Phosphorus availability changes the internal and external endomycorrhizal colonization and affects symbiotic effectivenes

Nogueira, Marco Antônio; Cardoso, Elke Jurandy Bran Nogueira

doi:10.1590/s0103-90162007000300013

Cited by 17 publications

(12 citation statements)

References 17 publications

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“…Nevertheless, mycorrhizal colonized plants and metaltolerant fungal ecotypes have been found in metal contaminated soils (Hildebrandt et al, 2007), and so they may have higher potential for phytoremediation purposes than non-metal adapted ecotypes. Recently, Nogueira and Cardoso (2007) observed a relationship between intra-radical colonization, extra-radical mycelium length and mycorrhizal effectiveness which may be mutually affected by P availability. Our data corroborate these findings since we observed a positive correlation (r 2 = 0.571, P < 0.003) between root colonization and the amount of extra-radical mycelium, showing the relation between fungal intra-radical colonization rate and its extra-radical development.…”

Section: Discussionmentioning

confidence: 99%

Mycorrhiza influence on maize development under Cd stress and P supply

Andrade

Silveira

2008

Braz. J. Plant Physiol.

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The role of arbuscular mycorrhizal fungi (AMF) on cadmium (Cd) accumulation and on the possible attenuation of Cd stress was studied in maize plants (Zea mays L. var. Exceller). Plants inoculated or not with Glomus macrocarpum were exposed to Cd (0-20 µmol L -1 ), at two P levels (5 and 10 mg L -1 ) in the nutrient solution. The experiment was conducted in a hydroponic system, using a randomized 2 x 2 x 2 factorial design. The mycorrhiza-Cd interaction on plant growth, nutrients and Cd accumulation, AMF root colonization and on extra-radical mycelium was investigated. Mycorrhiza promoted plant growth whereas Cd addition reduced plant biomass production. No difference in plant Cd concentrations was found between mycorrhizal (M) and non-mycorrhizal (NM) plants, where Cd accumulated mainly in roots. In general, roots showed a slightly higher Cd concentration in the cell wall than in the cytoplasmic fraction, with M roots presenting 26% more Cd in the cell wall fraction than NM roots. Mycorrhizal plants showed higher P/Cd, N/Cd and S/Cd ratios in shoots and roots compared to NM plants. Mycorrhizal colonization and the length of extra-radical mycelium were diminished by Cd addition, the reduction being more pronounced under high-P supply. Addition of Cd induced guaiacol peroxidase (GPOX) activity in roots; however, M plants, in addition to the higher root protein contents, showed no induction of GPOX activity in the presence of Cd, suggesting higher tolerance to Cd. It is concluded that Cd affected mycorrhizal symbiosis by decreasing root colonization and the development of the extraradical mycelium. Nevertheless, the higher growth and nutrients/Cd ratios observed in M plants indicate an efficient symbiosis capable of alleviating Cd stress. Key words: arbuscular mycorrhizal fungi, Cd distribution, extra-radical mycelium, heavy metals, peroxidase, phosphorus Micorriza influencia o desenvolvimento do milho sob estresse de Cd e suprimento de P: A influência dos fungos micorrízicos arbusculares (FMA) no acúmulo e na atenuação potencial do estresse causado pelo Cd foi estudada em plantas de milho (Zea mays L. var. Exceller). Plantas associadas ou não com o FMA Glomus macrocarpum foram expostas ao Cd (0-20 mmol L -1 ) em dois níveis de P (5 e 10 mg L -1 ), em solução nutritiva. O experimento foi conduzido em sistema hidropônico, com delineamento totalmente casualizado, em esquema fatorial 2 x 2 x 2. Avaliou-se o efeito da interação micorriza-Cd sobre o crescimento da planta, o acúmulo de Cd e de nutrientes, a colonização micorrízica da raiz e a produção de micélio extra-radical. A micorriza promoveu o crescimento da planta enquanto a adição de Cd reduziu a produção de biomassa vegetal. Não foram observadas diferenças nas concentrações de Cd de plantas micorrizadas (M) e não-micorrizadas (NM), acumulando-se o Cd principalmente nas raízes. Em geral, as raízes mostraram maior concentração de Cd na fração da parede celular do que na citoplasmática, sendo que raízes de plantas M apresentaram quantidade de Cd 26% maior na fração...

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Section: Discussionmentioning

confidence: 99%

Mycorrhiza influence on maize development under Cd stress and P supply

Andrade

Silveira

2008

Braz. J. Plant Physiol.

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“…1B). Many researchers showed that application of high P levels suppressed root colonization of AM fungi in host plants [12][13][14] . The results from this study showed a much smaller effect of P on root colonization by AM fungi than those reported.…”

Section: Resultsmentioning

confidence: 99%

“…The results from this study showed a much smaller effect of P on root colonization by AM fungi than those reported. For example, Nogueira and Cardoso 14 reported that root colonization of Gigaspora rosea and Glomus intraradices in soybean decreased sharply with increasing P levels from 50 to 200 mg/kg soil. The key to this difference may be the existence of a diverse population of local AM fungi that respond differently to soil conditions.…”

Section: Resultsmentioning

confidence: 99%

Untitled

Youpensuk¹,

Lordkaew

Rerkasem³

2008

ScienceAsia

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There are many tangerine (Citrus reticulata) orchards in northern Thailand. These orchards are supplied with different levels of fertilizers. The objective of this study is to investigate arbuscular mycorrhizal (AM) fungi associated with tangerine in Chiang Mai province, northern Thailand, and the effect of AM fungi on the growth of the air layered tangerine variety 'Sai Num Phung' with different levels of nitrogen (N) and phosphorus (P) fertilizers in a pot experiment. Percentage of AM colonization in the tangerine roots and spore density in the rhizosphere varied significantly with the available P levels in the orchard soil. Means of root colonization and spore density were significantly depressed at >500 mg P/kg soil. Twenty-two species of AM fungi were found to be associated with tangerine in orchards of the Chiang Mai province. The effects of AM fungi, and N and P fertilizers on air layered tangerine plants were investigated in pots for ten months. AM fungi increased growth of the host plant especially in pots with N but without P fertilizers. AM fungi increased concentrations of P and Mg in leaves of tangerine. Application of N and P fertilizers depressed root colonization of AM fungi in the pot experiment. This study has shown that a wide range of AM fungi is associated with tangerine in commercial orchards, but with high levels of N and P fertilizers the increase in growth of tangerine trees due to the association with AM fungi may be limited.

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“…Manganese was extracted with 1 mol L -1 NH 4 AO c (pH 7.0) solution at 1:10 soil-to-solution ratio, incubated with shaking for 6 min, centrifuged at 2500 rpm for 10 min, and determined by ICP (Inductively Coupled Plasma). The mycorrhizal effectiveness (ME) was calculated based on the total leaf area per plant variable: ME = (total leaf area of the mycorrhizal plant -total leaf area of non-mycorrhizal plant) / total leaf area of nonmycorrhizal plant x 100 (Nogueira and Cardoso, 2007). Results were submitted to the analysis of variance (ANOVA) test considering both AMF inoculation and P addition level factors.…”

Section: Methodsmentioning

confidence: 99%