-, tissue-, and NP-dependent upregulation of gene expression. Iron NP treatment promoted the expression of all tested genes in roots; additionally, the expression of three drought-responsive genes increased in leaves of all NP-treated plants, while the expression of GmERD1 (Early Responsive to Dehydration 1) was induced in both roots and shoots under the four NP treatments tested. Our findings suggest that NP application can improve drought tolerance of soybean plants by triggering drought-associated gene expression.

中文翻译：

---

金属基纳米颗粒增强大豆的耐旱性

干旱是一种主要的非生物胁迫，会对植物生长和农作物产量产生负面影响。在用于减轻植物干旱胁迫的各种技术中，纳米粒子的应用被认为是有效和有前途的。在这项研究中，分析了干旱条件下大豆中铁，铜，钴和氧化锌纳米颗粒（NPs）处理过的植物的响应。所得结果表明，这些基于金属的NP支持NP处理的植物的耐旱性。所需的生理特性，即相对含水量，耐旱指数和生物量减少率得到了显着提高，尤其是在铁NP处理的植物中。在分子水平上，对几种干旱反应基因的定量PCR分析揭示了基因表达的基因，组织和NP依赖性上调。铁NP处理促进了所有受试基因在根中的表达。另外，所有NP处理植物的叶片中三个干旱响应基因的表达均增加，而在测试的四种NP处理下，GmERD1（对脱水1的早期反应）在根和芽中均被诱导。我们的发现表明，NP的应用可以通过触发干旱相关基因的表达来提高大豆植物的抗旱性。