SEARCH · PubMed Health

Results for “root exudates”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 289 records · Page 16Linked to original sources

PubMed2004

Differential accumulation of Cd in durum wheat cultivars: uptake and retranslocation as sources of variation.

Durum wheat (Triticum turgidum L. var. durum) accumulates Cd from the soil depending on various factors. When grown in hydroponic solution containing Cd (20 microg l(-1)), roots had higher tissue Cd concentrations than shoots or heads. Kyle (the higher grain-Cd accumulating cultivar) had lower root-Cd, and greater shoot-Cd and head-Cd concentrations than Arcola (the lower grain-Cd accumulating cultivar). These cultivar differences were greater at flowering and ripening than at tillering. Much of the root-Cd was lost between the flowering and ripening stages of development. Distribution of (106)Cd among plant parts, after a single 24 h feeding, demonstrated that root-to-shoot transfer of Cd in Arcola was similar to that of Kyle at tillering, but it had ceased at flowering in Arcola but not Kyle. None of the Cd in wheat heads at ripening originated from (106)Cd exposure in the previous 24 h, suggesting that grain-Cd is a function of total shoot accumulation. Both cultivars demonstrated basipetal translocation of Cd; Arcola at tillering translocated more Cd from shoots to roots than Kyle. The proportion of Cd(2+)/Cd(total) in the nutrient solution decreased with time, suggesting that plant activity altered the solution chemistry. The alteration probably resulted from either preferential depletion of solution Cd(2+) and/or addition of root exudates. Lower grain-Cd accumulation in Arcola possibly resulted from a combination of reduced root-to-shoot transfer of Cd at flowering, as well as enhanced shoot-to-root retranslocation of Cd, at least in younger plants. Plant-mediated changes in solution-Cd speciation did not play a role.

Biological Transport↗

PubMed2000

[Factors affecting colonization of introduced microorganisms on plant roots].

Microorganisms such as biological control agents (BCA), plant growth-promoting rhizobacteria (PGPR) and yield increasing bacteria (YIB) were introduced along growing roots. The colonization process of introduced bacteria was proved that they attached root tipfirst, then distributed along roots, multiplicated there, and survived as certain population size. The colonization location was closely related with root exudates, which was usually at the junction between cortex cells or at the base of lateral roots or root hairs. The variation of colonization by introduced microorganisms in the rhizosphere was caused by biotic and abiotic factors. Biotic factors included the physiological characters of introduced microorganisms and interactions between introduced microorganisms and native microbes. The more important factors were plant genotypes which associated with introduced beneficial microbes and regulated the population and community of those microbes affecting the colonization of introduced microorganisms. Abiotic factors here referred to soil environmental conditions, e.g., soil texture, water content, soil temperature and pH value.

Ecosystem↗

PubMed1996

Phosphorus deficiency in Lupinus albus. Altered lateral root development and enhanced expression of phosphoenolpyruvate carboxylase.

The development of clustered tertiary lateral roots (proteoid roots) and the expression of phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) in roots were studied in white lupin (Lupinus albus L.) grown with either 1 mM P (+P-treated) or without P (-P-treated). The +P-treated plants initiated fewer clustered tertiary meristems and the emergence of these meristems was delayed compared with - P-treated plants. Proteoid root zones could be identified 9 d after emergence in both P treatments. Amounts of PEPC mRNA, PEPC specific activity, and enzyme protein were greater in proteoid roots than in normal roots beginning at 10, 12, and 14 d after emergence, respectively. The increases in PEPC mRNA, PEPC enzyme, and PEPC specific activity suggest that this enzyme is in part under transcriptional regulation. Recovery of organic acids from root exudates coincided with the increases in PEPC specific activity. The -P-treated plants exuded 40-, 20-, and 5-fold more citrate, malate, and succinate, respectively, than did +P-treated plants. Data presented support the hypothesis that white lupin has concerted regulation of proteoid root development, transcriptional regulation of PEPC, and biosynthesis of organic acids for exudation in response to P deficiency.

Fabaceae↗

PubMed2003

Interactions in the tomato rhizosphere of two Pseudomonas biocontrol strains with the phytopathogenic fungus Fusarium oxysporum f. sp. radicis-lycopersici.

