Biofortification and phytoremediation of selenium in China

Abstract

Selenium (Se) is an essential trace element for humans and animals but at high concentrations, Se becomes toxic to organisms due to Se replacing sulfur in proteins. Selenium biofortification is an agricultural process that increases the accumulation of Se in crops, through plant breeding, genetic engineering, or use of Se fertilizers. Selenium phytoremediation is a green biotechnology to clean up Se-contaminated environments, primarily through phytoextraction and phytovolatilization. By integrating Se phytoremediation and biofortification technologies, Se-enriched plant materials harvested from Se phytoremediation can be used as Se-enriched green manures or other supplementary sources of Se for producing Se-biofortified agricultural products. Earlier studies primarily aimed at enhancing efficacy of phytoremediation and biofortification of Se based on natural variation in progenitor or identification of unique plant species. In this review, we discuss promising approaches to improve biofortification and phytoremediation of Se using knowledge acquired from model crops. We also explored the feasibility of applying biotechnologies such as inoculation of microbial strains for improving the efficiency of biofortification and phytoremediation of Se. The key research and practical challenges that remain in improving biofortification and phytoremediation of Se have been highlighted, and the future development and uses of Se-biofortified agricultural products in China has also been discussed.

Indications of Selenium Protection against Cadmium and Lead Toxicity in Oilseed Rape (Brassica napus L.)

“…Selenium, an essential element for animals and humans, has also been found to be beneficial to plants (Ellis and Salt, 2003; Wu et al, 2015). However, Se often exerts a dual effect on plant growth.…”

“…Selenium (Se) is an essential trace element for humans and animals, and some findings suggest that Se may be a beneficial element, which plays a novel role in plant biology for innovative crop production (Trumble et al, 1998; Rayman, 2000; Terry et al, 2000; Ellis and Salt, 2003; Hartikainen, 2005; Pilon-Smits et al, 2009; Zhu et al, 2009; Bañuelos et al, 2011; Hatfield et al, 2014; Wu et al, 2015). Selenium at low concentrations exerts positive effects for plants such as promoting growth, increasing antioxidative capacity, improving yield and quality, and delaying ripening and senescence (Hartikainen et al, 2000; Xue et al, 2001; Turakainen et al, 2004; Broadley et al, 2010; Pukacka et al, 2011; Pezzarossa et al, 2012).…”

Phytoremediation: recent advances in plant-endophytic synergistic interactions

“…For instance, Se-phytoremediation, as discussed before, occurs primarily via phytoextraction opening the possibilities of using Se-rich biomass harvested from phytoremediating plants as a sustainable replacement of green manures and other supplementary sources meant to yield Se-fortified agricultural products for biofortification (Wu et al 2015). However, the feasibility of improving such biofortification processes with microbial inoculation still needs to be explored (Surade Jong et al 2015).…”

“…Recently, it has only been speculated that the hyperaccumulator-associated microflora plays a significant role in the establishment of interaction between plants and soil (Sura-de Jong et al 2015;Wu et al 2015). Using cultivation-based techniques, it has been shown that two selenium (Se)-hyperaccumulators, namely Astragalus bisulcatus and Stanleya pinnata are capable of harboring well-structured endophytic bacterial populations in their natural Se-rich surroundings.…”

Selenium Phytoremediation by Giant Reed

“…Thus, there are demands that the example of Finland should be followed and soil Se levels increased by the addition of selenium to fertilizers (Reilly 2006 ). It could be noticed that, the range between the benefi cial and harmful doses of Se is quite narrow; the minimal Se nutrition levels for animals is about 0.05-0.10 mg kg −1 dry forage feed, while the toxic exposure level is 2-5 mg kg −1 dry forage (Wu et al 2015 ). Yuan et al ( 2012 ) reported that, there are two well-known endemic diseases linked to soil Se defi ciency and low Se daily intake.…”