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Chui-hua Kong - One of the best experts on this subject based on the ideXlab platform.
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Inducible effects of methyl jasmonate on Allelochemicals from rice
Acta Ecologica Sinica, 2020Co-Authors: Chui-hua Kong, Fei Hu, Chaoxian Zhang, Xiaohua XuAbstract:Methyl jasmonate is a signaling molecule that is mediated through air between plants. It plays important role in activating self-defensive system and induces secondary metabolites production in plants. One of the most important defensive systems in allelopathic rice varieties against associated weeds is to produce and release Allelochemicals. Therefore, inducible effects by methyl jasmonate on rice Allelochemicals production were investigated under both laboratory and field conditions. The results demonstrated that rice Allelochemicals (m-arabinose-pentadecanyl-resorcinol, m-arabinose- pentadecenyl-8-resorcinol, 7-xylose-luteolin, 3-glucose-hydroxmaic acid and 3-glucose -7-methoxy-hydroxamic acid) productions were elicited by exogenously applied methyl jasmonate in rice leaves. This inducible effect was dose-dependent and inducible period-dependent. The application of 0.4mmol/L methyl jasmonate effectively induced to synthesize significant amounts of Allelochemicals in allelopathic rice plants in the laboratory and field. The levels of Allelochemicals increased rapidly in methyl jasmonate-elicited rice leaves and reached maximum values in 48h after treatments. Furthermore, the inducible response to allelochemical production depended on different rice varieties. Allelopathic rice varieties, PI312777 and Fenghuazhan, could be induced to synthesize a large amount of Allelochemicals by methyl jasmonate at different concentrations. However, Allelochemicals amounts of non-allelopathic Huajingxian were slightly increased and could not reach the levels to express its allelopathic potential. In addtion, the inducible effects by methyl jasmonate on rice Allelochemicals also were time-dependent and could not be maintained for a long period. As a result, rice allelochemical production began 12h after treatment with methyl jasmonate and required 48h for obtaining a maximum accumulation, and then allelochemical amounts were gradually reduced. The results showed that the accumulation of rice Allelochemicals in response to exogenous methyl jasmonate was dynamic, and the allelochemical production in rice plant could be triggered by exogenously applied methyl jasmonate. This finding suggests that allelochemical elicitation by exogenously applied methyl jasmonate is worthwhile in future study for the understanding of allelopathic rice variety against associated weeds.
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Allelochemicals and Signaling Chemicals in Plants
Molecules, 2019Co-Authors: Chui-hua Kong, Tran Dang Xuan, Tran Dang Khanh, Hoang-dung Tran, Nguyen Thanh TrungAbstract:Plants abound with active ingredients. Among these natural constituents, Allelochemicals and signaling chemicals that are released into the environments play important roles in regulating the interactions between plants and other organisms. Allelochemicals participate in the defense of plants against microbial attack, herbivore predation, and/or competition with other plants, most notably in allelopathy, which affects the establishment of competing plants. Allelochemicals could be leads for new pesticide discovery efforts. Signaling chemicals are involved in plant neighbor detection or pest identification, and they induce the production and release of plant defensive metabolites. Through the signaling chemicals, plants can either detect or identify competitors, herbivores, or pathogens, and respond by increasing defensive metabolites levels, providing an advantage for their own growth. The plant-organism interactions that are mediated by Allelochemicals and signaling chemicals take place both aboveground and belowground. In the case of aboveground interactions, mediated air-borne chemicals are well established. Belowground interactions, particularly in the context of soil-borne chemicals driving signaling interactions, are largely unknown, due to the complexity of plant-soil interactions. The lack of effective and reliable methods of identification and clarification their mode of actions is one of the greatest challenges with soil-borne Allelochemicals and signaling chemicals. Recent developments in methodological strategies aim at the quality, quantity, and spatiotemporal dynamics of soil-borne chemicals. This review outlines recent research regarding plant-derived Allelochemicals and signaling chemicals, as well as their roles in agricultural pest management. The effort represents a mechanistically exhaustive view of plant-organism interactions that are mediated by Allelochemicals and signaling chemicals and provides more realistic insights into potential implications and applications in sustainable agriculture.
