Phytohormone Activity Research Articles

Increasing Application of Multifunctional Bacillus for Biocontrol of Pests and Diseases and Plant Growth Promotion: Lessons from Brazil

The microbial genus Bacillus inhabits a diverse range of environments and is widespread across all global biomes, with a significant presence in soil habitats. In agriculture, Bacillus strains play multifaceted roles, serving as biocontrol agents against pests and diseases, and promoting plant growth by facilitating nutrient availability and enhancing stress tolerance. Through mechanisms such as phosphate solubilization, ACC-deaminase activity, and synthesis of phytohormones and siderophores, Bacillus spp. contribute to soil health and crop productivity, in a new approach of regenerative agriculture. The ability of Bacillus spp. to solubilize phosphate makes essential nutrients more accessible to plants, while ACC-deaminase activity helps plants withstand environmental stresses. Additionally, the synthesis of phytohormones can stimulate plant growth and development, and siderophores may facilitate the uptake of nutrients such as iron by plants. As the agricultural industry embraces Bacillus-based formulations for pest management and crop enhancement, future research holds promising prospects for optimizing their applications and harnessing their full potential in agroecosystems. Continued exploration of Bacillus spp. diversity and their interactions with plants and soil microbiota will further advance sustainable agricultural practices. This review contributes to understanding how Bacillus strains can revolutionize agriculture by enhancing soil health, increasing crop productivity, and providing effective biological solutions against pests and diseases. The successful application of Bacillus-based technologies in millions of hectares in Brazilian agriculture demonstrates the synergy between the need for more sustainable agricultural practices and the use of bio-inputs.

Whole-Genome Sequencing and Analysis of Tumour-Forming Radish (Raphanus sativus L.) Line.

Spontaneous tumour formation in higher plants can occur in the absence of pathogen invasion, depending on the plant genotype. Spontaneous tumour formation on the taproots is consistently observed in certain inbred lines of radish (Raphanus sativus var. radicula Pers.). In this paper, using Oxford Nanopore and Illumina technologies, we have sequenced the genomes of two closely related radish inbred lines that differ in their ability to spontaneously form tumours. We identified a large number of single nucleotide variants (amino acid substitutions, insertions or deletions, SNVs) that are likely to be associated with the spontaneous tumour formation. Among the genes involved in the trait, we have identified those that regulate the cell cycle, meristem activity, gene expression, and metabolism and signalling of phytohormones. After identifying the SNVs, we performed Sanger sequencing of amplicons corresponding to SNV-containing regions to validate our results. We then checked for the presence of SNVs in other tumour lines of the radish genetic collection and found the ERF118 gene, which had the SNVs in the majority of tumour lines. Furthermore, we performed the identification of the CLAVATA3/ESR (CLE) and WUSCHEL (WOX) genes and, as a result, identified two unique radish CLE genes which probably encode proteins with multiple CLE domains. The results obtained provide a basis for investigating the mechanisms of plant tumour formation and also for future genetic and genomic studies of radish.

Zinc Nutrition in Rice Based Cropping Systems: A Comprehensive Review

Rice-based cropping systems being the most practiced cropping system in India, it suffers zinc deficiency as majority of the Indian soils are deficient in the Zn micronutrient. Zn is considered the fourth most important yield limiting nutrient of Agricultural crops. Apart from plant nutrition Zn also plays crucial role in human nutrition. Zn plays a vital role in the physiological function of plants and it is associated with phytohormone activity, protein synthesis and carbohydrate metabolism. To understand better zinc nutrition and its associated benefits from optimum nutrition and ways to manage Zn in rice-based cropping systems, the present review critically examines nutrient mobilization and transformation of Zn in rice-based cropping systems of India.

