Effect of Boron Stress on Growth, Carbohydrate, Protein and Phenol Metabolism In The Leaves and Roots of Sunflower Seedlings

To evaluate the effect of boron on growth, carbohydrate, protein and phenol metabolism, seeds of sunflower (Helianthus annus L. var. sungold) were grown in solution culture with variable boron supply (0.0033, 0.033, 0.33, 3.3 and 33 mg B I"¹) under controlled conditions in green house. Seedlings grown under boron deficient (0.0033 and 0.033, mg B I"¹) and excess (3.3 and 3 3 mg B I"¹) supply showed growth retardation, decreased shoot and root length with decreased dry weight. Photosynthetic pigments in leaves were found to be decreased under boron stress. Altered carbohydrate, protein and phenol metabolism was observed in leaves and roots under deficiency and excess supply of boron.