The effect of aluminum exposure on root respiration in an aluminum-sensitive and an aluminum-tolerant cultivar of Triticum aestivum

Collier, Donald E.; Ackermann, Frank; Somers, Daryl J.; Cummins, W. Raymond; Atkin, Owen K.

doi:10.1034/j.1399-3054.1993.870402.x

Cited by 2 publications

(1 citation statement)

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“…Total rates of respiration were measured polarographically with the roots submerged in a buffered nutrient solution (10 mM Hepes and 10 mM Mes, pH 5.8) identical with that in which the plants were grown, except that iron, which chelates with SHAM, was excluded. Although the effect of buffering of the nutrient solutions was not determined for the above species, previous studies have found no effect on root respiratory rates of several species Collier et al, 1993;Atkin and Cummins, 1994).…”

Section: Respiratory Measurementsmentioning

confidence: 99%

Partitioning of Electrons between the Cytochrome and Alternative Pathways in Intact Roots

1995

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To test the hypothesis that the cytochrome pathway is not invariably saturated when the alternative pathway is engaged, we titrated root respiration of several species with KCN (an inhibitor of the cytochrome pathway), both in the absence and presence of an inhibitor of the alternative pathway (salicylhydroxamic acid, SHAM). The slopes of the resultant KCN p plots (pcyt) were then used to determine whether the cytochrome pathway was saturated in each species. The species used were Festuca ovina ssp. ovina L., Phaseolus vulgaris L., and six Poa species (Poa pratensis L., Poa compressa L., Poa trivialis L., Poa alpina L., Poa cosfiniana Vick., and Poa fawcettiae Vick.). Although the cytochrome pathway was saturated in a number of species (i.e. pcyt values were 1 A), several others exhibited pcvt values of less than 0.5. Alternative pathway capacity correlated negatively with pcyt, with pCyt values of less than 1 .O occurring in tissues in which the alternative pathway capacity was greater than 25 to 30% of total respiration. l h e species that did not show full engagement of the cytochrome pathway rarely exhibited SHAM inhibition in the absence of KCN. We conclude that this lack of SHAM inhibition is not due to a lack of alternative pathway engagement but rather to the diversion of electrons from the alternative pathway to the unsaturated cytochrome path following the addition of SHAM.

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Section: Respiratory Measurementsmentioning

confidence: 99%