Plant-incorporated Protectants Research Articles

Differential susceptibility of Spodoptera frugiperda (Lepidoptera: Noctuidae) to single versus pyramided Bt traits in Brazilian soybean: what doesn't kill you makes you stronger?

Lepidopteran pest control in agriculture has become heavily dependent on cultivars that express Bacillus thuringiensis (Bt) toxins as 'plant-incorporated protectants'. However, populations of Spodoptera frugiperda (Smith) in Brazil appear resistant to the Bt traits currently available in commercial soybean cultivars. This study evaluated S. frugiperda life history when feeding on three different Bt soybean cultivars. Cultivars expressing Cry1Ac + Cry1F and Cry1A.105 + Cry2Ab2 + Cry1Ac Bt toxins caused 100% larval mortality in S. frugiperda. Both non-Bt and Cry1Ac-expressing soybean induced transgenerational effects that increased the survival of subsequent generations. A Cry1Ac soybean diet reduced the generation time (T) of S. frugiperda relative to non-Bt soybean, resulting in shorter generation time and more rapid population growth. The implications of these results revealed how diet can alter aspects of insect life history and biology, and have important implications for sustainable management of S. frugiperda on soybean. © 2024 Society of Chemical Industry.

Current Status of the Main Olive Pests: Useful Integrated Pest Management Strategies and Genetic Tools

Mediterranean olive cultivation faces challenges in the global environmental change context. Pests and diseases caused by arthropods such as Bactrocera oleae, Prays oleae, and certain vectors of Xylella fastidiosa are expected to increase and spread in part due to this global scenario. The control of these arthropods has relied on synthetic pesticides, the misuse of which has led to pest population resistance and concerns about their negative impacts on biodiversity and global health. Integrated pest management (IPM) methods have emerged through the careful consideration of all available control techniques and the subsequent integration of appropriate measures that discourage the development of pest populations. This paper reviews the IPM guidelines for olive cultivation, prioritizing the use of biological control methods, and the integration of genetics and biotechnology, which bring precision, efficacy, and safety. It evidences the importance of genetic analysis in pest populations, pesticide resistance and in the contributions of predators to pest control. Advances in formulations and delivery systems for pesticides such as Bacillus thuringiensis, plant-incorporated protectants, improved SIT techniques, and the specific efficacy of biologicals pesticides are covered. Finally, this paper explores promising tools such as RNAi and gene drive while recognizing the ethical, environmental, and regulatory challenges associated with their use. Shortly, these innovations have the potential to reduce the environmental impacts of pests while ensuring the long-term viability of the olive industry.

Biopesticide Consumption in India: Insights into the Current Trends

Biopesticides are formulations derived from naturally occurring compounds that manage pests through non-toxic and environmentally favorable means. Being living organisms (natural enemies) or products, biopesticides represent less of a risk to the environment and to human health. Biopesticides, classified into three broad classes, are increasingly used in pest control, and include semiochemicals, plant-incorporated protectants (PIPs), and compounds derived from plants and microorganisms. Because of their advantages for the environment, target-specificity, efficacy, biodegradability, and applicability in integrated pest management (IPM) programs, biopesticides are gaining interest. Although biopesticides have seen significant advances in market penetration, they still make up a relatively small fraction of pest management solutions. Over 3000 tons are produced globally per annum, and this number is rising rapidly. In India, biopesticides account for just 4.2% of the country’s total pesticide market. Although the government has promoted the use of biopesticides by including them in several agricultural programs, biopesticides face numerous difficulties at a local level, but are predicted to expand at an astonishing 10% yearly pace. Under the Insecticides Act 1968, the Ministry of Agriculture in India controls the use of pesticides. Among the major biopesticides produced and used in India are Trichoderma, Bacillus thuringiensis, nuclear polyhedrosis virus, and neem-based pesticides.

U.S. EPA oversight of pesticide traits in genetically modified plants and recent biotechnology innovation efforts.

