Recent advances in nano-enabled immunomodulation for enhancing plant resilience against phytopathogens.

Plant diseases caused by microbial pathogens pose a severe threat to global food security. Although genetic modifications can improve plant resistance; however, environmentally sustainable strategies are needed to manage plant diseases. Nano-enabled immunomodulation involves using engineered nanomaterials (ENMs) to modulate the innate immune system of plants and enhance their resilience against pathogens. This emerging approach provides unique opportunities through the ability of ENMs to act as nanocarriers for delivering immunomodulatory agents, nanoprobes for monitoring plant immunity, and nanoparticles (NPs) that directly interact with plant cells to trigger immune responses. Recent studies revealed that the application of ENMs as nanoscale agrochemicals can strengthen plant immunity against biotic stress by enhancing systemic resistance pathways, modulating antioxidant defense systems, activating defense-related genetic pathways and reshaping the plant-associated microbiomes. However, key challenges remain in unraveling the complex mechanisms through which ENMs influence plant molecular networks, assessing their long-term environmental impacts, developing biodegradable formulations, and optimizing targeted delivery methods. This review provides a comprehensive investigation of the latest research on nano-enabled immunomodulation strategies, potential mechanisms of action, and highlights future perspectives to overcome existing challenges for sustainable plant disease management.

Modulation of rhizosphere microbial community and metabolites by bio-functionalized nanoscale silicon oxide alleviates cadmium-induced phytotoxicity in bayberry plants.

Cadmium (Cd) is an extremely toxic heavy metal that can originate from industrial activities and accumulate in agricultural soils. This study investigates the potential of biologically synthesized silicon oxide nanoparticles (Bio-SiNPs) in alleviating Cd toxicity in bayberry plants. Bio-SiNPs were synthesized using the bacterial strain Chryseobacterium sp. RTN3 and thoroughly characterized using advanced techniques. A pot experiment results demonstrated that Cd stress substantially reduced leaves biomass, photosynthesis efficiency, antioxidant enzyme activity, and induced oxidative damage in bayberry (Myrica rubra) plants. However, Bio-SiNPs application at 200 mg kg-1 significantly enhanced plant biomass, chlorophyll content (26.4 %), net photosynthetic rate (8.6 %), antioxidant enzyme levels, and mitigated reactive oxygen species production under Cd stress. Bio-SiNPs modulated key stress-related phytohormones by increasing salicylic acid (13.2 %) and abscisic acid (13.7 %) contents in plants. Bio-SiNPs augmented Si deposition on root surfaces, preserving normal ultrastructure in leaf cells. Additionally, 16S rRNA gene sequencing demonstrated that Bio-SiNPs treatment favorably reshaped structure and abundance of specific bacterial groups (Proteobacteria, Actinobacteriota, and Acidobacteriota) in the rhizosphere. Notably, Bio-SiNPs application significantly modulated the key metabolites (phenylacetaldehyde, glycitein, maslinic acid and methylmalonic acid) under both normal and Cd stress conditions. Overall, this study highlights that bio-nanoremediation using Bio-SiNPs enhances tolerance to Cd stress in bayberry plants by beneficially modulating biochemical, microbial, and metabolic attributes.

Amelioration of chromium toxicity in wheat plants through exogenous application of nano silicon.

Chromium (Cr) contamination in agricultural soils poses a risk to crop productivity and quality. Emerging nano-enabled strategies show great promise in remediating soils contaminated with heavy metals and enhancing crop production. The present study was aimed to investigate the efficacy of nano silicon (nSi) in promoting wheat growth and mitigating adverse effects of Cr-induced toxicity. Wheat seedlings exposed to Cr (K2Cr2O7) at a concentration of 100 mg kg-1 showed significant reductions in plant height (29.56%), fresh weight (35.60%), and dry weight (38.92%) along with enhanced Cr accumulation in roots and shoots as compared to the control plants. However, the application of nSi at a concentration of 150 mg kg-1 showcased substantial mitigation of Cr toxicity, leading to a decrease in Cr accumulation by 27.30% in roots and 35.46% in shoots of wheat seedlings. Moreover, nSi exhibited the capability to scavenge oxidative stressors, such as hydrogen peroxide (H2O2), and malondialdehyde (MDA) and electrolyte leakage, while significantly enhancing gas exchange parameters, total chlorophyll content, and antioxidant activities (enzymatic and nonenzymatic) in plants grown in Cr-contaminated soil. This study further found that the reduced Cr uptake by nSi application was due to downregulating the expression of HMs transporter genes (TaHMA2 and TaHMA3), alongwith upregulating the expression of antioxidant-responsive genes (TaSOD and TaSOD). The findings of this investigation highlight the remarkable potential of nSi in ameliorating Cr toxicity. This enhanced efficacy could be ascribed to the distinctive size and structure of nSi, which augment its ability to counteract Cr stress. Thus, the application of nSi could serve as a viable solution for production of crops in metal contaminated soils, offering an effective alternative to time-consuming and costly remediation techniques.

