Effects Of Arbuscular Mycorrhizal Colonization Research Articles

LbKAT3 may assist in mycorrhizal potassium uptake, and overexpression of LbKAT3 may promote potassium, phosphorus, and water transport from arbuscular mycorrhizal fungi to the host plant.

Potassium plays important roles in most plant physiological processes. Arbuscular mycorrhizal (AM) fungi promote plant water and mineral nutrient acquisition to promote plant growth. However, few studies have focused on the effect of AM colonization on potassium uptake by the host plant. In this study, the effects of an AM fungus (Rhizophagus irregularis) and potassium concentration (0, 3, or 10 mM K+) on Lycium barbarum were evaluated. A split-root test with L. barbarum seedlings was conducted, and the potassium uptake capacity of LbKAT3 was verified in yeast. A tobacco line overexpressing LbKAT3 was generated and mycorrhizal functions under two potassium concentrations (0.2 and 2 mM K+) were studied. Inoculation of R. irregularis and application of potassium increased the dry weight, and potassium and phosphorus contents of L. barbarum, and increased the colonization rate and arbuscule abundance of R. irregularis. In addition, the expression of LbKAT3 and AQP genes in L. barbarum was upregulated. Inoculation of R. irregularis induced LbPT4, Rir-AQP1, and Rir-AQP2 expression, and application of potassium upregulated the expression of these genes. Inoculation with the AM fungus locally regulated the expression of LbKAT3. Inoculation of R. irregularis improved the growth, and potassium and phosphorus contents, and induced NtPT4, Rir-AQP1, and Rir-AQP2 expression in tobacco overexpressing LbKAT3 under both potassium concentrations. Overexpression of LbKAT3 in tobacco improved the growth, potassium accumulation, and AM colonization, and upregulated the expression of NtPT4 and Rir-AQP1 in mycorrhizal tobacco. The results suggest that LbKAT3 may assist in mycorrhizal potassium uptake, and overexpression of LbKAT3 may promote potassium, phosphorus, and water transport from the AM fungus to tobacco.

Analysis of the AMT gene family in chili pepper and the effects of arbuscular mycorrhizal colonization on the expression patterns of CaAMT2 genes

BackgroundAmmonium (NH4+) is a key nitrogen source supporting plant growth and development. Proteins in the ammonium transporter (AMT) family mediate the movement of NH4+ across the cell membrane. Although several studies have examined AMT genes in various plant species, few studies of the AMT gene family have been conducted in chili pepper.ResultsHere, a total of eight AMT genes were identified in chili pepper, and their exon/intron structures, phylogenetic relationships, and expression patterns in response to arbuscular mycorrhizal (AM) colonization were explored. Synteny analyses among chili pepper, tomato, eggplant, soybean, and Medicago revealed that the CaAMT2;1, CaAMT2.4, and CaAMT3;1 have undergone an expansion prior to the divergence of Solanaceae and Leguminosae. The expression of six AMT2 genes was either up-regulated or down-regulated in response to AM colonization. The expression of CaAMT2;1/2;2/2;3 and SlAMT2;1/2;2/2;3 was significantly up-regulated in AM fungi-inoculated roots. A 1,112-bp CaAMT2;1 promoter fragment and a 1,400-bp CaAMT2;2 promoter fragment drove the expression of the β-glucuronidase gene in the cortex of AM roots. Evaluation of AM colonization under different NH4+ concentrations revealed that a sufficient, but not excessive, supply of NH4+ promotes the growth of chili pepper and the colonization of AM. Furthermore, we demonstrated that CaAMT2;2 overexpression could mediate NH4+ uptake in tomato plants.ConclusionIn sum, our results provide new insights into the evolutionary relationships and functional divergence of chili pepper AMT genes. We also identified putative AMT genes expressed in AM symbiotic roots.