Transcriptome analysis suggests the role of expansin genes in the improved germination of sunflower (Helianthus annuus L.) seeds after hydropriming

AbstractSunflower (Helianthus annuus L.) is widely utilized for seed oil production. Priming seeds prior to sowing is a technique used to enhance the germination rate and uniformity of seedling growth. Priming times of 6 and 18 h were selected to be the optimal and extended durations, respectively. Three biological replicates per treatment were used for next‐generation sequencing via the Illumina platform. In this study, priming conditions decreased the time to 50% radicle emergence, implying earlier and more uniform germination without affecting the final germination percentage. Transcriptome analysis identified 6171 differentially expressed genes (DEGs) for 0–6 h, 7241 DEGs for 0–18 h, and 1527 DEGs for 6–18 h. The number of expressed DEGs during the early hours of priming exceeded those identified during the extended priming time, suggesting more metabolic processes were taking place in the earlier priming period. Noteworthy DEGs are related to stress responses, the biosynthesis of metabolites, and the activation of antioxidants and phytohormones. Moreover, these DEGs were significantly enriched in translation, metabolic processes, and biosynthesis for the priming times of 0–6 h and 0–18 h, whereas anaerobic respiration, detection of hypoxia, and lipid transport were differentially expressed between 6 and 18 h. Furthermore, expansin genes, namely, EXPA1, EXPA9, EXPA15, EXLA3, and EXP/Lol pI 3B GAG‐pre‐integrase domain, were significantly expressed. These expansins are cell wall‐loosening proteins that are involved in the processes of physiological development in higher plants, including seed germination. The data obtained in this study contribute toward deciphering the molecular mechanisms associated with seed priming in sunflower seeds.

"Genome-wide identification of bZIP gene family in Pearl millet and transcriptional profiling under abiotic stress, phytohormonal treatments; and functional characterization of PgbZIP9".

Abiotic stresses are major constraints in crop production, and are accountable for more than half of the total crop loss. Plants overcome these environmental stresses using coordinated activities of transcription factors and phytohormones. Pearl millet an important C4 cereal plant having high nutritional value and climate resilient features is grown in marginal lands of Africa and South-East Asia including India. Among several transcription factors, the basic leucine zipper (bZIP) is an important TF family associated with diverse biological functions in plants. In this study, we have identified 98 bZIP family members (PgbZIP) in pearl millet. Phylogenetic analysis divided these PgbZIP genes into twelve groups (A-I, S, U and X). Motif analysis has shown that all the PgbZIP proteins possess conserved bZIP domains and the exon-intron organization revealed conserved structural features among the identified genes. Cis-element analysis, RNA-seq data analysis, and real-time expression analysis of PgbZIP genes suggested the potential role of selected PgbZIP genes in growth/development and abiotic stress responses in pearl millet. Expression profiling of selected PgbZIPs under various phytohormones (ABA, SA and MeJA) treatment showed differential expression patterns of PgbZIP genes. Further, PgbZIP9, a homolog of AtABI5 was found to localize in the nucleus and modulate gene expression in pearl millet under stresses. Our present findings provide a better understanding of bZIP genes in pearl millet and lay a good foundation for the further functional characterization of multi-stress tolerant PgbZIP genes, which could become efficient tools for crop improvement.

Genome-wide identification and expression analysis of the glycosyl hydrolase family 1 genes in Medicago sativa revealed their potential roles in response to multiple abiotic stresses

Glycoside hydrolase family 1 (GH1) β-glucosidases (BGLUs), are encoded by a large number of genes, which participate in the development and stress response of plants, particularly under biotic and abiotic stresses through the activation of phytohormones. However, there are few studies systematically analyzing stress or hormone-responsive BGLU genes in alfalfa. In this study, a total of 179 BGLU genes of the glycoside hydrolase family 1 were identified in the genome of alfalfa, and then were classified into five distinct clusters. Sequence alignments revealed several conserved and unique motifs among these MsBGLU proteins. Many cis-acting elements related to abiotic stresses and phytohormones were identified in the promoter of some MsBGLUs. Moreover, RNA-seq and RT-qPCR analyses showed that these MsBGLU genes exhibited distinct expression patterns in response to different abiotic stress and hormonal treatments. In summary, this study suggests that MsBGLU genes play crucial roles in response to various abiotic stresses and hormonal responses, and provides candidate genes for stress tolerance breeding in alfalfa.

