A tale of two toxicities: malformed selenoproteins and oxidative stress both contribute to selenium stress in plants

Abstract

Malformed selenoproteins and oxidative stress are two distinct types of stress that drive selenium toxicity in plants and could impact cellular processes in plants that have yet to be thoroughly explored. Although challenging, deciphering whether the extent of selenium toxicity in plants is imparted by selenoproteins or oxidative stress could be helpful in the development of crops with fortified levels of selenium.

Effects of selenium on the growth and photosynthetic characteristics of flue-cured tobacco (Nicotiana tabacum L.)

“…4 Se accumulation in roots, stems, and leaves of tobacco plants under different levels of Se treatment.…”

“…Similarly, other studies revealed that Se promotes the growth of ryegrass [3], tea [9], rice [10], and soybean [11]. However, excess Se accumulation (>0.1% plant DW) is generally toxic to plants, except for rare Se-hyperaccumulating plants [4].…”

“…However, high Se concentrations may elicit toxic effects on plants [3]. The difference between the deficiency and toxicity of Se, as in other essential trace elements, is narrow [4]. Plant species differ in Se uptake and accumulation in shoots and roots, as well as in tolerance to high Se concentrations in solution or soil [5].…”

“…Plants subjected to Se stress exhibit different physiological changes, including stunted root growth, reduced biomass, chlorosis, reduced photosynthetic efficiency, and ultimately plant death [4]. Previous studies reported that Se improves the antioxidant capacity of plants [3,12].…”

Szelén-indukált stresszválaszok vizsgálata Arabidopsis thaliana L. és Pisum sativum L. növényekben, a biofortifikáció lehetősége

“…Redox szenzitív elemként a szelén a környezet pH-jától és elektronaktivitástól függően 4 oxidációs állapotban lehet jelen a talajban. A szelénnek emberi és állati szervezetben, baktériumokban, valamint néhány zöld algában betöltött szerepe ma már jól ismert, de ez idáig nincs meggyőző bizonyíték a szelenoproteinek magasabb rendű növényekben való létét illetően (Van Hoewyk, 2013).…”