Heavy metals and metalloids (HMs) contamination in the environment has heightened recently due to increasing global concern for food safety and human livability. Zinc (Zn2+) is an important nutrient required for the normal development of plants. It is an essential cofactor for the vital enzymes involved in various biological mechanisms of plants. Interestingly, Zn2+ has an additional role in the detoxification of HMs in plants due to its unique biochemical-mediating role in several soil and plant processes. During any exposure to high levels of HMs, the application of Zn2+ would confer greater plant resilience by decreasing oxidative stress, maintaining uptake of nutrients, photosynthesis productivity and optimising osmolytes concentration. Zn2+ also has an important role in ameliorating HMs toxicity by regulating metal uptake through the expression of certain metal transporter genes, targeted chelation and translocation from roots to shoots. This review examined the vital roles of Zn2+ and nano Zn in plants and described their involvement in alleviating HMs toxicity in plants. Moving forward, a broad understanding of uptake, transport, signalling and tolerance mechanisms of Zn2+/zinc and its nanoparticles in alleviating HMs toxicity of plants will be the first step towards a wider incorporation of Zn2+ into agricultural practices.

Heavy metals (HMs) contamination in agricultural soils poses significant risks to crop production and human health through bioaccumulation in the food chain. While traditional remediation techniques exist, they often face limitations including high operational costs, low efficiency, and time-intensive processes. Nano-enabled agrochemicals have emerged as a promising solution for HM remediation in contaminated soils. In this review, we highlight distinct nano-enabled mechanisms involved in HMs remediation in agricultural soils. Further, this review describes HM remediation potential of three different classes of nano-agrochemicals exhibiting unique physicochemical properties, such as surface charge, controlled release capability, and metal chelating ability, etc. Nano-agrochemicals also enhance plant resilience through multiple pathways, such as the regulation of nutrient profiles and photosynthesis, activation of antioxidant defense systems, modulation of protein and osmolyte synthesis, stimulation of phytohormone pathways, and activation of stress-responsive transcription factors. While nano-agrochemicals show tremendous potential for sustainable agriculture, their environmental impact and safety considerations require careful assessment. The review highlights the need for continued research to fully understand nano-agrochemical interactions with plants and soil ecosystems, and to develop improved strategies for their safe and effective implementation in agricultural systems. Future studies should focus on optimizing nano-agrochemical formulations, investigating long-term effects, and establishing comprehensive risk assessment frameworks.

Yellow leaf mutants are useful genetic variants to explore the mechanism of chloroplast development. In this study, we developed and characterized a new rice (Orzya sativa L.) yellow leaf mutant, ygl54, with ethylmethane sulfonate (EMS) treatment on Zhenong 34, which exhibited leaf yellowing at early stage. By map-based cloning, OsYGL54 was located on long arm of chromosome 11 with a physical distance of 26 kb, and the substitution from G to A at the first exon of LOC_Os11g36440 was identified. Silent mutation in subsequent codon of ATG, disturbed the translation initiation, which caused lower expression level of OsYGL54 across the tissues. The histological analysis revealed that the chloroplast of mesophyll cells in ygl54 was disrupted with reduction in size of starch granules and higher number of plastoglobuli, which resulted in decreased chlorophyll contents, lower photosynthetic parameter, and lower expression level of genes associated with pigment metabolism and photosynthesis. The disruption in chloroplast caused higher accumulation of H₂O₂ and MDA contents. In conclusion, our results revealed the importance of sequence of second codon suggests that OsYGL54 was possibly involved in pigment metabolism and valuable for further study to explore the mechanism of chloroplast development.

Nitrogen (N) losses from fertilized fields pose a major concern in modern agriculture due to environmental implications. Urease inhibitors, such as N-(n-butyl) thiophosphoric triamide (NBPT), nitrification inhibitors (NI), like dicyandiamide (DCD), and sulfur-oxidizing bacteria (SOB) could have potential in reducing N losses. For evaluating their effectiveness, investigations were undertaken through incubation and greenhouse experiments by mixing a urea fertilizer with sole NBPT, DCD, and SOB, as well as combined, on ammonia volatilization losses from silt loam soil. An incubation experiment was conducted in 1 L airtight plastic jars with adequate aeration and constant temperature at 25 °C for 10 days. Three replications of each treatment were conducted using a completely randomized designed. The ammonia emission rate gradually increased until the highest (17.21 mg NH₃ m^-2 h^-1) value on the third day with sole urea and some other treatments except NBPT alone, which prolonged the hydrolysis peak until the fifth day with the lowest ammonia emission rate (12.1 mg NH₃ m^-2 h^-1). Although the DCD and SOB treatments reduced ammonia emission, their difference with urea was nonsignificant. Additionally, mixing NBPT with urea exhibited the highest population of nitrifying bacteria in soil, indicating its potential role in promoting the nitrification process. In a greenhouse experiment, 10 treatments, i.e., T₁ = control, T₂ = N₁₂₀ (urea fertilizer equivalent to 120 kg N ha^-1), T₃ = N₉₀ (90 kg N ha^-1), T₄ = N₉₀ + NBPT, T₅ = N₉₀ + DCD, T₆ = N₉₀ + SOB, T₇ = N₉₀ + NBPT + DCD, T₈ = N₉₀ + NBPT + SOB, T₉ = N₉₀ + DCD + SOB, and T₁₀ = N₉₀ + NBPT + DCD + SOB, were applied to investigate the wheat yield and N uptake efficiency. The highest N recovery efficiency (31.51%) was recorded in T₅ where DCD was combined with urea at 90 kg ha^-1.