Non-target Plants Research Articles

Plasma Membrane (PM) H+-ATPase Mediates Rhizosphere Acidification and Regulates Herbicide Imazethapyr Toxicity in Wheat.

The plasma membrane (PM) H+-ATPase is crucial for a plant defense system. However, there is currently no consensus on whether the PM H+-ATPase plays a role in alleviating the toxic effects of herbicides on nontarget plants. We found that under the herbicide imazethapyr (IM) exposure, PM H+-ATPase activity in wheat roots increased by approximately 69.53%, leading to rhizosphere acidification. When PM H+-ATPase activity is inhibited, the toxicity of IM significantly increases: When exposed to IM alone, the total Fe content of wheat roots decreased by 29.07%, the relative Fe2+ content increased by 27.75%, and the ROS content increased by 27.74%. When the PM H+-ATPase activity was inhibited, the corresponding data under IM exposure were 37.36%, 215%, and 57.68%, respectively. This work delves into the role of PM H+-ATPase in mediating the detoxification mechanism in plants exposed to herbicides, offering new insights into enhancing crop resistance against herbicides.

Investigating the host finding behaviour of the weevil Phytobius vestitus for the biological control of the invasive aquatic weed Myriophyllum aquaticum

Biological control programmes involve pre-release studies that include host range tests to predict likely negative effects on native species. Behavioural responses of potential biological control agents to olfactory signals emitted by target and non-target species provide information on the host-finding and selection behaviour for safer agent selection. The weevil Phytobius vestitus (Coleoptera: Curculionidae) was identified as a potential biological control agent for the sustainable management of the aquatic weed Myriophyllum aquaticum (Haloragaceae). Using olfactometer-based bioassays, we analysed the host-finding and host-selection behaviour of P. vestitus across a variety of plant species closely related to M. aquaticum using a glass olfactometer. We further analysed the volatile organic compounds emitted by the target and non-target plant species to explain the weevil's observed preferences. We demonstrated that P. vestitus was able to recognise and discriminate between eight closely related Haloragaceae plant species and was significantly more attracted to the olfactory cues emitted by the target plant, M. aquaticum, compared to the other plant species. This study provides a first important indication of the specificity of P. vestitus and shows the role of plant chemistry in host selection and the possibility of refining host range assessment for potential biological control agents. However, exhaustive risk assessment for possible release into targeted new environments still requires further investigations.

Basal bark herbicide treatment of Lonicera maackii (Amur honeysuckle) is effective regardless of application timing, with limited nontarget effects on native plant diversity

Abstract Managers tasked with controlling invasive species require effective methods that are quick and easy to use without inflicting extensive nontarget damage, while also being compatible with other scheduled management responsibilities. Lonicera maackii (Amur honeysuckle) is a non‐native shrub that has invaded eastern and midwestern North American deciduous forests, altering ecosystem function and reducing biodiversity. This study explores prescribed fire and seasonal basal applications of triclopyr ester as control methods and examines the extent of nontarget damage. We used paired‐split plots to implement basal bark treatments in different seasons within burned and unburned units, and we tracked individual L. maackii to determine mortality and hyperlocal impacts of management. Basal bark treatments killed 98.4% of L. maackii across seasonal timings. Nontarget plant cover declined similarly for all herbicide application seasons, but there were some signs of recovery within 4 years, and the early‐ and late spring treatments were less affected overall. Species richness showed biologically small but statistically different declines across treatment times. Prescribed fire did not impact L. maackii mortality or interact with herbicide efficacy. Basal bark applications of triclopyr are an effective means of L. maackii control regardless of application timing, which allows managers to implement it at their convenience to avoid interfering with other management tasks that have time constraints.

Transcriptomic and metabolomic analysis provides insight into imazethapyr toxicity to non-target plants.

