Root border cells take up and release glucose-C

被引:26
作者
Stubbs, VEC
Standing, D
Knox, OGG
Killham, K
Bengough, AG
Griffiths, B
机构
[1] Univ Aberdeen, Sch Biol Sci, Aberdeen AB21 7AL, Scotland
[2] Scottish Crop Res Inst, Plant Soil Interface Programme, Dundee DD2 5DA, Scotland
基金
英国生物技术与生命科学研究理事会;
关键词
glucose exchange; carbon flow; border cells; glucose uptake; sugar efflux;
D O I
10.1093/aob/mch019
中图分类号
Q94 [植物学];
学科分类号
071001 ;
摘要
Background and Aims Border cells are released from the root tips of many plant species, and can remain viable in the rhizosphere for 1 week. Whether border cells are capable of controlled glucose exchange with their environment was investigated. Methods Border cells were removed from Zea mays L. root tips, and immersed in C-14-labelled D-glucose. In one experiment, the hexose transport inhibitor, phlorizin, was used to investigate active glucose uptake from a range of glucose concentrations. In another experiment, glucose efflux from border cells was monitored over time. Key Results Glucose uptake by the border cells increased with increasing glucose concentration from 0.2 to 20 mM. At 0.2 mM glucose, uptake was mainly active, as evidenced by the approx. 60% inhibition with phlorizin. At 2 and 20 mm glucose, however, uptake was mainly via diffusion, as phlorizin inhibition was negligible. Glucose efflux increased with time for live border cells in both 2 and 20 mm glucose. There was no clear efflux/ time pattern for heat-killed border cells. Conclusions Border cells actively take up glucose, and also release it. Under our experimental conditions, glucose uptake and efflux were of similar order of magnitude. In the rhizosphere net glucose exchange will almost certainly depend on local soil conditions. (C) 2004 Annals of Botany Company.
引用
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页码:221 / 224
页数:4
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