2. Phyto-Synthesis of Nanoparticles
2.1. Green Synthesis Approach
In recent years, the green synthesis approach has emerged as an eco-friendly and promising phyto-synthesized NP method. The inventive technique includes using plant-derived elements by reducing and stabilizing the agents to produce nanoparticles of different materials, like metal and metal oxide
[49,50,51][16][17][18]. This synthesis deals with numerous benefits, such as cost-effectiveness and sustainability. It decreases the potential threats linked to traditional chemical methods. A significant example of the green synthesis approach is the application of plant extract and bioactive compounds such as alkaloids, terpenoids, polyphenols, and flavonoids as reducing agents in the synthetic process.
Moreover, the extract acts as a stabilizing agent, inhibiting agglomeration and ensuring the stability of nanoparticles by increasing their capability and applicability in different fields. Furthermore, using plant-based materials to synthesize nanoparticles is a sustainable alternative to conventional methods using toxic chemicals and high energy. This approach of plant-derived compounds is readily available and biodegradable, contributing to the friendly environment
[63,64,65][19][20][21]. These green synthesized nanoparticles proved very applicable in drug delivery, catalysis, environmental remediation, and agriculture. According to previous studies, silver nanoparticle synthesis from leaf extracts of certain plants showed excellent antimicrobial properties, demonstrating that these plants have strong antibacterial properties
[63,64,65][19][20][21].
2.2. Advantages of Phyto-Synthesis over Other Methods
Phyto-synthesis has developed as an encouraging and sustainable alternative to conventional synthetic methods, putting away beneficial interests among industries and scientists. The significant benefit of Phyto-synthesis is the reduction in energy consumption compared to other physical and chemical conventional methods
[69,70,71][22][23][24]. Practice plant extract is a stabilizing and reducing agent, minimizing the need for high-temperature and energy-intensive processes. This approach is cost-saving and helps with achieving a greener community by reducing nanoparticles’ overall carbon footprint production
[72,73][25][26]. The critical advantage of phyto-synthesized NPs is biocompatibility, as plant extracts are used for synthesis. The obtained nanoparticles are inherently more compatible with biological systems
[74,75][27][28]. It opens up various applications in medicines like drug delivery systems, where the human body more freely consumes the nanoparticles by reducing potential adverse reactions. One major factor is the production of toxic-free end products in photosynthesis.
Further, most processes end with hazardous chemicals, which may lead to high risks to human health and cause environmental pollution. In contrast to phyto-synthesized NPs and chemical extracts, prior ones are safe for researchers and workers and eco-friendly for the environment
[79][29]. The previous study utilized green phyto-synthesis to produce silver nanoparticles using Aloe vera leaf extract. The scientists combine the plant extract with a sliver salt solution and allow the mixture to undergo a heating process. The resulting products maintain excellent biocompatibility and stability, making them suitable nanoparticles for active biomedical applications, such as wound-healing agents and antibacterial properties
[84,85][30][31]. The green synthesis process also offers better control over the size and shape of nanoparticles, a critical aspect for modifying their characteristics for specific use and function. Phyto-synthesis has an excess of advantages over other conventional methods. It is environmentally friendly, biocompatible, has no toxic chemicals, and decreases energy consumption costs, providing a promising path for sustainable production of nanoparticles.
3. Phyto-Synthesized-NPs and Their Applications in Agriculture
Various phyto-synthesized NPs have recently gained attention in the agricultural field. The use of these nanoparticles in agriculture proved to be more efficient and convenient for the environment and provide good crop health compared to other conventional synthetic nanoparticles. These play a vital role in avoiding toxic environmental components, keeping the ecosystem preserved, and safeguarding the health of consumers and farmers
[10,88][10][32]. One significant advantage of various phyto-synthesized NPs is their safety usage. In contrast to local synthetic nanoparticles that indeed have unknown prolonged effects, green synthetic nanoparticles have fewer adverse issues for human health and the environment
[89,90][33][34]. The alternative significant factor is cost-saving, which drives their practice in the agricultural field. Although the synthetic process relies on plant extracts, the production cost is relatively low.