Unveiling the aesthetic secrets: exploring connections between genetic makeup, chemical, and environmental factors for enhancing/improving the color and fragrance/aroma of Chimonanthus praecox.

Floral color and scent profiles vary across species, geographical locations, and developmental stages. The exclusive floral color and fragrance of Chimonanthus praecox is contributed by a range of endogenous chemicals that distinguish it from other flowers and present amazing ornamental value. This comprehensive review explores the intricate interplay of environmental factors, chemicals and genes shaping the flower color and fragrance of Chimonanthus praecox. Genetic and physiological factors control morpho-anatomical attributes as well as pigment synthesis, while environmental factors such as temperature, light intensity, and soil composition influence flower characteristics. Specific genes control pigment synthesis, and environmental factors such as temperature, light intensity, and soil composition influence flower characteristics. Physiological processes including plant hormone contribute to flower color and fragrance. Hormones, notably ethylene, exert a profound influence on varioustraits. Pigment investigations have spotlighted specific flavonoids, including kaempferol 3-O-rutinoside, quercetin, and rutin. Red tepals exhibit unique composition with cyanidin-3-O-rutinoside and cyanidin-3-O-glucoside being distinctive components. Elucidating the molecular basis of tepal color variation, particularly in red and yellow varieties, involves the identification of crucial regulatory genes. In conclusion, this review unravels the mysteries of Chimonanthus praecox, providing a holistic understanding of its flower color and fragrance for landscape applications. This comprehensive review uniquely explores the genetic intricacies, chemical and environmental influences that govern the mesmerizing flower color and fragrance of Chimonanthus praecox, providing valuable insights for its landscape applications. This review article is designed for a diverse audience, including plant geneticists, horticulturists, environmental scientists, urban planners, and students, offering understandings into the genetic intricacies, ecological significance, and practical applications of Chimonanthus praecox across various disciplines. Its appeal extends to professionals and enthusiasts interested in plant biology, conservation, and industries dependent on unique floral characteristics.

Silicon nanoparticles alleviate cadmium toxicity in rice (Oryza sativa L.) by modulating the nutritional profile and triggering stress-responsive genetic mechanisms.

This study investigated the physiological and molecular responses of rice genotype '9311' to Cd stress and the mitigating effects of silicon oxide nanoparticles (SiO NPs). Cd exposure severely hindered plant growth, chlorophyll content, photosynthesis, and Cd accumulation. However, SiO NPs supplementation, particularly the SiONP100 treatment, significantly alleviated Cd-induced toxicity, mitigating the adverse effects on plant growth while maintaining chlorophyll content and photosynthetic attributes. The SiONP100 treatment also reduced Cd accumulation, indicating a preference for Si uptake in genotype 9311. Complex interactions among Cd, Si, Mg, Ca, and K were uncovered, with fluctuations in MDA and H2O2 contents. Distinct morphological changes in stomatal aperture and mesophyll cell structures were observed, including changes in starch granules, grana thylakoids, and osmophilic plastoglobuli. Moreover, following SiONP100 supplementation, genotype 9311 increased peroxidase, superoxide dismutase, and catalase activities by 56%, 44%, and 53% in shoots and 62%, 49%, and 65% in roots, respectively, indicating a robust defense mechanism against Cd stress. Notably, OsNramp5, OsHMA3, OsSOD-Cu/Zn, OsCATA, OsCATB, and OsAPX1 showed significant expression after SiO NPs treatment, suggesting potential Cd translocation within rice tissues. Overall, SiO NPs supplementation holds promise for enhancing Cd tolerance in rice plants while maintaining essential physiological functions.

Fertilization of Microbial Composts: A Technology for Improving Stress Resilience in Plants.

Microbial compost plays a crucial role in improving soil health, soil fertility, and plant biomass. These biofertilizers, based on microorganisms, offer numerous benefits such as enhanced nutrient acquisition (N, P, and K), production of hydrogen cyanide (HCN), and control of pathogens through induced systematic resistance. Additionally, they promote the production of phytohormones, siderophore, vitamins, protective enzymes, and antibiotics, further contributing to soil sustainability and optimal agricultural productivity. The escalating generation of organic waste from farm operations poses significant threats to the environment and soil fertility. Simultaneously, the excessive utilization of chemical fertilizers to achieve high crop yields results in detrimental impacts on soil structure and fertility. To address these challenges, a sustainable agriculture system that ensures enhanced soil fertility and minimal ecological impact is imperative. Microbial composts, developed by incorporating characterized plant-growth-promoting bacteria or fungal strains into compost derived from agricultural waste, offer a promising solution. These biofertilizers, with selected microbial strains capable of thriving in compost, offer an eco-friendly, cost-effective, and sustainable alternative for agricultural practices. In this review article, we explore the potential of microbial composts as a viable strategy for improving plant growth and environmental safety. By harnessing the benefits of microorganisms in compost, we can pave the way for sustainable agriculture and foster a healthier relationship between soil, plants, and the environment.

