Abstract Hyperhydricity (HH) is one of the major problems in plant tissue culture. Increased frequency (75%) of HH in the cultures of . Dianthus chinensis L. cultivar telstar scarlet raised from nodal segments on agar (0.85%) gelled, benzyladenine (2.5 µM) supplemented Murashige and Skoog (MS) medium was noticed in the third subculture onwards. To reduce HH and to resume normal growth, the addition of silver nitrate is routinely recommended in the culture medium. However, the impact of biogenic silver nanoparticles (AgNPs) on HH reversion has not been well investigated. In this study, biogenic AgNPs prepared from leaf extract of D. chinensis were used to control HH in D. chinensis cultures. The characterization of bioynthesized AgNPs has been done by UV–Vis spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction analysis, energy-dispersive X-ray spectrum, transmission electron microscopy, and atomic force microscopy. Higher water content or addition of ethylene precursor, ethephon, in culture medium induced plantlet with unhealthy, pale green, glassy shoots (HH). Due to the biological activity of Ag + ions and water regulating mechanism, AgNPs treatment on hyperhydric explant (4 weeks) resulted in high retroversion coupled with reduced relative water content. Supplementation of 100 µg L −1 AgNPs in MS medium significantly reduced the percentage of HH to 13.3%, in contrast to control (100%). Addition of AgNPs effectively reduced hydrogen peroxide (H 2 O 2 ) content (50%) characterized by green, healthy shoots with proper stomata in contrast to hyperhydric shoots. The gene expression pattern of 1-aminocyclopropane-1-carboxylase synthase ( ACS1 ) and 1-aminocyclopropane-1-carboxylic acid oxidase ( ACO 1) showed reduced expression after the retroversion of microshoots in 100 µg L −1 AgNPs medium compared to hyperhydric shoot. The relative gene expression profile of ACS1 and ACO1 at 100 µg L −1 AgNPs treatment was 9.8 and 1.8-fold over normal shoots (1), respectively. Inter simple sequence repeat (ISSR) analysis on AgNPs directed HH reverted shoots showed genetic stability thus proved safe to adopt this technique to produce true to type plants. Combined manipulation, coordination of water permeability, and anti-ethylene activity of AgNPs were responsible for effective HH reversion. These finding will put forward the future utilization of bioencapsulated AgNPs in plant tissue culture and agriculture practices. Graphic Abstract

中文翻译：

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生物银纳米颗粒在体外模型培养中对石竹超氢恢复的作用

摘要 超水合（HH）是植物组织培养中的主要问题之一。培养物中 HH 的频率增加 (75%)。从第三次继代培养开始，在添加了 Murashige 和 Skoog (MS) 培养基的琼脂 (0.85%) 上的节段培养出的石竹 L. 栽培品种 telstar 猩红色凝胶状、苄基腺嘌呤 (2.5 µM)。为了减少 HH 并恢复正常生长，通常建议在培养基中添加硝酸银。然而，生物银纳米粒子 (AgNPs) 对 HH 逆转的影响尚未得到很好的研究。在这项研究中，从 D. chinensis 叶提取物制备的生物 AgNPs 用于控制 D. chinensis 培养物中的 HH。生物合成的 AgNPs 的表征已通过 UV-Vis 光谱、傅里叶变换红外光谱、X 射线衍射分析、能量色散 X 射线光谱、透射电子显微镜和原子力显微镜。培养基中较高的水含量或乙烯前体乙烯利的添加诱导了具有不健康、淡绿色、玻璃状枝条 (HH) 的小植株。由于 Ag + 离子的生物活性和水分调节机制，AgNPs 对高氢外植体（4 周）的处理导致高逆向性以及相对含水量的降低。与对照 (100%) 相比，在 MS 培养基中补充 100 µg L -1 AgNPs 显着降低了 HH 的百分比至 13.3%。添加 AgNPs 有效地降低了过氧化氢 (H 2 O 2 ) 含量 (50%)，与高氢枝条相比，其特征是具有适当气孔的绿色、健康枝条。1-氨基环丙烷-1-羧化酶合酶 (ACS1) 和 1-氨基环丙烷-1-羧酸氧化酶 (ACO 1) 的基因表达模式在 100 µg L -1 AgNPs 培养基中的微芽逆转后与高氢芽相比表达降低. ACS1 和 ACO1 在 100 µg L -1 AgNPs 处理下的相对基因表达谱分别是正常枝条 (1) 的 9.8 倍和 1.8 倍。对 AgNPs 定向的 HH 回复枝条的简单序列重复 (ISSR) 分析显示遗传稳定性，因此证明采用这种技术生产真正类型的植物是安全的。AgNPs 的组合操作、水渗透性的协调和抗乙烯活性是有效的 HH 逆转的原因。这些发现将提出生物封装的 AgNPs 在植物组织培养和农业实践中的未来利用。