Selenium Modulates Antioxidant Activity, Osmoprotectants, and Photosynthetic Efficiency of Onion under Saline Soil Conditions

Abstract

Selenium (Se) has been recently reported to play a crucial role in ameliorating the negative impact of abiotic stress, including salinity, on several plant species. Two field experiments (2016/17 and 2017/18) were carried out to investigate the possible effect of exogenous Se application at two levels (25, 50 mg L−1) on growth, bulb yield, physio-biochemical attributes, and antioxidant activities of onion grown under saline (5.25 dS m−1) soil condition. Se (25 or 50 mg L−1) foliar application enhanced growth characteristics, as well as membrane stability index (MSI) and relative water content (RWC) as a result of the osmotic adjustment by accumulating more osmoprotectants and enhancing the activity of antioxidants defense system, thus improving photosynthetic efficiency and bulb yield. Proline, glycine betaine, choline, and total soluble sugars content were higher in leaves and bulbs of Se-treated plants under salt stress. Se (25 or 50 mg L−1) significantly increased the activities of enzymatic (ascorbate peroxidase, superoxide dismutase, and catalase) and non-enzymatic (ascorbic acid and glutathione) antioxidants in both leaves and bulbs of salt-stressed onion. Se application at 25–50 mg L−1 may find, in the future, a potential application as anti-abiotic stresses for improving plant growth and productivity under saline soil condition.

Plant Growth-Promoting Rhizobacteria Improve Growth, Morph-Physiological Responses, Water Productivity, and Yield of Rice Plants Under Full and Deficit Drip Irrigation

“…In the present work the reduction of antioxidant defense system (e.g., peroxidase (PO), polyphenol oxidase (PPO), total phenol), N% (leaves), and N% (grains) under drought stress may be due to the influences of drought stress on the availability and transport of nutrients, as soil nutrients are carried to the roots by water. Our results are in line with those of Selvakumar and Panneerselvam (2012), Abd El-Mageed et al ( 2017) and Semida et al (2021a). They reported that water stress reduces nutrient diffusion and mass flow of water-soluble elements such as nitrate, K, Ca, Mg, and Si.…”

Plant Nutrition: An Effective Way to Alleviate Abiotic Stress in Agricultural Crops

“…Interestingly, nanoparticles of Se have been registered to improve the growth attributes, photosynthetic ability and antioxidant defence of crops for scavenging ROS under heat and chilling stress, with special reference to sorghum [ 299 ] and tomato [ 300 ]. There are also some other reports where the significant role of Se has been elucidated through modulations in metabolites transport, photosynthetic activity, membrane integrity and cellular turgor in ameliorating drought, salinity and heavy metal stress in the cases of rice [ 301 ], wheat [ 302 ], maize [ 258 ], onion [ 303 ], carrot [ 304 ], cucumber [ 305 ] etc. However, the beneficial effects of Se in terms of plant growth have been attributed to the antioxidative property of the element itself [ 285 , 306 ] by virtue of higher accumulation of soluble sugars and proline in the shoots [ 307 , 308 ] along with higher LRWC, biosynthesis of photosynthetic pigments and enzymatic upregulations to strengthen the metabolic balance inside moisture-stressed plants [ 309 ].…”

Coapplication of Effective Microorganisms and Nanomagnesium Boosts the Agronomic, Physio-Biochemical, Osmolytes, and Antioxidants Defenses Against Salt Stress in Ipomoea batatas

“…Salinity is a severe environmental factor having adverse effects on the growth and productivity of many crops ( Kamran et al, 2020 ; Semida et al, 2021a ; Shaaban et al, 2022 ). Globally, salt-affected soil was recorded as approximately 1,125 million hectares ( Shahid et al, 2018 ; Hossain, 2019 ).…”