Greenhouse Pot Research Articles

Study on the enhancement effect of EDTA and oxalic acid on phytoremediation of Cr(VI) from soil using Datura stramonium L.

This study investigated the enhancing effects of soil treatment with ethylene diamine tetraacetic acid (EDTA) and oxalic acid (OA) on the remediation of Cr(VI) contaminated soil by Datura stramonium L. A greenhouse pot experiment was conducted, where Cr(VI) contaminated soil was treated with 100 mg/kg Cr(VI) and varying concentrations of EDTA (5 and 10 mmol/kg) and OA (5 and 10 mmol/kg). The effects of these soil treatments on biomass, chlorophyll content, antioxidant enzyme activities, and Cr(VI) enrichment and translocation efficiency of D. stramonium were evaluated. The results showed that added OA to soil significantly increased the biomass and chlorophyll content of D. stramonium. The addition of 10 mmol/kg of OA to soil increased the plant biomass by 67.16 % and chlorophyll b content by 40.01 %. In addition, OA soil treatment significantly enhanced the activities of superoxide dismutase (SOD) by 6.36 %, peroxidase (POD) by 163.13 %, catalase (CAT) by 36.92 %, and ascorbate peroxidase (APX) by 32.12 %, which effectively alleviated the oxidative stress induced by Cr(VI). In contrast, soil treatment with a high concentration of EDTA (10 mmol/kg) significantly reduced plant biomass and chlorophyll content, although it increased the biological concentration factor (BCF) of the stem and leaf, as well as the translocation factor (TF). In conclusion, appropriate amounts of EDTA and OA added to soil can enhance the phytoremediation efficiency of D. stramonium grown in Cr(VI) contaminated soil, with OA added to soil being more effective than addition of EDTA. This study revealed the potential mechanisms of chelating agents EDTA and OA in enhancing the phytoremediation of Cr(VI) contaminated soil by D. stramonium, providing a scientific basis for further optimization of phytoremediation techniques.

Controlled-Release Iodine Fertilizer Improved Iodine Accumulation, Antioxidant Capacity, and Quality of Lettuce

To clarify the effects of newly developed controlled-release iodine fertilizer (CRIF) on enhancing lettuce (Lactuca sativa L.) iodine accumulation, improving the physiological traits, and reducing iodine leaching from soil, a greenhouse pot experiment was conducted. Polymer-coated iodate (PCIO), polymer-coated iodide (PCI), and two conventional iodine fertilizers—iodate (CIO) and iodide (CI)—were applied at a rate of 15 mg iodine per kg soil. The study found that the coating of iodine fertilizers had no significant effects on the biomass of lettuce. The iodine concentration in lettuce leaves subjected to PCIO treatment was elevated by 50.1% and 45.5%, respectively, in comparison to leaves treated with CIO and PCI. The soil-to-leaf transfer factor (TFleaf, dry weight basis) for plants treated with PCIO was significantly higher than that of PCI-treated plants. PCIO also significantly reduced iodine leaching by 46.3% compared to CIO. In lettuce leaves with PCIO treatment, the enzymatic activities of superoxide dismutase (SOD) and catalase (CAT) significantly increased by 50.8% and 27.6%, respectively. Likewise, malo-naldehyde (MDA) levels decreased by 23.2% compared to the control samples. PCIO also demonstrated advantages in enhancing the quality of the lettuce. In conclusion, the application of controlled-release iodine fertilizer could be a highly effective and eco-friendly approach to cultivating iodine-rich vegetables.

Enhancing Iron and Zinc Uptake in Spring Wheat Through Commercial Arbuscular Mycorrhizal Fungi Inoculation under Different Soil Phosphorus Addition Levels

