Separate Effects of Foliar Applied Selenate and Zinc Oxide on the Accumulation of Macrominerals, Macronutrients and Bioactive Compounds in Two Pea (Pisum sativum L.) Seed Varieties

Abstract

Selenium (Se) and zinc (Zn) are important cofactors for antioxidant enzymes. Foliar Se/Zn application is a highly efficient strategy of plant biofortification. However, its effect on the accumulation of macrominerals, macronutrients and bioactive compounds in the pea plant (Pisum sativum L.) have been poorly investigated. A two-year pot experiment was performed to study responses of two pea varieties (Ambassador, Premium) to foliar-applied sodium selenate (0/50/100 g Se/ha) and zinc oxide (0/375/750 g Zn/ha) at the flowering stage. Concentrations of Ca, Mg, K, Na, soluble solids (SSC), protein, chlorophyll a and b, total chlorophyll, total carotenoids and total condensed tannins (TCT) were determined in seeds. Mg concentration in Ambassador and chlorophyll a concentration in Premium were positively affected, in part, by selenate and zinc oxide, respectively. Selenate and zinc oxide increased, in part, protein concentration in Premium. Highest protein concentration was found in Premium treated with 375 g Zn/ha (27.6% DW) vs. the control (26.6% DW). Significant (all p < 0.001) positive correlations were found, among others, between concentrations of Zn and Mg (r2 = 0.735) and between Zn and protein (r2 = 0.437) for Ambassador, and between Mg and protein (r2 = 0.682), between Zn and Mg (r2 = 0.807), as well as between Zn and protein (r2 = 0.884) for Premium. TCT significantly (all < 0.05) and positively correlated with SSC (r2 = 0.131), chlorophyll b (r2 = 0.128) and total chlorophyll (r2 = 0.109) for Ambassador. This study provides new nutritional data on Se/Zn biofortified peas, important for improving agronomic biofortification of pea plants.

Foliar Selenate and Zinc Oxide Separately Applied to Two Pea Varieties: Effects on Growth Parameters and Accumulation of Minerals and Macronutrients in Seeds under Field Conditions

“…Selenate and zinc oxide did not produce beneficial changes on the levels of soluble solids in pea seeds ( Table 2 , Figure 1 F), which is consistent with our pot study [ 34 ]. However, previous studies did report increased concentrations of total sugars in seeds of pea [ 49 ], black gram [ 50 ], and common bean [ 51 ] following zinc sulphate application.…”

“…The pea varieties included in the study were chosen due to their reported high yield. Foliar application has been described as an efficient method for biofortification, bypassing the effect that soil may have on the bioavailability of examined minerals [ 34 ]. While Zn is an indispensable mineral vital for plants [ 44 ], the essentiality of Se to higher plants is yet to be established.…”

“…Our recent findings showed a positive effect of foliar-applied selenate and zinc oxide on the aggregation of phenolics in pea seeds [ 36 ]. In addition, upon these applications, total condensed tannins did not correlate with a lower accretion of selected minerals, macronutrients and plant bioactive constituents in pea seeds, which is encouraging in light of agronomic biofortification [ 34 ], as tannins have been reported to potentially hamper the nutritional value of many food items, including legumes, by interfering with the digestion and bioavailability of nutrients, including especially divalent minerals [ 47 ].…”

“…Consequently, in this investigation we studied the response of two pea varieties (Ambassador, Premium) to foliar application of Se and Zn during the flowering stage under field conditions. Growth parameters, accumulation of selected trace elements (including Se and Zn), macro elements, soluble solids and protein in seeds, as well as their respective correlations were evaluated and compared with previous findings, including our pot experiment [ 34 , 35 , 36 ].…”

Separate foliar sodium selenate and zinc oxide application enhances Se but not Zn accumulation in pea (Pisum sativum L.) seeds

“…The two pea varieties were selected based on their high-yielding capacity. Selenium and Zn solutions were administered via foliar application, as this approach reduced the impact of soil properties on interactions between the examined minerals ( Malka et al., 2022 ). However, differences between soils in 2014 and 2015, as well as climate differences could have contributed to additional variability in Se or Zn foliar uptake.…”