Protective Effects of Arbuscular Mycorrhizae against Fusarium Oxysporum F. Sp. Ranunculi in Ranunculus Asiaticus Cultivations for Flower Crop

The protective effects of arbuscular mycorrhizal colonization provided by use of Glomus sp. commercial formulates in Ranunculus Asiaticus against Fusarium Oxysporum F. Sp. Ranunculi have been evaluated. Soil parcels infected with the pathogen spores (1 × 108 CFU/ml) were used as substrates for Ranunculus Asiaticus plants: half of them with mycorrhized roots, and the other half without the fungal symbionts.

Local and distal effects of arbuscular mycorrhizal colonization on direct pathway Pi uptake and root growth in Medicago truncatula.

Two pathways exist for plant Pi uptake from soil: via root epidermal cells (direct pathway) or via associations with arbuscular mycorrhizal (AM) fungi, and the two pathways interact in a complex manner. This study investigated distal and local effects of AM colonization on direct root Pi uptake and root growth, at different soil P levels. Medicago truncatula was grown at three soil P levels in split-pots with or without AM fungal inoculation and where one root half grew into soil labelled with (33)P. Plant genotypes included the A17 wild type and the mtpt4 mutant. The mtpt4 mutant, colonized by AM fungi, but with no functional mycorrhizal pathway for Pi uptake, was included to better understand effects of AM colonization per se. Colonization by AM fungi decreased expression of direct Pi transporter genes locally, but not distally in the wild type. In mtpt4 mutant plants, direct Pi transporter genes and the Pi starvation-induced gene Mt4 were more highly expressed than in wild-type roots. In wild-type plants, less Pi was taken up via the direct pathway by non-colonized roots when the other root half was colonized by AM fungi, compared with non-mycorrhizal plants. Colonization by AM fungi strongly influenced root growth locally and distally, and direct root Pi uptake activity locally, but had only a weak influence on distal direct pathway activity. The responses to AM colonization in the mtpt4 mutant suggested that in the wild type, the increased P concentration of colonized roots was a major factor driving the effects of AM colonization on direct root Pi uptake.

Effect of soil salinity and nutrient levels on the community structure of the root-associated bacteria of the facultative halophyte, Tamarix ramosissima, in southwestern United States.

Tamarix ramosissima is a tree species that is highly resistant to salt and drought. The Tamarix species survives in a broad range of environmental salt levels, and invades major river systems in southwestern United States. It may affect root-associated bacteria (RB) by increasing soil salts and nutrients. The effects of RB on host plants may vary even under saline conditions, and the relationship may be important for T. ramosissima. However, to the best of our knowledge, there have been no reports relating to T. ramosissima RB and its association with salinity and nutrient levels. In this study, we have examined this association and the effect of arbuscular mycorrhizal colonization of T. ramosissima on RB because a previous study has reported that colonization of arbuscular mycorrhizal fungi affected the rhizobacterial community (Marschner et al., 2001). T. ramosissima roots were collected from five locations with varying soil salinity and nutrient levels. RB community structures were examined by terminal restriction fragment (T-RF) length polymorphism, cloning, and sequencing analyses. The results suggest that RB richness, or the diversity of T. ramosissima, have significant negative relationships with electrical conductivity (EC), sodium concentration (Na), and the colonization of arbuscular mycorrhizal fungi, but have a significant positive relationship with phosphorus in the soil. However, at each T-RF level, positive correlations between the emergence of some T-RFs and EC or Na were observed. These results indicate that high salinity decreased the total number of RB species, but some saline-tolerant RB species multiplied with increasing salinity levels. The ordination scores of nonmetric multidimensional scale analysis of RB community composition show significant relationships with water content, calcium concentration, available phosphorus, and total nitrogen. These results indicate that the RB diversity and community composition of T. ramosissima are affected by soil salinity and nutrient levels. Sequence analysis detected one Bacteroidetes and eight Proteobacteria species. Most 16S rRNA gene sequences had high similarities with the bacteria isolated from saline conditions, indicating that at least a portion of the RB species observed in T. ramosissima was halotolerant.

