An apparent seleniferous leaf wax from Stanleya bipinnata

McColloch, R. J.; Hamilton, John; Brown, Stanley K.

doi:10.1016/0006-291x(63)90018-4

Cited by 11 publications

(4 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Se was not detected in the cuticle or in any cuticular wax crystals tested. This is noteworthy because an earlier finding reported a potential seleniferous leaf wax in Stanleya bipinnata (McColloch et al, 1963). No Se was detected in leaf hairs, the predominant site of sequestration in another hyperaccumulator, A. bisulcatus (Freeman et al, 2006b).…”

Section: Discussionmentioning

confidence: 68%

Molecular Mechanisms of Selenium Tolerance and Hyperaccumulation in Stanleya pinnata

Freeman

Tamaoki²,

Stushnoff³

et al. 2010

Plant Physiol.

220

187

View full text Add to dashboard Cite

The molecular mechanisms responsible for selenium (Se) tolerance and hyperaccumulation were studied in the Se hyperaccumulator Stanleya pinnata (Brassicaceae) by comparing it with the related secondary Se accumulator Stanleya albescens using a combination of physiological, structural, genomic, and biochemical approaches. S. pinnata accumulated 3.6-fold more Se and was tolerant to 20 mM selenate, while S. albescens suffered reduced growth, chlorosis and necrosis, impaired photosynthesis, and high levels of reactive oxygen species. Levels of ascorbic acid, glutathione, total sulfur, and nonprotein thiols were higher in S. pinnata, suggesting that Se tolerance may in part be due to increased antioxidants and up-regulated sulfur assimilation. S. pinnata had higher selenocysteine methyltransferase protein levels and, judged from liquid chromatography-mass spectrometry, mainly accumulated the free amino acid methylselenocysteine, while S. albescens accumulated mainly the free amino acid selenocystathionine. S. albescens leaf x-ray absorption near-edge structure scans mainly detected a carbon-Se-carbon compound (presumably selenocystathionine) in addition to some selenocysteine and selenate. Thus, S. albescens may accumulate more toxic forms of Se in its leaves than S. pinnata. The species also showed different leaf Se sequestration patterns: while S. albescens showed a diffuse pattern, S. pinnata sequestered Se in localized epidermal cell clusters along leaf margins and tips, concentrated inside of epidermal cells. Transcript analyses of S. pinnata showed a constitutively higher expression of genes involved in sulfur assimilation, antioxidant activities, defense, and response to (methyl)jasmonic acid, salicylic acid, or ethylene. The levels of some of these hormones were constitutively elevated in S. pinnata compared with S. albescens, and leaf Se accumulation was slightly enhanced in both species when these hormones were supplied. Thus, defense-related phytohormones may play an important signaling role in the Se hyperaccumulation of S. pinnata, perhaps by constitutively up-regulating sulfur/Se assimilation followed by methylation of selenocysteine and the targeted sequestration of methylselenocysteine.

show abstract

Section: Discussionmentioning

confidence: 68%

Molecular Mechanisms of Selenium Tolerance and Hyperaccumulation in Stanleya pinnata

Freeman

Tamaoki²,

Stushnoff³

et al. 2010

Plant Physiol.

220

187

View full text Add to dashboard Cite

show abstract

“…LC-MS revealed both MeSeCys (88%) and SeCysth (12%) in these leaf edges. Intriguingly, S. pinnata leaves have been reported to have a seleniferous wax, which is unique to this species (McColloch et al, 1963). However, judging from our EDXMA studies, the major storage site for Se was in the epidermal cells rather than the cuticle, and it is possible that the globular structures shown by m-XAS are large epidermal cells (Fig.…”