The fungus Fusarium oxysporum f. sp. radicis-lycopersici causes foot and root rot of tomato plants, which can be controlled by the bacteria Pseudomonas fluorescens WCS365 and P. chlororaphis PCL1391. Induced systemic resistance is thought to be involved in biocontrol by P. fluorescens WCS365. The antifungal metabolite phenazine-1-carboxamide (PCN), as well as efficient root colonization, are essential in the mechanism of biocontrol by P. chlororaphis PCL1391. To understand the effects of bacterial strains WCS365 and PCL1391 on the fungus in the tomato rhizosphere, microscopic analyses were performed using different autofluorescent proteins as markers. Tomato seedlings were inoculated with biocontrol bacteria and planted in an F. oxysporum f. sp. radicis-lycopersici-infested gnotobiotic sand system. Confocal laser scanning microscope analyses of the interactions in the tomato rhizosphere revealed that i) the microbes effectively compete for the same niche, and presumably also for root exudate nutrients; ii) the presence of either of the two bacteria negatively affects infection of the tomato root by the fungus; iii) both biocontrol bacteria colonize the hyphae extensively, which may represent a new mechanism in biocontrol by these pseudomonads; and iv) the production of PCN by P. chlororaphis PCL1391 negatively affects hyphal growth and branching, which presumably affects the colonization and infecting ability of the fungus.

Fusarium↗

PubMed2004

Microbial products trigger amino acid exudation from plant roots.

Plants naturally cycle amino acids across root cell plasma membranes, and any net efflux is termed exudation. The dominant ecological view is that microorganisms and roots passively compete for amino acids in the soil solution, yet the innate capacity of roots to recover amino acids present in ecologically relevant concentrations is unknown. We find that, in the absence of culturable microorganisms, the influx rates of 16 amino acids (each supplied at 2.5 microm) exceed efflux rates by 5% to 545% in roots of alfalfa (Medicago sativa), Medicago truncatula, maize (Zea mays), and wheat (Triticum aestivum). Several microbial products, which are produced by common soil microorganisms such as Pseudomonas bacteria and Fusarium fungi, significantly enhanced the net efflux (i.e. exudation) of amino acids from roots of these four plant species. In alfalfa, treating roots with 200 microm phenazine, 2,4-diacetylphloroglucinol, or zearalenone increased total net efflux of 16 amino acids 200% to 2,600% in 3 h. Data from (15)N tests suggest that 2,4-diacetylphloroglucinol blocks amino acid uptake, whereas zearalenone enhances efflux. Thus, amino acid exudation under normal conditions is a phenomenon that probably reflects both active manipulation and passive uptake by microorganisms, as well as diffusion and adsorption to soil, all of which help overcome the innate capacity of plant roots to reabsorb amino acids. The importance of identifying potential enhancers of root exudation lies in understanding that such compounds may represent regulatory linkages between the larger soil food web and the internal carbon metabolism of the plant.

Amino Acids↗

PubMed1991

Inoculation of Vicia sativa subsp. nigra roots with Rhizobium leguminosarum biovar viciae results in release of nod gene activating flavanones and chalcones.

Flavonoids released by roots of Vicia sativa subsp. nigra (V. sativa) activate nodulation genes of the homologous bacterium Rhizobium leguminosarum biovar viciae (R. l. viciae). Inoculation of V. sativa roots with infective R. l. viciae bacteria largely increases the nod gene-inducing ability of V. sativa root exudate (A.A.N. van Brussel et al., J Bact 172: 5394-5401). The present study showed that, in contrast to sterile roots and roots inoculated with R. l. viciae cured of its Sym plasmid, roots inoculated with R. l. viciae harboring its Sym plasmid released additional nod gene-inducing flavonoids. Using 1H-NMR, the structures of the major inducers released by inoculated roots, 6 flavanones and 2 chalcones, were elucidated. Roots extracts of (un)inoculated V. sativa contain 4 major non-inducing, most likely glycosylated, flavonoids. Therefore, the released flavonoids may either derive from the root flavonoids or inoculation with R. l. viciae activates de novo flavonoid biosynthesis.

Chalcone↗

PubMed2002

Reduced Cd accumulation in Zea mays: a protective role for phytosiderophores?