Influence of arbuscular mycorrhiza on growth and reproductive response of plants under water deficit: a meta-analysis

Despite a large body of literature that describes the effects of arbuscular mycorrhizal colonization on plant response to water deficit, reviews of these works have been mainly in narrative form, and it is therefore difficult to quantify the magnitude of the effect. We performed a meta-analysis to examine the effect of mycorrhizal colonization on growth and yield of plants exposed to water deficit stress. Data were compared in the context of annual vs. perennial plants, herbaceous vs. woody plants, field vs. greenhouse conditions, degree of stress, functional group, regions of plant growth, and mycorrhizal and host species. We found that, in terms of biomass measurements, mycorrhizal plants have better growth and reproductive response under water stress compared to non-mycorrhizal plants. When variables such as habit, life cycle, or water stress level are considered, differences in mycorrhizal effect on plant growth between variables are observed. While growth of both annual and perennial plants is improved by symbiosis, perennials respond more favorably to colonization than annuals. Overall, our meta-analysis reveals a quantifiable corroboration of the commonly held view that, under water-deficit conditions, plants colonized by mycorrhizal fungi have better growth and reproductive response than those that are not.

A study on the effects of lead, cadmium and phosphorus on the lead and cadmium uptake efficacy of Viola baoshanensis inoculated with arbuscular mycorrhizal fungi

The effect of indigenous arbuscular mycorrhizal (AM) fungi on lead (Pb) and cadmium (Cd) uptake by the hyperaccumulator plant Viola baoshanensis was studied in greenhouse pot experiments. Seedlings of V. baoshanensis inoculated without or with indigenous AM fungi were grown in paddy soil with the addition of Pb at 0, 500, 1000 and 1500 mg kg(-1), or of Cd at 0, 50,100, 200 mg kg(-1), or in mine soil with the addition of phosphorus at 0, 50, 250, 500 mg kg(-1). AM colonization increased shoot biomass at low phosphorus levels, and this beneficial effect was diminished or reversed by high phosphorus availability. AM colonization decreased shoot Cd concentrations regardless of the availability of Cd and phosphorus, but the mechanisms involved varied with Cd availability. At low Cd bioavailability, reduced Cd uptake was due to decreased Cd translocation from the roots to the shoots, whereas that was attributed to reduced root uptake at high Cd bioavailability. In contrast, the effect of AM colonization on shoot Pb varied with the availability of phosphorous and Pb. Our results show that the interactions between V. baoshanensis and indigenous AM fungi were modified by the availability of Pb, Cd and phosphorus.

Effects of Arbuscular Mycorrhizal Colonization on Soybean Nutrient Uptake during Ripening Period with Barley Cover Cropping

前作のオオムギを登熟期に刈り敷き，不耕起でダイズを栽培するオオムギカバークロップ―不耕起ダイズ栽培には増収効果が認められるが，養分的な効果がその要因であることが示唆されている．その一つとして，ダイズのアーバスキュラー菌根菌（以下AM菌）感染率向上によるリン吸収の促進が考えられる．AM菌による生育促進効果の報告は，生育初期についてのものがほとんどだが，本研究では子実生産と関係の深い着莢期以降のダイズの生育，AM菌感染率，収穫期のリン集積量および根粒重についてカバークロップ―ダイズ栽培1作目および3作目の二つの圃場で調査を行い，AM菌がダイズ収量に及ぼす影響を解析した．その結果，1作目圃場では，ダイズ収量は単作区に比較してカバークロップ区で高かったが，3作目圃場では，両区間の差異は明らかでなかった．カバークロップ区では，1作目，3作目圃場ともに着莢期のAM菌感染率は高かった．葉色値は1作目圃場では子実肥大期から成熟始期まで単作区より高い傾向がみられたが，3作目圃場では開花始期および成熟始期のみで高かった．根粒重はカバークロップ区で高い傾向が認められた．これらのことから1作目圃場のカバークロップ区では，着莢期までAM菌感染率が高く維持されたことによるリン吸収の促進と，AM菌感染率の向上による根粒菌着生期間の拡大に伴う窒素吸収の増加が増収に貢献したと判断された．一方，3作目圃場におけるカバークロップ区では窒素が制限要因となって増収効果がみられなかったものと考えられた．