Overview and Recent Progress on the Biosynthesis and Regulation of Flavonoids in Ginkgo biloba L.

Flavonoids and their derivatives play important roles in plants, such as exerting protective activity against biotic and abiotic stresses, functioning in visual signaling to attract pollinators, and regulating phytohormone activity. They are also important secondary metabolites that are beneficial to humans. Ginkgo biloba L. is a well-known relict plant considered to be a "living fossil". Flavonoids present in ginkgo leaves have antioxidant and anti-aging capacities and show good therapeutic effects on a variety of neurological diseases. To date, studies on flavonoids have mainly focused on their extraction, pharmacological effects, and component analysis and on the expression levels of the key genes involved. However, a systematic review summarizing the biosynthesis and regulatory mechanisms of ginkgo flavonoids is still lacking. Thus, this review was conducted to comprehensively introduce the biological characteristics, value, and utilization status of ginkgo; summarize the effects, biosynthetic pathways, and transcriptional regulation of flavonoids; and finally, discuss the factors (ecological factors, hormones, etc.) that regulate the biosynthesis of flavonoids in ginkgo. This review will provide a reference basis for future research on the biosynthesis and efficient utilization of flavonoids in ginkgo.

The Inferior Grain Filling Initiation Promotes the Source Strength of Rice Leaves

Poor grain-filling initiation in inferior spikelets severely impedes rice yield improvement, while photo-assimilates from source leaves can greatly stimulate the initiation of inferior grain-filling (sink). To investigate the underlying mechanism of source-sink interaction, a two-year field experiment was conducted in 2019 and 2020 using two large-panicle rice cultivars (CJ03 and W1844). The treatments included intact panicles and partial spikelet removal. These two cultivars showed no significant difference in the number of spikelets per panicle. However, after removing spikelet, W1844 showed higher promotion on 1000-grain weight and seed-setting rate than CJ03, particularly for inferior spikelets. The reason was that the better sink activity of W1844 led to a more effective initiation of inferior grain-filling compared to CJ03. The inferior grain weight of CJ03 and W1844 did not show a significant increase until 8 days poster anthesis (DPA), which follows a similar pattern to the accumulation of photo-assimilates in leaves. After removing spikelets, the source leaves of W1844 exhibited lower photosynthetic inhibition compared to CJ03, as well as stronger metabolism and transport of photo-assimilates. Although T6P levels remained constant in both cultivars under same conditions, the source leaves of W1844 showed notable downregulation of SnRK1 activity and upregulation of phytohormones (such as abscisic acid, cytokinins, and auxin) after removing spikelets. Hence, the high sink strength of inferior spikelets plays a role in triggering the enhancement of source strength in rice leaves, thereby fulfilling grain-filling initiation demands.

Phytohormone synthesis for PDH activation and phytochemical screening for the treatment of endometriosis