Cadmium is a nonessential trace metal and a frequent soil contaminant. Because plants vary in their accumulation of Cd, an understanding of the specific processes that control uptake could reveal methods for reducing Cd levels in edible plant tissues and conversely increasing Cd accumulation in plants used for phytoremediation. Phytosiderophores are iron chelators excreted by graminaceous plants under conditions of iron limitation, but they also complex other metals including cadmium. Here we examine the influence of Cd exposure on phytosiderophore production by hydroponically grown maize. Cd increased the rate of the phytosiderophore 2'-deoxymugineic acid (DMA) release under both Fe-sufficient and Fe-limiting conditions (+/-Fe). In addition, the -Fe plants released more DMA while taking up less Cd than the +Fe plants. In other short-term Cd uptake experiments, plants exposed to Cd in the presence of root exudates in which the DMA-Cd complex was likely the dominant Cd species displayed reduced Cd accumulation in root tissue, and plants similarly exposed to strongly chelated Cd in the presence of EDTA (employed as a positive control) contained the least Cd. Collectively, these results indicate that Cd stress causes Fe deficiency symptoms that result in greater DMA production by maize roots, and then the DMA appears to reduce Cd accumulation.

Azetidinecarboxylic Acid↗

PubMed2006

The two-component colR/S system of Pseudomonas fluorescens WCS365 plays a role in rhizosphere competence through maintaining the structure and function of the outer membrane.

Pseudomonas fluorescens strain PCL1210, a competitive tomato root tip colonization mutant of the efficient root colonizing wild type strain WCS365, is impaired in the two-component sensor-response regulator system ColR/ColS. Here we show that a putative methyltransferase/wapQ operon is located downstream of colR/colS and that this operon is regulated by ColR/ColS. Since wapQ encodes a putative lipopolysaccharide (LPS) phosphatase, the possibility was studied that the integrity of the outer membrane of PCL1210 was altered. Indeed, it was shown that mutant PCL1210 is more resistant to various chemically unrelated antibiotics which have to pass the outer membrane for their action. In contrast, the mutant is more sensitive to the LPS-binding antibiotic polymyxin B. Mutant PCL1210 loses growth in competition with its wild type when grown in tomato root exudate. Mutants in the methyltransferase/wapQ operon are also altered in their outer membrane permeability and are defective in competitive tomato root tip colonization. A model for the altered outer membrane of PCL1210 is discussed.

Adaptation, Physiological↗

PubMed2004

Proton-transfer-reaction mass spectrometry as a new tool for real time analysis of root-secreted volatile organic compounds in Arabidopsis.

Plant roots release about 5% to 20% of all photosynthetically-fixed carbon, and as a result create a carbon-rich environment for numerous rhizosphere organisms, including plant pathogens and symbiotic microbes. Although some characterization of root exudates has been achieved, especially of secondary metabolites and proteins, much less is known about volatile organic compounds (VOCs) released by roots. In this communication, we describe a novel approach to exploring these rhizosphere VOCs and their induction by biotic stresses. The VOC formation of Arabidopsis roots was analyzed using proton-transfer-reaction mass spectrometry (PTR-MS), a new technology that allows rapid and real time analysis of most biogenic VOCs without preconcentration or chromatography. Our studies revealed that the major VOCs released and identified by both PTR-MS and gas chromatography-mass spectrometry were either simple metabolites, ethanol, acetaldehyde, acetic acid, ethyl acetate, 2-butanone, 2,3,-butanedione, and acetone, or the monoterpene, 1,8-cineole. Some VOCs were found to be produced constitutively regardless of the treatment; other VOCs were induced specifically as a result of different compatible and noncompatible interactions between microbes and insects and Arabidopsis roots. Compatible interactions of Pseudomonas syringae DC3000 and Diuraphis noxia with Arabidopsis roots resulted in the rapid release of 1,8-cineole, a monoterpene that has not been previously reported in Arabidopsis. Mechanical injuries to Arabidopsis roots did not produce 1,8-cineole nor any C6 wound-VOCs; compatible interactions between Arabidopsis roots and Diuraphis noxia did not produce any wound compounds. This suggests that Arabidopsis roots respond to wounding differently from above-ground plant organs. Trials with incompatible interactions did not reveal a set of compounds that was significantly different compared to the noninfected roots. The PTR-MS method may open the way for functional root VOC analysis that will complement genomic investigations in Arabidopsis.

Animals↗

PubMed1982

Collection and Identification of Allelopathic Compounds from the Undisturbed Root System of Bigalta Limpograss (Hemarthria altissima).