Before pesticides can be sold in the United States, the United States Environmental Protection Agency (EPA) must evaluate them thoroughly to ensure that they meet U.S. federal pesticide registration standards for human health and the environment. EPA considers pesticidal substances produced and used in plants as pesticides and defined them in the regulations as "plant-incorporated protectants" (PIPs). PIPs that are created through conventional breeding are exempted from registration requirements, while those created through biotechnology require individual assessments and approval by EPA before they can be distributed or used. This currently includes PIPs that are identical to those that could be moved through conventional breeding but are created through biotechnology (e.g., through genome editing or via precision breeding techniques). EPA proposed an exemption in October 2020 to allow certain PIPs created through biotechnology to be exempt from EPA requirements for pesticides where those PIPs: 1) pose no greater risk than PIPs that EPA has already exempted, and 2) could have otherwise been created through conventional breeding.

Importance of Biotechnology in Controlling Insect Pests

Agriculture is considered an important source of national income for a lot of countries and most of inhabitants of these countries are dependent on farming for their food. Insects have been one of the most important sources of food production damage, accounting for 20% to 30% of global production losses. Approximately 67,000 insect species are thought to inflict harm to plantations and tropical regions, which are often the poorest in the world and are hit hardest by insect pests. Agriculture spends billions of dollars each year on insect control around the world. Pesticide use has resulted in pesticide-resistant insects, a drop in beneficial insect populations, and a slew of other negative effects for humans and the environment. These concerns have led researchers to consider a different approach in order to produce more environmentally friendly insect control tactics that use both synthetic and natural chemicals. The use of bio-pesticides in pest management has been increasing in recent years. There are three types of the ecofriendly management agents bio-pesticides have been identified as follows: bio-control organisms (pathogenic microorganism, predators and parasites); plant-incorporated protectants (transgenic Bt toxin); and biochemical pesticides (botanical pesticides and other natural compounds. Most of chemical companies such as Monsato, Dupont, and Ciba Geigy, are now promoting biotechnology as a strategy to ensure high productivity, these companies invests millions of dollars in biotechnology research to develop genetically modified crops, animals, and microorganisms to combat pests, produce fertilizer, and improve efficiency. Where they uploaded this businesses and scientific institutions are the slogans that biotechnology is the future of agriculture.

Exploiting Plant-Phytonematode Interactions to Upgrade Safe and Effective Nematode Control.

Plant-parasitic nematodes (PPNs) bring about substantial losses of economic crops globally. With the environmental and health issues facing the use of chemical nematicides, research efforts should focus on providing economically effective and safe control methods. The sound exploitation of plant-PPN interactions is fundamental to such efforts. Initially, proper sampling and extraction techniques should be followed to avoid misleading nematode data. Recent evolutions in plant-PPN interactions can make use of diverse non-molecular and molecular approaches to boost plant defenses. Therefore, PPN control and increasing crop yields through single, sequential, dual-purpose, and simultaneous applications of agricultural inputs, including biocontrol agents, should be seriously attempted, especially within IPM schemes. The use of biologicals would ideally be facilitated by production practices to solve related issues. The full investment of such interactions should employ new views of interdisciplinary specialties in the relevant modern disciplines to optimize the PPN management. Having an accurate grasp of the related molecular events will help in developing tools for PPN control. Nonetheless, the currently investigated molecular plant-PPN interactions favoring plant responses, e.g., resistance genes, RNA interference, marker-assisted selection, proteinase inhibitors, chemo-disruptive peptides, and plant-incorporated protectants, are key factors to expanding reliable management. They may be applied on broader scales for a substantial improvement in crop yields.