Introduction and Aim: Endometriosis is a challenging gynecological disorder that causes pelvic pain and infertility attributed to the prevalence of ectopic endometrial tissue outside the uterine tract. Endometrial tissue can travel to other areas of the body for inexplicable reasons. There are, nevertheless, certain patterns. Endometriosis could be treated in several ways, based on characteristics such as age, fertility, symptom severity, and disease degree. All endometriosis medications are available as contraceptives, restricting their use to pregnant mothers or intending to get children. By comparing human peritoneal mesothelial cells (HPMCs) derived from the pelvic peritoneum of women with endometriosis to HPMCs from women without endometriosis, the researchers found that HPMCs from women with endometriosis had reduced glycolysis, mitochondrial respiration, and pyruvate dehydrogenase (PDH) and improved lactate production. There is no treatment for endometriosis, even though various medications and management alternatives are available. The present study was carried out to find novel medications to treat endometriosis from medicinal plants which appear to be a promising endeavor. Methods and Materials: Phytohormone and phytochemical screening were performed to study the medication options that could possibly treat endometriosis. Phytochemicals were determined using GC-MS. Results: The phytohormone activity and phytochemical components of Mentha piperita, Curcuma longa, and Andrographis paniculata were identified using GC MS and FT-IR analysis. This initial data from the analytical methods will make it easier to perform follow-up research on finding bioactive ingredients, determining their efficacy through in vivo tests, and proving their safety and efficacy through clinical trials to treat endometriosis. Conclusion: Gibberellin, a phytohormone obtained from natural sources, is supposed to improve PDH activity and hence inhibit PDK. The demand for more modern medicines to increase survival in such cases remains unmet. As a result, there is an increasing interest in using herbal therapy to treat endometriosis.

Unraveling the intracellular and extracellular self-defense of Chlorella sorokiniana toward highly toxic pyridine stress

A bottleneck of microalgae-based techniques for wastewater bioremediation is activity inhibition of microalgae by toxic pollutants. The defense strategies of Chlorella sorokinana against toxic pyridine were studied. Results indicated that pyridine caused photoinhibition and reactive oxygen species overproduction in a concentration-dependent manner. The 50% inhibitory concentration of pyridine (147 mg L-1) destroyed C/N balance, disrupted multiple metabolic pathways of C. sorokinana. In response to pyridine stress, ascorbate peroxidase and catalase activities increased to scavenge reactive oxygen species under pyridine concentrations lower than 23 mg L-1. At higher pyridine concentrations, the activation of calcium signaling pathways and phytohormones represented the predominant defense response. Extracellular polymeric substances increased 3.6-fold in 147 mg L-1 group than control, which interacted with pyridine through hydrophobic and aromatic stacking to resist pyridine entering algal cells. Unraveling the intracellular and extracellular self-defense mechanisms of microalgae against pyridine stress facilitates the development of microalgal-based technology in wastewater bioremediation.

Discovery of Novel Hybrid-Type Strigolactone Mimics Derived from Cinnamic Amide.

Strigolactones (SLs) are a class of plant hormones and rhizosphere communication signals of great interest. They perform diverse biological functions including the stimulation of parasitic seed germination and phytohormonal activity. However, their practical use is limited by their low abundance and complex structure, which requires simpler SL analogues and mimics with maintained biological function. Here, new, hybrid-type SL mimics were designed, derived from Cinnamic amide, a new potential plant growth regulator with good germination and rooting-promoting activities. Bioassay results indicated that compound 6 not only displayed good germination activity against the parasitic weed O. aegyptiaca with an EC50 value of 2.36 × 10-8 M, but also exhibited significant inhibitory activity against Arabidopsis root growth and lateral root formation, as well as promoting root hair elongation, similar to the action of GR24. Further morphological experiments on Arabidopsis max2-1 mutants revealed that 6 possessed SL-like physiological functions. Furthermore, molecular docking studies indicated that the binding mode of 6 was similar to that of GR24 in the active site of OsD14. This work provides valuable clues for the discovery of novel SL mimics.

Стрес-протекторні та регуляторні властивості саліцилової кислоти і перспективи її використання в рослинництві