Moreover, the versatile nature of phyto-synthesized NPs opens up various applications in farming. The most important feature is their antimicrobial activity, which controls diseases linked to weeds, insects, and pests in crops
[66][35]. With various phyto-synthesized NPs, farmers can decrease the resilience of harmful pesticides by promoting safe cultivation practices and reducing the issues linked with chemical exposure
[118,119][36][37]. When harnessed into the soil, these will enhance nutrient availability, resulting in better plant growth and higher yields. The presence of nanoparticles in the soil can help against soil erosion, increasing sustainable land management practices
[120,121][38][39]. By understanding their potential threats, recent research has shown the successful preparation of silver nanoparticles synthesized from the
Azadirachta indica, natively known as the Neem tree. The plant extract of the Neem tree controls fungal pathogens in crops
[122,123][40][41].
3.1. Silver Nanoparticles (Ag-NPs)
Silver nanoparticles showed relatively good antifungal and antimicrobial properties, assisting them to control different diseases of plants and enhance their production rate. One convenient method for synthesizing Ag-NPs involves using various plant extracts, such as
Aloe Vera,
Azadirachta indica, and
Ocimum sanctum [153,154,155][42][43][44]. Ag-NPs proved very useful against multiple stresses, but drought or water stress is the most important. Recent studies demonstrated that silver nanoparticles enhanced the
Fusarium oxysporum growth rate of a root, leaf area, and shoot
[156,157,158][45][46][47]. The previous studies also showed that Ag-NPs synthesized with
Justica adhatoda leaf extract could improve chickpeas’ growth rate and yield by improving photosynthesis, antioxidant activity, and nutrient uptake
[159][48].
Earlier research concluded that their findings proved safe alternatives to chemical-based sprays to inhibit insecticide growth and create an eco-friendly environment. Another extract from
Justicia adhatoda leaf showed the properties of improving growth rate in chickpeas
[166,167,168][49][50][51]. Applying Ag-NPs on chickpeas revealed the positive aspects of increased photosynthesis, antioxidant activities, and nutrient absorption. Moreover, when silver nanoparticles were extracted from the leaf of
Carum copticum, plant development increased by increasing sunlight absorption and nutrient availability and reducing the damage caused by oxidation
[169,170,171,172][52][53][54][55]. Ag-NPs are very helpful in the production of the wheat crop by enhancing wheat grains’ quality and safety from different fungal attacks. Suggestions might be the effectiveness and protection of these NPs in the most popular staple food crop (wheat) globally
[172,173,174,175][55][56][57][58]. Ag-NPs can be used as safe fertilizers in agricultural sectors instead of chemical fertilizers. These NPs can cause several potential impacts on the environment and regulatory issues, so it is necessary to understand their mode of action in promoting plant growth and disease control actions
[85,176,177,178][31][59][60][61].
3.2. Gold Nanoparticles (Au-NPs)
In drought conditions of plants, the use of gold nanoparticles helps the plants to grow and also facilitates the process of photosynthesis. Moreover, Au-NPs have been shown to have incredible features in protecting plants from their oxidative reactions caused by drought conditions through anti-oxidative activity
[179,180,181][62][63][64]. To synthesize Au-NPs, some plant extracts such as green tea, grape seeds, and lemon peel are more efficient to a large extent. During dry seasons, plants can improve performance and physiology when they contact gold particles—specifically, growth rate and yield increase when green tea extract synthesizes Au-NPs
[182,183,184][65][66][67]. According to Wahab et al., 2023, Au-NPs help plants to take up nutrients efficiently from soil and enhance their photosynthetic pigments that provide the best food resources for plants
[185][68].
Moreover, Au-NPs not only help deliver micronutrients but also improve the germination of seeds and the growth rate of tissues. Au-NPs may also increase plant development by controlling gene expression and their activating pathways
[189][69]. Above and beyond influencing the expression of a gene, Au-NPs might also cooperate with plant membranes and enhance the ability of drought tolerance. However, the exact process of their activity is still unknown. For scavenging oxygen-reactive species, gold nanoparticles fight oxidative damage triggered during drought conditions
[190,191,192][70][71][72]. There are some safety measures when implanting Au-NPs in plants during drought conditions, such as checking their potential environmental impacts. Scientists are working on Au-NPs for their destiny and build-up in the atmosphere; their impressions on soil and plant systems and their possible threats to non-targeted species are also part of continuing research
[193,194][73][74]. Au-NPs extracted from plant bioactive compounds have emerged as a potential gizmo for increasing vegetative resilience against dry weather.