Improving the concentrations and bioavailability of micronutrients, especially iron (Fe) and zinc (Zn), in crop grains is important to alleviate their deficiencies in humans. Inoculating crops with arbuscular mycorrhizal fungi (AMF) can potentially enhance soil nutrient supply and crop yield, but the effectiveness is influenced by soil factors, particularly soil phosphorus (P) availability. A greenhouse pot experiment was conducted to evaluate the effect of a commercial AMF product on spring wheat (Triticum aestivum L.) yield and grain concentrations of Zn and Fe under different soil P addition levels (0, 5 and 20 mg P kg-1 dry soil). Results showed that AMF inoculation significantly increased root colonization rate of wheat across all P addition levels. Wheat growth, as evidenced by dry weights of shoot and grain, was significantly enhanced by AMF and high P addition treatments. AMF inoculation did not affect grain Zn concentration, but significantly increased grain Fe concentration compared to the un-inoculated control. As expected, P addition resulted in a significant reduction in grain concentrations of Fe and Zn, primarily due to a growth dilution effect. An integrated analysis using the radar plot concludes that AMF inoculation is most effective in increasing crop yield and grain micronutrient concentrations when soil P levels are low. Importantly, while adequate P supply is crucial for maintaining crop productivity, it may decrease grain micronutrient availability without complementary strategies.

Bacillus endophytic strains control Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici in tomato cv. Perinha.

Fusarium wilt is one of main phytopathology attacking tomato (Solanum lycopersicum L.) plantations in Brazil. Plant rhizosphere and endophytic beneficial microorganism are well known as plant growth promoters and biocontrol agents. The present study aims to evaluate the potential of different Bacillus strains as biocontrol agent to Fusarium oxysporum f. sp. lycopersici Race 3 strains; and also as plant growth promoting bacteria on Solanum lycopersicum cv Perinha. Different in vitro and greenhouse experiments were carried out to evaluate the direct and indirect bacterial-fungus antagonism, and they inoculation effects on plant traits. In vitro direct, metabolites, and volatile antagonism analysis demonstrated that B. toyonensis BR 10491(FORT 02) presented a broad antagonism to all tested race 3 FOL strains while B. megaterium BR 10466 (FORT 12), B. aryabhattai BR 10494 (FORT 25), B. stratosphericus BR 10438 (FORT 29) and B. cereus BR 10493 (FORT 113.1) strains showed significant antagonistic activity for at least two applied methods. Greenhouse pot experiments demonstrated a significant BCA effect of FORT 113.1 and FORT 02 against FOL Race 3 Fus 1302 strain during different tomato development stages (seedling, vegetative, and reproductive). Bacillus cereus (FORT 113.1) showed significantly higher shoot and height fresh weight, Chlorophyll a and Chlorophyll b content, stomata conductance, water use efficiency, and also a lower xylem infection percentage during vegetative and reproductive stages. Antioxidant enzymatic components analysis demonstrated a synergic effect of Fusarium and Bacillus inoculation, leading to a higher superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) activity. In conclusion, the results suggest that strain FORT113.1 could be considered as a good candidate for production of new biofungicide with high potential to augment the existing biocontrol strategies.

Inoculation of Bacillus velezensis Bv-116 and its bio-organic fertilizer serve as an environmental friendly biocontrol strategy against cucumber Fusarium wilt.

The aim of this study was to evaluate the effects of Bacillus velezensis Bv-116 and its bio-organic fertilizer on the control of cucumber Fusarium wilt caused by Fusarium oxysporum f. sp. Cucumerinum (FOC), the promotion of growth of cucumber seedlings, and the soil microbial community. B. velezensis Bv-116 exhibited an inhibition rate of 84.93% against FOC, as well as broad-spectrum inhibitory activities against other soil-borne plant pathogenic fungi. Fermentation products of B. velezensis Bv-116 destroyed the cell structure of FOC and inhibited the growth of FOC mycelium. These products were identified as volatile antimicrobial gases, proteases and cellulases. In the greenhouse pot experiment, both B. velezensis Bv-116 and its bio-organic fertilizer exhibited significant promoting effects on cucumber growth, and a significant reduction in the incidence and disease severity index of cucumber wilt (p < 0.05). Analysis of the microbial community structure of cucumber rhizosphere soil revealed that inoculation of B. velezensis Bv-116 and its bio-organic fertilizer increased the abundance of genera with biocontrol capabilities against plant pathogens. In addition, inoculation of the bio-organic fertilizer reversed the excessive proliferation of Fusarium and Acidobacteria. Our results suggest the potential of inoculating B. velezensis Bv-116 and its bio-organic fertilizer as an environmentally friendly biocontrol strategy against cucumber wilt.