Salicylic acid (SA), as a secondary phenolic metabolite with phytohormonal activity, is an important component of the plant defense system against biotic and abiotic stresses. The scale of industrial synthesis of SA in the world is constantly growing, it is used as an intermediate for the synthesis of drugs and dyes, it is also used in cosmetology, food industry, plant biotechnology, etc. Recently, it has been considered as a promising growth-regulating agent in crop production for decreasing harmful effects of biotic and abiotic stresses in plants. Over the past two decades, numerous data have been published concerning the metabolic pathways of SA synthesis and its signaling in plant immunity. It regulates and affects various stages of plant ontogenesis and metabolism: seed germination, flowering, stomatal movements, pigment synthesis, photosynthesis and respiration, ethylene biosynthesis, thermoregulation, the activity of antioxidant enzymes, nutrient absorption, membrane integrity and functioning, nodulation in legumes, synthesis of secondary metabolites, general growth and development of plants. Numerous studies have confirmed that endogenous SA and/or its derivatives are involved in stress responses to heavy metals (HMs), hyper- and hypothermia, salinity, water deficiency, and, primarily, pathogenic infections. In parallel with fundamental studies of regulatory functions of SA and/or its derivatives, new ways of their exogenous application are constantly discovered. The use of low concentrations of exogenous SA (0.1–0.5 mM) for seed priming or foliar treatment is reported as an economically viable alternative approach for increasing plant tolerance from both economic and environmental points of view. Exogenous SA leads to an increase in endogenous SA levels that induces plant adaptive responses by changing phytohormonal status, increased synthesis of a number of secondary metabolites (alkaloids, cyanogenic glycosides, phenolics, terpenes), by increasing activity of antioxidant enzymes. One of the main advantages of using SA in crop production is the ability to reduce the dosage of pesticides and fertilizers that are potentially harmful to the environment and human health. It is also reported that the use of SA in some cases may lead to negative results – growth retardation, sterility, and yield decrease; the causes of this phenomenon are actively investigated. Further studies are necessary to clarify the mechanisms of exogenic SA action and its use on various crops in different growing conditions. This review aims to analyze the recent data on SA, crop production, and biotechnology areas where it is possible to effectively apply the SA and/or its derivatives.

Impact of Presowing Electron Beam Irradiation of Seeds on Barley Seedling Development and Activities of Enzymes and Phytohormones

Impact of Presowing Electron Beam Irradiation of Seeds on Barley Seedling Development and Activities of Enzymes and Phytohormones

The effect of pre-sowing electron radiation on the development of barley seedlings and the activity of enzymes and phytohormones

In a laboratory experiment, the effect of pre-sowing low-energy (160 keV) electron radiation at doses of 1, 3, and 5 kGy at a dose rate of 500 Gy/pulse was studied. on sowing qualities, morphometric parameters of barley seedlings of the Vladimir spring variety, their susceptibility to fungal diseases against a natural infectious background, as well as on the activity of enzymes and the concentration of phytohormones in 7-day-old seedlings. The repetition in the experiment was 3-fold, non-irradiated seeds served as control. Irradiation of seeds at a dose of 3 kGy caused a statistically significant increase in comparison with the control of laboratory germination (LV) by 6 % and seed growth force (SPC) by 10 %, and at a dose of 1 kGy, an increase in root length by 24.6 % and had no significant effect on morphometric parameters at a dose of 5 kGy. Seed treatment did not affect the green and dry weight of the seedlings and the percentage of water content in them. Irradiation completely suppressed the development of Penicillium spp. at doses of 1, 3 and 5 kGy, Fusarium spp. - at doses of 3 and 5 kGy and significantly increased the prevalence of Bipolaris sorokiniana seedlings by 2.1 times and its prevalence by 1.8 times at a dose of 5 kGy. Electron irradiation of barley seeds had no effect on the activity of enzymes and phytohormones, except for a significant increase in 7-day-old seedlings of the content of IAA at a dose of 5 kGy by 1.5 times and IBA at a dose of 1 kGy by 2.7 times compared with the control.

Information potential of an ubiquitous phytochemical cue.

This article is a Commentary on Li et al. (2023), 238: 2099–2112.

