Effects of Salinity Stress during Plant Development in Barley (Hordium velgare L.) on Subsequent Seed Quality and Redox State

Abstract

Salinity can have significant effects on seed quality, particularly in salt-sensitive species. In the present study fifteen-day-old barley seedlings were subjected to 200 mM NaCl for 0, 15, 30, 45, or 60 days. The seed quality derived from these plants was assessed by measuring (1) the amount of inorganic ions and organic nitrogen, (2) total germination, (3) germination rate at 25°C under 16 hours of light or in darkness, (4) glutathione contents and redox state, (5) rate of water uptake, and (6) rate of radicle and coleoptile extension. The results showed that the seeds produced by seedlings salt-stressed for 15 days had enhanced germination rates and seedling vigor, while those stressed for 60 days had poor quality and showed signs of stress. Notably, seeds from the 60-day stress group had a two-fold higher cumulative rate of water uptake than all other treatments and double the glutathione content (GSH) compared to seeds from non-treated plants. Regardless of the salinity stress duration, exposure to light consistently stimulated the speed of germination and germination capacity. In summary, this study underscores that brief exposure of barley seedlings to 200 mM NaCl can improve subsequent seed germination, whereas prolonged salinity treatments adversely affect seed quality.