A potential biocontrol and growth-promoting agent Streptomyces luteoverticillatus B4 for managing cabbage Fusarium wilt and cucumber Alternaria leaf blight

Cabbage Fusarium wilt and cucumber Alternaria leaf blight are two widespread diseases caused by Fusarium oxysporum and Alternaria cucumerina that severely affect cabbage and cucumber output across the world. However, very few biocontrol actinomycete resources have been identified for these two diseases. An antagonistic actinomycete B4 was isolated and identified as Streptomyces luteoverticillatus. It is effective against a wide range of plant pathogens. The purpose of this study was to look into the inhibitory impact of S. luteoverticillatus B4 on F. oxysporum and A. cucumerina, as well as to create the theoretical groundwork and research technologies for the use of B4 as a biopesticide. It was found that B4 has the ability to detoxify organic phosphorus and produce siderophores, IAA, and glucoamylase. In the greenhouse pot test, B4 had a control efficiency of 56 % against F. oxysporum and 76 % against A. cucumerina. Further investigation into the inhibitory mechanism indicated that once the B4 fermentation broth operated on the two pathogens, their mycelial morphology was altered, and mycelial growth was suppressed, particularly for F. oxysporum. B4 could create volatile organic compounds that may have an inhibiting impact. In addition, B4 fermentation broth dramatically increased seed germination and seedling development in both cabbage and cucumber. S. luteoverticillatus B4 is a possible biocontrol agent that inhibits F. oxysporum and A. cucumerina while also encouraging cabbage and cucumber development.

Dynamic alterations and ecological implications of rice rhizosphere bacterial communities induced by an insect-transmitted reovirus across space and time

BackgroundCereal diseases caused by insect-transmitted viruses are challenging to forecast and control because of their intermittent outbreak patterns, which are usually attributed to increased population densities of vector insects due to cereal crop rotations and indiscriminate use of pesticides, and lack of resistance in commercial varieties. Root microbiomes are known to significantly affect plant health, but there are significant knowledge gaps concerning epidemics of cereal virus diseases at the microbiome-wide scale under a variety of environmental and biological factors.ResultsHere, we characterize the diversity and composition of rice (Oryza sativa) root-associated bacterial communities after infection by an insect-transmitted reovirus, rice black-streaked dwarf virus (RBSDV, genus Fijivirus, family Spinareoviridae), by sequencing the bacterial 16S rRNA gene amplified fragments from 1240 samples collected at a consecutive 3-year field experiment. The disease incidences gradually decreased from 2017 to 2019 in both Langfang (LF) and Kaifeng (KF). BRSDV infection significantly impacted the bacterial community in the rice rhizosphere, but this effect was highly susceptible to both the rice-intrinsic and external conditions. A greater correlation between the bacterial community in the rice rhizosphere and those in the root endosphere was found after virus infection, implying a potential relationship between the rice-intrinsic conditions and the rhizosphere bacterial community. The discrepant metabolites in rhizosphere soil were strongly and significantly correlated with the variation of rhizosphere bacterial communities. Glycerophosphates, amino acids, steroid esters, and triterpenoids were the metabolites most closely associated with the bacterial communities, and they mainly linked to the taxa of Proteobacteria, especially Rhodocyclaceae, Burkholderiaceae, and Xanthomonadales. In addition, the greenhouse pot experiments demonstrated that bulk soil microbiota significantly influenced the rhizosphere and endosphere communities and also regulated the RBSDV-mediated variation of rhizosphere bacterial communities.ConclusionsOverall, this study reveals unprecedented spatiotemporal dynamics in rhizosphere bacterial communities triggered by RBSDV infection with potential implications for disease intermittent outbreaks. The finding has promising implications for future studies exploring virus-mediated plant-microbiome interactions.2AL1xEb7k2nunVBmbuNCsVVideo

Foliar iodine application: a strategy for tomato biofortification and yield optimization

