Growth Regulators Research Articles

Land suitability evaluation in the Northern Limestone Mountains of Tuban Regency, East Java for torch ginger (Etlingera elatior Smith) cultivation

Torch ginger (Etlingera elatior) is a herbaceous plant from Southeast Asia, traditionally used as herbal medicine by local people due to its antibacterial, antiviral, anti-inflammatory, anti-allergic, antioxidant, and anti-cancer properties. Despite its various benefits, this plant has struggled to enter the market because it has not been cultivated on a large scale. Therefore, the opportunity for commercial cultivation of this plant remains wide open. Tuban Regency is a potential agricultural district in Java, strategically positioned on the main road between Central Java Province and East Java Province. Unfortunately, little research has been conducted on land suitability evaluation in Tuban Regency’s agricultural areas. This research aimed to evaluate land suitability for torch ginger cultivation in Tuban Regency. Based on the studies conducted, agricultural land in Tuban Regency is quite fertile, but adequate irrigation is necessary to help the plants survive during the dry season. Torch ginger naturally grows in densely vegetated areas with sufficient water availability. Therefore, cultivating torch ginger in Tuban requires several special treatments, such as maintaining water availability, providing shade and mulch to regulate temperature and humidity, applying phosphorus and organic fertilizers to address phosphorus fixation in limestone soil, and using growth regulators like paclobutrazol to overcome flowering inhibition. From the various literature that has been studied, it was found that the land in the Northern Limestone Mountains of Tuban Regency, is quite fertile and suitable for agricultural land.

The effect of several growth regulators and biostimulant on biochemical and physiological changes in acclimation of micropropagated Echinacea purpurea Moench. ‘Raspberry Truffle’

Micropropagation is currently one of the primary methods for plant propagation, known for its efficiency in producing disease-free and vigorous plants. However, the final stage of this—acclimatization, is critical due to the transfer from a controlled in vitro environment to an external one. To reduce mortality and alleviate acclimation stress, plant growth regulators (PGRs) or biostimulants can be employed. This study investigated the effects of exogenously sprayed PGRs: 0.001 mg L−1 abscisic acid (ABA), 0.001 mL L−1 brassinolide (BL), 0.001 mL L−1 24-epibrassinolide (24-epiBL), and 0.3 mL L−1 biostimulant Goteo on the physiological and biochemical responses of Echinacea purpurea ‘Raspberry Truffle’ plantlets during the acclimation process. The effects of treatments at various acclimation stages on chlorophyll (chl) and carotenoids content, hydrogen peroxide (H2O2), catalase (CAT), malondialdehyde (MDA), free amino acids, soluble proteins, total soluble sugar and reduced soluble sugars were tested in this research. The results confirmed changes in biochemical parameters, including an increase in chlorophyll and carotenoids in the acclimatization period where the highest level obtained by BL spraying. A decline in stomatal conductance was also observed, where ABA influenced the most on drop. It was also recorded the decrease in H2O2 and MDA concentration. CAT activity increased, especially with biostimulant treatment. We recorded an increase in total soluble proteins along acclimatization. Goteo affected the most on morphology parameters, ABA, BL and 24-epiBL increased acclimatization efficiency. Our studies indicate that potentially the most effective substances in the acclimatization of E. purpurea ‘Raspberry Truffle’ are brassinosteroids and ABA.

A sexually and vegetatively reproducible diploid seedless watermelon inducer via ClHAP2 mutation.

Seedless watermelon production relies on triploid cultivation or the application of plant growth regulators. However, challenges such as chromosomal imbalances in triploid varieties and concerns about food safety with growth regulator application impede progress. To tackle these challenges, we developed a sexually and vegetatively reproducible inducer line of diploid seedless watermelon by disrupting the double fertilization process. This innovative approach has enabled the successful induction of diploid seedless watermelon across diverse varieties.

Spatially restricted ecto-5'-nucleotidase expression promotes the growth of uterine leiomyomas by modulating Akt activity.

