Effect of Salt Stress on Viability, Germination and Endogenous Levels of Some Metabolites and Ions in Maize (Zea mays L.) Pollen

Maize plants, subjected to 0, 80, 120 and 160 meq l−1 salinity using NaCl, showed adverse effects on viability, germination and tube growth of pollen, besides enhancing the bursting of pollen. The endogenous levels of various metabolites in pollen were also affected. Pollen grains from salinized plants had more soluble carbohydrates, free amino acids, especially proline, phenols and DNA and less starch, protein and RNA compared to the non-saline controls. Salinity also resulted in the accumulation of ions such as Na+, K+ and Cl− while it caused a reduction in the boron content of pollen. These metabolic disturbances possibly lead to decreased viability, germination and tube growth of pollen thereby resulting into a reduction in reproductive capacity of the plants under salt stress.