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Mobility and Microbial Activity of Allelochemicals in Soil
Journal of Agricultural and Food Chemistry, 2013Co-Authors: Xiao-jing Li, Chui-hua Kong, Xiaohua XuAbstract:The action of Allelochemicals in soil needs their presence in the vicinity of the target plants. Using a soil TLC combined with bioassay approach, the mobility of 10 typical Allelochemicals was evaluated. Ferulic, p-hydroxymandelic, p-hydroxybenzoic, and vanillic acids always had the lowest mobility (Rf 0.5). The Rf values of daidzein, 1α-angeloyloxycarotol, DIMBOA, and m-tyrosine ranged from 0.24 to 0.32. Binary mixtures of these Allelochemicals led to an increase in mobility factors for selected combinations. Phospholipid fatty acid profiling indicated that there were different soil microbial communities in the segments containing Allelochemicals residues in the developed TLC soil layer. A difference in microbial community structure occurred between two nitrogenous DIMBOA and m-tyrosine and another eight Allelochemicals. The results suggest that the soil activity of Allelochemicals on bioassay species...
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Allelochemicals and activities in a replanted chinese fir cunninghamia lanceolata lamb hook tree ecosystem
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Chui-hua Kong, Peng Wang, Xinfu Xu, Liang Chen, Shuangxi WangAbstract:Autotoxicity is a major reason for replant problems in managed tree ecosystems. Studies have related phenolics-based Allelochemicals to autotoxicity. We selected a 20-year-old replanted Chinese fir [Cunninghamia lancealata (Lamb.) Hook] tree ecosystem to isolate, identify, determine the biological activity of, and quantify soil phytotoxins. Eight common phenolics (coumarin, vanillin, isovanillin, and p-hydroxybenzoic, vanillic, benzoic, cinnamic, and ferulic acids), friedelin, and a novel cyclic dipeptide (6-hydroxy-1,3-dimethyl-8-nonadecyl-[1,4]-diazocane-2,5-diketone) were obtained by using the bioassay-guided isolation technique from toxic soil of the replanted Chinese fir tree ecosystem. Chemical structures were determined by spectroscopic means, including 2D-NMR (COSY, HMQC, HMBC, and NOESY) experiments. High concentrations of soil phenolics and friedelin were observed in the natural evergreen broadleaf forest (CK) rather than in the Chinese fir tree ecosystem. The phenolics and friedelin were not phytotoxic to Chinese fir trees. However, the cyclic dipeptide inhibited Chinese fir growth at soil concentrations determined in the replanted Chinese fir tree ecosystem. There was a significantly higher soil concentration of cyclic dipeptide in the replanted Chinese fir tree ecosystem than in a fresh Chinese fir tree ecosystem. The results suggest that phenolics and friedelin are not key Allelochemicals since they are weakly phytotoxic and are detected in low concentrations in the replanted Chinese fir tree ecosystem, while cyclic dipeptide is a highly active allelochemical with a phytotoxic effect that limits offspring growth in the replanted Chinese fir tree ecosystem. The discovery of cyclic dipeptide, as well as a further understanding of its potential action mechanism in the replanted Chinese fir tree ecosystem, may contribute to solving the replant problems in managed tree ecosystems.