TRITERPENE GLYCOSIDES AS PLANT GROWTH REGULATORS: POTENTIAL AND PROSPECTS FOR USE (RE-VIEW)

The increased interest in the study of the growth-regulating activity of triterpene glycosides (TG) in recent years is largely due to the need to create new highly effective environmentally friendly plant growth biostimulants, the use of which is considered as an important strategy in managing the productivity and stress resistance of agricultural crops. Тhe review presents information available in the literature on phytoregulatory activity TG with an emphasis on their growth-stimulating properties. The physiological effects of TG in bioassays on phytohormonal activity are considered. The auxin- gibberellin- and cytokinin-like effect of TG on growth and metabolism (changes in the activity of enzymes: α-amylase, peroxidase, catalase, polyphenol oxidase, IAA oxidase, nitrate reductase, chlorophyll and protein content), was shown depending on the structure of TG, concentration and the tested plant. The issues of the mechanism of the growth-stimulating action and the possible involvement of TG and free triterpenes in physiological processes in plants are discussed. The relationships between the structure and phytoregulatory activity of TG was analyzed. The effect of exogenous TG and triterpenoids on plants under abiotic stresses, as well as the possibility of using some TG, extracts of saponin-bearing plants (Сamellia sp., Silphium perfoliatum, Medicago sativa, Glycine max, Vigna radiata, Glycyrrhiza glabra, Moringa oleifera, Solidago gigantea, Centella asiatica, Eclipta alba, Quillaja saponaria, Bacopa monnieri et al.) and plant extracts containing triterpenoids (Abies sibirica, Betula sp.) in crop production as plant growth regulators, is considered.

Determination of cadmium and/or drought stress effects on some plant phytohormone contents and hormone gene expressions in bean (Phaseolus vulgaris L)

Plants can sometimes be under the influence of more than one stress factor. In this case, combined stress factors can cause different responses in plants. In this study, the phytohormonal activity and hormone gene expressions of beans (Phaseolus vulgaris L.) were investigated in different drought levels and soils with different levels of cadmium accumulation. Plants were grown at 4 different cadmium (Cd) levels (Cd: 0, Cd1: 100, Cd2: 150, and Cd3: 200 mg kg$^{-1}$) and 3 irrigation levels (D0: 100%, D1: 75%, and D2: 50% of field capacity). Abscisic acid (ABA), indole acetic acid (IAA), gibberellic acid (GA), salicylic acid (SA), cytokinin, zeatin, and jasmonic acid contents and gene expressions related to them were investigated. As a result of the study, we determined that there was a significant decrease in the content of IAA, GA, SA, cytokinin, zeatin, and jasmonic acid with increasing doses of drought and Cd. Especially with the coexistence of both stress factors, this reducing effect (the reductions in these hormones were 86.6%, 64.1%, 71.9%, 66.7%, 45.5%, and 73.9% as compared to D0, respectively) on the measured parameters was greater. However, ABA content increased significantly with drought and/or Cd stresses, especially with Cd3D2, about a thousand times higher than the control. On the other hand, mRNA transcript levels of some hormone genes (ABA 8'-hydroxylase, adenylate isopentenyltransferase (AIPT3), auxin-related protein (AUX/ IAA), MeJA biosynthesis and gibberellin 20-oxidase and NRAMP2 gene known to be involved in Cd transport, were detected. According to the results, while ABA 8'-hydroxylase, gibberellin 20-oxidase, and NRAMP2 genes were overexpressed in all stress treatments, AIPT3 and AUX/IAA genes were down-regulated and also, MeJA biosynthesis gene varied depending on dose and stress.