The Potential and Green Chemistry Attributes of Biopesticides for Sustainable Agriculture

Chemotherapy has advanced modern agriculture with costly side effects such as the extinction of beneficial species, resistant pest resurgence, environmental pollution, tainted food consumption, and health implications. Attention is now focused on biopesticides as a solution to the abovementioned disadvantages. Additionally, there is a growing need to understand the range and relative effectiveness of biopesticides in controlling pests and promoting sustainable agriculture. The latter is the major driver of the Sustainable Development Goals (SDGs). In comparison to synthetic pesticides, biopesticides offer nearly similar protection against the most notorious pests, except Albugo candida (oomycetes), Ustilago maydis (fungi), Phytomonas spp. (protozoa), Nacobbus aberrans (nematode), and Cyperus rotundus (weed). This study shows that viruses are more vulnerable to essential oils, nematodes and weeds to natural enemies, herbivorous insects to biochemical insecticides, and plant pathogens to plant-incorporated protectants and microbial pesticides. This work also demonstrates that it is preferable to use plant-derived biopesticides in a field concurrently. Incorporating these findings into large-scale farming via the integrated pest management method would improve the outcome of sustainable agriculture (SA), which connects 11 of the 17 SDGs. Despite their proven efficacy and sustainable attributes, biopesticides have some deficiencies, such as slow action and a short shelf life span, which can be improved by omics, RNA interference, and nano-based technologies. This field of technologies provides relevant prospects for improving existing biopesticides and discovering and developing new bio-controlling agents (BCA).

A Review of the Microbial Biopesticides: Types and Applications

The aim of this study is to carry out a detailed review of the literature on microbial pesticides, types and applications. This is because the term microbial biopesticides is a broad array from micro-organisms and other natural sources, and processes involving the genetic incorporation of DNA into agricultural commodities that confer protection against pest damage (plant-incorporated protectants). Some microbial pesticides, such as Bacillus thuringiensis, have a long history of safe and effective use as a biological insecticide. More recent developments in microbial pest control include the utilization of other bacterial and fungal species that may competitively inhibit the growth of pathogenic and toxigenic micro-organisms on important agricultural commodities. The study adopts an extensive review of literature such as conference papers, journal articles, internet sources, books to find out the effects of microbial biopesticides, types and applications as reported by past authors with the help of standard literature procedures in their research work. These secondary sources of information were reviewed to understand the microbial biopesticides, types and applications. Authors in this study found that the use of microbes and their gene products introduces additional considerations to the toxicological dose-response relationship, including a need to determine the plausibility of infectious and immunological effects in association with human exposure to these biopesticides in food or the environment. Studies of substantial equivalence suggest that foods currently derived from plant-incorporated protestants are not likely to differ from conventional foods. However, there is general consensus that the scientific methods to assess risks from genetically modified foods and micro-organisms will continue to evolve in the future. Keywords: Microbial Biopesticides: Types: Applications: Pest Control

Safety of Bacillus thuringiensis Cry1Ah and Vip3Aa toxins for the predatory stink bug Arma custos (Hemiptera: Pentatomidae)

The widespread adoption of Bt crops expressing insecticidal proteins derived from Bacillus thuringiensis has created a need to assess the potential effects of these toxins on non-target organisms, especially species such as Arma custos, a generalist predator that provides important biological control services in many field crops in Asia. Direct dietary exposure of A. custos to Cry1Ah and Vip3Aa proteins produced no adverse effects on life history traits, despite continuous exposure throughout development and early adult life to concentrations significantly higher than the Bt protein concentration likely encountered by A.custos in the field, even when feeding directly on Bt plants. Enzyme-linked immunosorbent assay confirmed the presence of Bt proteins in A. custos midguts, but quantitative real-time PCR analysis of 12 genes associated with detoxification, antioxidative responses, immune responses, and metabolism revealed no significant changes in expression in adult bugs. Indirect exposure to these toxins via consumption of intoxicated prey, larvae of Helicoverpa armigera (Hübner), likewise produced no negative impacts on survival, development, adult weight, or female fecundity in either the F0 (exposed) or F1 (unexposed) generation, but female fresh weight was reduced in the F0 generation by the Cry1Ah (50 μg/g) treatment. Finally, a competitive binding assay with labelled protein and a ligand blotting assay both demonstrated that the Cry1Ah protein could not bind to receptors on the midgut brush border membrane vesicles (BBMVs) of A. custos adults. Therefore, we conclude that Cry1Ah and Vip3Aa proteins are unlikely to have significant negative effects on A. custos populations if employed as plant-incorporated protectants in field crops.