Collection of allelopathic chemicals from the undisturbed plant root system is difficult because of their low concentrations and the high level of contaminants in growth media such as soil. A new approach for the continuous trapping of quantities of extracellular chemicals from donor plants is described. Bigalta limpograss (Hemarthria altissima), a tropical forage with allelopathic activities, was established in sand culture. Nutrient solution was circulated continuously through the root system and a column containing XAD-4 resin. Extracellular hydrophobic metabolites were selectively adsorbed by the resin, while inorganic nutrients were recycled to sustain plant growth. Columns were eluted with methanol and the eluate separated into neutral, acidic, and basic fractions. Bioassays of trapped root exudates using lettuce seed combined with paper and thin layer chromatography showed that the inhibitors were mainly phenolic compounds. The active neutral fraction was methylated and analyzed by gas chromatography-mass spectrometry. Twelve compounds were identified, with two additional compounds tentatively identified. 3-Hydroxyhydrocinnamic, benzoic, phenylacetic, and hydrocinnamic acids were the major rhizospheric compounds with known growth regulatory activities.Inasmuch as the root system was undisturbed and the recovery of exudates was highly efficient compared to conventional solvent extraction methods, this trapping system should be useful for a wide range of studies that relate to the chemistry of the rhizosphere.

Journal Article↗

PubMed2002

The effect of nitrogen nutrition on cluster root formation and proton extrusion by Lupinus albus.

Nitrogen nutrition can influence cluster root formation in many wild species, but the effect of N form on cluster root formation and root exudation by white lupin is not known. In a solution culture study, we examined the effect of N nutrition (ammonium, nitrate, both or N2 fixation) on cluster root formation and H+ extrusion by white lupin plants under deficient and adequate P supply. The number of cluster roots increased greatly when plants were supplied with I microM P compared with 50 microM P, the increase being 7.8-fold for plants treated with (NH4)2SO4, 3-fold for plants treated with KNO3 and NH4NO3, and 2-4-fold for N2-fixing plants. Under P deficiency. NH4+-N supply resulted in production of a greater number and biomass of cluster roots than other N sources. Dry weight of cluster roots was 30 % higher than that of non-cluster roots in P-deficient plants treated with (NH4)2SO4 and NH4NO3. In plants treated with sufficient P (50 microM), the weight of non-cluster roots was approx. 90 % greater than that of cluster roots. Both total (micromol per plant h(-1)) and specific (micromol g(-1) root d. wt h(-1)) H+ extrusions were greatest from roots of plants supplied with (NH4)2SO4, followed by those supplied with NH4NO3 and N2 fixation, whereas plants receiving KNO3 had negative net H+ extrusion between the third and fifth week of growth (indicating uptake of protons or release of OH- ions). The rate of proton extrusion by NH4+-N-fed plants was similar under P-deficient and P-sufficient conditions. In contrast, proton exudation by N2-fixing plants and KNO3-treated plants was ten-fold greater under P deficiency than under P sufficiency. In comparison with P deficiency, plants treated with 50 microM P had a significantly higher concentration of P in roots, shoots and youngest expanded leaves (YEL). Compared with the N2 fixation and KNO3 treatments, total N concentration was highest in roots, shoots and YEL of plants supplied with (NH4)2SO4 and NH4NO3, regardless of P supply. Under P deficiency, K concentrations in roots decreased at all N supplies, especially in plants treated with (NH4)2SO4 and NH4NO3, which coincided with the greatest H+ extrusion at these P and N supplies. In conclusion, NH4-N nutrition stimulated cluster root formation and H+ extrusion by roots of P-deficient white lupin.

Biomass↗

PubMed1989

Interactions among Flavonoid nod Gene Inducers Released from Alfalfa Seeds and Roots.