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fate and impact on microorganisms of rice Allelochemicals in paddy soil
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Chui-hua Kong, Peng Wang, Yucheng Gu, Xinfu Xu, M L WangAbstract:Allelopathic rice can release Allelochemicals from roots to inhibit neighboring plant species, but little is currently known about their fate and impact on microorganisms in paddy soil. This study showed that allelopathic rice P1312777 released much higher concentrations of allelochemical (5,7,4'-trihydroxy-3',5'-dimethoxyflavone) than non-allelopathic rice Liaojing-9 in field. When quantitative 5,7,4'-trihydroxy3',5'-dimethoxyflavone was added into soil, flavone gave a short half-life of 18.27 +/- 2.32 h (r(2) = 0.94) and could easily be degraded into benzoic acid. Benzoic acid with a half-life of 29.99 +/- 2.19 h (r(2) = 0.96) was more resistant toward degradation in paddy soil. Furthermore, both the culturable microbial population and the entire microbial community structure of soil incubated with flavone and benzoic acid were evaluated using the soil dilution plate method and phospholipid fatty acid (PLFA) analysis, respectively. It appeared from the results that flavone could reduce microorganisms especially for fungi present in paddy soil, while benzoic acid could induce a higher response for soil microorganisms especially for bacteria. Consequently, flavone would be responsible for the dynamics of soil microorganisms during the early period, and any observed effect during the late period would be very likely due to its degradation product. benzoic acid rather than flavone itself. These results suggested that allelopathic rice varieties could modify soil microorganisms to their advantage through the release of Allelochemicals. The concentration and fate of discriminating 5,7,4'-trihydroxy-3',5'-dimethoxyflavone between allelopathic and non-alleloparhic varieties tested in rice soil would result in the different patterns of microbial population and community structure in paddy ecosystems.
Min An - One of the best experts on this subject based on the ideXlab platform.
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12 . Recent Advances in Wheat Allelopathy
Allelopathy in Sustainable Agriculture and Forestry, 2008Co-Authors: Hanwen Wu, Deng Cai Liu, Jim Pratley, Min An, Deirdre LemerleAbstract:Wheat (Triticum aestivum), as one of the world's important crops, has been studied in depth for its allelopathic potential in weed management. Research on wheat allelopathy has progressed rapidly from the initial evaluation of allelopathic potential to the identification of Allelochemicals and genetic markers associated with wheat allelopathy. Allelopathic activity varied among wheat accessions. Significant varietal differences in the production of Allelochemicals were also found. In comparison with weakly allelopathic accessions, strongly allelopathic accessions produced significantly higher amounts of Allelochemicals in the shoots or roots of young seedlings, and also exuded larger amounts of Allelochemicals into the growth medium. Genetic markers associated with wheat allelopathy and plant cytochrome P450s encoding the biosynthesis of wheat Allelochemicals have been identified. Recent advances in metabolomics, transcriptomics and proteomics will greatly assist in the identification of novel allelopathy genes. Ultimately, the allelopathy genes could be manipulated to regulate the biosynthesis of Allelochemicals, thereby resulting in better weed suppression via elevated levels of allelopathic potential in commercial wheat cultivars.
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Implementation of card: curve-fitting allelochemical response data.
Nonlinearity in Biology Toxicology and Medicine, 2005Co-Authors: Min AnAbstract:: Bioassay techniques are essential methods used to study the effects of Allelochemicals on plant processes. It is often observed that the biological processes are stimulated at low allelochemical concentrations and inhibited as the concentrations increase. Liu et al., (2003) developed a simple model to fit this type of allelochemical response data. Based on the model, CARD (curve-fitting allelochemical response data) was developed as a Windows based program that can be used to fit a stimulation-inhibition response data. An example of using CARD is given.
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mathematical modelling of allelopathy ii the dynamics of Allelochemicals from living plants in the environment
Ecological Modelling, 2003Co-Authors: Min An, I R Johnson, J V LovettAbstract:The contents of Allelochemicals in living plants, and their fate and dynamics in environment are an important aspect in the study of allelopathy. A mechanistic model developed proposes that there are two kinds of allelochemical productions in a plant, which are dictated by age and plant stress, and are reflected by the corresponding dynamics in the environment. The decline of allelochemical contents in living plants with increasing age of plants may be a general case, while periodic production may be a special case. The ecological roles of such phenomena in plant allelopathy are discussed.