Effects of Arbuscular Mycorrhizal Colonization on the Growth of Upland Rice (Oryzal Sativa L.) in Soil Experimentally Contaminated with Cu and Pb

A pot culture experiment was carried out to investigate the roles of Glomus mosseae in plant Cu and Pb acquisition by Oryzal sativa L., and Cu-Pb interactions. Cu was applied to the soil with different Cu levels including 0 (Cu0), 100 (Cu100), 200 (Cu200) mg kg-1 and Pb addition including 0, 300, 600 mg kg-1. All the treatments were designed with (+M) or without (-M) Glomus mosseae as randomized block. The results indicated that Cu addition and Pb addition decreased root colonization significantly. AM (arbuscular mycorrhizal) inoculation increased the root biomass under all the Cu and Pb treatments and increased the shoot biomass under Cu200 with Pb600 treatments observably compared with -M treatments. +M treatments enhanced plant Cu acquisition by Oryzal sativa L. compared with -M treatments except for shoot Cu uptake of Cu200-Pb300 treatments. However, plant Cu concentrations were decreased markedly by the root colonization under all the Cu-Pb interactions except for shoot Cu concentrations of Cu200-Pb600 treatments compared with –M treatments. Irrespective of Cu and Pb addition levels, +M plant had higher Pb uptake than –M plants. On the contrary, the roots of +M plants had significantly lower Pb concentrations than those of –M plant.

Effects of Arbuscular Mycorrhizal Colonization on Microbial Community in Rhizosphere Soil and Fusarium Wilt Disease in Tomato

Fusarium wilt is caused by soil-borne pathogen Fusarium oxysporum. Tomato (Lycopersicon esculentum Mill.) is susceptible to Fusarium oxysporum f. sp. lycopersici race 1 and was infected with wilt disease. A pot experiment was conducted to investigate effects of inoculating arbuscular mycorrhizal (AM) fungus (Glomus etunicatium) on the microbial community in the rhizosphere soil and Fusarium wilt in tomato (cv. Oogatafukuju). The results indicated that AM fungal inoculation suppressed the Fusarium number in the rhizosphere soil of tomato and decreased the Fusarium wilt disease index. Compared to the control, AM fungal inoculation increased the actinomycete number but increased bacterial number. Bacterial and fungal numbers were high but actinomycetes number was low when tomato basal stems became discolored brown. Fusarium inoculation significantly suppressed development of AM colonization and decreased polyphenol oxidase (PPO) activity in leaves and roots of tomato. Inoculation with AM fungi and Fusarium maintained high PPO activity in leaves and roots. The AM colonization increased root growth of tomato, whereas Fusarium inoculation had no significant effect on tomato growth. These findings suggest that because AM fungal inoculation changes microbial communities and enhances PPO activity, it should suppress occurrence of Fusarium wilt in tomato.

Nickel remediation by AM-colonized sunflower

This greenhouse study aimed to examine the contribution of arbuscular mycorrhizal (AM) colonization on the uptake of and tolerance to nickel (Ni) in sunflower (Helianthus annuus L.). We hypothesized that AM colonization increases Ni content and tolerance in sunflower grown under varying soil Ni concentrations. The combined effect of AM colonization and soil Ni input on the assimilation of nitrogen, in particular the activity of glutamine synthetase (GS), in sunflower plants was also investigated. A factorial experimental design was performed with sunflower cv. Lemon Queen, with or without the AM fungus, Glomus intraradices Schenck & Smith, and treated with 0, 100, 200, or 400 mg Ni kg(-1) dry soil (DS). The AM colonization significantly enhanced plant growth and Ni content, especially at the lower soil Ni treatments. Furthermore, the AM plants exposed to the highest soil Ni level of 400 mg Ni kg(-1) DS had a significantly higher shoot Ni extracted percentage than non-AM plants, suggesting that the AM symbiosis contributed to Ni uptake, then its translocation from roots to shoots. The AM colonization also significantly increased the GS activity in roots, this being likely an indicator of an enhanced Ni tolerance. These findings support the hypothesis that AM symbiosis contributes to an enhanced Ni plant uptake and tolerance and should be considered as part of phytoremediation strategies.