Iodine (I) is a beneficial micronutrient for crop plants and essential for human health, yet approximately two billion people worldwide suffer from I deficiency, resulting in significant health issues. Agricultural soils often lack sufficient I, resulting in crops with low I content. However, tomatoes have shown potential to accumulate I when supplemented externally, making them an ideal candidate for I biofortification, particularly as an alternative to iodized salt for individuals on low-sodium diets. This two-year greenhouse pot experiment evaluated the effectiveness of foliar application of potassium iodide (KI) in biofortifying two commercial tomato hybrids. Different concentrations of I (0, 1, 3, 6, and 9 mM/plant) were applied as foliar treatments to assess their effects on physiological parameters, yield attributes, and quality traits, especially I enrichment in tomato fruit. The results demonstrated that foliar application of KI significantly increased fruit I contents at concentrations that also promoted overall plant growth and development. These findings underscored the efficient translocation of I through the phloem in tomatoes. I enrichment in tomato fruits ranged up to 5.27 mg/kg, exceeding the recommended daily allowance (RDA) of 150 μg/day. Even lower doses of 1–3 mM KI were effective in achieving significant I enrichment suitable for biofortification programs. In conclusion, tomato emerged as an excellent candidate for agronomic biofortification with I due to the practicality, and affordability of foliar application. The study highlights the potential of foliar I application as a feasible strategy for addressing global I deficiency, emphasizing its suitability for widespread adoption by farmers.

Identification and Antagonistic Potential of Bacillus atrophaeus against Wheat Crown Rot Caused by Fusarium pseudograminearum

Fusarium pseudograminearum (Fpg) is a significant pathogen responsible for fusarium crown rot (FCR) in wheat (Triticum aestivum L.), a disease with devastating impacts on crop yield. The utilization of biocontrol bacteria to combat fungal diseases in plants is a cost-effective, eco-friendly, and sustainable strategy. In this trial, an endophytic bacterial species, designated as SW, was isolated from the roots of wheat. The strain exhibited potent antagonistic effects against Fpg and reduced the FCR disease severity index by 76.07 ± 0.33% in a greenhouse pot trial. Here, 106 colony-forming units (CFUs)/mL of the SW strain was determined to be the minimum dose required to exhibit the antagonism against Fpg. The strain was identified as Bacillus atrophaeus using genome sequencing and comparison with type strains in the NCBI database. Whole-genome sequencing analysis revealed that SW harbors genes for siderophores, antifungal metabolites, and antibiotics, which are key contributors to its antagonistic activity. Additionally, the strain’s ability to utilize various carbon and nitrogen sources, successfully colonize wheat root tissues as an endophyte, and form biofilms are critical attributes for promoting plant growth. In summary, these findings demonstrate the ability of Bacillus atrophaeus to control FCR disease in wheat in a sustainable agricultural setting.

Sustainable crop fertilization by combining biogenic nano-hydroxyapatite and P solubilizing bacteria: Observations on barley

Nano-enabled agriculture involves researching smart nano-agrochemicals for sustainable farming. Nano-hydroxyapatite (nHAP), a phosphorus-rich compound, has the potential to be used as a fertilizer with reduced environmental impact. This study tests the effectiveness of nHAP produced from waste materials (animal bones) on barley plants (Hordeum vulgare). Two different nHAPs were prepared by thermal treatment of chicken bones at 300 °C and 700 °C (nHAP300 and nHAP700, respectively). The nanopowders were then tested in a seed toxicity trial and in a greenhouse pot experiment with barley, using Pseudomonas alloputida, a P-solubilizing bacterium (PSB). The treatments were unfertilized soil, conventional triple superphosphate (TSP), and the nHAP treatments alone. The results indicated that: (i) the nHAP materials had particle sizes of 1 micrometer (nHAP300, due to aggregation) and 50–70 nm (nHAP700), with P contents of 12.8 % and 19.6 %, respectively; (ii) no toxicity was observed on barley seeds, and nHAP300 at maximum dose stimulated root length by 45.6 % compared to the control; (iii) compared to conventional P fertilizer TSP, nHAP300 and nHAP700 stimulated root growth by 7 % and 18 %, respectively; (iv) the fraction of available P produced through nHAP300-PSB (40.6 mg kg−1) was higher than that from TSP (39.2 mg kg−1); (v) ions associated with the nHAP structure supplied supplementary nutrients, predominantly allocated in root tissues. This study provides valuable insights for future investigations to assess the implications of P nano-fertilizations in achieving sustainability in agriculture.

