ISSN:
1573-5036
Keywords:
Fe3+-reductase activity
;
genotypical differences
;
iron chlorosis
;
medium acidification
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Iron chlorosis induced by Fe-deficiency is a widespread nutritional disorder in many woody plants and in particular in grapevine. This phenomenon results from different environmental, nutritional and varietal factors. Strategy I plants respond to Fe-deficiency by inducing physiological and biochemical modifications in order to increase Fe uptake. Among these, acidification of the rhizosphere, membrane redox activities and synthesis of organic acids are greatly enhanced during Fe-deficiency. Grapevine is a strategy I plant but the knowledge on the physiological and biochemical responses to this iron stress deficiency in this plant is still very poor. In this work four different genotypes of grapevine were assayed for these parameters. It was found that there is a good correlation between genotypes which are known to be chlorosis-resistant and increase in both rhizosphere acidification and FeIII reductase activity. In particular, when grown in the absence of iron, Vitis berlandieri and Vitis vinifera cv Cabernet sauvignon and cv Pinot blanc show a higher capacity to acidify the culture medium (pH was decreased by 2 units), a higher concentration of organic acids, a higher resting transmembrane electrical potential and a greater capacity to reduce FeIII-chelates. On the contrary, Vitis riparia, well known for its susceptibility to iron chlorosis, fails to decrease the pH of the medium and shows a lower concentration in organic acids, lower capacity to reduce FeIII and no difference in the resting transmembrane electrical potential. H Marschner Section editor
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00010276
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