Effect of Arbuscular Mycorrhizal Colonization on Nitrogen and Phosphorus Uptake and Growth of Aloe vera L.

The effect of arbuscular mycorrhizal (AM) colonization on nitrogen (N) and phosphorus (P) uptake and shoot growth of Aloe vera was investigated. Plants were inoculated with one of two AM fungi, Glomus clarum or Gigaspora decipiens. Control plants were not inoculated. Plants were grown under glasshouse conditions in a peat land soil without fertilizers for 12 months. Inoculated A. vera plants were colonized with AM fungi. Total length of leaves and number of leaves were higher in inoculated plants than uninoculated plants 12 months after inoculation. Shoot N and P concentrations were higher in inoculated plants than uninoculated plants. Shoot fresh weight was increased by AM colonization. This result suggests that AM colonization can increase the nutrient uptake and growth of A. vera.

Effect of arbuscular mycorrhizal colonization and two levels of compost supply on nutrient uptake and flowering of pelargonium plants

Two challenges frequently encountered in the production of ornamental plants in organic horticulture are: (1) the rate of mineralization of phosphorus (P) and nitrogen (N) from organic fertilizers can be too slow to meet the high nutrient demand of young plants, and (2) the exclusive use of peat as a substrate for pot-based plant culture is discouraged in organic production systems. In this situation, the use of beneficial soil microorganisms in combination with high quality compost substrates can contribute to adequate plant growth and flower development. In this study, we examined possible alternatives to highly soluble fertilizers and pure peat substrates using pelargonium (Pelargonium peltatum L'Her.) as a test plant. Plants were grown on a peat-based substrate with two rates of compost addition and with and without arbuscular mycorrhizal (AM) fungi. Inoculation with three different commercial AM inocula resulted in colonization rates of up to 36% of the total root length, whereas non-inoculated plants remained free of root colonization. Increasing the rate of compost addition increased shoot dry weight and shoot nutrient concentrations, but the supply of compost did not always completely meet plant nutrient demand. Mycorrhizal colonization increased the number of buds and flowers, as well as shoot P and potassium (K) concentrations, but did not significantly affect shoot dry matter or shoot N concentration. We conclude that addition of compost in combination with mycorrhizal inoculation can improve nutrient status and flower development of plants grown on peat-based substrates.

Effects of AM colonization on “wild tobacco” plants grown in zinc-contaminated soil

This greenhouse study aimed to determine the effect of colonization by the arbuscular mycorrhizal (AM) fungus (Glomus intraradices Schenck & Smith) on the "wild" tobacco (Nicotiana rustica L. var. Azteca), under soil-zinc (Zn) conditions. Plants of N. rustica were grown in AM or non-AM inoculated substrate and subjected to four soil-[Zn] concentrations (0, 50, 100, and 250 mg Zn kg(-1) dry soil). The AM root colonization increased markedly from 14 to 81% with the increasing soil-[Zn] and the mycorrhizal structures were significantly more abundant at the highest soil-[Zn], suggesting that Zn may be involved directly or indirectly in AM root colonization. In addition, total Zn content or Zn concentrations in shoots and roots were shown to increase as soil-[Zn] increased in both AM and non-AM plants. As for the growth parameters studied, there were no significant differences between treatments despite the increase in Zn content or concentration. The AM roots subjected to the highest soil-[Zn] had a significant reduction by about 50% of total Zn content and Zn concentration compared to non-AM roots. Still, the relative extracted Zn percentage decreased dramatically as soil-[Zn] increased. Soil pH was significantly lower in non-AM than AM treatments at the highest soil-[Zn]. In summary, AM plants (particularly roots) showed lower Zn content and concentration than non-AM plants. In this regard, the AM fungi have a protective role for the host plant, thus playing an important role in soil-contaminant immobilization processes; and, therefore, are of value in phytoremediation, especially when heavy metals approach toxic levels in the soil.

