Differential Responses of Common Bean, (Phaseolus vulgaris L.) to the Interactive Effects of Ascorbic Acid and Trichoderma harzianum under Salinity Stress

Recent ecological perturbations are presumed to be minimized by the application of biofertilizers as a safe alternative to chemical fertilizers. The current study aims to use biofertilizers ( Trichoderma harzianum ) and non-enzymatic antioxidants (ascorbic acid) in combination with NaCl on growth and some metabolic activities as well as esterase enzyme in Phaseolus vulgaris cv Bronko. Results showed that NaCl inhibited both fresh and dry weights, shoot and root lengths. Treatment of plants with either ascorbic acid or Trichoderma enhanced these parameters. All pigments (Chl.a, Chl.b, Chl.a+b and carotenoids) were enhanced at lower and higher salinity levels. Plants treated with either ascorbic acid or Trichoderma promoted carotenoids at moderate and higher levels of salinity. Soluble proteins, soluble carbohydrates and amino acids were increased in shoots and decreased in roots with increasing salinity, treatment of plants with either ascorbic acid or Trichoderma reduced these components in shoots. Treatment of plants with either ascorbic acid or Trichoderma decreased MDA and significantly increased proline in both shoots and roots. Salinity increased the DPPH% activity in both shoots and roots, and treatment with either ascorbic acid or Trichoderma significantly enhanced the scavenging activity of DPPH in both organs. Plants treated with either ascorbic acid or Trichoderma exhibited a reduction in phenols and increment in flavonoids, especially with Trichoderma. The assessment of esterase isozyme profiles on 7.5% polyacrylamide gel revealed the presence of 6 isoforms in response to water presoaking and treatments with either ascorbic acid or Trichoderma under different concentrations