Imazethapyr is a widely used imidazolinone herbicide worldwide, and its potential adverse effects on non-target plants have raised concerns. Understanding the mechanisms of imazethapyr phytotoxicity is crucial for its agro-ecological risk assessment. Here, the comprehensive molecular responses and metabolic alterations of Arabidopsis in response to imazethapyr were investigated. Our results showed that root exposure to imazethapyr inhibited shoot growth, reduced chlorophyll contents, induced photoinhibition and decreased photosynthetic activity. By non-target metabolomic analysis, we identified 75 metabolites that were significantly changed after imazethapyr exposure, and they are mainly enriched in carbohydrate, lipid and amino acid metabolism. Transcriptomic analysis confirmed that imazethapyr significantly downregulated the genes involved in photosynthetic electron transport and the carbon cycle. In detail, 48 genes in the photosynthetic lightreaction and 11 genes in Calvin cycle were downregulated. Additionally, the downregulation of genes related to electron transport in mitochondria provides strong evidence for imazethapyr inhibiting photosynthetic carbon fixation and cellular energy metabolism as one of mechanisms of toxicity. These results revealed the molecular and metabolic basis of imazethapyr toxicity on non-target plants, contributing to environmental risk assessment and mitigate negative impact of imazethapyr residues in agricultural soils.

Investigating physiological effects due to artificial infections of grapevine with <i>Verticillium nonalfalfae</i>

Ailanthus altissima is among the most invasive woody species worldwide, outcompeting native trees. The fungus Verticillium nonalfalfae (VN) is promising for A. altissima biocontrol, and its effects on the host have been studied via visual assessment in a range of host species. However, little research was performed to address fungal effects on the physiological processes of non-target woody plants. We investigated the occurrence of visual and non-visually recognisable perturbations of VN infection on potted vines to evaluate the potential risks of the biocontrol pathogen on viticulture. Eighteen four-years-old Vitis vinifera (cultivar Grüner Veltliner grafted on Kober 5BB) potted plants were inoculated with VN conidial suspension of the fungus (F), while nine plants were treated with sterile water (C, control). Disease symptoms and physiological parameters were monitored throughout the experiment (seven evaluation dates), while leaf water potential, leaf mass per area (LMA) and biomass were measured at the end of the study when plant tissue was sampled for re-isolation of the fungus. In our trial, inoculations with VN induced characteristic wilting symptoms only in Ailanthus (used as side control of the inoculum), while vines remained asymptomatic, thus indicating a high degree of host specificity of VN. Limited or no impact was detected on the physiology of the non-target V. vinifera. Furthermore, the LMA and biomass measured in the two experimental groups were not different. Although fungal colonisation induced vascular discolouration in both species, the fungus could only be re-isolated from dying Ailanthus but not from vine tissue. Results suggest that V. vinifera cv Grüner Veltliner is resistant to the applied VN isolate. However, the susceptibility and physiology of additional grapevine cultivars, as well as other native woody species to VN, should be studied before promoting large-scale use of the biocontrol agent.

Using Plant Growth Regulators to Stimulate Growth of Napier Grass Under Atrazine Contamination

ABSTRACT Phytotoxic effects of herbicides have been reported on non-target plant species. This study was performed to investigate the growth of Napier grass cv. Pak Chong 1 in herbicide atrazine-contaminated soil; the effect of 1-naphthalene acetic acid, 6-benzyladenine and thidiazuron to stimulate the growth of grass grown in atrazine-contaminated soil; and to determine the remaining atrazine in the soil. The experiment was performed in a factorial completely randomized design with 2 × 10 factors. The first factor was atrazine concentration and the second factor was the application of plant growth regulator. The growth of the plants and atrazine remaining in the soil was analyzed at the end of the experiment (after 26 days). The results showed that Napier grass cv. Pak Chong 1 was tolerant to 6.8 mg/kg atrazine contamination in soil. The shoot growth and root growth of grass grown in atrazine-contaminated soil did not significantly differ from that grown in non-contaminated soil. Thidiazuron and 6-benzyladenine at 0.1 mg/l tended to increase the shoot dry weight of the grass grown in both atrazine-contaminated and non-contaminated soil. Additionally, 10 mg/l of thidiazuron and 1-naphthalene acetic acid tended to decrease the shoot growth of grass grown in both contaminated and non-contaminated soil. Moreover, decreases in atrazine were detected in soil planted with Napier grass cv. Pak Chong 1 by about 67.65% within 26 days.

