Extracts of Emmer Wheatgrass Grown with Distilled Water, Salinity or Selenium Differently Affect Germination and Cytosolic Ca2+ of Maize Pollen

In this work, the biological activity of emmer (Triticum turgidum L. spp. dicoccum (Schrank ex Shubler) Thell.) wheatgrass extracts obtained from grains sprouted with distilled water, or salinity (50 mM) or selenium (45 mg L−1 of Na2SeO3), was tested through an experimental biological model based on the germination and cytosolic Ca2+ homeostasis of maize pollen grains. The effects of thapsigargin (TG) and of four phenolic acids (PAs: ferulic, coumaric, salicylic and 3-HO benzoic) on maize pollen were also tested as controls. Wheatgrass extracts influenced both pollen cytosolic Ca2+ and germination. The Ca2+ agonist activity of emmer wheatgrass was transient, different from that of TG, which caused a depletion of the stored Ca2+ and a permanent alteration of Ca2+ homeostasis. The results obtained with extracts compared to those obtained with pure PAs suggest that PAs in unconjugated forms, which are known to be well represent in emmer wheatgrass, contribute to the biological activity of extracts. The extent of the biological response of emmer wheatgrass extracts was influenced by emmer sprouting conditions (i.e., distilled water, or salinity or selenium). Maize pollen treated with Se-enriched wheatgrass extracts showed a less perturbed cytosolic Ca2+ and a higher germination rate.