3.3. Iron Oxide Nanoparticles (Fe
3
O
4
-NPs)
Due to their vast characteristics, Fe
3O
4-NPs are increasingly efficient in agronomy for drought management. These nanoparticles are highly effective and extremely useful for the safety of soil and plants
[198][75]. Fe
3O
4 nanoparticles are very peculiar for absorbing and adsorbing. They can hold a large amount of water, therefore proving helpful in drought-stressed regions
[199][76]. On the other hand, Fe
3O
4 nanoparticles provide a protective covering for plants and boost crop quality and yield in drought conditions
[200,201][77][78]. Most studies have shown that Fe
3O
4-NPs can hold water in the soil, increase the photosynthetic rate, and reduce water evaporation. This enables plants to grow under drastic environmental conditions. Also, Fe
3O
4 nanoparticles are environmentally friendly and can manage high drought stresses. One major factor is to sustain a firm basis with non-toxic and biodegradable compounds
[29,202,203][79][80][81]. Fe
3O
4-NPs are also cost-saving and more appealing to farmers for better crop production and development. Concluding the features of Fe
3O
4-NPs, they may be a promising tool for decreasing drought stress in cultivation systems by providing a safety coating to soil and plants from the atmospheric barriers. These are eco-friendly and money-saving, making them an ideal choice for cultivars in their farming sectors
[204,205,206][82][83][84].
3.4. Copper Nanoparticles (Cu-NPs)
In recent years, Cu-NPs have gained attention for their potential use for stress management in the agricultural sector. A particularly significant way is using plants’ bioactive compounds to synthesize Cu-NPs. Thus, their eco-friendly nature provides various beneficial aptitudes to plant crops
[80,207][85][86]. Previous studies showed that Cu-NPs synthesized from plant materials positively impact the development and growth of plants. Similarly, these proved to be a protector against challenging environmental conditions like dryness in the atmosphere. Case in point, when tomato plants were treated with copper nanoparticles synthesized from the basil leaf extract, Tripathi et al. (2022) unveiled properties like photosynthesis and antioxidant activity under drought conditions
[4,208,209][4][87][88].
Consequently, the typical range of a nanoparticle varies from 1 to 1000 nanometers. It retains exceptional catalytic activity, antimicrobial properties, and electrical and thermal conductivity. There are many ways to synthesize Cu-NPs, such as green synthesis, chemical reduction, and Sono chemical processes posing control over the surface’s shape, size, and functionality to develop their characteristics for specific applications
[218,219][89][90].
3.5. Zinc Oxide Nanoparticles (ZnO-NPs)
In previous research endeavors, the significant merits of ZnO-NPs extracted from plant materials have garnered attention due to their innovative role in facilitating plant development and their capacity to endure challenging environmental conditions
[223,224,225][91][92][93]. Within global warming, heightened concern surrounds the impact of drought stress on the agricultural sector, manifesting as reduced productivity and posing challenges in adequately nourishing the global population
[226,227][94][95]. For example, an inclusive review by Gupta et al. in 2022 underscored that applying ZnO-NPs to drought-exposed plants elicits heightened plant growth performance rates, concurrently bestowing a spectrum of notable functions. Notably, these nanoparticles facilitate augmentation in chlorophyll content, thereby fostering an upswing in photosynthetic activity
[228,229][96][97]. Consequently, this augmentation translates to an enhanced energy storage and conservation capacity, even with limited water availability. Applying Zinc oxide nanoparticles (ZnO-NPs) has been demonstrated to effectively regulate the activity of antioxidant enzymes such as catalase and superoxide dismutase
[230,231,232][98][99][100]. These enzymes are crucial in counteracting oxidative damage caused by accumulating reactive oxygen species (ROS), particularly under drought-induced conditions. ZnO-NPs function as protective barriers for essential cellular components, enabling plants to withstand the adverse impacts of drought by mitigating oxidative reactions
[103,233,234][101][102][103]. Remarkably, ZnO-NPs offer an additional advantage to plants by enhancing their resilience to arid conditions at the molecular level. Despite the direct interaction of nanoparticles with plant cells, they can modulate the expression of stress-responsive genes. This modulation subsequently triggers a cascade of defense mechanisms and adaptable responses, ultimately enhancing the plants’ capacity to tolerate drought
[202,210,235][80][104][105].