Application progress of plant-mediated RNAi in pest control.

RNA interference (RNAi)-based biopesticides are novel biologic products, developed using RNAi principles. They are engineered to target genes of agricultural diseases, insects, and weeds, interfering with their target gene expression so as to hinder their growth and alleviate their damaging effects on crops. RNAi-based biopesticides are broadly classified into resistant plant-based plant-incorporated protectants (PIPs) and non-plant-incorporated protectants. PIP RNAi-based biopesticides are novel biopesticides that combine the advantages of RNAi and resistant transgenic crops. Such RNAi-based biopesticides are developed through nuclear or plastid transformation to breed resistant plants, i.e., dsRNA-expressing transgenic plants. The dsRNA of target genes is expressed in the plant cell, with pest and disease control being achieved through plant-target organism interactions. Here, we review the action mechanism and strategies of RNAi for pest management, the development of RNAi-based transgenic plant, and the current status and advantages of deploying these products for pest control, as well as the future research directions and problems in production and commercialization. Overall, this study aims to elucidate the current development status of RNAi-based biopesticides and provide guidelines for future research.

Federal regulation of plant-incorporated protectants in the United States: implications for use of bioengineered pesticides in forest restoration

Federal regulation of plant-incorporated protectants in the United States: implications for use of bioengineered pesticides in forest restoration

RNAi for Western Corn Rootworm Management: Lessons Learned, Challenges, and Future Directions.

Simple SummaryThe western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, is an annual pest of maize in the United States Corn Belt. Larval feeding on the root system can promote significant yield loss through reduced water and nutrient uptake and decreased plant stability. Various management tactics, including crop rotation, insecticides, and transgenic crops expressing Bacillus thuringiensis Berliner proteins, have been used to manage WCR densities. However, resistance has evolved to each of these tactics in local areas, highlighting the need for new management strategies. The use of RNA interference (RNAi) technology for WCR management represents the next phase of species-specific pest management. This paper reviews the current knowledge of RNAi for WCR management. We present an overview of traits that have been explored and the accumulated knowledge acquired on mode of action, resistance, ecological risk assessment, and mammalian safety. We conclude by highlighting the challenges and future directions of this technology for WCR management.The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, is considered one of the most economically important pests of maize (Zea mays L.) in the United States (U.S.) Corn Belt with costs of management and yield losses exceeding USD ~1–2 billion annually. WCR management has proven challenging given the ability of this insect to evolve resistance to multiple management strategies including synthetic insecticides, cultural practices, and plant-incorporated protectants, generating a constant need to develop new management tools. One of the most recent developments is maize expressing double-stranded hairpin RNA structures targeting housekeeping genes, which triggers an RNA interference (RNAi) response and eventually leads to insect death. Following the first description of in planta RNAi in 2007, traits targeting multiple genes have been explored. In June 2017, the U.S. Environmental Protection Agency approved the first in planta RNAi product against insects for commercial use. This product expresses a dsRNA targeting the WCR snf7 gene in combination with Bt proteins (Cry3Bb1 and Cry34Ab1/Cry35Ab1) to improve trait durability and will be introduced for commercial use in 2022.

