Germination Of Plants Research Articles

Оценка применимости почвогрунтов, произведённых из твёрдых отходов для выращивания лекарственных растений

The production of artificial soils – products of solid-phase fermentation of municipal solid waste – is one of the main areas of processing waste from megacities containing organic substances and is a “green” alternative to their incineration or burial. The possibility of using products of solid-phase fermentation of waste for growing medicinal plants was studied using the examples of mountain savory (Satureja montana L.), common basil (Ocimum basilikum L.), marshmallow (Althaea officinalis L.), oregano (Origanum vulgare L.). It was revealed that the optimal germination of plants occurs on the artificial soils “Klasmann Substrates Select” and “Grunt ECO” and it is comparable to the control soil of field crop rotation.The changes in the biochemical parameters of plants (enzyme activity, chlorophyll content) grown on soils under normal conditions, under the influence of heavy metals and at low temperatures are shown. High chlorophyll content was noted in all studied plants, however, in mountain savory grown on the “Veltorf” substrate, destructive phenomena were revealed, expressed in a decrease in the content of chlorophyll a with a simultaneous increase in the content of chlorophyll b. The activity of catalase and acid phosphatase enzymes in the studied plants is within normal limits. The effect of unfavorable factors – low temperature and heavy metals – leads to an increase in enzyme activity, which is a sign of the formation of adaptation. When assessing the germination of plants of various species and their biochemical parameters, it was found that the domestic soil of the Grunt ECO company is optimal for growing medicinal plants and can be used for medicinal plant growing purposes.

Allelopathic interactions of brown mustard (Brassica juncea L.) with other aromatic plants during germination and seedling development

Organic compounds originating from plant metabolism and reaching the environment may inhibit or stimulate germination and early developmental processes of other plants grown in the vicinity. The aim of this study was to investigate the allelopathic interactions of brown mustard with four other aromatic plants (summer savoury, coriander, caraway and common sage). While health-promoting metabolites of brown mustard are thoroughly investigated and the plant receives an increasing interest from cultivators of aromatic and medicinal plants, its allelopathic interactions with other aromatic plants are poorly documented. The experiments were performed in closed germination vessels, under controlled conditions. The influence of the presence or absence of light, as well as of a sufficient or reduced water supply on the co-germination of brown mustard seeds with each of the other four aromatic plants was also evaluated. The presence of brown mustard reduced the germination velocity of caraway, coriander, sage and savoury. It inhibited stem elongation, but stimulated root growth of savoury. Shoot growth of coriander seedlings was enhanced by the vicinity of brown mustard plantlets. Caraway slowed down the germination of brown mustard seeds, but it stimulated root and stem elongation of the seedlings. The presence of savoury enhanced the fresh biomass production of brown mustard. Common sage inhibited root growth, but stimulated stem elongation of brown mustard plantlets. Most of the allelopathic effects were more pronounced under water shortage than under sufficient water supply. Positive interspecific influences on biomass production were, in most cases, more pronounced in the presence of light. The findings may contribute to optimization of brown mustard cultivation in small parcels, in the vicinity of other aromatic plants, some allelopathic interactions being able to stimulate growth and developmental processes in an environmental-friendly and cost-effective manner.

Ultra-fast mass spectrometry for plant biochemistry: proteomics response of winter wheat to iron pre-sowing treatment