Alfalfa (Medicago sativa L.) seeds and roots can create complex rhizosphere effects by releasing flavonoids that induce nodulation (nod) genes in Rhizobium meliloti. Previous reports identified luteolin and 4,4'-dihydroxy-2'-methoxychalcone as strong inducers that are released from seeds and roots, respectively, and 4',7-dihydroxyflavone and 4',7-dihydroxyflavanone as weaker inducers which are exuded by roots. As a first step toward identifying flavonoid interactions that may occur in the rhizosphere, combinations of these molecules were tested for transcriptional effects on a nodABC-lacZ fusion in R. meliloti. At low concentrations (e.g. 8.4 nanomolar), interactions of the three nod gene inducers from root exudate were additive. When the strong inducers 4,4'-dihydroxy-2'-methoxychalcone and luteolin were present separately at higher concentrations (e.g. 21 nanomolar), their effect could be decreased significantly by the weaker inducers 4',7-dihydroxyflavone and 4',7-dihydroxyflavanone. In contrast, when low concentrations of luteolin from seed rinses and 4,4'-dihydroxy-2'-methoxychalcone from root exudate were present together, they produced synergistic increases in nod gene transcription. Tests with mixtures of the three nod gene inducers from root exudate indicated that alfalfa seedlings might easily decrease the strong inductive effect of the chalcone by releasing modest amounts of the weaker inducers. In addition, mixtures of luteolin and the nod gene inducers in root exudate suggested that interactions between nod gene inducers from seeds and roots may create a zone highly favorable to root nodule formation near the top of the primary root.

Journal Article↗

PubMed1991

Temperature-dependent water and ion transport properties of barley and sorghum roots : I. Relationship to leaf growth.

Root temperature strongly affects shoot growth, possibly via "nonhydraulic messengers" from root to shoot. In short-term studies with barley (Hordeum vulgare L.) and sorghum (Sorghum bicolor L.) seedlings, the optimum root temperatures for leaf expansion were 25 degrees and 35 degrees C, respectively. Hydraulic conductance (L(p)) of both intact plants and detached exuding roots of barley increased with increasing root temperature to a high value at 25 degrees C, remaining high with further warming. In sorghum, the L(p) of intact plants and of detached roots peaked at 35 degrees C. In both species, root temperature did not affect water potentials of the expanded leaf blade or the growing region despite marked changes in L(p). Extreme temperatures greatly decreased ion flux, particularly K(+) and NO(3) (-), to the xylem of detached roots of both species. Removing external K(+) did not alter short-term K(+) flux to the xylem in sorghum but strongly inhibited flux at high temperature in barley, indicating differences in the sites of temperature effects. Leaf growth responses to root temperature, although apparently "uncoupled" from water transport properties, were correlated with ion fluxes. Studies of putative root messengers must take into account the possible role of ions.

Journal Article↗

PubMed1985

Strain-specific chemotaxis of Azospirillum spp.

Chemotactic responses of three Azospirillum strains originating from different host plants were compared to examine the possible role of chemotaxis in the adaptation of these bacteria to their respective hosts. The chemotaxis to several sugars, amino acids, and organic acids was determined qualitatively by an agar plate assay and quantitatively by a channeled-chamber technique. High chemotactic ratios, up to 40, were obtained with the latter technique. The chemotactic response did not rely upon the ability of the bacteria to metabolize the attractant. Rather, it depended on the attractant concentration and stereoconfiguration. Chemotaxis was found to be strain specific. Differences were particularly observed between a wheat isolate and strains originating from the C4-pathway plants maize and Leptochloa fusca. In contrast to the other two strains, the wheat isolate was strongly attracted to D-fructose, L-aspartate, citrate, and oxalate. The other strains showed maximal attraction to L-malate. The chemotactic responses to organic acids partially correlate with the exudation of these acids by the respective host plants. Additionally, a heat-labile, high-molecular-weight attractant was found in the root exudates of L. fusca, which specifically attracted the homologous Azospirillum strain. It is proposed that strain-specific chemotaxis probably reflects an adaptation of Azospirillum spp. to the conditions provided by the host plant and contributes to the initiation of the association process.

Chemotaxis↗

PubMed2000

Roots of nutrient-deprived Brachiaria species accumulate 1,3-di-O-trans-feruloylquinic acid.

A novel di-hydroxycinnamoylquinic acid ester, 1,3-di-O-trans-feruloylquinic acid (DFQA), was isolated from roots of nutrient-deprived Brachiaria species--the most widely sown tropical forage grasses in South America. In contrast to other so far characterized quinic-acid esters, DFQA exists in a chair conformation with the carboxylic group in the axial orientation. It accumulates in older parts of the root system, but not in root apices or shoots. Higher levels were found in B. ruziziensis, which is poorly adapted to infertile acid soils, than in well adapted B. decumbens. DFQA was also found in the soil, most likely as a result of root decay, because it was not detected in root exudates of plants cultivated in solution culture. Nitrogen and phosphorus deficiency--but not aluminum toxicity or deprivation of other nutrients--stimulated its synthesis in roots. Its accumulation was correlated with a shift in biomass partitioning toward the root system.

