Protective Effects of Selenium on Wheat Seedlings under Salt Stress

Chiu-Yueh Lan,Wen-Dar Huang,Chang-Chang Chen,Kuan-Hung Lin

doi:10.3390/agronomy9060272

Abstract

Wheat is a staple food worldwide, but its productivity is reduced by salt stress. In this study, the mitigative effects of 22 μM selenium (Se) on seedlings of the wheat (Triticum aestivum L.) cultivar Taichung SEL. 2 were investigated under different salt stress levels (0, 100, 200, 300, and 400 mM NaCl). Results of the antioxidative capacity showed that catalase (CAT) activity, non-enzymatic antioxidants (total phenols, total flavonoids, and anthocyanins), 1,1-Diphenyl-2-Picryl-Hydrazyl (DPPH) radical-scavenging activity, and the reducing power of Se-treated seedlings were enhanced under saline conditions. The more-stabilized chlorophyll fluorescence parameters (maximal quantum yield of photosystem II (Fv/Fm), minimal chlorophyll fluorescence (F0), effective quantum yield of photosystem II (ΦPSII), quantum yield of regulated energy dissipation of photosystem II (Y(NPQ)), and quantum yield of non-regulated energy dissipation of photosystem II (Y(NO)) and the less-extensive degradation of photosynthetic pigments (total chlorophyll and carotenoids) in Se-treated seedlings were also observed under salt stress. The elongation of shoots and roots of Se-treated seedling was also preserved under salt stress. Protection of these physiological traits in Se-treated seedlings might have contributed to stable growth observed under salt stress. The present study showed the protective effect of Se on the growth and physiological traits of wheat seedlings under salt stress.

Highlights

Wheat (Triticum stivum L.), the third most important primary cereal with more than 600 million tons of global production, preceded only by corn and rice [1], provides the main source of carbohydrates for 35%~40% of the world’s population [2]
Root lengths of Se-treated seedlings were significantly longer (p < 0.05) than those of seedlings without Se treatment (Figure 1b). These results showed that Se effectively promoted the growth of seedlings grown under salt stress
Chls and Cars are both involved in the light reaction of photosynthesis. Chl b, and their sum, and carotenoid concentrations in leaves of seedlings from all treatments in this study are presented in all values of photosynthetic pigments of Se-treated seedlings were higher than those of untreated seedlings. These results revealed that Se treatment served as a protectant for photosynthetic pigments to prevent their salt-stress induced degradation in wheat seedlings

Summary

Introduction

Wheat (Triticum stivum L.), the third most important primary cereal with more than 600 million tons of global production, preceded only by corn and rice [1], provides the main source of carbohydrates for 35%~40% of the world’s population [2]. Wheat yields are markedly reduced in saline soils, due to improper fertilization that causes osmotic and drought stresses [3]. Studies reported that Se mitigated disadvantageous phenomena caused by various stressful situations, such as heat [8,9,10], cold [11], heavy metals [12,13], ultraviolet (UV)-B [14,15,16,17], drought [18,19], and salt stress [20,21]. Possible protective mechanisms of Se in plants against stresses include its enhancement of antioxidant enzyme activities (peroxidase (POD), catalase (CAT), etc.) and increasing antioxidant compounds (anthocyanins, flavonoids, phenolic compounds, etc.), and these antioxidant systems reduce stress-induced oxidative situations [11].

Methods

Results

Discussion

Conclusion