BIOINSECTICIDES AS FUTURE MAINSTREAM PEST CONTROL AGENTS: OPPORTUNITIES AND CHALLENGES

<List> <ListItem><ItemContent> •Wide use of botanical insecticides is limited by the availability of certain plants. </ItemContent></ListItem> <ListItem><ItemContent> •Studies are needed to improve RNAi efficiency and to assess their safety risk. </ItemContent></ListItem> <ListItem><ItemContent> •Microbial insecticides are promising, but they only control a narrow range of pests. </ItemContent></ListItem> <ListItem><ItemContent> •Multitarget approach should be a promising strategy in future pest control. </ItemContent></ListItem> <ListItem><ItemContent> •Nanoformulation could enhance stability and control the release of bioinsecticides. </ItemContent></ListItem></List> Bioinsecticides are naturally-occurring substances from different sources that control insect pests. Ideal bioinsecticides should have low toxicity to non-target organisms. They should also be easily degraded in sewage treatment works and natural environments, highly effective in small quantities and affect target pests only. Public concerns about possible side-effects of synthetic pesticides have accelerated bioinsecticide research and development. However, to develop bioinsecticides into mainstream products, their high production costs, short shelf-life and often uncertain modes of action need to be considered. This review summarizes current progress on bioinsecticides which are categorized as biochemical insecticides and their derivatives, plant-incorporated protectants, and microbial bioinsecticides. The current constraints that prevent bioinsecticides from being widely used are discussed and future research directions are proposed.

GPCR-Based Bioactive Peptide Screening Using Phage-Displayed Peptides and an Insect Cell System for Insecticide Discovery.

The discovery of new insecticides improves integrated pest management (IPM), but is usually a long high-risk process with a low probability of success. For over two decades, insect neuropeptides (NPs) and their G-protein coupled receptors (GPCRs) have been considered as biological targets for insect pest control, because they are involved in almost all physiological processes associated with insect life stages. A key roadblock to success has been the question of how large volume chemical libraries can be efficiently screened for active compounds. New genomic and proteomic tools have advanced and facilitated the development of new approaches to insecticide discovery. In this study, we report a novel GPCR-based screening technology that uses millions of short peptides randomly generated by bacteriophages, and a method using an insect Sf9 cell expression system. The fire ant is a good model system, since bioactive peptides have been identified for a specific GPCR. The novel small peptides could interfere with the target GPCR-ligand functions. Therefore, we refer to this new mechanism as “receptor interference” (RECEPTORi). The GPCR-based bioactive peptide screening method offers multiple advantages. Libraries of phage-displayed peptides (~109 peptides) are inexpensive. An insect cell-based screening system rapidly leads to target specific GPCR agonists or antagonists in weeks. Delivery of bioactive peptides to target pests can be flexible, such as topical, ingestion, and plant-incorporated protectants. A variety of GPCR targets are available, thus minimizing the development of potential insecticide resistance. This report provides the first proof-of-concept for the development of novel arthropod pest management strategies using neuropeptides, and GPCRs.

Fused: a promising molecular target for an RNAi-based strategy to manage Bt resistance in Plutella xylostella (L.)

Bacillus thuringiensis (Bt), a naturally occurring entomopathogenic soil bacterium, has been the active ingredient of sprayable Bt biopesticides for over a century. Insecticidal Bt Cry proteins are particularly well suited for use as plant-incorporated protectants in transgenic crops (Bt crops) due to their specificity against insect pests and safety for non-target organisms. The sustainability of these Bt products, however, has been challenged by the development of resistance in the field. RNA interference (RNAi), a species-specific control alternative that has been deregulated and commercialized in the USA and Canada, provides a new mode of action to complement the existing Bt products. Based on our preliminary research, we hypothesized that pyramiding/integrating Bt with RNAi can address/manage resistance issues related to Bt traits. To examine this overarching hypothesis, we (1) cloned and characterized a serine/threonine kinase gene (fused) of the Hedgehog (Hh) signaling pathway in the diamondback moth, Plutella xylostella (L.), a global superpest; (2) profiled Pxfused expression in Bt-resistant P. xylostella strains; and (3) investigated the involvement of Pxfused in Bt Cry1Ac resistance in P. xylostella. Pxfused expression was elevated ubiquitously in all Bt-resistant strains, and silencing of Pxfused led to larval and pupal mortality in both Cry1Ac-susceptible and -resistant strains, suggesting that Pxfused is a potential target for RNAi-based resistance management. Taken together, our results not only identify a molecular target to control a devastating lepidopteran pest, but also shed light on a novel resistance management strategy through the integration of two biotechnological techniques with distinct modes of action.