In recent years, ultrafast chromatography-mass spectrometry profiling of proteomes has been actively developed for biochemical studies. These methods are intended for fast/rapid monitoring of cell response to a biotic stimulus, correlation of molecular changes with biological processes and phenotype changes. To increase agricultural production, new biotechnologies are being introduced, including the use of nanomaterials. At the same time, thorough testing of new fertilizers and investigation of mechanisms of biotic effects on the germination, growth, and development of plants are required. The aim of this work was to adapt the method of ultrafast chromatography and mass spectrometry for rapid quantitative profiling of molecular changes in 7-day-old wheat seedlings that occur in response to pre-sowing seed treatment with iron compounds. The experimental method is capable of analyzing up to 200 samples per day; its practical value lies in carrying out the proteomic express diagnostics of the biotic action of new treatments, including those for agricultural needs. The regulation of photosynthesis, biosynthesis of chlorophyll, porphyrin- and tetrapyrrole-containing compounds, glycolysis in shoot tissues, and polysaccharide metabolism in root tissues were shown after seed treatments with suspensions containing a polymeric film former (PEG-400, Na-CMC, Na2-EDTA), iron (II, III) nanoparticles or iron (II) sulfate. Observations at the protein level were consistent with the results of morphometry, measurements of superoxide dismutase activity and microelement analysis of 3-day-old germinated seeds and shoots and roots of 7-day-old seedlings. A characteristic molecular signature has been proposed to determine the regulation of photosynthesis and glycolytic process at the protein level. Such a signature is considered as a potential marker of the biotic effect of seed treatment with iron compounds and will be confirmed by further studies.

Gibberellin-Producing Bacteria Isolated from Coastal Soil Enhance Seed Germination of Mallow and Broccoli Plants under Saline Conditions.

Salinity hinders plant growth, posing a substantial challenge to sustainable agricultural yield maintenance. The application of plant growth-promoting rhizobacteria (PGPR) offers an emerging strategy to mitigate the detrimental effects of high salinity levels. This study aimed to isolate and identify gibberellin-producing bacteria and their impact on the seed germination of Malva verticillata (mallow) and Brassica oleracea var. italica (broccoli) under salt stress. In this study, seven bacterial isolates (KW01, KW02, KW03, KW04, KW05, KW06, and KW07) were used to assess their capacity for producing various growth-promoting traits and their tolerance to varying amounts of salinity (100 mM and 150 Mm NaCl). The findings revealed that KW05 and KW07 isolates outperformed other isolates in synthesizing indole-3-acetic acid, siderophores, and exopolysaccharides and in solubilizing phosphates. These isolates also enhanced phosphatase activity and antioxidant levels, including superoxide dismutase and catalase. Both KW05 and KW07 isolate highlight the growth-promoting effects of gibberellin by enhancing of growth parameters of Waito-C rice. Further, gas chromatography-mass spectrometry validation confirmed the ability of KW05 and KW07 to produce gibberellins (GAs), including GA1, GA3, GA4, and GA7. Seed germination metrics were enhanced due to the inoculation of KW05 and KW07. Moreover, inoculation with KW05 increased the fresh weight (FW) (7.82%) and total length (38.61%) of mallow under salt stress. Inoculation with KW07 increased the FW (32.04%) and shoot length of mallow under salt stress. A single inoculation of these two isolates increased broccoli plants' FW and shoot length under salt stress. Gibberellin-producing bacteria helps in plant growth promotion by improving salt tolerance by stimulating root elongation and facilitating enhanced absorption of water and nutrient uptake in salty environments. Based on these findings, they can play a role in boosting agricultural yield in salt-affected areas, which would help to ensure the long-term viability of agriculture in coastal regions.

Agro-industrial by-products as alternative additives for the agronomic valorization of pig slurry through pH modification