ANALYSIS OF SOCIO-PERSONAL CHARACTERISTICS OF COTTON GROWERS

Agriculture is an important occupation of rural people and it is the backbone of the economy of many countries. Cotton is most important fiber crop in Indian agriculture and India ranks first with respect to area and production and eighth rank with respect to productivity of cotton. Consumption of pesticides is particularly high in cotton cultivation as the crop yield is seriously affected by pest attacks. Pesticides overuse can contaminate soil, water, turf, killing insects, beneficial insects, non-target plants and also create health hazard in human.so considering this fact to know cotton growers profile present study was conducted in Rajkot, Amreli and Jamnagar district of Saurashtra region. Six talukas were selected randomly and two villages were selected randomly from each selected taluka and twelve respondents were randomly selected from each village. Thus, 144 cotton growers were selected for the study. The study revealed that majority of the respondents were (52.08%) belonged to middle age group, (36.11%) belonged to middle school (9th to 10th standard) level of education, (31.25%) had high farming experience, (35.42%) had medium level of health value, (34.72 %) had semi medium size of land holding (2 ha to 4 ha), (31.25%) had annual income ₹ 1,00,001 to ₹ 1,50,000, (59.02%) had medium environmental orientation, (63.20%) had medium level of sustainability, (35.41%) had high risk orientation, (40.30%) had medium Economic motivation, (37.50%) had high scientific orientation (35.42%) had high innovativeness, (65.28%) had medium mass media exposure and (61.80%) of cotton growers had medium source of information.

Additional host range testing of Eucryptorrhynchus brandti (Coleoptera: Curculionidae) for the biological control of tree-of-heaven, Ailanthus altissima (Simaroubaceae) in the U.S.A.

ABSTRACT Ailanthus altissima, native to China, is a highly invasive plant in North America, Europe, and other continents. This species displaces native plants by forming dense clonal thickets. Ailanthus altissima is shade intolerant, quickly invades fields, rights-of-way, urban areas, and areas in forests disturbed by logging, fire, or pests. This species is also a primary host of the economically damaging spotted lanternfly, Lycorma delicatula, recently introduced into the U.S. Eucryptorrhynchus brandti is native to China and has been identified as a potential biological control agent of A. altissima. Oviposition studies conducted on 11 non-target plant species demonstrated that E. brandti oviposited only on the U.S. native Leitneria floridana. All non- Leitneria species had adult feeding of less than 2% compared to A. altissima, with no oviposition or larval development. Longevity of E. brandti in no-choice tests with L. floridana and L. pilosa subsp. ozarkana, was shorter and the weevils consumed less foliage compared to A. altissima. Seventeen percent of the L. floridana trees tested had larval feeding and 18 E. brandti adults emerged from 10 replicates. No L. floridana trees with larval feeding died. All the A. altissima trees with larval development died. Eucryptorrhynchus brandti is projected to be an effective agent against A. altissima and pose no significant risk to native North American plant species, with potential to be an additional management tool for the spotted lanternfly.

Host-virus interaction between tobacco mild green mosaic virus strain U2 and tropical soda apple resulting in systemic hypersensitive necrosis and the host range, survival, spread, and molecular characterization of the virus.

Tobacco mild green mosaic virus strain U2 (TMGMV-U2) is a registered active ingredient in a bioherbicide to control tropical soda apple (TSA), Solanum viarum, an invasive weed. As required for registration, we developed empirical data on the host-virus interaction and the virus's host range, survival, spread, and genomic sequence. TMGMV-U2 killed TSA plants by causing systemic hypersensitive necrosis (SHN). It elicited local lesions in inoculated leaves which was followed by the plant's wilting and death. It moved from inoculated terminal leaves through the vasculature to roots and then to newly developed leaves. Phloem death was implicated in wilting and plant death. The SHN response was attenuated in plants grown at constant 32 °C. TMGMV-U2 titer in TSA was low compared to a systemically susceptible tobacco. The virus remained infective for up to 6 months in infected dead TSA tissues and in soil in which infected plants had grown. Susceptible tobacco and pepper plants grown in soil that previously had infected dead TSA or in soil amended with the virus remained asymptomatic and virus-free. A susceptible pepper crop grown in a field block following two consecutive crops of TMGMV-U2-infected susceptible tobacco grew disease-free and virus-free and without yield loss. Purified TMGMV-U2 was infective for 1 year when stored at -20 °C or 5 °C and for 1 month at room temperature. No virus spread was found in the field. Genomic analyses confirmed the registered isolate to be a U2 strain and free of satellite TMV. The TMGMV-U2-susceptible species preponderantly belonged to the Solanaceae. A few hosts that were killed belonged to this family. Several new hosts to TMGMV-U2 were found. These data enabled registration of TMGMV-U2. TMGMV-U2 can be used safely as a bioherbicide without risks to nontarget plants and the environment. © 2023 Society of Chemical Industry.

