To overcome soil nutrient limitation, many plants have developed complex nutrient acquisition strategies including altering root morphology, root hair formation or colonization by arbuscular mycorrhizal fungi (AMF). The interactions of these strategies and their plasticity are, however, affected by soil nutrient status throughout plant growth. Such plasticity is decisive for plant phosphorus (P) acquisition in P‐limited soils. We investigated the P acquisition strategies and their plasticity of two maize genotypes characterized by the presence or absence of root hairs. We hypothesized that in the absence of root hairs plant growth is facilitated by traits with complementary functions, e.g., by higher root mycorrhizal colonization. This dependence on complementary traits will decrease in P fertilized soils. At early growth stages, root hairs are of little benefit for nutrient uptake. Regardless of the presence or absence of root hairs, plants produced average root biomass of 0.14 g per plant and exhibited 23% root mycorrhizal colonization. At later growth stages of maize, contrasting mechanisms with functional complementarity explained similar plant biomass production under P limitation: the presence of root hairs versus higher root mycorrhizal colonization (67%) favored by increased fine root diameter in absence of root hairs. P fertilization decreased the dependence of plant on specific root traits for nutrient acquisition. Through root trait plasticity, plants can minimize trade‐offs for developing and maintaining functional traits, while increasing the benefit in terms of nutrient acquisition and plant growth. The present study highlights the plasticity of functional root traits for efficient nutrient acquisition strategies in agricultural systems with low nutrient availability. 相似文献
Arbuscular mycorrhizal fungi (AMF) play an important role in plants growth and soils dynamic in all most ecosystems. The main objective of the present study was to evaluate the plant-AMF interactions on soil functions under arid protected area ‘Zarat-Gabès’ in Tunisia.
AMF colonization was evaluated by visual observation of AMF in fine roots of eight herbaceous plants. The level of mycorrhizal colonization varied between plants. Astragalus corrugatus and Hippocrepis areolata showed the highest mycorrhizal performance. The relative spore number was significantly different across rhizosphere soils. Statistical analysis showed a clearly positive correlation between the number of spores and plant-mycorrhizal intensity.
For microbiological parameters, our results showed that mycorrhizal plants improved significantly the various microbiological parameters. Rhizosphere soils of Astragalus corrugatus and Hippocrepis areolata presented the necessary microbial densities and microorganisms more stable compared to unplanted soil. This study allowed obtaining a new result that challenges us about the need for efficient management of natural resources in the objective of nature conservation. 相似文献
Grapevine leaves are widely discarded in open fields despite their known antioxidant properties. We tested the cytotoxicity of leaf extracts from three clones (CL-260, CL-1048, CL-8) of Vitis vinifera L. cv. Tempranillo against four human cancer cell lines: colon, HT-29; breast, MCF-7; lung HTB-54; and lymphoblastic leukemia, CCRF-CEM. Grapevines were cultivated at either ambient (24/14 °C) or elevated (28/18 °C) day/night temperatures, and inoculated (+M) or not (-M) with arbuscular mycorrhizal fungi (AMF). Cytotoxicity was analysed by MTT assays. Elevated air temperatures enhanced the cytotoxicity of leaf extracts from CL-260 against HT-29, CCRF-CEM and HTB-54 and that from CL-8 against MCF-7. Mycorrhization improved the cytotoxicity of leaf extracts from CL-1048 against HT-29, CCRF-CEM, HTB-54 and MCF-7. The cytotoxic activities of CL-260 against HTB-54 and CL-1048 against HT-29 were correlated, respectively, with total phenols and total antioxidant capacity. We conclude that the predicted increase in air temperature for the future climate and the mycorrhizal association of grapevines may enhance the cytotoxicity of leaves, which strengthens the potential application of these agricultural residuals for biomedicine. However, the clonal diversity in the response to AMF and air temperature highlights the importance of choosing the most adequate clone for a concrete environmental scenario. 相似文献
Arbuscular mycorrhizal fungi(AMF)in the soil encompass a diversity of species and play an important role in maintaining ecosystem balance.However,little research has focused on the AMF diversity of Rosa acicularis Lindl.’Luhe’,which has been cultivated in northeastern saline areas,because of its strong salt tolerance and cold resistance.In the present study the AMF in the rhizosphere of R.acicularis Luhe were identified and AMF diversity and community composition were assessed using morphological and molecular techniques.Vesicles,hyphae,and arbuscular structures were observed in seedlings of different ages.Result shows that AMF established a good symbiotic relationship with R.acicularis Luhe.The colonization rate and spore density tended to increase over time.The AMF diversity in the rhizosphere of R.acicularis Luhe was low and four species of AMF were validated:Rhizophagus irregularis,Glomus aggregatum,Septoglomus furcatum,and Funneliformis mosseae.Of these,R.irregularis and G.aggregatum were dominant and have high salt tolerance.Determining the AMF diversity in the rhizosphere of R.acicularis Luhe will aid in screening AMF species with strong resistance and using mycorrhizas for plant establishment in breeding programs. 相似文献
Seasonal variation of mycorrhization attributes in a degraded ecosystem seems to be key information in conceiving rehabilitation programs that use mycorrhized plantations specific to that ecosystem. In order to record seasonality of arbuscular mycorrhizal fungi in an Atlantic sand dunes forest, root colonization and spores abundance alongside rhizospheric phosphorus and nitrogen of two plant species: Juniperus phoenicea and Retama monosperma, endemic to Essaouira sand dunes forest, were followed through three years. The findings were tested for statistical significance and correlated among each and to some meteorological variables: temperatures, precipitations, and humidity. Results showed that mycorrhization frequencies and intensities and spores densities changed seasonally. They had their peak at late winter-early spring and their low at summer. Phosphorus and nitrogen evolved significantly following seasons. Significant negative correlation was noted between phosphorus and mycorrhizal attributes evolution. Nitrogen correlated positively and significantly though weakly with R. monosperma mycorrhizal attributes. The correlations between mycorrhizal attributes and meteorological variables were not all evident except for temperatures and temperatures-precipitations combination, which had a direct negative impact on mycorrhizal attributes. 相似文献