The use of animal slurry in modern agricultural systems is receiving considerable attention, mainly due to the latest increase in chemical fertilizer prices. However, the use of raw animal slurry to fertilize horticultural crops can, on the one hand, lead to significant ammonia emissions and, on the other hand, be an important source of zoonotic pathogens. Therefore, proper treatment is required. The present study explored the modification of the pH value of pig slurry using by-products from different agro-industrial activities as a strategy to control these two problems. Three approaches were used, namely acidification and biological acidification (bio-acidification) to pH 5 and alkalization to pH 9.5. The most promising of the 14 different additives and additive combinations initially considered should be able to reach the target pH at a dose of less than 20% (m/m). The presence of Salmonella and the number of Escherichia coli colony forming units (CFU) were evaluated in the slurry for each selected treatment. To ensure that treated slurry remains of interest as an organic fertilizer, the impact of treated slurry on plant germination and nitrogen (N) availability was also assessed. The by-products from the brewing and yeast industry failed to reduce the pH to 5. In fact, the bio-acidification of pig slurry was only possible with additives rich in carbon. Although slurry sanitization (<1000 CFU E.coli g−1 slurry) was not guaranteed by all treatments, a reduction in E.coli numbers was observed with all additives. The ammonium content of the treated slurry was significantly reduced (up to 20%) with treatments involving bio-acidification. N mineralization was evidenced for all additives used for slurry alkalinization but no N mineralization was observed when using acidification with H2SO4 or by-product spent acid. The phytotoxicity bioassay showed that most additives do not have a negative impact on germination. The results presented here suggest that agro-industrial by-products are capable of modifying the pH of pig slurry. Depending on the pH modification strategy and additive used, treated slurry may be safer and of higher fertilizing value than untreated (raw) slurry.

Waste feather keratin composited geopolymer hydrogels for improving plant water retention and N nutrients utilization

To improve cyclic utilization of waste feather resources and enhance the efficiency of crop fertilizer, a novel superabsorbent slow-release hydrogels were prepared by feather keratin (FK), diatomite geopolymer (DG), urea and acrylic acid (AA) with thiol−ene click reaction and in-situ polymerization, which afforded FK composited DG polymer hydrogels containing urea (Urea@FK/DG-HGs). After characterizing structure and microscopic morphology, its swelling capacity, water retention and slow-release behavior were investigated. The obtained Urea@FK/DG-HGs presented good swelling, cyclic stability, foliar adhesion, water retention and slow-release properties. The swelling ratios got to 666.67 g/g in distilled water and 107.53 g/g in the saline solution (0.9% NaCl), respectively. The swelling rate was still 209.9 g/g after recycling 8 times. It enhanced the water retention performance of the soil and prolonged nutrients release, which the cumulative release of urea was 34.8% after 45 days, and the release behavior was belong to Fickian diffusion. Furthermore, the obtained Urea@FK/DG-HGs was used in agricultural applications to improve plant growth and proved to have a promotional effect on the germination and growth of holly seeds. In summary, it was an effective strategy for re-utilization of agricultural waste by adding waste feathers keratin into slow-release hydrogel. And the obtained multifunctional materials (Urea@FK/DG-HGs) with excellent water retention, slow-release and promotion of plant germination, has great application potential in agriculture industry.

Influence of temperature and variety on seed germination of soybean (Glycine max L. Merr) at different germination times

Seed germination is an important stage in crop development that affects plant performance, crop yield, and quality. Many factors influence seed germination, and one of the most important factors is temperature. The closer the temperature is to the optimum, the faster germination will occur. Temperature affects seed germination in various plants and varies depending on the variety. Therefore, the effect of temperature on seed germination is necessary to investigate, also for soybean varieties. Soybean is one of the world's most valuable oil-seed crops. Generally, proper seedling establishment and germination of soybean seeds are crucial processes in the survival and growth cycle of the crop. Thus, a study was done to investigate the influence of temperature and variety on soybean seed germination at different times after sowing. The experiment was carried out at the Institute of Agronomy, Hungarian University of Agriculture and Life Sciences (MATE), Crop Production Laboratory. Seeds of two soybean varieties were subjected to three different temperatures: 15, 25, and 35 °C, and two soybean varieties, Martina and Johanna were tested. There were four germination times based on the days after sowing: Days 3, 5, 7, and 9. This experiment was set up with a completely randomized block design and four replications. According to the findings of this study, the Martina variety showed a better germination rate as well as higher vigor and viability than the Johanna variety in the first 12 days after sowing. At temperatures of 15 °C and 25 °C, both varieties achieved comparable percentages of viability, but they were more vigorous at 25 °C due to better total seedling length. Thus, the information gained from this study will indirectly determine and confirm the proper temperature for the initial growth of the Martina and Johanna varieties.