Antifungal triazoles affect key non-target metabolic pathways in Solanum lycopersicum L. plants

Several 1,2,4-triazoles are widely used as systemic fungicides in agriculture because they inhibit fungal 14ɑ-demethylase. However, they can also act on many non-target plant enzymes, thereby affecting phytohormonal balance, free amino acid content, and adaptation to stress. In this study, tomato plants (Solanum lycopersicum L. var. ‘Cherrola‘) were exposed to penconazole, tebuconazole, or their combination, either by foliar spraying or soil drenching, every week, as an ecotoxicological model. All triazole-exposed plants showed a higher content (1.7–8.8 ×) of total free amino acids than the control, especially free glutamine and asparagine were increased most likely in relation to the increase in active cytokinin metabolites 15 days after the first application. Conversely, the Trp content decreased in comparison with control (0.2–0.7 ×), suggesting depletion by auxin biosynthesis. Both triazole application methods slightly affected the antioxidant system (antioxidant enzyme activity, antioxidant capacity, and phenolic content) in tomato leaves. These results indicated that the tomato plants adapted to triazoles over time. Therefore, increasing the abscisic and chlorogenic acid content in triazole-exposed plants may promote resistance to abiotic stress.

Intergenerational consequences of an auxin-like herbicide on plant sensitivity to a graminicide mediated by a fungal endophyte

In agroecosystems, herbicides are the predominant anthropogenic selection pressure for agriculture weed species. While weeds are the primary target, herbicides can have adverse impacts on non-target plant beneficial microorganisms. We aimed to investigate the influence of a foliar endophytic fungus (Epichloë occultans) on the sensitivity of Lolium multiflorum to a graminicide herbicide (diclofop-methyl) during both plant ontogeny and progeny. Susceptible individuals to diclofop-methyl with and without endophyte were pre-exposed to the auxin 2,4-D herbicide. This herbicide is known to stimulate the metabolic detoxification mechanism (CYP-450) of diclofop-methyl. Regardless of the endophyte, 2,4-D pre-treatment increased mother plant survival to nearly 100 % under diclofop treatment but not in the progeny. Furthermore, maternal plant exposure to 2,4-D reduced endophyte transmission to the seeds and from seed-to-seedlings. Our findings suggest that, despite a reduction in diclofop-methyl sensitivity during the ontogeny of mother plants, 2,4-D-mediated induction of likely CYP-450 metabolism is not intergenerationally transmitted and shows detrimental effects on the symbiotic endophyte persistence.

Reproducibility, reliability, and regulatory relevance of plant visual injury assessments.

The registration of herbicides in the European Union requires an assessment of risks to nontarget terrestrial plants (NTTPs). Regulatory plant studies are performed to determine risk-assessment-relevant endpoints (50% effect rate) for quantitative parameters, mostly biomass and survival. Recently, the European Food Safety Authority stated that endpoints for qualitatively assessed plant visual injuries (PVIs) such as necrosis, chlorosis, and so forth should be considered for the risk assessment as equal to endpoints derived from quantitatively determined parameters. However, the lack of guidance in the NTTP test guidelines on how to assess PVI and how to derive a statistically meaningful endpoint for PVI makes their use in risk assessments challenging. To evaluate and improve the reliability, reproducibility, and regulatory relevance of PVI assessments in NTTP studies, the PVI Working Group was formed in 2022 within the SETAC Plant Interest Group. In a first exercise, research needs, guidance gaps, and shortcomings in current methodologies were identified and are presented together with recommendations for a future, validated, and harmonized method for the assessment of PVI. Survey results revealed a high variability in how PVI are currently assessed, and that the reliability of these data is unclear. Under current conditions, the PVI data can rather be seen as supportive information instead of using the data for the statistically sounddetermination of a regulatory endpoint. Consequently, standardization and harmonization of procedures for the assessment of PVI are needed. An improved scoring methodology should be developed that allows for a precise, statistically sound endpoint determination. Regarding the regulatory relevance of PVI, further research is required to assess the biological meaning of PVI data and how this is connected to the regulatory requirements and protection goals. Last but not least, guidance is required on how to evaluate the historically available PVI data that are based on various assessment methodologies. Integr Environ Assess Manag 2024;20:915-923. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Physical and physiological pathways of off-target triclopyr movement and associated non-target injury following basal bark application