Found in as many as 80% of women, uterine leiomyomas are a frequent cause of abnormal uterine bleeding, pelvic pain, and infertility. Despite their significant clinical impact, the mechanisms responsible for driving leiomyoma growth remain poorly understood. After obtaining IRB permission, expression of ecto-5'-nucleotidase (NT5E, CD73) was assessed in matched specimens of myometrium and leiomyoma by real-time qPCR, Western blot, and immunohistochemistry (IHC). Adenosine concentrations were measured by enzyme-linked assay. Primary cultures were used to assess the impact of adenosine and/or adenosine receptor agonists on proliferation, apoptosis, and patterns of intracellular signaling invitro. When compared to matched specimens of healthy myometrium, uterine leiomyomas were characterized by reduced CD73 expression. Largely limited to thin-walled vascular structures and the pseudocapsule of leiomyomas despite diffuse myometrial distribution. Restricted intra-tumoral CD73 expression was accompanied by decreased levels of intra-tumoral adenosine. Invitro, incubation of primary leiomyoma cultures with adenosine or its hydrolysis-resistant analog 2-chloro-adenosine (2-CL-AD) inhibited proliferation, induced apoptosis, and reduced proportion of myocytes in S- and G2-M phases of the cell cycle. Decreased proliferation was accompanied by reduced expression of phospho-Akt, phospho-Cdk2-Tyr15, and phospho-Histone H3. Enforced expression of the A2B adenosine receptor (ADORA2B) and ADORA2B-selective agonists similarly suppressed proliferation and inhibited Akt phosphorylation. Collectively, these observations broadly implicate CD73 and reducedextracellular concentrations ofadenosine as key regulators of leiomyoma growth and potentiallyidentify novel strategies for clinically managing these common tumors.

Newborn adiposity is associated with cord blood DNA methylation at IGF1R and KLF7.

This study aimed to identify whether cord blood DNA methylation at specific loci is associated with neonatal adiposity, a key risk factor for childhood obesity. An epigenome-wide association study was conducted using the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study as a discovery sample. Linear regression models adjusted for maternal and offspring covariates and cell counts were used to analyze associations between neonatal adiposity as measured by sum of three skinfold thicknesses and cord blood DNA methylation. Assays were performed with Illumina EPIC arrays (791,359 CpG sites after quality control). Replication was performed in an independent cohort, Genetics of Glucose regulation in Gestation and Growth (Gen3G). In 2740 HAPO samples, significant associations were identified at 89 CpG sites after accounting for multiple testing (Bonferroni-adjusted p < 0.05). Replication analyses conducted in 139 Gen3G participants confirmed associations for seven CpG sites. These included IGF1R, which encodes a transmembrane receptor involved in cell growth and survival that binds insulin-like growth factor I and insulin, and KLF7, which encodes a regulator of cell proliferation and inhibitor of adipogenesis; both are key regulators of growth during fetal life. These findings support epigenetic mechanisms in the developmental origins of neonatal adiposity and as potential biomarkers of metabolic disease risk.

Pde3a and Pde3b regulation of murine pulmonary artery smooth muscle cell growth and metabolism.

A role for metabolically active adipose tissue in pulmonary hypertension (PH) pathogenesis is emerging. Alterations in cellular metabolism in metabolic syndrome are triggers of PH-related vascular dysfunction. Metabolic reprogramming in proliferative pulmonary vascular cells causes a metabolic switch from oxidative phosphorylation to glycolysis. PDE3A and PDE3B subtypes in the regulation of metabolism in pulmonary artery smooth muscle cells (PASMC) are poorly understood. We previously found that PDE3A modulates the cellular energy sensor, AMPK, in human PASMC. We demonstrate that global Pde3a knockout mice have right ventricular (RV) hypertrophy, elevated RV systolic pressures, and metabolic dysfunction with elevated serum free fatty acids (FFA). Therefore, we sought to delineate Pde3a/Pde3b regulation of metabolic pathways in PASMC. We found that PASMC Pde3a deficiency, and to a lesser extent Pde3b deficiency, downregulates AMPK, CREB and PPARγ, and upregulates pyruvate kinase dehydrogenase expression, suggesting decreased oxidative phosphorylation. Interestingly, siRNA Pde3a knockdown in adipocytes led to elevated FFA secretion. Furthermore, PASMC exposed to siPDE3A-transfected adipocyte media led to decreased α-SMA, AMPK and CREB phosphorylation, and greater viable cell numbers compared to controls under the same conditions. These data demonstrate that deficiencies of Pde3a and Pde3b alter pathways that affect cell growth and metabolism in PASMC.