Effects of arbuscular mycorrhizal fungi and soil developmental stages on herbaceous plants growing in the early stage of primary succession on Mount Fuji

AbstractA pot culture experiment was conducted to examine the effects of arbuscular mycorrhizal (AM) fungi and soil developmental stages on the growth and nutrient absorption of pioneer plants growing in the early stage of primary succession on Mt. Fuji. Four herbaceous plants, Polygonum cuspidatum (Polygonaceae), Miscanthus oligostachyus (Gramineae), Aster ageratoides var. ovatus (Compositae), and Hedysarum vicioides (Leguminosae), were grown from seed in soils collected from two different successional stages, bare ground and an herbaceous plant community. Spores of indigenous AM fungi collected from the herbaceous plant community were used as inoculum. The initial colonizer P. cuspidatum showed very low levels of AM colonization (<0.4%), whereas the average AM colonization levels of M. oligostachyus, A. ageratoides var. ovatus, and H. vicioides were within the range of 13–49%. AM fungi had positive effects on the growth and N acquisition of the leguminous species (H. vicioides) irrespective of soil developmental stages. In contrast, AM colonization did not increase the plant dry weight and N content of the non‐leguminous species (P. cuspidatum, M. oligostachyus, and A. ageratoides var. ovatus) in both soil developmental stages. A positive effect of AM colonization on P content was observed in M. oligostachyus, A. ageratoides var. ovatus, and H. vicioides only in soil collected from the herbaceous plant community. P. cuspidatum showed no or a negative response to AM colonization in all cases. These results suggest that the effect of AM fungi on plant growth depends more on the plant species than soil developmental stages in the early stage of primary succession in this volcanic area.

Effects of arbuscular mycorrhizal colonization and phosphorus application on nuclear ploidy in Allium porrum plants

Arbuscular mycorrhizal (AM) colonization can strongly affect the plant cell nucleus, causing displacement from the periphery to the center of the cell, hypertrophy and polyploidization. The hypertrophy response has been shown in a variety of AM plants whilst polyploidization has been reported only in Lycopersicon esculentum, a multiploid species with a small genome. In order to determine whether polyploidization is a general plant response to AM colonization, analyses were performed on Allium porrum, a plant with a large genome, which is much less subject to polyploidization than L. esculentum. The ploidy status of leaves, complete root systems and four zones of the adventitious roots was investigated in relation to phosphorus content, AM colonization and root differentiation in A. porrum plants grown under two different regimes of phosphate nutrition in order to distinguish direct effects of the fungus from those of improved nutrition. Results showed the presence of two nuclear populations (2C and 4C) in all treatments and samples. Linear regression analyses suggested a general negative correlation between phosphorus content and the proportion of 2C nuclei. The percentage of 2C nuclei (and consequently that of 4C nuclei), was also influenced by AM colonization, differentiation and ageing of the root cells, which resulted in earlier occurrence, in time and space, of polyploid nuclei.

Multitrophic links between arbuscular mycorrhizal fungi and insect parasitoids

AbstractThe effects of arbuscular mycorrhizal colonization of Leucanthemum vulgare on parasitism of a leaf‐mining insect was studied in a field and a laboratory experiment. In the field, parasitism of Chromatomyia syngenesiae by Diglyphus isaea was lower on mycorrhizal plants, compared with plants where the association was reduced. A laboratory experiment, in which L. vulgare was inoculated with three species of AM fungi, showed that the effects on parasitism rates were mycorrhizal species‐dependent. Some fungal combinations increased parasitism, some decreased it, while others had no effect. It is concluded that the most likely cause of these differences is plant size, with parasitoid searching efficiency being reduced on the larger plants, resulting from certain mycorrhizal species combinations. However, a mycorrhizal effect on herbivore‐produced plant volatiles cannot be ruled out.