AbstractBasal bark treatment with triclopyr butoxyethyl ester is used to control woody invasive plants, including Brazilian peppertree (Schinus terebinthifolia Raddi). However, the ester formulation cannot be applied where standing water is present, which includes wetlands where S. terebinthifolia is found. In 2009, a low-volatile acid formulation of triclopyr was labeled for use in aquatic sites, which allows for basal bark applications when standing water is present. This formulation may have utility for controlling woody plants in standing water. However, anecdotal observations of injury to non-target plants following applications during periods of inundation have been reported. To address this, mesocosm studies were conducted to assess non-target injury through triclopyr root exudation or release from the surface of treated stems via flooding. Mesocosms contained S. terebinthifolia as the treated target, while sugarberry (Celtis laevigata Willd.), buttonbush (Cephalanthus occidentalis L.), and red maple (Acer rubrum L.) were included as non-targets. In the first study, the pathway of root exudation for non-target injury following triclopyr (34 g L−1) basal bark application was isolated with activated charcoal placed at the soil surface. In the second study, mesocosms were flooded to assess triclopyr release from the surface of treated stems and subsequent non-target injury. Defoliation of non-target species posttreatment was ≤8%, and triclopyr was detected at ≤5 µg L−1 in mesocosm wells when activated charcoal was present. Posttreatment non-target defoliation up to 92%, coupled with triclopyr concentrations in surface waters and wells as high as 4,637 µg L−1, indicated triclopyr movement as a result of flooding. Additionally, triclopyr non-target injury from soil activity independent of flooding was observed. These findings provide limited evidence of triclopyr root exudation but considerable evidence of triclopyr release during flooding following basal bark treatment and support a cautionary approach to basal bark application when standing water is present.

Ecotoxicology of the herbicide paraquat: effects on wildlife and knowledge gaps.

Paraquat (PQ) is an organic herbicide introduced to the commercial market in 1962 and since linked to a variety of human health effects, including lung fibrosis, liver tumors, and Parkinson's disease. Although PQ is banned in the European Union, it is still frequently used in agricultural areas of the United States and Asia. The general mechanism of PQ's toxicity is the disruption of the redox cycle in cells. This mini-review summarizes our current understanding of PQ toxicity in non-target plants and animals. Among vertebrates, PQ sensitivity tends follow the pattern of fish > amphibians > mammals > birds. Aquatic plants are particularly vulnerable to PQ, with EC50 values ranging from ~28-280 μg/L. A number of convenient but non-specific biomarkers have been identified for non-target species, including the activities of antioxidant enzymes such as superoxide dismutase and catalase, histological changes in the gill structures of fish, and the upregulation of genes associated with the cytochrome p450 monooxygenase system. Significant literature gaps include a lack of data for environmentally realistic conditions (i.e., chronic, low concentration, multi-stressor), toxicity in reptiles, and population- and ecosystem-level effects. Although PQ is a useful herbicide, considering the many human and ecological health impacts, it may be time for regulators and the agricultural industry to reconsider its use.

Occurrence, multiphase partitioning, drivers, and ecological risks of current-use herbicides in a river basin dominated by rice–vegetable rotations in tropical China

Rice–vegetable rotation practices prevail in subtropical and tropical agriculture worldwide, with applications of current-use herbicides (CUHs) vital for nontarget plant control. After application, CUHs migrate to environmental compartments, where the occurrence, fate, and ecological risks have not been well characterized. To further understand the occurrence and multiphase partitioning, as well as to evaluate potential drivers and mixture risks in environmental compartments, we analyzed 11 CUHs in 576 samples from 36 rice–vegetable rotations in Nandu River basin, Hainan, China. Samples included soil, water, suspended particulate matter, and sediment collected during both rice and vegetable planting periods. The CUH concentrations varied across environmental compartments, but with high levels of glyphosate and aminomethylphosphonic acid organophosphorus herbicides (OPHs) frequently detected, accounting for 82.3 % to 99.0 % in environmental compartments. Phenoxy acid (PAA) and chloroacetanilide (ANH) herbicides were detected at lower frequencies. Spatiotemporal variation was significantly different among OPHs, ANHs, and PAAs, with geographic and crop-related patterns most evident for CUHs rather than OPHs. Structural equation model, redundancy, and boosted regression tree analyses indicated environmental compartment properties (pH, organic matter, and Fe/Al oxides), crop type, and wet/dry climate were important drivers of spatiotemporal patterns. Fugacity ratios indicated multiphase partitioning and transport of CUHs differed in rice and vegetable planting periods. A new assessment framework based on species-sensitive distributions and environmental compartment weight index indicated unacceptable risks of CUHs (risk quotient >1 in >50 % of sites), with most risks from OPHs (10.5 % to 98.0 %) and butachlor, acetochlor, and 2,4-dichlorophenoxyacetic acid. Risk hot spots were identified as the soil, the central region, and the vegetable planting period, potentially threatening nontarget organisms (e.g., Lemna minor, Glomus intraradices, and Apis mellifera). This study provides a new risk assessment framework and demonstrates the domination of OPHs in CUH contamination and risks in the tropics, thus helping guide policymakers and stakeholders on herbicide management.