Towards Environmental Sustainability: Integrating RS and GIS for Ecology Assessment

The environment provides numerous benefits for human well-being, such as ecosystem services. These services directly and indirectly depend on the physical state of the ecosystem. However, the over-exploitation of natural resources along with socio-economic factors, i.e. economic growth, poverty, agriculture expansion, population growth and weak environmental governance and regulation for fulfilling the human needs for food, fuel, and shelter, is leading to the degradation of the ecological health of an area. Therefore, monitoring and assessment of spatial and temporal changes in the ecology of a region in terms of vital ecological services is very critical and would help the decision-makers to develop and plan appropriate adaptation and mitigation measures for the conservation of natural ecosystems at various scales to ensure environmental sustainability. The present study aimed to assess the ecological status of the Mahi Bajaj Sagar catchment area in Rajasthan (India) from the year 2000 to 2020, using remote sensing-based indices. Indicators such as greenness, dryness, and heat index have been selected as per the pressure-state-response (PSR) framework. Multi-spectral remote sensing data and image processing methods have been used to estimate these indicators, and a remote sensing-based Ecological Status Index (RSBI) has been generated by their integration using the principal component analysis (PCA) to assess the ecological status of the Mahi Bajaj Sagar catchment. Findings from the study indicate a consistent decline in the overall ecological status of the Mahi Bajaj catchment, where decreased forest areas have a pronounced effect on ecological health. Interestingly, approximately 43.6% of the area displayed resilience to changes in ecological status; however, 36.4% of the area exhibited signs of ecological degradation. Our study underscores the efficacy of a remote sensing-based approach in quantifying and detecting ecological changes, offering a promising methodology for monitoring and assessing the ecological health of large areas that can help promote environmental sustainability. Keywords: Environmental Sustainability, Ecological Status, RSBI, Remote Sensing, PSR Framework

Exploring the mechanisms of benzanilide crystal growth and morphology: Crystal surface structure, solvent diffusion and solvent-interface interactions

Flaky crystals are fragile, rendering them unsuitable for various applications including use, processing, storage and transportation. This work investigates the growth and morphology regulation mechanisms of flaky crystals using benzanilide as a model material. Initially, block-like crystals are prepared by solvent screening and cooling crystallization with its morphology greatly improved. Subsequently, growth kinetics of (111), (1–10) and (020) faces are established with crystal growth experiments. The crystal growth of (001) face is also determined to follow a two-dimensional nucleation model with the microscopic surface analysis using atomic force microscopy. The changes of the surface integration resistance and the growth step height are regarded as kinetic mechanisms of the growth behavior and crystal morphology modulation by solvent and supersaturation. Finally, the molecular mechanism of the modulation of the solvent in crystal morphology is revealed base on crystal surface structure analysis and molecular dynamics simulations. The weak solvent-interface polar interactions facilitate the incorporation of benzanilide molecules into the weak polarity (001) face, leading to the surface roughening and increased crystal thickness when employing strongly polar solvents such as acetonitrile. Unlike the former, the relatively weak hydrogen bonding interactions between solvents and strong polarity (020) face, and the higher diffusion ability of molecules promote the rapid growth and disappearance of (020) face in ethanol and acetonitrile with strong hydrogen bond formation ability. This study can contribute to a deeper understanding of the solvent effect on crystal morphology and provide guidance for optimizing crystallization conditions to obtain shape-tailored crystal products.