Water depth influences survival and predator-specific patterns of nest loss in three secretive marsh bird species.

Wetlands have become increasingly rare in the United States, negatively influencing wetland-dependent birds, and many remaining wetlands are intensively managed through seasonal dewatering mimicking historic flood pulses during spring and summer. However, water around nests may provide protection from terrestrial predators, and lowering water levels during the breeding season of wetland birds may increase predation risk and exacerbate marsh bird population declines. Understanding interactions between water depth, nesting marsh birds, and nest predators is critical to aid managers in developing a multi-species management approach in emergent wetlands. During the 2020 and 2021 breeding seasons, we examined nest survival of 148 marsh bird nests (American Coot, Fulica americana, n = 1; Common Gallinule, Gallinula galeata, n = 64; and Least Bittern; Ixobrychus exilis, n = 83) and installed cameras at 78 nests to identify predators at a large, restored floodplain wetland in Illinois where the primary management technique is seasonal water removal to stimulate germination of moist soil plants. We found nest predation of, and abandonment by, Least Bittern and Common Gallinule were related to shallower water, and early season, high volume dewatering. Least Bitterns nested more commonly along wetland edges and nests farther from the shore were more likely to survive. Similarly, we found mammalian depredation of nests and nest abandonment decreased when deeper water was present around nests. Alternatively, snake predation was observed earlier in the year prior to water removal from inundated emergent vegetation. Our results demonstrate water depth may be an important deterrent of nest predators, especially mammals, during the breeding season. Further, we recommend managers delay dewatering until after the nesting season at sites where management for conservation-priority marsh birds is a focus.

The effect of vermicompost and K+amino on the winter rape growth

Vermicompost contains a high concentration of macro- and micronutrients, vitamins, growth hormones, enzymes such as proteases, amylases, lipases, cellulases, and chitinases, as well as immobilized microflora. Vermicompost improves plant germination, growth, biomass, and yield. K+amino is a biologically active liquid soil amendment that is suitable for organic gardens of all types. It is a 100 % veganic growth- and health-promoting liquid microbial inoculant for all plant types, particularly fast-growing crops like vegetables, fruits, and blooms. The purpose of investigation was to look the effect of vermicompost and k+amino on the winter rape germination and growth. Methods: There were six treatments: 1. A rape (means a rape crop in Aru Agricultural Ltd. soil), 2. A rape+YaraBela AXAN 0.3g per pot, 3. A rape+vermicompost 7.9 g per pot in the soil+the vermiextract is sprayed on the plants 1 week after sowing, 2 weeks after sowing, both treatments 1:30, 33 ml extract per 1 L water, 4. A rape+vermicompost 7.9 g per pot in the soil, 5. A rape+vermiextract is sprayed on the plants 1 week after sowing, 2 weeks after sowing, both treatments 1:30, 33 ml extract per 1 L water, 6. A rape+K+Amino biostimulator is sprayed on the plants 1 week after sowing, 2 weeks after sowing, both treatments 5 ml K+Amino per 1 L water. Results: Rape plants were elongated in treatment with YaraBela AXAN. Stem diameter was largest in K+Amino treatment. Root length was lowest in treatment with vermicompst extract (soil was too moisty and compacted). Conclusions: Vermicompost tended to improve plant growth, while stem diameter was largely increased by using k+amino fertilizer. It turns out both actually are good sources of mineral nutrients and also different enzymes and microbes, which help plants grow

Macromolecular Size and Architecture of Humic Substances Used in the Dyes’ Adsorptive Removal from Water and Soil