3.6. Titanium Dioxide Nanoparticles (TiO
2-
NPs)
TiO
2-NPs have demonstrated their potential as beneficial and promising tools in the agricultural domain, primarily due to their positive effects on plant development, growth, and stress tolerance capabilities
[241,242][106][107]. Like other nanoparticles, TiO
2-NPs can be synthesized from plant extracts, revealing noteworthy growth rates, improved photosynthetic plant efficiency, and enhanced antioxidant activities. A specific study involving tomato plants highlighted that applying TiO
2-NPs resulted in heightened chlorophyll content, increased biomass, and elevated food production rates under drought conditions with limited water availability
[243,244,245][108][109][110]. Furthermore, TiO
2-NPs have effectively alleviated oxidative stress conditions caused by environmental adversities. These nanoparticles have shown significant scavenging abilities against reactive oxygen species (ROS), which tend to accumulate in plant tissues during drought conditions, detrimentally impacting plant health, growth, and cellular integrity
[246,247][111][112]
3.7. Nanoparticle–Plant Interactions: Mechanisms of Uptake, Translocation, and Implications for Agricultural Applications
It is important to note that the scholarly discussion about how nanoparticles enter and move through different crops is based on specific plant species and nanoparticle types, which have already been discussed in a thorough review. The root system is a significant way that nanoparticles can be taken up by more than one crop. When a plant’s roots take Silver Nanoparticles in, they help it take in more water and change how genes that respond to stress work. This happens in plants like Sorghum (
Sorghum bicolor L.) and Corn (
Zea mays L.). Nanoparticles move through plants in two main ways: Apoplastic and symplastic. Wheat (
Triticum aestivum L.) roots can grow better during drought because of these routes. The leaf can also take in nanoparticles like Titanium Dioxide or Silica through foliar uptake. Potato (
Solanum tuberosum L.) plants can keep more water and make more food by spraying Titanium Dioxide Nanoparticles on them as a fog.
The xylem and phloem of plants help nanoparticles move over long distances. Zinc oxide nanoparticles that travel through the xylem to other parts of the plant help control stress hormones and enzymes that fight free radicals. Using nanoparticles like Iron Oxide and Copper Oxide has been shown to improve how well spinach (
Spinacia oleracea) uses water and how much chlorophyll it has and to make lettuce (
Lactuca sativa) more resistant to water stress. The physicochemical features of the nanoparticles and the environment change how these complicated dynamics work. Silica is found in rice (
Oryza sativa). The size and charge on the surface of nanoparticles affect how they are taken in and distributed, making cell walls stiffer and helping them keep water.
Nanoparticle uptake and movement inside the plant depend on the type of nanoparticle and crop type. Nanoparticles like silver, gold, and zinc oxide have been shown to affect Sorghum, Corn, and Wheat differently, depending on whether they are taken in through the roots or the leaves and whether they move through apoplastic or symplastic paths. Scientists from different fields must work together to fully understand how nanoparticles and plants interact. This is because physical and environmental factors also affect this complex interaction. Understanding this is important to make nanoparticles useful in sustainable agriculture and improve risk assessment procedures.
4. Mechanisms of Nanoparticle-Mediated Drought Stress Alleviation
These methods guarantee reproducible, practical, and optimized results. The essential laboratory method of in vitro culture requires a precise sequence of steps
[103,255,256][101][113][114]. One must avoid contamination by carefully selecting and sterilizing explants based on plant tissue type. Each plant species has different nutritional needs, so the culture medium includes nutrients, vitamins, and plant growth regulators
[257,258][115][116]. The explants are first placed on the culture medium, and subculturing ensures growth and differentiation. Shoot, root, and somatic embryo regeneration requires precise hormonal balances. Finally, acclimatization helps regenerated plantlets adjust to life outside the lab. Modern cryopreservation uses multiple methods to preserve plant genetic resources. Most plans use vitrification and controlled freezing. Ice crystals can damage cells, but controlled freezing can reduce them.
4.1. Enhancement of Seed Germination and Seedling Growth
Phyto-synthesized NPs are specifically engineered to regulate seed germination and enhance seed growth during dry weather by facilitating water uptake and modulating osmotic regulations
[314][117]. For example, silver nanoparticles synthesized from plant extracts are pivotal in promoting seed germination and crop growth
[315][118]. The underlying mechanism of these NPs involves nutrient absorption from the soil and subsequent translocation to the plant’s stems, branches, and leaves, even under drought stress. This process aids in osmotic adjustments as well
[316][119]. Despite limited water resources, the nanoparticles expedite water absorption and retention within plant tissues, supporting seed germination and early seedling development.