PavSPLs are key regulators of growth, development, and stress response in sweet cherry

SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) genes are plant-specific transcription factors essential for plant growth, development, and stress responses; however, their roles in sweet cherry are not well understood. In this study, we identified and isolated 16 SPL genes from the sweet cherry genome, categorizing them into five subfamilies, with 12 PavSPLs predicted as miR156 targets. The promoter regions of PavSPLs contain cis-elements associated with light, stress, and phytohormone responses, indicating their role in biological processes and abiotic stress responses. Seasonal expression analysis showed that PavSPL regulates sweet cherry recovery after dormancy. Gibberellin (GA) treatment reduced PavSPL expression, indicating its role in GA-mediated processes. Overexpression of PavSPL14 in Arabidopsis thaliana resulted in earlier flowering, increased plant height, and enhanced growth. Yeast two-hybrid assays revealed an interaction between PavSPL14 and DELLA protein PavDWARF8, suggesting the involvement of PavSPLs in GA-regulated processes through protein interactions. These findings lay the groundwork for future studies on PavSPL function in sweet cherry.

Nanoparticles and their crosstalk with stress mitigators: A novel approach towards abiotic stress tolerance in agricultural systems

Plants are exposed to adverse environmental conditions, including cold, drought, heat, salinity, and heavy metals, which negatively impact plant growth and productivity of edible crops worldwide. Although the previous literature summarized the nanoparticle’s involvement in abiotic stress mitigation, the interaction of nanoparticles with other stress mitigators to overcome abiotic stress from plants remains unclear. Currently, nanotechnology is considered a growing new field in agriculture for understanding plants’ adapted stress tolerance mechanisms. Recent research has shown that nanoparticles can effectively mitigate abiotic stress by interacting synergistically with plant growth regulators. To address this, we comprehensively demonstrated the combined positive potential of nanoparticles in combination with plant growth regulators (signaling molecules, phytohormones, nanoparticles-nanoparticles interaction, fungi, plant growth promoting rhizobacteria and other metal salts) to improve plant growth and mitigate abiotic stresses. Their co-applications augment the plant’s growth, nutrient uptake, antioxidant defense system, water absorption, cell viability, water use efficiency, and photosynthetic and biochemical attributes by reducing oxidative stressors under various abiotic stresses in different plant species. This review provides a comprehensive overview of the combined applications of nanoparticles and plant growth regulators, a novel strategy to reduce the harmful effects of abiotic stress on plants. It identifies research gaps and recommends future studies to overcome their phytotoxicity worldwide.

A Mini-Review on the Structural Characteristics and Anticancer Activity of Nagilactones

Abstract: Natural products provide abundant resources for the development of new drugs. Podocarpus nagi is an arbor of Podocarpus L'Hér. ex Persoon. Its fruits, leaves, and roots exhibit a broad spectrum of pharmacological activities (such as antitumor, plant growth regulation, termite killing, and insect larval toxicity), which have been used in Yao folk for a long history. Nagilactone is one of the key components discovered in Podocarpus nagi, which has a variety of structures and a broad spectrum of antitumor activities. In this mini-review, the structures and spectral characteristics, together with the antitumor activities and the structure-activity relationships of nagilactones, are summarized by searching the database in order to provide detailed references for researchers to elucidate and modify their structures.

Enhancing carotenoid accumulation in Dunaliella bardawil by combined treatments with fulvic acid and optimized culture conditions

Natural carotenoids from microalgae have received more attention as an alternative source. In this study, fulvic acid (FA), a plant growth regulator, was used to enhance carotenoid accumulation in microalgae Dunaliella bardawil rich in lutein. However, the addition of FA promoted pigment synthesis but also exhibited an inhibitory effect on biomass. Therefore, the optimization of culture conditions was performed to further enhance carotenoid accumulation, including high light stress (10,000 lx) and the two-stage cultivation comprising 1-aminocyclopropane-1-carboxylic acid (ACC) and FA. Under both culture conditions, the growth inhibition caused by FA was alleviated, leading to a further increase in the contents of chlorophylls and carotenoids. HPLC analysis revealed that the production of lutein, α-carotene and β-carotene increased by 0.44-, 0.37- and 0.54-fold under the treatment of 400 mg/L FA with high light intensity and 0.91-, 1.15- 0.29-fold under the two-stage cultivation comprising 11 mM ACC and 500 mg/L FA. Furthermore, algal cells under FA treatment and the two-stage cultivation stained with Bodipy505/515 emitted stronger fluorescence under a laser confocal microscope, suggesting that lipid accumulation was increased. Additionally, the transcription levels of carotenogenic genes were also found to be up-regulated by qRT-PCR. These results indicated an enhancement in both the storage capacity and synthesis of carotenoids in D. bardawil. This study revealed the potential application of plant growth regulators in promoting carotenoid accumulation in D. bardawil which could be further improved by optimizing the culture conditions, providing a reference for efficient carotenoid production in microalgae.

