Comparison of histopathological response and quantitative measurement of giant cell(GC)induced by Meloidogyne javanica in tomato root were studied under potassium-deficient(0.2 mmol/L K+)and replete conditions(control,6.0 mmol/L K+).K+-deficient stress did not impede the formation and maintenance of GC.The mean number of GC per feeding site as well as the mean diameter of GC did not differ between the treatments.However,the thickness of cell wall including components resulted from the accumulated polysaccharide and the length of cell-wall ingrowth increased 5-25 d after inoculation in K+-deficient as compared with K+-replete conditions.An increase of cell-wall ingrowth suggested a kind of compensational response to the potassium stress.