Section: Discussionmentioning

confidence: 76%

Spatial Imaging, Speciation, and Quantification of Selenium in the Hyperaccumulator PlantsAstragalus bisulcatusandStanleya pinnata

et al. 2006

View full text Add to dashboard Cite

Astragalus bisulcatus and Stanleya pinnata hyperaccumulate selenium (Se) up to 1% of plant dry weight. In the field, Se was mostly present in the young leaves and reproductive tissues of both hyperaccumulators. Microfocused scanning x-ray fluorescence mapping revealed that Se was hyperaccumulated in trichomes in young leaves of A. bisulcatus. None of 10 other elements tested were accumulated in trichomes. Micro x-ray absorption spectroscopy and liquid chromatography-mass spectrometry showed that Se in trichomes was present in the organic forms methylselenocysteine (MeSeCys; 53%) and g-glutamyl-MeSeCys (47%). In the young leaf itself, there was 30% inorganic Se (selenate and selenite) in addition to 70% MeSeCys. In young S. pinnata leaves, Se was highly concentrated near the leaf edge and surface in globular structures that were shown by energy-dispersive x-ray microanalysis to be mainly in epidermal cells. Liquid chromatography-mass spectrometry revealed both MeSeCys (88%) and selenocystathionine (12%) inside leaf edges. In contrast, both the Se accumulator Brassica juncea and the nonaccumulator Arabidopsis thaliana accumulated Se in their leaf vascular tissues and mesophyll cells. Se in hyperaccumulators appears to be mobile in both the xylem and phloem because Se-treated S. pinnata was found to be highly toxic to phloem-feeding aphids, and MeSeCys was present in the vascular tissues of a S. pinnata young leaf petiole as well as in guttation fluid. The compartmentation of organic selenocompounds in specific storage areas in the plant periphery appears to be a unique property of Se hyperaccumulators. The high concentration of Se in the plant periphery may contribute to Se tolerance and may also serve as an elemental plant defense mechanism.

show abstract

“…With respect to Se metabolism, S. pinnata has been shown to be similar to the Se‐accumulating Astragalus species, producing the characteristic Se‐methylselenocysteine and selenocystathionine (Shrift, 1969). Additionally, S. pinnata produces a seleno‐wax unknown in any other species (McColloch et al. , 1963).…”

Section: Introductionmentioning

confidence: 99%

Ecotypic variation in selenium accumulation among populations of Stanleya pinnata

2001

View full text Add to dashboard Cite

Summary• Ecotypic variation in selenium (Se) hyperaccumulation in plants is reported here among populations of Stanleya pinnata (Brassicaceae), which has a broad biogeographical range in the western USA.• In a glasshouse study, Se and sulfur accumulation were examined in 16 populations of S. pinnata. Plants grown from seed (collected from sites representing the species range) were subjected to five treatments differing in selenate (SeO 4 2 − ) and• The populations differed in shoot Se concentration by 1.4-to 3.6-fold, depending on the treatment, and these concentrations were positively correlated with the indigenous soil Se levels at the collection sites. Shoot S concentrations varied by less than two-fold, and did not correlate with the shoot Se levels. All populations accumulated SeO 4 2 − preferentially over SO 4 2 − . By contrast, Brassica juncea seedlings grown in a similar solution series consistently accumulated SO 4 2 − preferentially over SeO 4 2 − . Biomass production differed up to three-fold between populations.• S. pinnata is a primary Se accumulator, but populations exhibit significant ecotypic differences in Se accumulation. Environmental concerns about Se are common, and the broad adaptation of S. pinnata makes it an attractive candidate for phytoremediation.

show abstract

An apparent seleniferous leaf wax from Stanleya bipinnata

Cited by 11 publications

References 5 publications

Molecular Mechanisms of Selenium Tolerance and Hyperaccumulation in Stanleya pinnata

Molecular Mechanisms of Selenium Tolerance and Hyperaccumulation in Stanleya pinnata

Spatial Imaging, Speciation, and Quantification of Selenium in the Hyperaccumulator PlantsAstragalus bisulcatusandStanleya pinnata

Ecotypic variation in selenium accumulation among populations of Stanleya pinnata

Contact Info

Product

Resources

About