Effect of Benzylaminopurine (BAP) and Coconut Water on the Growth of Bucephalandra sp. in Vitro

Tissue culture is useful as a way to obtain seeds in large quantities of seedlings in a short time as an effort to preserve Bucephalandra sp. in nature. The use of PGR has problems such as expensive prices and difficult to find, therefore its use can be replaced by natural PGR that are easy to obtain and have relatively cheap prices such as coconut water. The aim of this research was to determine the effect of Benzylaminopurine (BAP) and coconut water on the growth of Bucephalandra sp. in vitro. This research is a 2-factor factorial experiment using a completely randomized design. The factors are concentration of BAP (0; 1; 3; 5 mg/l) and concentration of coconut water (0; 50; 100 ml/l). The results showed Murashige and Skoog (MS) media with the addition of BAP 1 mg/l + coconut water 50 ml/l (4.11 shoots), BAP 5 mg/l + coconut water 50 ml/l (4.33 shoots), and BAP 3 mg/l (6.22 shoots) were able to provide the number of shoots with high results. The addition of coconut water did not affect the growth of Bucephalandra sp. MS media can grow shoots with the best results in measurements of shoot emergence time, number of roots, shoot and root length. Keywords: Aquatic plant, Endemic plant, Plant growth regulators, Tissue culture.

Development of In Vitro Regeneration Protocol for Sweet Pepper (Capsicum annuum L.) using Cotyledon as Explant

Plant tissue culture techniques offer a promising avenue for the efficient propagation of sweet pepper (Capsicum annuum L.), a valuable crop with significant agricultural importance. An effective and repeatable in vitro plant regeneration protocol was developed for the CKN-1 (Lemon yellow) and CKN-8 (Red) genotypes of sweet pepper. Utilizing cotyledonary leaf and cotyledonary node explants, various concentrations and combinations of growth regulators were tested for shoot rejuvenation. For both explants, MS medium supplemented with 8 mg/L BAP, 0.02 mg/L NAA, and 0.5 mg/L IAA was found to be most effective for achieving high rates of response and shoot induction. Notably, cotyledonary node explants outperformed cotyledonary leaf explants, displaying a remarkable 80% response within 11-12 days. Additionally, the supplementation of 1 mg/L IBA with MS medium significantly improved root initiation, with cotyledonary node explants exhibiting the highest responsiveness at 83.77%. Throughout all stages, the genotype CKN-8 (Red) consistently outperformed CKN-1 (Lemon yellow), including in the percentage of regenerated plant establishment. J Bangladesh Agril Univ 22(3): 310–316, 2024

Effect of plant growth regulators on phenological study and growth analysis of mung bean (Vigna radiata L.) under central plain zone of Uttar Pradesh

Effect of plant growth regulators on phenological study and growth analysis of mung bean (Vigna radiata L.) under central plain zone of Uttar Pradesh

Amorphophallus muelleri Blume Shoot Induction on Different Media Types and Plant Growth Regulator Combinations

Amorphophallus muelleri Blume Shoot Induction on Different Media Types and Plant Growth Regulator Combinations

The Degradation and Migration of Cyclanilide in Soil and Sediment in China.