Adsorption of double-stranded ribonucleic acids (dsRNA) to iron (oxyhydr-)oxide surfaces: comparative analysis of model dsRNA molecules and deoxyribonucleic acids (DNA).

Double-stranded ribonucleic acid (dsRNA) molecules are novel plant-incorporated protectants expressed in genetically modified RNA interference (RNAi) crops. Ecological risk assessment (ERA) of RNAi crops requires a heretofore-missing detailed understanding of dsRNA adsorption in soils, a key fate process. Herein, we systematically study the adsorption of a model dsRNA molecule and of two double-stranded deoxyribonucleic acid (DNA) molecules of varying lengths to three soil iron (oxyhydr-)oxides - goethite, lepidocrocite, and hematite - over a range of solution pH (4.5-10), ionic strength (I = 10-100 mM NaCl) and composition (0.5, 1, and 3 mM MgCl2) and in the absence and presence of phosphate (0.05-5 mM) as co-adsorbate. We hypothesized comparable adsorption characteristics of dsRNA and DNA based on their structural similarities. Consistently, the three nucleic acids (NAs) showed high adsorption affinities to the iron (oxyhydr-)oxides with decreasing adsorption in the order goethite, lepidocrocite, and hematite, likely reflecting a decrease in the hydroxyl group density and positive charges of the oxide surfaces in the same order. NA adsorption also decreased with increasing solution pH, consistent with weakening of NA electrostatic attraction to and inner-sphere complex formation with the iron (oxyhydr-)oxides surfaces as pH increased. Adsorbed NA concentrations increased with increasing I and in the presence of Mg2+, consistent with adsorbed NA molecules adopting more compact conformations. Strong NA-phosphate adsorption competition demonstrates that co-adsorbates need consideration in assessing dsRNA fate in soils. Comparable adsorption characteristics of dsRNA and DNA molecules to iron (oxyhydr-)oxides imply that information on DNA adsorption to soil particle surfaces can inform dsRNA ERA.

Microbiome Innovation in Agriculture: Development of Microbial Based Tools for Insect Pest Management

According to the Entomological Society of America’s (ESA) recent position statement, invasive insects incur control costs of over $2.5 billion and cause economic damages to crops, lawns, forests, and pastures totaling $18 billion per year (“The Not-So-Hidden Dangers of Invasive Species” 2018). The threat of invasive crop pests to food security continues to be driven by complex dynamics of human movements, global trade activities, climate change, and changing agricultural practices. Chemical insecticides have been central to crop protection against invasive insects. However, a growing demand for reduced agricultural chemical use due to environmental and human health concerns in addition to pesticide resistance issues are fueling interests in innovative approaches to manage invasive pests. For decades, the role of microbes in pest management has been largely confined to using entomopathogens, with only a handful of microbial species being developed into bioinsecticides. The paradigm is shifting owing to the advent of high-throughput sequencing, functional omics, and gene editing technologies, which greatly accelerate microbial discovery, as well as a better understanding of microbial functions in complex communities across different habitats. There is also overwhelming evidence that symbiotic microbes play pivotal roles in shaping various insect traits. The collection of microbes associated with a given environment (both biotic and abiotic) and their collective genetic materials is termed the microbiome. In this paper, we survey the latest development in microbiome research that could be leveraged into novel management tools for agricultural insect pests (Figure 1). We first review the diverse insect traits shaped by insect-microbe associations that span nutrition, immunity, ecological interactions with natural enemy, insecticide resistance, and behavior. This is followed by a discussion on different microbiome manipulation approaches to alter pest traits, describing some of the opportunities and obstacles for each approach. We then highlight microbiomes as untapped chemical inventories to discover novel biopesticides, including plant-incorporated protectants and semiochemicals. The last topic covered is the use of beneficial microbes to improve performance of mass-reared insects for autocidal programs, including sterile insect technique and incompatible insect technique, in which we identify topics where data are limited or inconclusive for future research.