Humic substances are naturally occurring materials composed of complex biogenic mixtures of substituted aromatic and aliphatic hydrocarbon core materials derived from the degradation and decomposition of dead plant and animal matter. They are ubiquitous in both terrestrial and aquatic systems constituting biotic pools and are characterized by unique properties; they are amphiphilic redox compounds with exceptional chelating features. Humic substances play a crucial role in both agriculture and the environment as carbon sequestrators, soil improvers, plant health promoters, as well as stabilizers of soil aggregates and regulators of organic/inorganic nutrients bioavailability. This review article attempts to summarize current knowledge about the molecular nature and characterization techniques employed for the study of humic substances worldwide as the chemistry of their components differs markedly and depends on natural processes, several abiotic and biotic factors, the origin of the organic matter, and their complexation with inorganic, e.g., metal-ion, compounds. This work is equally concerned with the association of humic substances with dyes, a notorious pollutant, responsible for various environmental issues generally arising from the discharge of untreated effluents into soils and water bodies. Azo dyes, in particular, negatively affect soil microbial communities, as well as plant germination and growth. The aim is to feature the potential contribution of humic substances as novel materials for environment-friendly and sustainable processes.

Introducing Autochthonous Bacterium and Fungus Composition to Enhance the Phytopathogen-Suppressive Capacity of Composts against Clonostachys rosea, Penicillium solitum and Alternaria alternata In Vitro

Given their numerous positive characteristics, composts are widely used agriculturally in sustainable development and resource-saving technologies. The management of phytopathogen-suppressive potential and the fertilizing capacity of composts are of great interest. This study examines the impact of introducing the autochthonous compost species Bacillus subtilis, B. amyloliquefaciens, Pseudomonas aeruginosa, and Aspergillus corrugatus, both individually and in combination, to composts containing dry matter comprising 36% solid compost and 7% compost suspensions to study their phytopathogen-suppressive and phytostimulation activity. The test phytopathogens were Clonostachys rosea, Penicillium solitum, and Alternaria alternata. This is the first report on compost’s potential to biologically control C. rosea and P. solitum. Classical microbiological and molecular biological methods were used to evaluate the survival rate of microorganisms in compost and validate these results. Test plant (Raphanus sativus) germination indexes were determined to evaluate the phytotoxic/phytostimulation effects of the substrates. To assess the effectiveness of biocontrol, mycelial growth inhibition was measured using in vitro tests. The introduction of composition increased the composts’ fertilizing properties by up to 35% and improved antagonistic activity by up to 91.7%. Autochthonous bacterial–fungal composition can promote resistance to fungal root and foliar phytopathogens and raise the fertilizing quality of compost.

EFFECTS OF TIO2 NANO-PRIMING ON TOMATO SEED GERMINATION AND PLANT DEVELOPMENT

The effect of nano-TiO2 on seed germination and plant development as a priming agent has not been thoroughly studied. This study aimed to evaluate the effect of TiO2 nano-priming on seed germination, plant growth and yield of tomato plants relying on experiments that have been conducted both under laboratory and greenhouse conditions. During the laboratory experiments, the seed germination, seed vigor index and water uptake of seeds were determined after 5, 10, 50 and 100 mg L-1 of TiO2 nano-priming while hydropriming was used as control. The biomass of tomato seedling was increased the most for the 10 mg L-1 TiO2 nano-priming condition. With follow-up experiments, the effect of 10 mg L-1 TiO2 nano-priming was investigated further under greenhouse conditions, where hydropriming was also used as control. The physiological traits of tomato plants, like chlorophyll content, stomatal conductance and transpiration rate were increased by TiO2 nano-priming treatment. Although the photosynthesis rate was boosted by nano-priming, the yield was not affected. The application of 10 mg L-1 TiO2 as nano-priming agent increased plant development and chlorophyll content under both laboratory and greenhouse conditions without translocation in the plant, which is one of the most important concerts of using nanoparticles in plant production. Key words: Nano-priming, priming, TiO2, tomato, seed

Promotion of Ca2+ Accumulation in Roots by Exogenous Brassinosteroids as a Key Mechanism for Their Enhancement of Plant Salt Tolerance: A Meta-Analysis and Systematic Review.