Discovering Novel Bioherbicides: The Impact of Hemp-derived Phytocannabinoid Applications on Zea mays L. and Relevant Weeds

In addition to competition, phytotoxic plant metabolites contribute to the weed-suppressing properties of cover crops, which could be the basis for the development of novel bioherbicides. We investigated the impact of five Cannabis sativa L. -derived neutral phytocannabinoids and an aqueous C. sativa tissue extract (HE) at six concentrations on the germination rate (GR) and seedling root length (RL) of Zea mays L., two monocotyledonous and two dicotyledonous weed species in laboratory Petri dish bioassays. Additionally, the effect of pre-emergence applications of HE, cannabidiol (CBD), and cannabidivarin (CBDV) formulations on GR and shoot dry matter (SDM) were examined in greenhouse pot studies. The effects of phytocannabinoids and HE were analyzed in dose-response curves. For the highest rates, the effects on GR, RL and SDM were calculated by ANOVA and HSD test (p < 0.05). HE exhibited the greatest suppression on GR and RL for all plant species in the Petri dish bioassay, with RGR, RL exceeding −90%. Phytocannabinoids reduced mainly RL of all plants and decreased the GR of most weed species. Effects varied among plants and phytocannabinoids, with CBDV and CBD showing similar high inhibitory effects on RL as HE in the Petri dish bioassay. All pre-emergence applications resulted in a positive RGR across all studied plants and in a positive RSDM in Z. mays and Echinochloa crus-galli (L.) P. Beauv, whereas in the other weed species the RSDM was negative. In conclusion, phytocannabinoids play a major role in weed suppression of HEs. CBDV and CBD are the most promising candidates for bioherbicide development especially against annual dicotyledonous weed species.

Invasive plant species support each other's growth in low-nutrient conditions but compete when nutrients are abundant.

Globally, numerous ecosystems have been co-invaded by multiple exotic plant species that can have competitive or facilitative interactions with each other and with native plants. Invaded ecosystems often exhibit spatial heterogeneity in soil moisture and nutrient levels, with some habitats having more nutrient-rich and moist soils than others. The stress-gradient hypothesis predicts that plants are likely to engage in facilitative interactions when growing in stressful environments, such as nutrient-deficient or water-deficient soils. In contrast, when resources are abundant, competitive interactions between plants should prevail. The invasional meltdown hypothesis proposes that facilitative interactions between invasive species can enhance their establishment and amplify their ecological impact. Considering both hypotheses can offer insights into the complex interactions among invasive and native plants across environmental gradients. However, experimental tests of the effects of soil moisture and nutrient co-limitation on interactions between invasive and native plants at both interspecific and intraspecific levels in light of these hypotheses are lacking. We performed a greenhouse pot experiment in which we cultivated individual focal plants from five congeneric pairs of invasive and native species. Each focal plant was subjected to one of three levels of plant-plant interactions: (1) intraspecific, in which the focal plant was grown with another individual of the same species; (2) interspecific, involving a native and an invasive plant; and (3) interspecific, involving two native or invasive individuals. These plant-plant interaction treatments were fully crossed with two levels of water availability (drought vs. well-watered) and two levels of nutrient supply (low vs. high). Consistent with the stress-gradient and invasional meltdown hypotheses, our findings show that under low-nutrient conditions, the biomass production of invasive focal plants was facilitated by invasive interspecific neighbors. However, under high-nutrient conditions, the biomass production of invasive focal plants was suppressed by invasive interspecific neighbors. When competing with native interspecific neighbors, high-nutrient conditions similarly enhanced the biomass production of both invasive and native focal plants. Invasive and native focal plants were neither competitively suppressed nor facilitated by conspecific neighbors. Taken together, these results suggest that co-occurring invasive exotic plant species may facilitate each other in low-nutrient habitats but compete in high-nutrient habitats.

Closely related species differ in their traits, but competition induces high intra-specific variability.