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distribution and exudation of Allelochemicals in wheat triticum aestivum
Journal of Chemical Ecology, 2000Co-Authors: Hanwen Wu, Jim Pratley, Deirdre Lemerle, T Haig, Min AnAbstract:Wheat allelopathy has potential for weed suppression. Allelochemicals were identified in wheat seedlings, and they were exuded from seedlings into agar growth medium. p-Hydroxybenzoic, trans-p-coumaric, cis-p-coumaric, syringic, vanillic, trans-ferulic, and cis-ferulic acids and 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) were identified in both the shoots and roots of 17-day-old wheat seedlings and their associated agar growth medium. Wheat accessions with previously identified allelopathic activity tended to contain higher levels of Allelochemicals than poorly allelopathic ones. The allelopathic compounds present in the shoots generally also were identified in the roots and in the agar medium. Allelochemicals were distributed differentially in wheat, with roots normally containing higher levels of Allelochemicals than the shoots. When the eight Allelochemicals were grouped into benzoic acid and cinnamic acid derivatives, DIMBOA, total coumaric, and total ferulic acids, the amount of each group of Allelochemicals was correlated between the roots and the shoots. Most of the Allelochemicals identified in the shoots and roots could be exuded by the living roots of wheat seedling into the agar growth medium. However, the amounts of Allelochemicals in the agar growth medium were not proportional to those in the roots. Results suggest that wheat plants may retain Allelochemicals once synthesized. The presence of Allelochemicals in the agar growth medium demonstrated that wheat seedlings were able to synthesize and to exude phytotoxic compounds through their root system that could inhibit the root growth of annual ryegrass.
Stephen O. Duke - One of the best experts on this subject based on the ideXlab platform.
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Is (−)-Catechin a Novel Weapon of Spotted Knapweed (Centaurea stoebe)?
Journal of Chemical Ecology, 2009Co-Authors: Stephen O. Duke, Franck E Dayan, Amy C. Blair, Robert D. Johnson, Kumudini M. Meepagala, Daniel Cook, Joanna BajsaAbstract:The novel weapons hypothesis states that some invasive weed species owe part of their success as invaders to allelopathy mediated by Allelochemicals that are new to the native species. Presumably, no resistance has evolved among the native species to this new allelochemical (i.e., the novel weapon). In their native habitat, however, the plants that co-evolved with these invasive species have theoretically evolved defenses that obviate the allelochemical advantage. Previous studies have claimed that catechin is such a novel weapon of spotted knapweed ( Centaurea stoebe = C. maculosa ), an invasive species in the non-native habitat of North America. These studies indicated that (−)-catechin is more phytotoxic than (+)-catechin. Other studies have not found sufficient catechin in field soils to support this theory. We report that (−)-catechin and (+)-catechin are essentially equal, but poorly phytotoxic to a variety of plant species in bioassays without soil. In a dose/response experiment with Montana soils, we found the lowest dose for a growth reduction of two native Montana grasses ( Koeleria macrantha and Festuca idahoensis ) by a racemic mixture of (±)-catechin that ranged from about 25 to 50 mM, concentrations, orders of magnitude higher than expected in nature. Autoclaving the soil before adding the catechin did not affect the activity of catechin. We found (−)-catechin to be a potent antioxidant, in contrast to a previous claim that it acts as an allelochemical by causing oxidative stress. Our findings suggest that catechin is not a novel weapon of spotted knapweed and that other allelochemical(s) or alternative mechanisms must be found to explain the success of this species as an invader in North America.
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biological activity of Allelochemicals
2009Co-Authors: Franck E Dayan, Stephen O. DukeAbstract:All plants produce compounds that are phytotoxic to another plant species at some concentration. In some cases, these compounds function, at least in part, in plant/plant interactions, where a phytotoxin donor plant adversely affects a target plant, resulting in an advantage for the donor plant. This review discusses how such an allelochemical role of a phytotoxin can be proven and provides examples of some of the more studied phytochemicals that have been implicated in allelopathy. These include artemisinin, cineoles, β-triketones, catechin, sorgoleone, juglone and related quinones, rice Allelochemicals, benzoxazinoids, common phenolic acids, l-DOPA, and m-tyrosine. Mechanisms of avoiding autotoxicity in the donor species are also discussed.
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Ecophysiological aspects of allelopathy
Planta, 2003Co-Authors: Stephen O. DukeAbstract:Allelochemicals play an important role in explaining plant growth inhibition in interspecies interactions and in structuring the plant community. Five aspects of Allelochemicals are discussed from an ecophysiological perspective: (i) biosynthesis, (ii) mode of release, (iii) mode of action, (iv) detoxification and prevention of autotoxicity, and (v) joint action of Allelochemicals. A discussion on identifying a compound as an allelochemical is also presented.
