In Vitro Oxidative Stress Threatening Maize Pollen Germination and Cytosolic Ca2+ Can Be Mitigated by Extracts of Emmer Wheatgrass Biofortified with Selenium

Alberto Marco Del Pino; Beatrice Falcinelli; Roberto D'Amato; Daniela Businelli; Paolo Benincasa; Carlo Alberto Palmerini

doi:10.3390/plants11070859

In Vitro Oxidative Stress Threatening Maize Pollen Germination and Cytosolic Ca²⁺ Can Be Mitigated by Extracts of Emmer Wheatgrass Biofortified with Selenium

Plants (Basel). 2022 Mar 24;11(7):859. doi: 10.3390/plants11070859.

Authors

Alberto Marco Del Pino¹, Beatrice Falcinelli¹, Roberto D'Amato¹, Daniela Businelli¹, Paolo Benincasa¹, Carlo Alberto Palmerini¹

Affiliation

¹ Department of Agricultural, Food, and Environmental Sciences, University of Perugia, 06121 Perugia, Italy.

Abstract

In this work, we studied the effects of in vitro oxidative stress applied by H₂O₂ to maize pollen germination and cytosolic Ca²⁺, taken as an experimental model to test the biological activity of extracts of emmer (Triticum turgidum L. spp. dicoccum (Schrank ex Shubler) Thell.) wheatgrass obtained from grains sprouted with distilled water, or salinity (50 mM) or selenium (45 mg L^-1 of Na₂SeO₃). Wheatgrass extracts were obtained in two ways: by direct extraction in methanol, which represented the free phenolic fraction of extracts (Ef), and by residual content after alkaline digestion, which made it possible to obtain extracts with the bound fraction (Eb). Comparative tests on maize pollen were carried out by differently combining H₂O₂ and either wheatgrass extracts or pure phenolic acids (4-HO benzoic, caffeic, p-coumaric and salicylic). The cytosolic Ca²⁺ of maize pollen was influenced by either H₂O₂ or pure phenolic acids or Ef, but not by Eb. The negative effect of H₂O₂ on maize pollen germination and cytosolic Ca²⁺ was mitigated by Ef and, slightly, by Eb. The extent of the biological response of Ef depended on the sprouting conditions (i.e., distilled water, salinity or selenium). The extracts of Se-biofortified wheatgrass were the most effective in counteracting the oxidative stress.

Keywords: Triticum dicoccum; calcium homeostasis; hydrogen peroxide; phenolic acid; salinity; sprouting.