Determining the common patterns of the action of nanoparticles of various compositions and structures on physiological and biochemical processes in plants

Technogenic and natural nanomaterials are alien to living systems. The negative effect of nanomaterials may be due to their accumulation in intracellular organelles. The properties of nanoparticles are determined not only by their size, which manifests itself in the activation of a thermodynamic variable, but also by their chemical structure and shape, their ability to aggregate. The effect of metal nanoparticles and oxides of cobalt and titanium on the development and growth of plants has been studied. An important established fact is the ability of oxide nanoparticles, unlike metals themselves, to accumulate in living systems. Transmission electron microscopy, carried out by means of electron microscopic analysis, has revealed interstitial bioaccumulation of nanoparticles of cobalt oxide and titanium oxide in the form of aggregates 80-300 nm in size. If nanoparticles quickly aggregate, they are less dangerous for organisms than single nanoparticles, since a large aggregate of nanoparticles cannot get inside the cell. The rate and dynamics of deposition of nanoparticles of metals and their oxides in water are different. Metal NPs are deposited much more slowly than titanium dioxide. Moreover, the safety of NPs depends on their size and concentration. Biogenic nanoparticles with a size of 35-75 nm have high biological activity, biocompatibility and environmental safety. There is a direct correlation between the energy produced in cells, which is necessary for seed viability, and an increase in the number of protons under the action of metal nanoparticles, which leads to an increase in the permeability of cell membranes and the activity of enzymes and phytohormones.

A Review – Some Approaches to Combat Salt Stress in Wheat Crop

Wheat constitutes a central position for ensuring food and nutritional security; however, rapidly rising soil and water salinity pose a serious threat to its production globally. Salinity stress is a universal dilemma that is happening due to climate change. It affects hectares of arable land. Main focus regarding improving salinity tolerance in plants has been given to Na+ exclusion/ Na+ compartmentalization and enhanced ROS system. Besides this, ameliorative activity of phytohormones, nutrients, amino acids and organic osmolytes has also been widely studied. Exploring traits in wild genotype aids search for better solutions. Based upon phenotype screening, novel genes involving salinity tolerance will be easily identified. Moreover, selected mutants can be used to validate the functions of salt genes. Wheat plants utilize a range of physiological biochemical and molecular mechanisms to adapt under salinity stress at the cell, tissue as well as whole plant levels to optimize the growth, and yield by off-setting the adverse effects of saline environment. Recently, various adaptation and management strategies have been developed to reduce the deleterious effects of salinity stress to maximize the production and nutritional quality of wheat. Thereby, this review highlights effects of salt tolerance, physiological mechanisms behind salt tolerance and transgenic wheat that are potential indicators of salinity stress tolerance.

Mugwort (Artemisia vulgaris L.) Aqueous Extract: Hormesis and Biostimulant Activity for Seed Germination and Seedling Growth in Vegetable Crops

The evaluation of potential biostimulants to be used in sustainable horticulture production is a crucial goal of research. Most research has focused on the effects of biostimulants on plant growth, and less on the effects on seed germination and seedling growth. This study evaluated the biostimulatory effects of mugwort extract on seed germination and seedling growth in several vegetable crops (onion, carrot, tomato, rapeseed, cauliflower and lettuce), in order to test its application as a potential biostimulant. The phenolic acid composition of the extract and the acids’ rankings were: homovanillic > gentisic > gallic > caffeic = chlorogenic > salicylic = syringic > p/m-coumaric = ferulic = synaptic = p-hydroxybenzoic. The extract of mugwort (at 0.2, 0.4, 0.8, 1.56, 3.13, 6.25 and 12.5 % w/v concentrations) was analyzed using Petri dish bioassays, quantifying its stimulatory effects on seed germination and the radicle and hypocotyl length of the seedlings, according to hormetic log-logistic models. The mugwort extract was not able to biostimulate all the tested species. Seed germination was stimulated in carrot (+70%) and rapeseed (+11%), while in the other species, no effects (i.e., onion, tomato and lettuce) or inhibition (i.e., cauliflower) were observed. Hypocotyl length stimulation was observed in all the species except carrot and onion, while radicle length was mainly inhibited by mugwort extract, except in rapeseed (+30%). The biostimulation effects of mugwort extract seem to be “specie specific” and “part of plant specific”, and need to be further investigated in terms of the involved substances and physiological aspects, although phytohormone activity is certainly involved.