Theories explaining community assembly assume that biotic and abiotic filters sort species into communities based on the values of their traits and are thus based on between-species trait variability (BTV). Nevertheless, these filters act on individuals rather than on species. Consequently, the selection is also influenced by intraspecific trait variability (ITV) and its drivers. These drivers may be abiotic (e.g., water availability) or biotic (e.g., competition). Although closely related species should have similar traits, many of them coexist. We investigated the relative magnitudes of BTV and ITV in coexisting closely related species and how their individual traits differ under different drivers of ITV. We manipulated conditions in a greenhouse pot experiment with four common Carex species, where individuals of each species originated from four source localities. Individuals were grown in factorial combinations of two moisture levels, with and without a competitor (grass species Holcus lanatus, a frequent competitor). We analyzed the variability of six morphological traits on individuals in the greenhouse and three morphological traits in the source localities. Species identity was the main determinant of differences in most traits. Competition exerted a greater effect than water availability. For leaf dry matter content (LDMC) and vegetative height, competition's effect even exceeded the variability among species. On the contrary, for specific leaf area (SLA) and clonal spread, the interspecific differences exceeded ITV induced by experimental treatments. SLA measured in the greenhouse closely correlated with values measured in field populations, while LDMC did not. The variability caused by source locality of ramets in the greenhouse was small, although sometimes significant. Closely related species differ in their traits, but for some traits, ITV can exceed BTV. We can expect that ITV can modify the processes of community assembly, particularly among coexisting closely related species.

Suppression of Plastidial Glucan Phosphorylase (PHO1) Increases Drought Tolerance in Potato (Solanum tuberosum L.)

Glucan phosphorylase is present in plants in two isozymes, namely, a plastidial isoform (PHO1) and a cytosolic isoform (PHO2), and is involved in starch-related carbohydrate metabolism. The aim of this study was to determine whether mutations in the genes encoding glucan phosphorylase caused these plants to have increased resistance to short-term drought. One of the strategies plants use to defend themselves against drought stress is to change their starch content, which may be due to changes in glucan phosphorylase activity. In our greenhouse pot experiment, we used potato leaves from wild-type plants and transgenic mutant lines with reduced expression of genes encoding both PHO isozymes. The plants were exposed to drought or were grown under optimal conditions. A lack of water strongly affected the water saturation deficit (WSD) and leaf protein content. The activity of the plastidial glucan phosphorylase isoform (PHO1) in mutant plants increased under drought stress, in contrast to its activity in wild-type plants. After analyzing several physiological parameters, we found that suppressed expression of the gene encoding one of the subunits of plastidial glucan phosphorylase, PHO1a, resulted in increased tolerance to drought in potatoes.

Contrasting responses of naturalized alien and native plants to native soil biota and drought

Abstract Terrestrial plant communities often become invaded by alien species, which may benefit from high growth rates, strong phenotypic plasticity and reduced negative impacts from local soil communities. At the same time, terrestrial communities are increasingly more often exposed to periods of drought. However, how drought affects the competition between alien and native plants directly, and indirectly, through changing impacts of soil communities on plant performance, remains poorly understood. Here, we performed a greenhouse pot experiment in which we examined biomass responses of five native and five naturalized alien species (all occurring in mesic grasslands) to drought and benign soil moisture conditions, while growing in interspecific, intraspecific or absence of competition, in the presence or absence of native soil biota. We expected that alien plant species are less negatively affected by soil biota, but more negatively affected by drought than native species, and that drought indirectly weakens soil‐community‐driven competitive benefits of alien plant species over native ones. On average, soil‐community effects on plant biomass were positive, but native performance was less positively affected by soil communities than alien performance, suggesting reduced impacts of soil‐borne enemies on alien plants. Drought more negatively affected alien‐ than native plant performance. Drought impacts on plant biomass did not depend on soil community presence, but in the presence of soil biota, plants overall invested more in root biomass when exposed to drought. The effects of competition were subtle and species‐specific. To better understand the observed positive soil‐community effects on plant performance in our study, we examined mycorrhizal root colonization of plants grown in absence of competition. Among‐species variation in mycorrhizal colonization explained plant performance differences between soils with and without live soil communities, indicating a key role for arbuscular mycorrhizal fungi as driver of plant performance. However, mycorrhizal colonization did not differ between alien and native plants and was unaffected by drought. Overall, our study suggests that drought may weaken alien plant invasions through stronger direct negative impacts on alien than on native plant performance, but that drought does not affect soil‐biota‐driven differences in plant performance between alien and native plants. Read the free Plain Language Summary for this article on the Journal blog.