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searching for rice Allelochemicals
Agronomy Journal, 2001Co-Authors: Agnes M. Rimando, Franck E Dayan, Maria Olofsdotter, Stephen O. DukeAbstract:agement strategies for rice, which would be less dependent on synthetic herbicides. A bioactivity-guided isolation method was developed with the obThe search for Allelochemicals in rice necessitates jective of isolating the Allelochemicals in rice (Oryza sativa L.). Roots evaluating the activity in a laboratory set-up to distinof the allelopathic rice cultivar Taichung Native 1, grown hydroponiguish between competition and allelopathy, which cancally, were extracted and fractionated, with the activity of the fractions not be distinctly separated in field studies (Olofsdotter followed using a 24-well culture plate microbioassay. Some of the fractions obtained consisted of pure compounds, but none inhibited et al., 1997). Depending on one’s objectives, different the growth of barnyardgrass [Echinochloa crusgalli (L.) Beauv.] at methods could be followed in searching for active conthe lower concentration at which they were tested. Identified com- stituents from plants. These include bioassay-guided isopounds were azelaic acid; r-coumaric acid; 1H-indole-3-carboxalde- lation, fractionation-driven bioassay, isolate and assay, hyde; 1H-indole-3-carboxylic acid; 1H-indole-5-carboxylic acid; and and biochemical combinatorial chemistry approaches. 1,2-benzenedicarboxylic acid bis(2-ethylhexyl)ester. r-Coumaric acid, The advantages and disadvantages of each of these a known allelochemical, inhibited the germination of lettuce (Lactuca methods are discussed in more detail by Duke et al. sativa L.) seedlings at 1 mM. However, r-coumaric acid was active (2000a). We chose bioassay-guided isolation as the best against barnyardgrass only at concentrations higher than 3 mM. The way to proceed because the active component is not two most active fractions obtained from the bioassay-guided isolation known. were still a mixture of compounds as analyzed by gas chromatography‐ Bioassay-guided isolation integrates the processes of mass spectrometry (GC-MS). Further fractionation is being done to isolate and identify the allelochemical(s) in these active fractions. separation of compounds in a mixture, using various This work has demonstrated the use of bioassay-guided isolation in analytical methods, with results obtained from biologiidentifying Allelochemicals in rice and has correlated observed field cal testing. The process begins with testing an extract activity with laboratory experiments. to confirm its activity, followed by crude separation of the compounds in the matrix and testing the crude fractions (Fig. 1). Further fractionation is carried out
Giovanni Mauromicale - One of the best experts on this subject based on the ideXlab platform.
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Plant Allelochemicals: agronomic, nutritional and ecological relevance in the soil system
Plant and Soil, 2019Co-Authors: Aurelio Scavo, Cristina Abbate, Giovanni MauromicaleAbstract:Background Allelopathy is an ecological phenomenon consisting of both positive and negative effects between organisms determined by the release of secondary metabolites into the environment. Root exudation represents the most important pathway of releasing Allelochemicals. Once released into the soil, Allelochemicals interact with the organic and inorganic soil phases, as well as with soil microorganisms. The set of these interactions fix Allelochemicals bioavailability and phytotoxic level. Scope Here we critically review the interactions between plant Allelochemicals and physical, chemical and biological soil characteristics by reporting the literature available and pointing out both positive and negative relationships affecting Allelochemicals phytotoxicity and nutrient availability. In addition, we have reported a qualitative balance of Allelochemicals in the soil. Thirdly, we reviewed the exudation process of Allelochemicals and the transport mechanisms across plasma membranes. Conclusions A two-way relationship exists between soil characteristics and Allelochemicals. The level of phytotoxicity is not affected only by a single soil characteristic, but they are closely linked to each other and exert a multiple-effect on retention, transport and transformation processes of Allelochemicals in soil. Further efforts are needed to better understand the interactions involved in soil allelopathy and to create new opportunities for a sustainable control of agroecosystems.