Coumaric Acids↗

PubMed1999

Rhizosphere bacteria enhance selenium accumulation and volatilization by indian mustard

Indian mustard (Brassica juncea L.) accumulates high tissue Se concentrations and volatilizes Se in relatively nontoxic forms, such as dimethylselenide. This study showed that the presence of bacteria in the rhizosphere of Indian mustard was necessary to achieve the best rates of plant Se accumulation and volatilization of selenate. Experiments with the antibiotic ampicillin showed that bacteria facilitated 35% of plant Se volatilization and 70% of plant tissue accumulation. These results were confirmed by inoculating axenic plants with rhizosphere bacteria. Compared with axenic controls, plants inoculated with rhizosphere bacteria had 5-fold higher Se concentrations in roots (the site of volatilization) and 4-fold higher rates of Se volatilization. Plants with bacteria contained a heat-labile compound in their root exudate; when this compound was added to the rhizosphere of axenic plants, Se accumulation in plant tissues increased. Plants with bacteria had an increased root surface area compared with axenic plants; the increased area was unlikely to have caused their increased tissue Se accumulation because they did not accumulate more Se when supplied with selenite or selenomethionine. Rhizosphere bacteria also possibly increased plant Se volatilization because they enabled plants to overcome a rate-limiting step in the Se volatilization pathway, i.e. Se accumulation in plant tissues.

Journal Article↗

PubMed2001

Heritable variation in quinone-induced haustorium development in the parasitic plant Triphysaria.

We are using the facultative hemiparasite, Triphysaria, as a model for studying host-parasite signaling in the Scrophulariaceae. Parasitic members of this family form subterranean connections, or haustoria, on neighboring host roots to access host water and nutrients. These parasitic organs develop in response to haustorial-inducing factors contained in host root exudates. A well-characterized inducing factor, 2, 6-dimethoxy-p-benzoquinone (DMBQ), can be used to trigger in vitro haustorium formation in the roots of Triphysaria. We have assayed three species, Triphysaria eriantha (Benth.) Chuang and Heckard, Triphysaria pusilla (Benth.) Chuang and Heckard, and Triphysaria versicolor Fischer and C. Meyer, for haustorium development in response to DMBQ. There were significant differences between the species in their ability to recognize and respond to this quinone. Ninety percent of T. versicolor individuals responded, whereas only 40% of T. pusilla and less than 10% of T. eriantha formed haustoria. Within field collections of self-pollinating T. pusilla, differential responsiveness to DMBQ was seen in distinct maternal families. Assaying haustorium development in subsequent generations of self-pollinated T. pusilla showed that DMBQ responsiveness was heritable. Reciprocal crosses between T. eriantha and T. versicolor demonstrated that DMBQ responsiveness was influenced by maternal factors. These results demonstrate heritable, natural variation in the recognition of a haustorial-inducing factor by a parasitic member of the Scrophulariaceae.

Asteraceae↗

PubMed2005

Dependence of arbuscular-mycorrhizal fungi on their plant host for palmitic acid synthesis.

Lipids are the major form of carbon storage in arbuscular-mycorrhizal fungi. We studied fatty acid synthesis by Glomus intraradices and Gigaspora rosea. [(14)C]Acetate and [(14)C]sucrose were incorporated into a synthetic culture medium to test fatty acid synthetic ability in germinating spores (G. intraradices and G. rosea), mycorrhized carrot roots, and extraradical fungal mycelium (G. intraradices). Germinating spores and extraradical hyphae could not synthesize 16-carbon fatty acids but could elongate and desaturate fatty acids already present. The growth stimulation of germinating spores by root exudates did not stimulate fatty acid synthesis. 16-Carbon fatty acids (16:0 and 16:1) were synthesized only by the fungi in the mycorrhized roots. Our data strongly suggest that the fatty acid synthase activity of arbuscular-mycorrhizal fungi is expressed exclusively in the intraradical mycelium and indicate that fatty acid metabolism may play a major role in the obligate biotrophism of arbuscular-mycorrhizal fungi.

Acetates↗