Brassinosteroids (BRs), the sixth major phytohormone, can regulate plant salt tolerance. Many studies have been conducted to investigate the effects of BRs on plant salt tolerance, generating a large amount of research data. However, a meta-analysis on regulating plant salt tolerance by BRs has not been reported. Therefore, this study conducted a meta-analysis of 132 studies to elucidate the most critical physiological mechanisms by which BRs regulate salt tolerance in plants from a higher dimension and analyze the best ways to apply BRs. The results showed that exogenous BRs significantly increased germination, plant height, root length, and biomass (total dry weight was the largest) of plants under salt stress. There was no significant difference between seed soaking and foliar spraying. However, the medium method (germination stage) and stem application (seedling stage) may be more effective in improving plant salt tolerance. BRs only inhibit germination in Solanaceae. BRs (2 μM), seed soaking for 12 h, and simultaneous treatment with salt stress had the highest germination rate. At the seedling stage, the activity of Brassinolide (C28H48O6) was higher than that of Homobrassinolide (C29H50O6), and post-treatment, BRs (0.02 μM) was the best solution. BRs are unsuitable for use in the germination stage when Sodium chloride is below 100 mM, and the effect is also weakest in the seedling stage. Exogenous BRs promoted photosynthesis, and antioxidant enzyme activity increased the accumulation of osmoregulatory and antioxidant substances and reduced the content of harmful substances and Na+, thus reducing cell damage and improving plant salt tolerance. BRs induced the most soluble protein, chlorophyll a, stomatal conductance, net photosynthetic rate, Glutathione peroxidase, and root-Ca2+, with BRs causing Ca2+ signals in roots probably constituting the most important reason for improving salt tolerance. BRs first promoted the accumulation of Ca2+ in roots, which increased the content of the above vital substances and enzyme activities through the Ca2+ signaling pathway, improving plant salt tolerance.

Long term impacts of endozoochory and salinity on germination of wetland plants after entering simulated seed banks.

Migratory waterbirds disperse a broad range of angiosperms by endozoochory (seed dispersal via gut passage), especially plants in coastal wetlands. However, there is no previous information about the capacity of seeds to remain in the seed bank after waterbird endozoochory, and very little about how wetland salinity can influence the effect of gut passage on germination. We collected seeds of Juncus subulatus (Juncaceae), Bolboschoenus maritimus, and Schoenoplectus litoralis (Cyperaceae) from Doñana marshes in Spain. All three species are considered to have physiological dormancy. After gut passage following ingestion by ducks, seeds were stored in darkness in solutions with six different conductivities (1, 2, 4, 8, 16, and 32 dSm-1), for periods of 1, 6, or 12 months to simulate presence in a seed bank. After storage, 1800 seeds of each plant species assigned to these treatments were subjected to germination tests in demineralized water, together with 1800 control seeds that had not been ingested before storage. All species germinated readily after storage, with or without gut passage beforehand. Storage time and salinity both had important effects on germinability and time to germination, which differed between control and ingested seeds, and between plant species. After ≥6 months, germinability of Cyperaceae was enhanced by gut passage (≤25% higher than control seeds) at some salinities. Only J. subulatus showed consistently lower germinability after passage (≤30%). Only B. maritimus showed consistently slower germination after passage (≤33%). Salinity effects were more complex after passage, but increasing salinity did not generally have a negative impact on germination of ingested seeds. When compared to additional seeds that had not been stored before germination tests, storage reduced germinability in J. subulatus (≤39% reduction), but increased it in B. maritimus (≤17%) and S. litoralis (≤46%). Seeds dispersed by waterbird endozoochory may be easily incorporated into wetland seed banks, where they can remain halotolerant and delay germination until conditions become suitable. This can benefit wetland plants by increasing rates of long-distance dispersal, gene flow, and establishment of new populations. Avian gut passage can have positive and species-specific effects on germination in plants with persistent seed banks and/or physiological dormancy.