Dietary RNAi toxicity assay exhibits differential responses to ingested dsRNAs among lady beetles

Most recently, major federal regulatory agencies deregulated an in planta RNA interference (RNAi) trait against a devastating corn pest, the western corn rootworm Diabrotica virgifera virgifera, in the United States and Canada. The impact of double-stranded RNA (dsRNA) plant-incorporated protectants (PIPs) and dietary RNAi to non-target organisms, however, still needs further investigation. In this study, we assessed the potential risks of a Diabrotica virgifera virgifera active dsRNA to a group of predatory biological control agents, including Hippodamia convergens, Harmonia axyridis, Coleomegilla maculata, and Coccinella septempunctata. The overarching hypothesis is that the insecticidal dsRNA targeting Diabrotica virgifera virgifera has no or negligible adverse effect on lady beetles. A 400-bp fragment with the highest sequence similarity between target and tested species was selected as the template for dsRNA synthesis. For the dietary RNAi toxicity assay, newly hatched first instar larvae were administered with v-ATPase A dsRNAs designed from Diabrotica virgifera virgifera and the four lady beetles, respectively. A dsRNA from β-glucuronidase (GUS), a plant gene, and H2 O were served as the negative controls. The endpoint included both sub-organismal (gene expression), and organismal (survival rate, development time, pupa and adult weight) measurements. The results from dietary RNAi toxicity assay demonstrate significantly impacts of Diabrotica virgifera virgifera-active dsRNAs on lady beetles under the worst-case scenario at both transcriptional and phenotypic level. Interestingly, substantial differences among the four lady beetle species were observed toward the ingested exogenous dsRNAs. Such differential response to dietary RNAi may shed light on the mechanisms underlying the mode-of-action of RNAi-based biopesticides. © 2020 Society of Chemical Industry.

Dissipation of DvSnf7 RNA from Late‐Season Maize Tissue in Aquatic Microcosms

The commercialization of RNA-based agricultural products requires robust ecological risk assessments. Ecological risk is operationally defined as a function of exposure and adverse effects. Information on the environmental fate of RNA-based plant-incorporated protectants is essential to define routes and duration of exposure to potentially sensitive nontarget organisms. Providing these details in problem formulation helps focus the ecological risk assessment on the relevant species of concern. Postharvest plant residue is often considered to be the most significant route of exposure for genetically modified crops to adjacent aquatic environments. Previous studies have shown that DvSnf7 RNA from SmartStax PRO maize dissipates rapidly in both terrestrial and aquatic environments. Although these studies suggest that direct exposure to DvSnf7 RNA is likely to be low, little is known regarding the fate of DvSnf7 RNA produced in plants after entering an aquatic environment. This exposure scenario is relevant to detritivorous aquatic invertebrates that process conditioned maize tissues that enter aquatic environments. To assess potential exposure to shredders, dissipation of DvSnf7 RNA expressed maize tissue was evaluated following immersion in microcosms containing sediment and water. Concentrations of DvSnf7 RNA in the tissue were measured over a duration of 21 d. The DvSnf7 RNA dissipated rapidly from immersed maize tissue and was undetectable in the tissues after 3 d. Concentrations of DvSnf7 RNA found in tissue as well as calculated water column concentrations were below levels known to elicit effects in a highly sensitive surrogate species, supporting the conclusion of minimal risk to aquatic nontarget organisms. Environ Toxicol Chem 2020;39:1032-1040. © 2020 SETAC.

Biopesticides as Promising Alternatives to Chemical Pesticides: A Review of Their Current and Future Status

Biopesticides are living organisms or natural products that control agricultural pests including bacteria, fungi, weeds, viruses and insects. Biopesticides can be classified into different categories, such as microbial pesticides, plant-incorporated protectants and biochemicals. Biopesticides are a crucial component of integrated pest management programs for pest control, which lead to more natural alternatives to chemical pesticides that are eco-friendly and safer. Since the emergence of biopesticides for potential pest management, numerous products have been released and some of them dominate the market. This review paper will discuss the current status, future prospect and challenges associated with the use of biopesticides in pest control.