Selenium Fortification Alters the Growth, Antioxidant Characteristics and Secondary Metabolite Profiles of Cauliflower (Brassica oleracea var. botrytis) Cultivars in Hydroponic Culture

Abstract

Nowadays the importance of selenium for human health is widely known, but most of the plants are poor in terms of selenium storage and accumulation because of the low selenium mineralization potential of the soil. For this purpose, foliar application of different sodium selenate concentrations (0, 5, 10, 15, 20 mg/L) was used to treat the cauliflower cultivars “Clapton” and “Graffiti”. Higher yields and other related vegetative attributes were improved at 10 and 15 mg/L sodium selenate application. At a concentration of 10 mg/L sodium selenate, photosynthetic pigments, total phenolic compounds and antioxidant capacity were enhanced in both cultivars, but the “Graffiti” cultivar responded stronger than the “Clapton” cultivar. The glucosinolates were accumulated in response to selenium fortification and the highest amounts were found in the “Graffiti” cultivar at 10 mg/L. Selenium accumulated concentration-dependently and rose with higher fertilization levels. In general, foliar application of selenium at 10 mg/L led to an accumulation of secondary metabolites and also positively affected the growth and yield of florets.

Enhanced accumulation of phenolics in pea (Pisum sativum L.) seeds upon foliar application of selenate or zinc oxide

“…The present study further revealed that selenate improved in part (though not consistently) the total antioxidant activity (FRAP) of pea seeds (Table 1, Figures 1C, D). Beneficial effects of foliar-applied selenate on total antioxidant activity were also reported previously for pea seeds (68) and cauliflower florets (70), although different tests were employed (2,2-diphenyl-1picrylhydrazyl; DPPH and/or photochemiluminescence). D'Amato et al (73) emphasized that stress in the plant, induced by increased Se levels, activates the phenylpropanoid pathway involved in the biosynthesis of phenolic compounds (including phenolic acids), which may enhance the scavenging capacity of reactive oxygen species (ROS).…”

“…The present study further revealed that selenate improved in part (though not consistently) the total antioxidant activity (FRAP) of pea seeds ( Table 1 , Figures 1C , D ). Beneficial effects of foliar-applied selenate on total antioxidant activity were also reported previously for pea seeds ( 68 ) and cauliflower florets ( 70 ), although different tests were employed (2,2-diphenyl-1-picrylhydrazyl; DPPH and/or photochemiluminescence).…”

“…Our study showed that selenate enhanced total phenolic content and in part (though not consistently) total flavonoid content in pea seeds ( Table 1 , Figures 1A , B ). Previous research also demonstrated that foliar-applied selenate positively affected total phenolic content in pea seeds ( 68 ), curly endive ( 69 ), and cauliflower florets ( 70 ), as well as total flavonoid content in Indian mustard leaves ( 71 ) and tomato fruits ( 72 ). The present study further revealed that selenate improved in part (though not consistently) the total antioxidant activity (FRAP) of pea seeds ( Table 1 , Figures 1C , D ).…”

Appraisal of Functions and Role of Selenium in Heavy Metal Stress Adaptation in Plants

“…Optimal doses of Se were known to cope up various types of biotic and abiotic stresses, including exposure to HMs by the regulation of antioxidant system [100]. Selenium is also a fundamental part of some antioxidant enzymes, which shield cells from being damaged by ROS [101,25]. Additionally, reports also showed that an ideal concentration of Se (1/2 µM) enhanced the antioxidant capabilities of photosynthetic pigments and slowed the ageing of leaf tissues in Brassica oleracea [102,25].…”

“…Among all the classes of SMs, phenolics are one of the major classes of SMs that participate in plant secondary defense. However, the exogenous supply of Se significantly enhanced the levels of phenolic metabolites under different type of metal stresses [25][26][27]13]. Furthermore, antagonistic results of Se on the production glucosinolates (GLS) were also observed in plants when exposed to metalloid toxicity [28][29][30].…”