Boron in Soils and Plants pp 213-220
The effect of boron deficiency on development in determinate nodules: changes in cell wall pectin contents and nodule polypeptide expression
The effect of boron (B) deficiency on nodule development and nitrogen fixation in bean (Phaseolus vulgaris) was studied. Nodules from plants grown without B in the nutrient solution were smaller in size and had a weight lower than the controls. In addition, B starvation resulted in a severe decrease in acetylene reduction activity after two weeks of treatment. Light microscopy examination of B deficient nodules showed dramatic changes in cell shape, amyloplast number, and cell wall structure, mainly in those cells located in the middle of the central zone. The use of the tissue-printing technique indicated that pectins are decreased in B-deficient nodules. Finally, one and two dimensional analysis of the nodule polypeptides showed the premature expression of a 116 kDa polypeptide in B-deficient compared to control nodules. These data suggest that B is an obligatory requirement for normal determinate nodule development and functioning.
Key wordsnitrogen fixation pectin polypeptide expresion Rhizobium symbiosis
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