Selenium Volatiles as Proxy to the Metabolic Pathways of Selenium in Genetically Modified <i>Brassica juncea</i>

Kubachka, Kevin M.; Meija, Juris; LeDuc, Danika L.; Terry, Norman; Caruso, Joseph A.

doi:10.1021/es0613714

Cited by 42 publications

(28 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In another genetic approach, DMeSe volatilization could be enhanced two-threefold by overexpression of cystathionine-g-synthase, the key enzyme for the conversion of (Se-)cysteine to (Se-)methionine [63]. Further identification of different volatile Se compounds could aid in the dissection of Se metabolic pathways in plants of different species, as well as in transgenics [64].…”

Section: Reviewmentioning

confidence: 99%

Selenium in higher plants: understanding mechanisms for biofortification and phytoremediation

Zhu¹,

Pilon-Smits²,

Zhao³

et al. 2009

Trends in Plant Science

514

347

View full text Add to dashboard Cite

Selenium (Se) is an essential micronutrient for many organisms, including plants, animals and humans. As plants are the main source of dietary Se, plant Se metabolism is therefore important for Se nutrition of humans and other animals. However, the concentration of Se in plant foods varies between areas, and too much Se can lead to toxicity. As we discuss here, plant Se uptake and metabolism can be exploited for the purposes of developing high-Se crop cultivars and for plant-mediated removal of excess Se from soil or water. Here, we review key developments in the current understanding of Se in higher plants. We also discuss recent advances in the genetic engineering of Se metabolism, particularly for biofortification and phytoremediation of Se-contaminated environments. Selenium in the environmentThe metalloid selenium (Se) is ubiquitous in the environment, and its concentration in most soils ranges from 0.01 to 2.0 mg kg, with a mean of 0.4 mg kg -1 ; however, higher concentrations (>10 mg kg -1

show abstract

Section: Reviewmentioning

confidence: 99%

Selenium in higher plants: understanding mechanisms for biofortification and phytoremediation

Zhu¹,

Pilon-Smits²,

Zhao³

et al. 2009

Trends in Plant Science

514

347

View full text Add to dashboard Cite

show abstract

“…On the other hand, tobacco plants transformed with a SMT transgene produced both dimethyl selenide and dimethyl diselenide. In Indian mustard plants watered with selenate or selenite, the ratio of dimethyl selenide to dimethyl diselenide produced has been successfully used to discriminate between wild-type, and SMT-and ATPS/SMT-overexpressing plants (Kubachka et al 2007). Such plants also produced smaller amounts of a third major Se-containing volatile, dimethyl selenosulfenate (Meija et al 2002;Kubachka et al 2007), which was similarly detected at low amounts in transgenic tobacco (Table 4).…”

Section: Discussionmentioning

confidence: 99%

Accumulation of an organic anticancer selenium compound in a transgenic Solanaceous species shows wider applicability of the selenocysteine methyltransferase transgene from selenium hyperaccumulators

et al. 2008

View full text Add to dashboard Cite

Tolerance to high selenium (Se) soils in Se-hyperaccumulating plant species is correlated with the ability to biosynthesise methylselenocysteine (MeSeCys), due to the activity of selenocysteine methyltransferase (SMT). In mammals, inclusion of MeSeCys in the diet reduces the incidence of certain cancers, so increasing the range of crop plants that can produce this compound is an attractive biotechnology target. However, in the non-Se accumulator Arabidopsis, overexpression of SMT does not result in biosynthesis of MeSeCys from selenate because the rate at which selenate is reduced to selenite by ATP sulfurylase (ATPS) is low. This limitation is less problematic in other species of the Brassicaceae that can produce MeSeCys naturally. We investigated the potential for biosynthesis of MeSeCys in other plant families using Nicotiana tabacum L., a member of the Solanaceae. When plants were watered with 200 microM selenate, overexpression of a SMT transgene caused a 2- to 4-fold increase in Se accumulation (resulting in increased numbers of leaf lesions and areas of necrosis), production of MeSeCys (up to 20% of total Se) and generation of volatile dimethyl diselenide derived directly from MeSeCys. Despite the greatly increased accumulation of total Se, this did not result in increased Se toxicity effects on growth. Overexpression of ATPS did not increase Se accumulation from selenate. Accordingly, lines overexpressing both ATPS and SMT did not show a further increase in total Se accumulation or in leaf toxicity symptoms relative to overexpression of SMT alone, but directed a greater proportion of Se into MeSeCys. This work demonstrates that the production of the cancer-preventing compound MeSeCys in plants outside the Brassicaceae is possible. We conclude that while the SMT gene from Se hyperaccumulators can probably be utilised universally to increase the metabolism of Se into MeSeCys, the effects of enhancing ATPS activity will vary depending on the species involved.

show abstract

“…1). MeSe 2 Me is the most commonly reported organoselenide in selenium accumulating organisms (Kubachka et al, 2007;Meija et al, 2002Meija et al, , 2003Shah et al, 2007;Zhang and Chasteen, 1994). MeSeSMe may arise from disproportionation of MeSe 2 Me and MeS 2 Me (Chasteen, 1993).…”

Section: Chemical Analysis Of Smt and Atps/smt Transformed Tobacco Plmentioning

confidence: 99%

“…3). A dominant feature of the fragmentation of alkylselenides is the loss of the alkyl group as an alkene, such as the loss of C 2 H 4 from an ethyl selenide or C 3 H 6 from a propyl selenide (Kubachka et al, 2007;Meija et al, 2002;Shah et al, 2007). No such fragments were observed (Fig.…”

Section: Chemical Analysis Of Smt and Atps/smt Transformed Tobacco Plmentioning

confidence: 99%

“…Dimethyl selenide (MeSeMe) is also produced in large quantities, but from methylselenomethionine, which does not require the SMT enzyme. An exchange reaction between MeS 2 Me and MeSe 2 Me produces dimethylselenosulfide (MeSeSMe) (Kubachka et al, 2007;McKenzie et al, 2009;Meija et al, 2002). Se-accumulating (de Souza et al, 1998 and non-accumulating plants, which have been genetically engineered for overexpression of a SMT transgene, have potential for the phytoremediation of Se-contaminated soils (Ellis et al, 2004;LeDuc et al, 2004LeDuc et al, , 2006.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Organoselenides from Nicotiana tabacum genetically modified to accumulate selenium

et al. 2009

View full text Add to dashboard Cite

Selenium Volatiles as Proxy to the Metabolic Pathways of Selenium in Genetically Modified Brassica juncea

Cited by 42 publications

References 25 publications

Selenium in higher plants: understanding mechanisms for biofortification and phytoremediation

Selenium in higher plants: understanding mechanisms for biofortification and phytoremediation

Accumulation of an organic anticancer selenium compound in a transgenic Solanaceous species shows wider applicability of the selenocysteine methyltransferase transgene from selenium hyperaccumulators

Organoselenides from Nicotiana tabacum genetically modified to accumulate selenium

Contact Info

Product

Resources

About