Dynamic crosstalk between silicon nanomaterials and potentially toxic trace elements in plant-soil systems.

Agricultural soil pollution with potentially toxic trace elements (PTEs) has emerged as a significant environmental concern, jeopardizing food safety and human health. Although, conventional remediation approaches have been used for PTEs-contaminated soils treatment; however, these techniques are toxic, expensive, harmful to human health, and can lead to environmental contamination. Nano-enabled agriculture has gained significant attention as a sustainable approach to improve crop production and food security. Silicon nanomaterials (SiNMs) have emerged as a promising alternative for PTEs-contaminated soils remediation. SiNMs have unique characteristics, such as higher chemical reactivity, higher stability, greater surface area to volume ratio and smaller size that make them effective in removing PTEs from the environment. The review discusses the recent advancements and developments in SiNMs for the sustainable remediation of PTEs in agricultural soils. The article covers various synthesis methods, characterization techniques, and the potential mechanisms of SiNMs to alleviate PTEs toxicity in plant-soil systems. Additionally, we highlight the potential benefits and limitations of SiNMs and discusses future directions for research and development. Overall, the use of SiNMs for PTEs remediation offers a sustainable platform for the protection of agricultural soils and the environment.

Biogenic silicon nanoparticles mitigate cadmium (Cd) toxicity in rapeseed (Brassica napus L.) by modulating the cellular oxidative stress metabolism and reducing Cd translocation.

Nano-enabled strategies have emerged as promising alternatives to resolve heavy metals (HMs) related harms in an eco-friendly manner. Here, we explored the potential of biogenic silicon nanoparticles (SiNPs) in alleviating cadmium (Cd) stress in rapeseed (Brassica napus L.) plants by modulating cellular oxidative repair mechanisms. Biogenic SiNPs of spherical shapes with size ranging between 14 nm and 35 nm were synthesized using rice straw extract and characterized through advanced characterization techniques. A greenhouse experiment results showed that SiNPs treatment at 250 mg kg-1 significantly improved growth parameters, including fresh weight (33.3 %) and dry weight (32.6 %) of rapeseed plants than Cd-treated control group. Photosynthesis and leaf gas exchange parameters were also positively influenced by SiNPs treatment, indicating enhanced photosynthetic efficiency. Additionally, SiNPs treatment at 250 mg kg-1 increased the activities of antioxidant enzymes such as superoxide dismutase (19.1 %), peroxidase (33.4 %), catalase (14.4 %), and ascorbate peroxidase (33.8 %), which may play a crucial role in ROS scavenging and reduction in Cd-induced oxidative stress. TEM analysis revealed that SiNPs treatment effectively mitigated Cd-induced damage to leaf ultrastructure, while qPCR analysis showed that SiNPs treatment changed the expressions of the antioxidant defense and stress related genes. Moreover, SiNPs treatment significantly influenced the Cd accumulation and Si contents in plants. Overall, our findings revealed that biogenic SiNPs have great potential to serve as a sustainable, eco-friendly, and non-toxic alternative for the remediation of Cd toxicity in rapeseed plants.

Transcriptomic and proteomic profiling reveals toxicity and molecular action mechanisms of bioengineered chitosan­iron nanocomposites against Xanthomonas oryzae pv. oryzae.

Bacterial leaf blight (BLB) pathogen, Xanthomonas oryzae pv. oryzae (Xoo) is the most devastating bacterial pathogen, which jeopardizes the sustainable rice (Oryza sativa L.) production system. The use of antibiotics and conventional pesticides has become ineffective due to increased pathogen resistance and associated ecotoxicological concerns. Thus, the development of effective and sustainable antimicrobial agents for plant disease management is inevitable. Here, we investigated the toxicity and molecular action mechanisms of bioengineered chitosan­iron nanocomposites (BNCs) against Xoo using transcriptomic and proteomic approaches. The transcriptomic and proteomics analyses revealed molecular antibacterial mechanisms of BNCs against Xoo. Transcriptomic data revealed that various processes related to cell membrane biosynthesis, antioxidant stress, DNA damage, flagellar biosynthesis and transcriptional regulator were impaired upon BNCs exposure, which clearly showing the interaction of BNCs to Xoo pathogen. Similarly, proteomic profiling showed that BNCs treatment significantly altered the levels of functional proteins involved in the integral component of the cell membrane, catalase activity, oxidation-reduction process and metabolic process in Xoo, which is consistent with the results of the transcriptomic analysis. Overall, this study suggested that BNCs has great potential to serve as an eco-friendly, sustainable, and non-toxic alternative to traditional agrichemicals to control the BLB disease in rice.