Effect of Silica on Physiological and Ultrastructure Characters in Barley (Hordeum Vulgare L.) Plant Under Salt Stress

Abstract

Salt stress is one of several major abiotic stresses that affect plant growth and development, and there are many evidences that silicon can ameliorate the injuries caused by high salinity. This study presents the results of an assay concerning: (1) the effect of NaCl induced salt stress in barely plant (cultivar Giza 123) and (2) the possible mitigating effect of silicon in saline conditions. In these study, different concentrations of NaCl (200 & 300 mM) used singly or in combination with silicon (0.5&1.0 mM potassium silicate). Morphological characters of shoot and roots, membrane stability index, relative water content, sodium, potassium, silica, photosynthetic pigments content and some antioxidant enzymes, as well as leaf electron microscope were evaluated. The results showed that, all parameters analyzed decreased except antioxidant enzymes and sodium content were drastically increased by increased salt levels. The supply of silicon (1mM) has successfully mitigated the effect of salinity at 300 mM NaCl. In conclusion, we affirmed that, salt stress is harmful for cape barley plants and the addition of silicon showed effective in mitigating the saline effects.

Higher activity of PSI compared to PSII accounts for the beneficial effect of silicon on barley (Hordeum vulgare L.) plants challenged with salinity

“…1, 2). Similar results have been observed in several plant species, such as common wheat (T. aestivum), durum wheat (Triticum turgidum), barley (H. vulgare), and sea barley (H. marinum) (Munns et al 1995, Chen et al 2014, El-khawaga 2018, Laifa et al 2021. Salt stress induces a reduction in plant growth mainly due to the osmotic pressure applied to the root area, which causes reduced water uptake and turgor pressure, stomatal closure, reduced photosynthesis, and toxic mineral disturbances (Bandehagh et al 2011, Adhikari et al 2019, Hurtado et al 2019, Attia et al 2022 as well as a combination of them (Ashraf 2004).…”

“…4). A similar effect was indicated in barley and tomato (Al-aghabary et al 2005, El-khawaga 2018. Srinieng et al (2015) linked this decrease to a nutritional deficiency caused by salt that inhibits the absorption of essential nutrients.…”