Chemometric analysis using infrared spectroscopy and PCA-LDA for early diagnosis of Fusarium oxysporum in tomato

AbstractThe interaction of phytopathogenic organisms and plants generates physiological and biochemical changes in the latter. However, the effects on the plants are rarely visible in the infection first stages. Novel optical techniques can help to improve the early detection of phytopathogenic organisms in tomato without the plant sacrifice. In this work, infrared spectroscopy and chemometric methods were used to determinate the effects of Fusarium oxysporum in tomato plants cultivated in pots, analyzing fully expanded leaves. Fusarium oxysporum was molecular identified and its pathogenicity was tested in vitro. Three plants treatments were evaluated for 55 days post infection in pots in greenhouse under semi-controlled conditions: control, water stress, and fungal inoculated (1 × 108 conidia/mL). Phenotypical results were followed twice a week for eight weeks; the phenotypical characteristics were very similar in almost all sampling times except in height, especially in the first 27 days post infection, after this time the height was similar in the three treatments. The stalk and root-dried matter analysis do not show statistical differences; however, the infrared results, acquired from the adaxial surface of leaves, show differences in peaks associated with salicylic acid, jasmonic acid, abscisic acid, and proline in the first 27 days post infection. The principal component analysis–linear discriminant analysis were used to distinguish subtle biochemical changes between the three treatments, facilitating the early detection of the pathogen and its monitoring over time.

Enhancing stress resilience in soybeans (Glycine max): assessing the efficacy of priming and cross-priming for mitigating water deficit and waterlogging effects.

Priming enables plants to respond more promptly, minimise damage, and survive subsequent stress events. Here, we aimed to assess the efficacy of priming and cross-priming in mitigating the stress caused by waterlogging and/or dehydration in soybeans (Glycine max ). Soybean plants were cultivated in a greenhouse in plastic pots in which soil moisture was maintained at pot capacity through irrigation. The first stress was applied in plants at the vegetative stage for 5days and involved either dehydration or waterlogging, depending on the treatment. Subsequently, the plants were irrigated or drained and maintained at pot capacity until the second stress. For the second stress, the conditions were repeated in plants at the reproductive stage. We then evaluated the levels of hydrogen peroxide (H2 O2 ), lipid peroxidation, total soluble sugars (TSS), amino acids, proline, and starch, and the activity of antioxidant, fermentative, and aminotransferase enzymes. Under waterlogging and dehydration, priming and cross-priming significantly increased the activity of antioxidant enzymes and the levels of TSS, amino acids, and proline while reducing H2 O2 concentration and lipid peroxidation. Under waterlogging, priming suppressed fermentative activity and increased carbohydrate content. This demonstrates that soybean plants activate their defence systems more promptly when subjected to priming.

Control efficacy and joint toxicity of broflanilide mixed with commercial insecticides to an underground pest, the black cutworm in highland barley.

The highland barley, Hordeum vulgare L., is a staple food crop with superior nutritional functions in Xizang, China. It is often damaged by the black cutworm, Agrotis ipsilon (Hufnagel), which is an underground pest and difficult to effectively manage. To introduce a novel insecticide with unique mode of action, broflanilide (BFL) and its binary mixtures with chlorantraniliprole (CAP), fluxametamide, β-cypermethrin or imidacloprid were screened out as seed treatment to control black cutworm in highland barley in the present study. In the laboratory bioassays, BFL had outstanding insecticidal activity to black cutworm with a median lethal dose (LD50) of 0.07 mg kg-1. The mixture of BFL × CAP at the concentration ratio of 7:40 exhibited the highest synergistic effect with a co-toxicity coefficient of 280.48. In the greenhouse pot experiments, BFL and BFL × CAP seed treatments at 8 g a.i. kg-1 seed could effectively control black cutworm, with a low percentage of injured seedlings <20% and high control efficacies of 93.33-100% during a period of 3-12 days after seed emergence. Moreover, BFL and BFL × CAP seed treatments could promote the seed germination and seedling growth of highland barley at the tested temperatures of 15, 20 and 25 °C. Our results indicated that BFL and BFL × CAP were effective and promising insecticides as seed treatment to control black cutworm in highland barley. © 2024 Society of Chemical Industry.