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Plant Allelochemicals: agronomic, nutritional and ecological relevance in the soil system
Plant and Soil, 2019Co-Authors: Aurelio Scavo, Cristina Abbate, Giovanni MauromicaleAbstract:Allelopathy is an ecological phenomenon consisting of both positive and negative effects between organisms determined by the release of secondary metabolites into the environment. Root exudation represents the most important pathway of releasing Allelochemicals. Once released into the soil, Allelochemicals interact with the organic and inorganic soil phases, as well as with soil microorganisms. The set of these interactions fix Allelochemicals bioavailability and phytotoxic level. Here we critically review the interactions between plant Allelochemicals and physical, chemical and biological soil characteristics by reporting the literature available and pointing out both positive and negative relationships affecting Allelochemicals phytotoxicity and nutrient availability. In addition, we have reported a qualitative balance of Allelochemicals in the soil. Thirdly, we reviewed the exudation process of Allelochemicals and the transport mechanisms across plasma membranes. A two-way relationship exists between soil characteristics and Allelochemicals. The level of phytotoxicity is not affected only by a single soil characteristic, but they are closely linked to each other and exert a multiple-effect on retention, transport and transformation processes of Allelochemicals in soil. Further efforts are needed to better understand the interactions involved in soil allelopathy and to create new opportunities for a sustainable control of agroecosystems.
Hanwen Wu - One of the best experts on this subject based on the ideXlab platform.
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12 . Recent Advances in Wheat Allelopathy
Allelopathy in Sustainable Agriculture and Forestry, 2008Co-Authors: Hanwen Wu, Deng Cai Liu, Jim Pratley, Min An, Deirdre LemerleAbstract:Wheat (Triticum aestivum), as one of the world's important crops, has been studied in depth for its allelopathic potential in weed management. Research on wheat allelopathy has progressed rapidly from the initial evaluation of allelopathic potential to the identification of Allelochemicals and genetic markers associated with wheat allelopathy. Allelopathic activity varied among wheat accessions. Significant varietal differences in the production of Allelochemicals were also found. In comparison with weakly allelopathic accessions, strongly allelopathic accessions produced significantly higher amounts of Allelochemicals in the shoots or roots of young seedlings, and also exuded larger amounts of Allelochemicals into the growth medium. Genetic markers associated with wheat allelopathy and plant cytochrome P450s encoding the biosynthesis of wheat Allelochemicals have been identified. Recent advances in metabolomics, transcriptomics and proteomics will greatly assist in the identification of novel allelopathy genes. Ultimately, the allelopathy genes could be manipulated to regulate the biosynthesis of Allelochemicals, thereby resulting in better weed suppression via elevated levels of allelopathic potential in commercial wheat cultivars.
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distribution and exudation of Allelochemicals in wheat triticum aestivum
Journal of Chemical Ecology, 2000Co-Authors: Hanwen Wu, Jim Pratley, Deirdre Lemerle, T Haig, Min AnAbstract:Wheat allelopathy has potential for weed suppression. Allelochemicals were identified in wheat seedlings, and they were exuded from seedlings into agar growth medium. p-Hydroxybenzoic, trans-p-coumaric, cis-p-coumaric, syringic, vanillic, trans-ferulic, and cis-ferulic acids and 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) were identified in both the shoots and roots of 17-day-old wheat seedlings and their associated agar growth medium. Wheat accessions with previously identified allelopathic activity tended to contain higher levels of Allelochemicals than poorly allelopathic ones. The allelopathic compounds present in the shoots generally also were identified in the roots and in the agar medium. Allelochemicals were distributed differentially in wheat, with roots normally containing higher levels of Allelochemicals than the shoots. When the eight Allelochemicals were grouped into benzoic acid and cinnamic acid derivatives, DIMBOA, total coumaric, and total ferulic acids, the amount of each group of Allelochemicals was correlated between the roots and the shoots. Most of the Allelochemicals identified in the shoots and roots could be exuded by the living roots of wheat seedling into the agar growth medium. However, the amounts of Allelochemicals in the agar growth medium were not proportional to those in the roots. Results suggest that wheat plants may retain Allelochemicals once synthesized. The presence of Allelochemicals in the agar growth medium demonstrated that wheat seedlings were able to synthesize and to exude phytotoxic compounds through their root system that could inhibit the root growth of annual ryegrass.