The environmental fate of a plant growth regulator cyclanilide was studied in this paper. The degradation, adsorption, and migration behaviors of cyclanilide were detailly measured in the laboratory. The results showed that the DT50 of cyclanilide degradation in the Jiangxi red, Taihu paddy, Changshu wushan, Shaanxi tide, and Dongbei black soils was 42.3 d, 31.9 d, 14.4 d, 30.4 d as well as 27.4 d under aerobic conditions and 32.3 d, 37.4 d, 29.3 d, 48.9 d as well as 27.0 d under water anaerobic conditions, respectively, with the main metabolite being 2,4-dichloroaniline (2,4-D). The DT50 of 2,4-D ranged from 5.26 to 27.1 days under aerobic conditions, and from 10.6 to 54.1 days under anaerobic conditions. The adsorption of cyclanilide by the soils was well fitted by the empirical linear adsorption isotherm, and the adsorption constant (Kd, H) values in the Jiangxi red, Taihu paddy, Changshu wushan, Shaanxi tide, and Dongbei black soils were 7.08, 4.49, 4.05, 3.20, and 1.41, respectively. The results of a mobility test showed that cyclanilide had strong mobility in the most test soils. Furthermore, soil pH is the dominant element affecting the adsorption of cyclanilide in the soils. Under aerobic environment, the DT50 of total cyclanilide in river and lake water-sediment systems were 30.7 d and 34.0 d, respectively; under anaerobic environment, their DT50 were 30.8 d and 31.4 d, respectively. In water-sediment systems, 2,4-D mainly exists in aqueous phase and the DT50 ranged from 5.23 to 8.76 days. This work demonstrated that cyclanilide has the potential risk to contaminate environment and attention should be paid to its application.

The revelance of the development of new reciples of protein-vitaminized products for sports nutrition in Kazakhstan (in Kazakh language)

The specificity of sports nutrition lies in the fact that a person uses various carbohydrate, protein and vegetable drinks to restore the body after physical activity. Currently, in the sports nutrition market of the CIS countries, including our country, products from other countries account for more than 95%. Because of this, the prices of sports products are very expensive. Therefore, the development of sports nutrition products containing highly digestible protein products for the body based on plant raw materials is very relevant. At the same time, the development of these products based on legumes, in particular, their peas and soybeans, is the most acceptable. In addition, pea protein can be used to build muscle mass - due to the high level of L-arginine contained in it, the protein stimulates the secretion of human growth hormone, which is involved in the regulation of growth, metabolism and muscle mass. This article presents materials on the relevance of the development of new formulations of protein - fortified products for sports nutrition in Kazakhstan.

Ethylene and hydrogen sulfide regulate hexavalent chromium toxicity in two pulse crops: Implication on growth, photosynthetic activity, oxidative stress and ascorbate glutathione cycle

Sustainable agriculture has become prime importance to feed growing population. To achieve this goal application of exogenous hormones and signaling molecules are gaining important. In this context, we have investigated potential of ethylene (25 μM ethephon; donor) and H2S (10 μM NaHS; donor) in mitigating hexavalent chromium [Cr (VI), 50 μM] toxicity in two pulse seedlings: black bean and mung bean. Cr(VI) declined growth and gas exchange parameters (photosynthetic rate, stomatal conductance, sub cellular CO2 concentration, and transpiration level) which was accompanied by intracellular accumulation of Cr in both pulse crops and the damaging effect was greater in mung bean seedlings. The suppression in the growth and related parameters was occurred due to higher buildup of oxidative stress markers; O2•‾, H2O2, lipid peroxidation (as malondialdehyde, MDA equivalents) and membrane injury in leaf and root of both pulse crops. Cr induced disturbance in AsA-GSH cycle (reduction in the activity of glutathione reductase, ascorbate peroxidase, monodehydroascorbate reductase and dehydroascorbate reductase, and the amount of ASA and GSH) could be one of the reasons for greater accumulation of H2O2. Further, exogenous application of ethylene and H2S significantly ameliorated Cr toxicity on growth and photosynthetic activity by significantly lowering the intracellular Cr accumulation and oxidative biomarkers, and also by strengthening the activity of AsA-GSH cycle. The exogenous application of biosynthesis inhibitors of ethylene (AVG) and H2S (PAG) caused greater damaging effect on these parameters due to more accumulation of Cr(VI), thereby suggesting that the endogenous levels of these regulators are critical for Cr(VI) tolerance. Interestingly, ET did not rescue adverse effects of Cr(VI) in absence of endogenous H2S, while H2S could do so even without endogenous ethylene, suggesting that H2S played downstream signaling to ethylene in regulating Cr(VI) toxicity. Hence, being cheap and easily available theses growth regulators may be considered for sustainable agriculture.