4.2. Improvement of Water Relations
In recent research, there has been a growing interest in exploring the potential impacts of using phyto-synthesized NPs as an innovative and biodegradable approach to understanding various aspects of plant physiology. This approach becomes particularly relevant when addressing ecological challenges such as water scarcity
[323,324][120][121]. One particularly dynamic aspect that has garnered considerable attention is the influence of phyto-synthesized NPs on water-related processes within plants. Through strategic utilization of phyto-synthesized NPs, researchers have uncovered compelling evidence of their positive effects on vital water-related pathways
[325][122]. These effects include enhanced water utilization efficiency and the maintenance of turgor pressure within plant cells. Fe
3O
4-NPs have demonstrated favorable outcomes for strengthening drought-induced water retention in plants. These Fe
3O
4-NPs can augment hydraulic root conductivity, effectively facilitating the efficient uptake and movement of water throughout the plant structure
[251,326][123][124].
4.3. Stimulation of Photosynthesis and Chlorophyll Content
The stimulation of chlorophyll and photosynthesis within plant cells using phyto-synthesized NPs has garnered significant attention in recent years due to its potential implications for environmental and agricultural sustainability. Photosynthesis is the fundamental process by which plants convert light energy into chemical energy, crucial for their growth and development. At the same time, carbon fixation plays a pivotal role in global ecosystems
[119,316,328][37][119][125]. During environmental challenges like drought, plants often encounter reduced photosynthetic rates and chlorophyll degradation, leading to diminished growth and productivity. However, research indicates that applying phyto-synthesized NPs can ameliorate these detrimental effects and enhance photosynthetic efficiency
[1,2,185,332,333,334][1][2][68][126][127][128].
4.4. Induction of Antioxidant Defense Systems
Researchers have been increasingly interested in exploring the potential of phyto-synthesized NPs to mitigate the adverse effects of drought stress on plants. Recent studies have highlighted the beneficial effects of these NPs in inducing antioxidant defense systems in plants
[339][129]. Among the different NPs studied, Au-NPs and TiO
2-NPs have shown promising results in enhancing the activities of essential antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX), when plants are exposed to drought stress
[340,341,342][130][131][132]. The induction of antioxidant defense systems by phyto-synthesized NPs is a significant development in plant stress tolerance research. These NPs help plants counteract the harmful effects of reactive oxygen species (ROS) generated during drought stress, thereby reducing overall oxidative stress levels
[343,344][133][134].
4.5. Regulation of Plant Hormones
Recently, interest in controlling plant hormones with phyto-synthesized NPs to improve plants’ capacity to withstand drought stress has been increasing. Researchers have determined the critical functions of various plant hormones in the responses of plants to stress, including abscisic acid (ABA), salicylic acid (SA), and jasmonic acid (JA). The amounts of these hormones can be influenced by phyto-synthesized NPs when plants are stressed by drought, potentially causing the plants to respond
[256,345,346][114][135][136]. Due to their numerous applications in industries, including agriculture and environmental cleanup, phyto-synthesized NPs have emerged as a promising study field, which also plays a significant role in plant hormonal regulations
[3,347,348][3][137][138].
Recently, interest has increased in employing phyto-synthesized NPs to regulate plant hormones and improve plants’ resistance to drought stress. These nanoparticles are made from plant extracts, which serve as sustainable and eco-friendly reducing and stabilizing agents, providing a more environmentally friendly option to conventional chemical processes
[67,349][139][140]. The passage also emphasizes the crucial functions of abscisic acid (ABA), salicylic acid (SA), and jasmonic acid (JA) as essential participants in how plants react to stress. These phyto-synthesized NPs can remarkably regulate the levels of these hormones in response to drought stress, which may lead to the onset of adaptive responses in plants. Abscisic acid (ABA) has a significant and multifaceted function in how plants respond to stress, particularly in drought-like conditions. Controlling stomata closure, which aids plants in water conservation by lowering transpiration, is one of its primary roles
[3,341,345,346,347,348][3][131][135][136][137][138]. When plants are under drought stress, phyto-synthesized NPs can help them conserve water by boosting the levels of ABA.
5. Plant Proteomics and Gene Expression Regulation of Drought Response by Nanoparticles
Nanoparticles like metal nanoparticles (like Silver Nanoparticles), silicon nanoparticles, and carbon nanoparticles (like Carbon Nanotubes) significantly affect how plants react to drought stress at the molecular level. The complicated chemical processes can be summed up by saying that silver nanoparticles can cause oxidative stress by making ROS. On a molecular level, they may raise the expression of genes that code for antioxidant enzymes like SOD and CAT. This makes these protective proteins more active. Silicon nanoparticles interact with guard cells in the stomata. At the level of molecules, this exchange can change how ion channels work and signals are sent. This can lead to better control of the stomata and less water loss. At the molecular level, carbon nanoparticles, especially carbon nanotubes, can stimulate the production of genes that respond to stress. They may increase the activity of transcription factors like DREB and MYB, which then turn on genes that help the cell deal with stress.
