Root influx parameters (Vmax and Km) of wheat (Triticum aestivum var. HD-2285) were determined at different stages of crop growth, viz. CRIS-Crown Root Initiation Stage, MTS-Maximum Tillering Stage, FLS-Flag Leaf Stage and DFS-Dough Formation Stage. Wheat was grown in sand medium with Hoagland nutrient solution (all nutrients except potassium). Plants were taken out from sand culture at 22, 41,...

The ion influx isotherms obtained by measuring unidirectional influx across root membranes with radioactive or stable tracers are mostly interpreted by enzyme-substrate-like modeling. However, recent analyses from ion transporter mutants clearly demonstrate the inadequacy of the conventional interpretation of ion isotherms. Many genetically distinct carriers are involved in the root catalytic f...

A novel technique was developed to spatially map the phosphorus net influx capacity in intact root systems. The method is based on digital autoradiography and permits the quantification of phosphorus influx at high spatial resolution (2 mm). Roots of 18-d-old common bean plants were exposed to (32)P-labelled orthophosphate, quickly frozen, excised, lyophilized, scanned, and exposed to a storage...

Using (13)NO(3) (-), effects of various NO(3) (-) pretreatments upon NO(3) (-) influx were studied in intact roots of barley (Hordeum vulgare L. cv Klondike). Prior exposure of roots to NO(3) (-) increased NO(3) (-) influx and net NO(3) (-) uptake. This ;induction' of NO(3) (-) uptake was dependent both on time and external NO(3) (-) concentration ([NO(3) (-)]). During induction influx was posi...

The protein family of anion channel (ClC) constitute a family of transmembrane trnsporters that either function as anion channel or as H+/anion exchanger. The expression of three genes of AtClCa, AtClCb and AtClCd in the model plant Arabidopsis thaliana were silenced by a T-DNA insertion . When the pH of the medium was slightly acidic the length of the primary root of plants with a disrupted At...

Free oxygen radicals are an irrefutable component of life, underlying important biochemical and physiological phenomena in animals. Here it is shown that free oxygen radicals activate plasma membrane Ca(2+)- and K(+)-permeable conductances in Arabidopsis root cell protoplasts, mediating Ca(2+) influx and K(+) efflux, respectively. Free oxygen radicals generate increases in cytosolic Ca(2+) medi...

Roots of Fe-sufficient and Fe-Deficient pea (Pisum sativum L.) were studied to determine the effect of Fe-deficiency on the activity of the root-cell plasmalemma Fe(2+) transport protein. Rates of Fe(III) reduction and short-term Fe(2+) influx were sequentially determined in excised primary lateral roots using Fe(III)-ethylene-diaminetetraacetic acid (Fe[III]-EDTA). Since the extracellular Fe(2...

Regulated auxin patterning provides a key mechanism for controlling root growth and development. We have developed a data-driven mechanistic model using realistic root geometry and formulated a principle to theoretically investigate quantitative auxin pattern recovery following auxin transport perturbation. This principle reveals that auxin patterning is potentially controlled by multiple combi...

BACKGROUND AND AIMS Zinc uptake in roots is believed to be mediated by ZIP (ZRT-, IRT-like proteins) transporters. Once inside the symplast, zinc is transported to the pericycle, where it exits by means of HMA (heavy metal ATPase) transporters. The combination of symplastic transport and spatial separation of influx and efflux produces a pattern in which zinc accumulates in the pericycle. Here,...