26 research outputs found

    The development of endomycorrhizal root systems VIII. Effects of soil phosphorus and fungal colonization on the concentration of soluble carbohydrates in roots

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    Concentrations of phosphorus in shoot and soluble carbohydrates (fructose, glucose, sucrose and fructans) in root were measured in non-mycorrhizal and vesicular-arbuscular (VA) mycorrhizal (Glomus mosseae) leek plants (Allium porrum) raised at six concentrations of soil phosphate. In conditions when an increased concentration of soil phosphate reduced VA mycorrhizal infection, the concentrations of soluble carbohydrates in the root were at a maximum. Therefore the hypothesis that greater concentrations of soluble carbohydrates in roots favour VA mycorrhizal infection is discounted. There was a specific effect of VA mycorrhizas, in that infected roots contained a larger concentration of sucrose than did uninfected roots, in plants with similar phosphorus concentrations in dry matter of shoots. We conclude, first, that increased phosphorus supply from either phosphate addition to soil or VA mycorrhizal infection increases concentration of soluble carbohydrates in leek roots and, secondly, that the VA mycorrhizal root behaves as a particularly strong physiological sink when there is an excess concentration of sucrose in the host

    Intracameral bevacizumab and mitomycin C Trabeculectomy for eyes with neovascular glaucoma: a case series

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    The purpose of this study was to describe the surgical outcomes and safety of intracameral bevacizumab during trabeculectomy in eyes with neovascular glaucoma. Pilot study included four eyes (four patients) with refractory neovascular glaucoma submitted to fornix-based trabeculectomy with adjunctive use of bevacizumab in the anterior chamber during the procedure. Patients were previously treated with panretinal photocoagulation as standard therapy. Variables evaluated were intraocular pressure, bleb appearance, iris neovascularization, intraoperative/postoperative complications, and visual outcomes. No intraoperative complication was observed. The mean follow-up period was 12.75 (range, 12–15 months). All eyes showed significant intraocular pressure control postoperatively. Iris neovascularization reduced significantly within 1 month after surgery. Mild anterior chamber inflammation was observed during follow-up in all eyes. No significant postoperative complication was observed, and no patient presented visual acuity deterioration. Intracameral bevacizumab may be used as an adjunctive therapy during trabeculectomy in eyes with neovascular glaucoma

    Nitrogen, phosphorus and potassium uptake and demand in Agrostis capillaris: the influence of elevated CO2 and nutrient supply.

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    Responses to elevated CO2 have been studied using Agrostis capillaris L., an upland grass which is abundant on nutrient-poor soils. Plants were grown in sand culture with a wide range of nitrogen, phosphorus and potassium concentrations, and the impact of CO2 on the demand for nutrients was determined using isotopic root bioassays. Plants grown with the smallest concentrations of N and P showed typical foliar symptoms associated with deficiency of these elements. However, even when supplies of N and P were limiting to growth, additional CO2 (250 ppm above ambient) influenced neither total N nor total P in above-ground tissues, nor nutrient demands as indicated by the bioassay. The estimates of the demand of the plants for K from the 86Rb bioassay indicated an appreciable increase when plants were raised in elevated CO2. For plants of the same size with the same nutrient supply, those grown in elevated CO2 consistently displayed an increased internal demand for K. Uptake of K was not however, enhanced by elevated CO2 even in non-limiting conditions and it might therefore be limited by a factor other than K supply. The overall conclusion from the experiments is that when A. capillaris is grown in elevated CO2, uptake of N, P and K fails to increase proportionally with dry mass. This was true even when nutrient supplies were adequate, and it appears that nutrient-use-efficiency might increase to enable the plants to maintain growth in elevated CO2
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