Persistent free radicals generated from a range of biochars and their physiological effects on wheat seedlings

Biochar is a promising soil conditioner and environmental remediation material. However, the amount, type, and environmental effect and risk of persistent free radicals (PFRs) associated with biochar need to be better understood. Thus, this study characterized PFRs in a range of biochar types and their effects on the growth and oxidative stress of wheat seedlings. Among the biochars prepared by pyrolysis of different types of biomass at 500 °C, the concentrations of PFRs in cow dung and egg shell biochar were the highest and the lowest, respectively. They both increased with artificial weathering treatment but decreased with aging. The dominant types of biochar PFRs were transformed from carbon-centered to oxygen and carbon/oxygen-centered free radicals with weathering. The amount and type of biochar PFRs in mixtures of biochar and soil varied with soil type and biochar dose. After 30 d incubation in different soil-biochar mixtures, measures of wheat plant germination and growth and antioxidant enzyme activity showed increases at lower biochar doses but decreases at higher doses. Catalase activity was 38.1 % greater at 20 g·kg−1 biochar dosage and 25.2 % less at 80 g·kg−1 dosage, on average. In contrast, leaf malondialdehyde content and staining by Evans Blue, both indicators of plant cell membrane damage, generally increased with increasing biochar dosages. Finally, soil hydrolase enzyme activity also displayed an inverted U-shaped dose response. The toxicity indicators showed an increasing trend with higher PFR concentrations in the soil-biochar combinations. While these findings provide evidence for significant potential agricultural and ecological risks associated with the application of biochar due to PFRs damage, it also points to ways that these risks could be mediated such as through biochar dosage restrictions and pre-aging. This study provides new insights into the potential toxicological mechanism and ecological risks associated with the application of biochar in agricultural and environmental settings.

Bet Hedging Is Not Sufficient to Explain Germination Patterns of a Winter Annual Plant.

AbstractBet hedging consists of life history strategies that buffer against environmental variability by trading off immediate and long-term fitness. Delayed germination in annual plants is a classic example of bet hedging and is often invoked to explain low germination fractions. We examined whether bet hedging explains low and variable germination fractions among 20 populations of the winter annual plant Clarkia xantiana ssp. xantiana that experience substantial variation in reproductive success among years. Leveraging 15 years of demographic monitoring and 3 years of field germination experiments, we assessed the fitness consequences of seed banks and compared optimal germination fractions from a density-independent bet-hedging model to observed germination fractions. We did not find consistent evidence of bet hedging or the expected trade-off between arithmetic and geometric mean fitness, although delayed germination increased long-term fitness in 7 of 20 populations. Optimal germination fractions were two to five times higher than observed germination fractions, and among-population variation in germination fractions was not correlated with risks across the life cycle. Our comprehensive test suggests that bet hedging is not sufficient to explain the observed germination patterns. Understanding variation in germination strategies will likely require integrating bet hedging with complementary forces shaping the evolution of delayed germination.

Unveiling the complexity of strigolactones: exploring structural diversity, biosynthesis pathways, and signaling mechanisms.

Strigolactone is the collective name for compounds containing a butenolide as a part of their structure, first discovered as compounds that induce seed germination of root parasitic plants. They were later found to be rhizosphere signaling molecules that induce hyphal branching of arbuscular mycorrhizal fungi, and, finally, they emerged as a class of plant hormones. Strigolactones are found in root exudates, where they display a great variability in their chemical structure. Their structure varies among plant species, and multiple strigolactones can exist in one species. Over 30 strigolactones have been identified, yet the chemical structure of the strigolactone that functions as an endogenous hormone and is found in the above-ground parts of plants remains unknown. We discuss our current knowledge of the synthetic pathways of diverse strigolactones and their regulation, as well as recent progress in identifying strigolactones as plant hormones. Strigolactone is perceived by the DWARF14 (D14), receptor, an α/β hydrolase which originated by gene duplication of KARRIKIN INSENSITIVE 2 (KAI2). D14 and KAI2 signaling pathways are partially overlapping paralogous pathways. Progress in understanding the signaling mechanisms mediated by two α/β hydrolase receptors as well as remaining challenges in the field of strigolactone research are reviewed.

CRISPR gene editing to improve crop resistance to parasitic plants.