Effective and green in-situ remediation strategies based on TEMPO-nanocellulose/lignin/MIL-100(Fe) hydrogel nanocomposite adsorbent for lead and copper in agricultural soils

Hydrogel adsorbents are promising tools for reducing heavy metals' bioavailability in contaminated soil. However, their practical feasibility remains limited by the low stability, inefficient removal efficiency, and potential secondary pollution. Optimizing the adsorption operation and the functional properties of hydrogel adsorbents could eliminate this method's drawbacks. Herein, three innovative in-situ remediation strategies for Pb/Cu-contaminated soil were adopted based on the concept of novel TEMPO-cellulose (TO-NFCs)/lignin/acrylamide@MIL-100(Fe) nanocomposite hydrogel adsorbent (NCLMH). Characteristic analyses revealed ideal Pb/Cu adsorption mechanisms by swelling, complexation, electrical attraction, and ion exchange via carboxyl/hydroxyl/carbonyl groups and unsaturated Fe(III) sites on ANCMH besides FeOOH formation. The highest maximum theoretical adsorption capacities of Pb(II) and Cu(II) on ANCMH were 416.39 and 133.98 mg/g, under pH 6.5, governed by pseudo-second-order/Freundlich models. Greenhouse pot experiments with contaminated soils amended with two-depth layers of 0.5% NCLMHs (SA@NCLMH) displayed a decline in Pb and Cu bioavailability up to 85.9% and 74.5% within 45 d. Soil column studies simulating continuous water soil flushing coupled with NCLMH layers, instead of conventional extractant fluids, and connected to NCLMH-sand column as purification unit (CF@NCLMH) achieved higher removal rates for Pb, and Cu of 89.5% and 77.2% within 24 h. Alternatively, conducting multiple-pulse soil flushing mode (MF@NCLMH) gained the highest Pb and Cu removal of 96.5% and 85.4%, as the water flushing-stop flux events allowed adequate water movement/residence period, promoting Pb/Cu desorption-adsorption from soil to NCLMH. Also, the NCLMH-sand column conducting and easy separation of the stable/reusable NCLMHs prevented the potential secondary pollution. Interestingly, the three remediated soils reached the corresponding regulation of the permissible limits for Pb and Cu residential scenarios in medium-to-heavily agricultural polluted soils, alleviating the Pb/Cu bioaccumulation and phytotoxicity symptoms in cultivated wheat, especially after MF@NCLMH treatment. This study introduces promising alternative remediation strategies with high sustainability and feasibility in acidic-to-neutral heavy metal-contaminated agricultural soil.

Isolation and Characterization of Potassium-Solubilizing Rhizobacteria (KSR) Promoting Cotton Growth in Saline-Sodic Regions.

Cotton is highly sensitive to potassium, and Xinjiang, China's leading cotton-producing region, faces a severe challenge due to reduced soil potassium availability. Biofertilizers, particularly potassium-solubilizing rhizobacteria (KSR), convert insoluble potassium into plant-usable forms, offering a sustainable solution for evergreen agriculture. This study isolated and characterized KSR from cotton, elucidated their potassium solubilization mechanisms, and evaluated the effects of inoculating KSR strains on cotton seedlings. Twenty-three KSR strains were isolated from cotton rhizosphere soil using modified Aleksandrov medium. Their solubilizing capacities were assessed in a liquid medium. Strain A10 exhibited the highest potassium solubilization capacity (21.8 ppm) by secreting organic acids such as lactic, citric, acetic, and succinic acid, lowering the pH and facilitating potassium release. A growth curve analysis and potassium solubilization tests of A10 under alkali stress showed its vigorous growth and maintained solubilization ability at pH 8-9, with significant inhibition at pH 10. Furthermore, 16S rRNA sequencing identified strain A10 as Pseudomonas aeruginosa. Greenhouse pot experiments showed that inoculating cotton plants with strain A10 significantly increased plant height and promoted root growth. This inoculation also enhanced dry biomass accumulation in both the aerial parts and root systems of the plants, while reducing the root-shoot ratio. These results suggest that Pseudomonas aeruginosa A10 has potential as a biofertilizer, offering a new strategy for sustainable agriculture.