Products of allelopathic plants for organic weed management: Environmentally approach

Allelopathic substances from different crops may have synergistic effects and can be applied in the mixture. In the previous research, several crop plants have been identified as phytotoxic against various weeds like sorghum, brassica, and sunflower. However, the effect of their tank mixture with each other was never studied in cotton before. Furthermore, it was not sure before this study whether the allele chemicals present in these crops viz. sorghum, sunflower and brassica can have synergistic or additive effects when applied in combination. Herbicides account for 42% of global pesticides’ use. Therefore, recent emphases have been on biological weed control measures so as to reduce dependence on synthetic herbicides and finding alternative strategies for weed control in agro ecosystems. Allelopathy is one of such strategies that can be explored for biological weed control of cropping systems. The mimosine that occurs in Leucaena has the potential to be used as a bio-herbicide in weed management. Mimosine is the main allelochemicals in Leucaena and is responsible for the strong allelopathic activity of the plant. The allelopathic effects of L. leucocephala towards several agricultural crops and forest trees have been reported. Plant seedlings of various crops possess allelopathic potential or weed-suppressing activity, including cucumber (Cucumber sativa L.), oat (Avena spp.) and rice (Oryza sativa L.). The main barley allelochemicals are the alkaloids gramine and hordenine which play a significant role in barley allelopathic potential and its defense against weeds, insects, or pathogens. In particular, barley allelopathic extracts have the ability to reduce emergence and growth of serious weeds like winter wild oat (Avena sterilis L.), hood canary grass (Phalaris paradoxa L.), black grass (Alopecurus myosuroides Huds.), great brome (Bromus diandrus Roth.), and wild mustard (Sinapis arvensis L.). This growth reduction has been mainly attributed to lipid peroxidation. Tamarindus contains allelochemicals on roots, leaves, seeds and bark , however, its allelopathic potential has not yet been compared to that of other allelopathic species such as Parthenium. Citharexylum (Citharexylum spinosum L) is equally a tree, a tropical plant with numerous usages but also know to have some allelopathic potential. Flower extracts have proved to be extremely potent to lettuce seed germination and seedlings growth and are very little known regarding its leaves phytotoxity. Consequently, the current experiment will provide additional information regarding Citharexylum leave allelopathic potential. Sunflower (Helianthus annuus L.). In Asteraceae members including sunflower, the main allelochemicals are sesquiterpenes, especially heliannuoles, sesquiterpene lactones and bisnorse squiterpenes, in addition to triterpenes and flavonoids Its allelopathic effects have been tested on both other crops and weeds, in field conditions and in vitro bioassays. In recent years, the allelopathic potential of Cynara cardunculus L., an herbaceous perennial species belonging to the Mediterranean basin, was assessed on seed germination and seedling growth of some weeds and target crops. Allelochemicals responsible for C. cardunculus allelopathy are the sesquiterpene lactones cynaropicrin, deacylcynaropicrin, 11, 13-dihydro-deacylcynaropicrin, aguerin B, grosheimin, 11,13-dihydroxy-8-deoxygrosheimin and cy-naratriol, as well as polyphenols such as caffeoylquinic and dicaffeoylquinic acids, luteolin and apigenin derivatives. Around 800 species of plants produce biologically active substances, but only a few of them are used in agricultural practice. However, in recent years, there has been an increase in interest in allelopathy due to the effective use of allelochemicals in plant protection, such as bioherbicides, bio insecticides, biofungicides and growth regulators.