The effect of nanoparticles on plants’ proteome and gene expression during drought stress is an important research topic. Intricate molecular modifications, such as those affecting nano clays, nano iron oxide, and nano-silica, are essential to understanding these effects. Nano clays, for instance, have been shown to alter proteomes in plants. The overexpression of stress-related proteins such as LEA and chaperones may be involved at the molecular level. Protein modifications like this aid plants in resisting the cellular stress brought on by drought. Nano-sized iron oxide particles change the way soil absorbs nutrients. This may entail alterations in the expression of genes involved in nutrition transport and assimilation at the molecular level. This guarantees that plants can obtain the nutrients they need despite poor conditions. Potential epigenetic alterations induced by silica nanoparticles in plants are being studied. Molecular modifications, such as those to DNA methylation and histone acetylation patterns, can have long-term effects on gene expression. Incorporating these case studies of nanoparticles into the headers provides a more nuanced understanding of the molecular-level interactions between nanoparticles and plants. Stress from drought has caused this. This has ramifications for various physiological processes and adaptive behaviors in plants.
6. Potential Risks and Challenges Associated with the Use of Phyto-Synthesized NPs in Agriculture
6.1. Toxicisty to Non-Target Organisms
As a popular choice for agricultural usage, phyto-synthesized NPs have attracted considerable attention for their promising capacity to increase plant growth and stress tolerance. As with any new technology, properly assessing dangers posed to agroecosystem non-target creatures is crucial
[370][141]. Responsible use of these phyto-synthesized NPs in agricultural techniques requires weighing their potential advantages against the need to protect the ecosystem. Because of their tiny size and unique features, nanoparticles can interact with living systems differently than larger particles or bulk materials, which raises concerns
[371][142]. When used in farming environments, phyto-synthesized NPs may be ingested by plants and then transferred through the food chain to other creatures, including unintended ones. This prospect necessitates careful investigation and assessment of the potential effects on the ecology of employing these nanoparticles in agriculture
[372][143]. For this technology to be used responsibly and sustainably, it is imperative to understand how these nanoparticles function in living systems. These nanoparticles can have a variety of consequences on species that are not their intended targets, depending on their composition, concentration, and duration of exposure. The overall productivity and sustainability of the agroecosystem might be disrupted, for instance, if soil microorganisms that are cr
6.2. Impact of Phyto-Synthesized Nanoparticles on Water Tables and Groundwater Quality in Agriculture
The widespread use of Phyto-synthesized nanoparticles (NPs) in agricultural activities may significantly affect water tables and groundwater quality. A study on their use in agriculture highlights the possible impact of phyto-synthesized NPs on groundwater levels. This has significant consequences for the future of agricultural water supplies
[323][120]. Long-term exposure of agricultural areas to these nanoparticles raises serious concerns because of the potential for their penetration into the soil and subsequent leaching into groundwater. Subterranean particle movement and behavior may be affected by the introduction of phyto-synthesized NPs, which may change the soil’s physicochemical features
[374][144]. This phenomenon’s possible influence on groundwater quality is the most pressing concern. Water chemistry may be altered due to interactions between these nanoparticles and minerals and organic matter in the soil as they move through the soil profile
[379][145]. Groundwater quality in these agricultural regions may suffer significantly if these changes are allowed to occur. A further concern is that nanoparticles in groundwater may upset the equilibrium of microbial communities in aquifers. In groundwater ecosystems, microorganisms are crucial to nutrient cycling and water filtration
[380][146]. These vital ecosystem services may be compromised by the persistence of NPs in these habitats, reducing microbial diversity and abundance.
6.3. Environmental Fate and Transport
Due to their rising utilization and potential ecological effects, there has been a significant interest in researching the environmental fate and transportation of phyto-synthesized NPs in recent years. Understanding how phyto-synthesized NPs act in the environment becomes crucial to judging potential hazards
[386][147]. According to previous studies, phyto-synthesized NPs can penetrate the soil profile and even reach subsurface water reservoirs. Further worries regarding water pollution are raised because they have access to numerous water bodies. For informed application decisions and to ensure the protection of our natural resources, it is crucial to comprehend how these nanoparticles behave in the environment. Numerous factors affect phyto-synthesized NPs’ rate and transport, such as their stability, surface charge, and physicochemical properties
[387][148].