Parasitic plants pose a significant threat to global agriculture, causing substantial crop losses and hampering food security. In recent years, CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) gene-editing technology has emerged as a promising tool for developing resistance against various plant pathogens. Its application in combating parasitic plants, however, remains largely unexplored. This review aims to summarise current knowledge and research gaps in utilising CRISPR to develop resistance against parasitic plants. First, we outline recent improvements in CRISPR gene editing tools, and what has been used to combat various plant pathogens. To realise the immense potential of CRISPR, a greater understanding of the genetic basis underlying parasitic plant-host interactions is critical to identify suitable target genes for modification. Therefore, we discuss the intricate interactions between parasitic plants and their hosts, highlighting essential genes and molecular mechanisms involved in defence response and multilayer resistance. These include host resistance responses directly repressing parasitic plant germination or growth and indirectly influencing parasitic plant development via manipulating environmental factors. Finally, we evaluate CRISPR-mediated effectiveness and long-term implications for host resistance and crop improvement, including inducible resistance response and tissue-specific activity. In conclusion, this review highlights the challenges and opportunities CRISPR technology provides to combat parasitic plants and provides insights for future research directions to safeguard global agricultural productivity.

Plant mediated fabrication of silver nanoparticles, process optimization, and impact on tomato plant

Nanotechnology is one of the fastest-growing markets, but developing eco-friendly products, their maximum production, stability, and higher yield is a challenge. In this study, silver nanoparticles were synthesized using an easily available resource, leaves extract of the Neem (Azadirachta indica) plant, as a reducing and capping agent, determined their effect on germination and growth of tomato plants. The maximum production of silver nanoparticles was noted at 70 °C after 3 h of reaction time while treating the 10 ml leaf extract of Neem plant with 10 ml of 1 mM silver nitrate. The impact of the extract preparation method and solvent type on the plant mediated fabrication of silver nanoparticles was also investigated. The UV-spectrophotometric analysis confirmed the synthesis of silver nanoparticles and showed an absorption spectrum within Δ420–440 nm range. The size of the fabricated silver nanoparticles was 22–30 nm. The functional groups such as ethylene, amide, carbonyl, methoxy, alcohol, and phenol attached to stabilize the nanoparticles were observed using the FTIR technique. SEM, EDX, and XRD analyses were performed to study the physiochemical characteristics of synthesized nanoparticles. Silver nanoparticles increased the germination rate of tomato seeds up to 70% while decreasing the mean germination time compared to the control. Silver nanoparticles applied at varying concentrations significantly increased the shoot length (25 to 80%), root length (10 to 60%), and fresh biomass (10 to 80%) biomass of the tomato plant. The production of total chlorophyll, carotenoid, flavonoids, soluble sugar, and protein was significantly increased in tomato plants treated with 5 and 10 ppm silver nanoparticles compared to the control. Green synthesized silver nanoparticles are cost-effective and nontoxic and can be applied in agriculture, biomedical, and other fields.

The influence of Azadirachta indica extract on the initial development of lettuce, cabbage and chive

The allelopathic effects can be listed based on their frequency of occurrence, and the main effect is the capacity of suppress the germination of concurrent species. The main objective of this paper was to verify the allelopathic potential of the neem leaf aqueous extract on the germination of lettuce, cabbage and chive plants. The bioassay was conducted in a lab of the Science and Technology Federal Institute of Tocantins - campus Araguatins. The green leaves of neem were grinded in a blender with distilled water and then sieved, and extract solution was stored. The statistical design was completely randomized, with 5 treatments (0, 20, 50, 75 and 100%) and 4 repetitions. The data was submitted to variance analysis and mean comparison through the Scott Knott test with a 5% level of probability, using the software R. The neem leaves aqueous extract has shown higher allelopathic potentialities, affecting the germination speed rate in all the studied species, in the concentrations of 0 and 25%. It has also affected the roots development, mainly in the lettuce and chive plants. However, regarding the fresh matter and dry matter there was not any affect on the aqueous extract