Effects of nutrients and arbuscular mycorrhizal colonization on the growth of Salix gracilistyla seedlings in a nutrient‐poor fluvial bar

A field survey and a pot culture experiment were conducted to examine the effects of nutrients (N and P) and arbuscular mycorrhizal (AM) fungi on the growth of Salix gracilistyla, a pioneer plant in riparian habitats. The plants growing in the field were colonized by AM and/or ectomycorrhizal fungi. However, the direct effect of AM colonization on seedling growth was not detected in the pot culture experiment. In contrast, N application significantly promoted plant growth, suggesting that the growth of S. gracilistyla seedlings is largely limited by the availability of N in the field.

Uptake of 15 trace elements in arbuscular mycorrhizal marigold: Measured by the multitracer technique

The effect of arbuscular mycorrhizal (AM) colonization on the uptake of trace elements in marigold (Tagetes patula L.) was studied using a multitracer consisting of radionuclides of 7Be, 22Na, 46Sc, 51Cr, 54Mn, 59Fe, 56Co, 65Zn, 74As, 75Se, 83Rb, 85Sr, 88Y, 88Zr, and 95mTc. Marigold plants were grown under controlled environmental conditions in sand culture either without mycorrhizas or in association with an AM fungus, Glomus etunicatum. The multitracer was applied to the pot, and plants were harvested at 7 and 21 d after tracer application. We found that the uptake of 7Be, 22Na, 51Cr, 59Fe, 65Zn, and 95mTc was higher in the mycorrhizal marigolds than in the non-mycorrhizal ones, while that of 46Sc, 56Co, 83Rb, and 85Sr was lower in the mycorrhizal marigolds than in the non-mycorrhizal ones. Thus, the multitracer technique enabled to analyze the uptake of various elements by plant simultaneously. It is suggested that this technique could be used to analyze the effects of AM colonization on the uptake of trace elements by plant.

Effect of arbuscular mycorrhizal colonization of four species of glomus on physiological responses of maize

This greenhouse study aimed to analyze the impact of arbuscular mycorrhizal (AM) fungal associations on maize (Zea mays L. hybrid Pioneer 3905) in order to compare their functional compatibility and efficiency. The AM fungus species used for this study were Glomus aggregatum, G. etunicatum, G. mosseae, and G. versiforme. Shoot and leaf masses, chlorophyll, soluble protein, total and reducing sugar, carbon (C), and nitrogen (N) concentrations, and glutamine synthetase (GS) activity in the maize leaves were analyzed. The root colonization ranged from 26% to 72% depending on the AM fungus species. Leaf mass was significantly higher when maize plants were colonized with G. etunicatum in comparison to the non‐AM control. The mycorrhizal effect on dry leaf mass ranged from 15.9% to 23.9% depending on the AM species. However, the total shoot mass did not differ significantly among the treatments. The mycorrhizal treatment had a marginally significant effect on the chlorophyll concentrations in maize leaves. The protein concentration was the highest in the plants colonized with G. etunicatum and the N percentage was significantly higher in the leaves of plants colonized by G. versiforme or G. aggregatum than those with G. mosseae. However, the AM colonization did not significantly alter the GS activity among the treatments. The highest sugar concentrations were detected in the leaves of plants colonized by G. versiforme. The sugar concentrations as well as the C percentage were lower in the leaves of plants colonized by G. etunicatum compared to the other mycorrhizal treatments but the values were comparable to the non‐AM control. Our overall results suggest that the expression of the mycorrhizal potential in the maize host plants varies among AM fungal species.