Editorial: Understanding plant responses and phytoremediation strategies for arsenic toxicity

This Editorial was prepared jointly by ZS, MAF, and MV.The foundation of effective crop management is accurate and rapid diagnosis of various environmental stressors. This is also necessary in case of arsenic (As) -a toxic metalloid that disrupts cellular homeostasis, triggers a cascade of physiological dysfunctions, thus greatly affects food security and ecosystem resilience (Souri et al., 2022;Patel et al., 2023;Sinha et al., 2023).Therefore, field-scale solutions to counteract As toxicity require a sophisticated, multi-pronged scientific approach. Understanding plant responses to As stress using novel non-invasive methods represents a significant leap from traditional destructive and time-consuming assays. In this special issue, Juárez et al. (2024) reported correlation of specific spectral fingerprints with established biochemical markers linked to lignin and phenolic metabolism and achieved approximately 89% accuracy in detecting As using Raman spectroscopy. The study enabled early detection of As toxicity before the onset of visible symptoms, thus allowing real-time phenotyping of As tolerance.Another report by Choudhary et al. (2025) employed biospeckle optical coherence tomography (bOCT), a non-invasive imaging technique capable of monitoring dynamic cellular activity and suggested it as a reliable tool for detecting As-induced stress in lentil plants. Additionally, Capabianco et al. (2026) using hyperspectral imaging (HSI) in the short-wave infrared range, combined with micro-X-ray fluorescence (micro-XRF) and spectroradiometric measurements obtained with a portable device on Pteris vittata showed that innovative multi-analytical approach can develop efficient and scalable tools for optimizing As-phytoremediation strategies and environmental monitoring. This clearly implicates that the featured research moves the field decisively beyond observational studies and singular approaches, presenting an integrated portfolio of strategies that span from novel diagnostic tools to engineered agro-ecological interventions.With precise diagnostics in hand, the question turns to mitigation of As toxicity in plants. Several methods and various types of amendments have been proposed in this respect, that include the interaction with other elements, like silicon (Si), sulfur (S) or selenium (Se) (e.g., Vaculík et al., 2020;Saifullah et al., 2018;Souri et al., 2021;Karimi et al., 2025) or use of materials, like biochar, nano-iron, and others (e.g., Batool et al., 2025;Iqbal et al., 2025;Su et al., 2025). In this view, two studies in this special issue addressed this through material science, offering complementary "bottom-up" solutions. In the first study, Fang et al. (2025) presented a sophisticated engineered composite termed "nano-ferro-silicon biochar" (NNFB), by embedding γ-Fe2O3 and SiO2 nanoparticles into rice straw biochar. This report suggested a synergistic soil amendment that tackles As contamination on multiple fronts: the porous biochar matrix sequestered toxins and improved soil health, the embedded nano-iron oxides specifically adsorbed and immobilized As, and the Si component enhanced the plant's own physiological defenses. This "three-in-one" strategy simultaneously locked As in the soil, improved the soil matrix, fortified the plant stress tolerance, exemplifying the next generation of agronomic tools by translating fundamental knowledge of As chemistry and plant Si benefits into a single, applicable technology. Further experiments of Fang et al. (2025) demonstrated that NNFB effectively adsorbed arsenite [As(III)] from both solution and contaminated soil. In hydroponic and pot trials with rice, application of NNFB (0.25-1.0%) significantly alleviated As toxicity across multiple growth stages. The mechanism involved reducing reactive oxygen species (ROS) accumulation by lowering H2O2 content and enhancing peroxidase (POD) activity, alongside downregulating key As transporter genes (OsLsi1, OsLsi2, and OsABCC1) to decrease As uptake and translocation. Most notably, in soil contaminated with 40 mg/kg As(III), the addition of 0.5% and 1% NNFB dramatically increased grain yield, with the seed number per plant rising by nearly 7-and 8-fold, respectively, compared to the As-stressed control. Therefore, NNFB was suggested to be a promising multifunctional soil amendment for simultaneously remediating As contamination and enhancing crop productivity in affected agricultural systems (Fang et al., 2025). Li et al. (2024) provided a crucial, nuanced comparison when evaluated zinc (Zn), copper (Cu), and Si amendments in three applied forms as nanoparticles (NPs), ionic salts, and bulk particles (BPs) on growth of As treated rice, a staple food for over 3.5 billion people. Their work revealed that under As stress, Zn amendments increased grain yield by 4.6-7.3 times, with ionic ZnSO₄ performing best by fully restoring yield to background levels and reducing the toxic As(III)/total As ratio in grains by 46.9%. Cu amendments also boosted yield by 3.8-5.6 times and significantly lowered the As(III)/total As ratio by 20.2-65.6%. The critical insight from their systematic evaluation is that while nanoparticles reduced As toxicity to some extent, they did not outperform their ionic or bulk counterparts in promoting rice growth. This work injects a necessary note of pragmatism into the nano-agriculture discourse, moving beyond technological novelty to emphasize the goal of identifying the most robust, scalable, and safe amendment. Their findings strongly suggested that ionic Zn and Cu amendments are particularly promising for protecting our staple crops and maintaining yield under duress, while highlighting the need for further field validation under diverse conditions.Development of modern technologies not only accelerates breeding programs for resilient crop varieties but also enables the precise monitoring of remediation efficacy in the field, serving as a critical feedback loop for applied As-mitigation strategies. Novel strategies to remediate soil As contamination or improved phytomanagement tools on As contaminated sites were of a great interest of this special issue. For example, Kama et al. (2025) offered an elegant, nature-inspired strategy of intercropping two crops with As-hyperaccumulating plants. The study designed a phytoremediation consortium where each plant played a complementary role: the hyperaccumulating fern (Pteris cretica) acting as the primary As extractor, the deep-rooted spinach (Spinacia oleracea L.) aided in soil structure and nutrient cycling, while the peanut (Arachis hypogaea L.), a valuable legume crop provided economic yield and nitrogen fixation. The pot experiment demonstrated that intercropping systems, particularly the three-species combination (A. hypogaea, P. cretica, S. oleracea), significantly enhanced soil As removal, achieving an 88% removal rate compared to monocropped peanuts. Concurrently, As uptake by peanut plants was substantially reduced, thereby minimizing the risk of food chain contamination (Kama et al., 2025). This system deliverred what single-species phytoremediation often cannot: enhanced total As removal, improved soil health, and economic viability for the landowner. It successfully shifted the paradigm from cleaning land by taking it out of production to remediating through sustainable production, a critical step for practical adoption by farming communities. The study of Kama et al. (2025) suggested that leveraging hyperaccumulator plant diversity within intercropping systems offers a sustainable and effective strategy for the phytoremediation of As-contaminated agricultural land while simultaneously ensuring food safety.