Can herbicides of different mode of action cause injury symptoms in non-herbicide-tolerant young soybean due to simulated drift?

Accidental herbicide drift onto neighboring crops, such as soybeans, can seriously harm non-target plants, affecting their growth and productivity. This study examined the impact of simulated drift from ten different herbicides (2,4-D, dicamba, glyphosate, saflufenacil, oxyfluorfen, hexazinone, diuron, diquat, nicosulfuron, and isoxaflutole) on young soybean plants. These herbicides were applied at three simulated drift levels (1/4, 1/16, and 1/32) equivalent to recommended commercial doses, and the resulting symptoms were carefully evaluated. Simulated drift caused distinctive symptoms, including chlorosis, twisting, necrosis, and growth abnormalities, varying depending on each herbicide’s mode of action. Dicamba proved more toxic than 2,4-D, and symptom severity increased with drift proportion, with all herbicides causing over 30% injury at the 1/16 proportion. Notably, 2,4-D, dicamba, glyphosate, hexazinone, and diquat exceeded the half-maximal inhibitory concentration (IC50) value, significantly reducing total biomass. Dicamba consistently caused 50% injury at all proportions, while hexazinone, at the highest dose proportion, led to plant mortality. Dicamba also had biomass accumulation beyond the growth reduction (GR50), whereas hexazinone exhibited less than 10% accumulation due to its capacity to induce plant mortality. This study emphasizes the importance of understanding herbicide drift effects on non-target crops for more effective and safe weed management strategies.

Phytotoxicity alleviation of imazethapyr to non-target plant wheat: active regulation between auxin and DIMBOA.

Effectively controlling target organisms while reducing the adverse effects of pesticides on non-target organisms is a crucial scientific inquiry and challenge in pesticide ecotoxicology research. Here, we studied the alleviation of herbicide (R)-imazethapyr [(R)-IM] to non-target plant wheat by active regulation between auxin and secondary metabolite 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazine-3(4H)-one (DIMBOA). We found (R)-IM reduced 32.4% auxin content in wheat leaves and induced 40.7% DIMBOA accumulation compared to the control group, which effortlessly disrupted the balance between wheat growth and defense. Transcriptomic results indicated that restoration of the auxin level in plants promoted the up-regulation of growth-related genes and the accumulation of DIMBOA up-regulated the expression of defense-related genes. Auxin and DIMBOA alleviated herbicide stress primarily through effects in the two directions of wheat growth and defense, respectively. Additionally, as a common precursor of auxin and DIMBOA, indole adopted a combined growth and defense strategy in response to (R)-IM toxicity, i.e., restoring growth development and enhancing the defense system. Future regulation of auxin and DIMBOA levels in plants may be possible through appropriate methods, thus regulating the plant growth-defense balance under herbicide stress. Our insight into the interference mechanism of herbicides to the plant growth-defense system will facilitate the design of improved strategies for herbicide detoxification.

Effect of biostimulant raw materials on soybean (Glycine max) crop, when applied alone or in combination with herbicides

IntroductionBiostimulants exert positive functions in plants, improving yield and quality, and alleviating the negative effects of abiotic stresses. Among them, the application of herbicides may cause damage to nontarget plants. At present, limited information is available regarding the interaction between biostimulants and herbicides.MethodsThe purpose of the present study was to assess the effect of an herbicide’s mixture (Harmony® 50 SX® + Tuareg® + Zetrola®), used in combination with several biostimulant raw materials (BRM), on the agronomic and physiologic characteristics of soybean. The experiments were conducted in two seasons, 2020 and 2021, applying the herbicides mixture alone or associated with 10 BRM.ResultsDifferences emerged between the two years, considering nitrate, total sugars concentration, flavonol, and chlorophyll a fluorescence-related parameters. Chlorophyll content significantly declined (−45% in 2020) in plants treated with the herbicides mixture alone but, in combination with potassium silicate, the chlorophyll values were restored to control levels. The same positive effect observed in response to the combination of potassium silicate and the herbicide mixture has been confirmed in the second year of experiment. At the same time, chlorophyll content and Nitrogen Index were positively increased (up to 8% and 30%, respectively) depending on the application of some BRM and the year. A significant effect of biostimulants on yield was confirmed by the application of Ascophyllum nodosum (+16%) and humic acids (+7%), in 2020. However, the combined use with the herbicides nullifies the increase. DiscussionThe results obtained from these experiments support the use of biostimulants in improving specific quality traits (chlorophyll content, leaves nitrogen status, and secondary metabolites accumulation). At the same time, the potential use of biostimulants in combination with herbicides needs to be further explored since of external factors (environment, year…) still have a strong effect on their efficacy.

Anti-cervical cancer mechanism of bioactive compounds from Alangium platanifolium based on the ‘compound-target-disease’ network

In this study, we analyzed the chemical compositions of Alangium platanifolium (Sieb. et Zucc.) Harms (AP) using ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) non-targeted plant metabolomics integration MolNetEnhancer strategy. A total of 75 compounds, including flavonoids, alkaloids, terpenes, C21 steroids, among others, were identified by comparing accurate mass-to-charge ratios, MS2 cleavage fragments, retention times, and MolNetenhancer-integrated analytical data, and the cleavage rules of the characteristic compounds were analyzed. A total of 125 potential cervical cancer (CC) therapeutic targets were obtained through Gene Expression Omnibus (GEO) data mining, differential analysis, and database screening. Hub targets were obtained by constructing protein-protein interaction (PPI) networks and CytoNCA topology analysis, including SRC, STAT3, TP53, PIK3R1, MAPK3, and PIK3CA. According to Gene ontology (GO) analysis, AP was primarily against CC by influencing gland development, oxidative stress processes, serine/threonine kinase, and tyrosine kinase activity. Enrichment analysis of the Kyoto Encyclopedia of Genes and Genomes (KEGG) indicated that the PI3K/AKT and MAPK signaling pathways play a crucial role in AP treatment for CC. The compound-target-pathway (C-T-P) network revealed that quercetin, methylprednisolone, and caudatin may play key roles in the treatment of CC. The results of molecular docking revealed that the core compound could bind significantly to the core target. In this study, the compounds in AP were systematically analyzed qualitatively, and the core components, core targets, and mechanisms of action of AP in the treatment of CC were screened through a combination of network pharmacology tools. Providing a scientific reference for the therapeutic material basis and quality control of AP.

Intoxication of newly implanted coffee plants by simulated drift of the dicamba herbicide

After the release of soybean cultivars resistant to the herbicide dicamba, this product should be used more frequently in weed management programs, which may increase the risk of drift to neighboring crops, since the molecules are volatile and might cause damage in non-target plants. This work was developed to evaluate the effects of sub-doses of the herbicide dicamba on young coffee plants, simulating a drift situation. The experiment was carried out in a greenhouse, with a randomized block design of eight treatments and five replications. Each plot consisted of a 4 L pot, filled with sieved clayey soil and tanned manure (3:1 v/v), with a seedling of Catuaí IAC 144 coffee. The treatments used were: 0 (control), 0.0001, 0.001, 0.01, 0.1, 1.0, 10.0, and 100.0 g ha−1 of dicamba. Plant's percentual phytotoxicity was evaluated up to 49 days after application (DAA), SPAD index (14, 28, and 42 DAA), and dry matter biomass, at 49 DAA. In all evaluations, no differences were observed regarding phytotoxicity for dicamba sub-doses of up to 0.01 g ha−1. The highest doses of dicamba caused visual injuries of up to 31%. At 49 DAA, there were no differences regarding dry matter biomass. Leaf symptoms caused by the herbicide were observed, such as curling, wrinkling, and epinasty. No plant death was observed. Compared to other crops, coffee might be considered more tolerant to sub-doses of dicamba, with adequate recovery capacity for reduced doses of this herbicide.