Silica Deposition in the Grass Leaf in Relation to Transpiration and the Effect of Dinitrophenol

Sangster, A. G.; Parry, D. W.

doi:10.1093/oxfordjournals.aob.a084511

Cited by 33 publications

(25 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Our findings of a correlation between stomatal conductance and Si support this hypothesis of a strong role of the transpiration stream in Si uptake also found in previous studies (Sangster and Parry, 1971; Henriet et al, 2006; Cornelis et al, 2010; Faisal et al, 2012; Kumar et al, 2016) and suggests a strong role of the transpiration stream in Si uptake. However, the clear differences in Si concentration between the varieties, despite no statistical differences observed in stomatal conductance between them, suggests other factors than transpiration stream may have some influence on Si accumulation and deposition in the undamaged plants.…”

Section: Discussionsupporting

confidence: 92%

Evidence for Active Uptake and Deposition of Si-based Defenses in Tall Fescue

et al. 2017

View full text Add to dashboard Cite

Silicon (Si) is taken up from the soil as monosilicic acid by plant roots, transported to leaves and deposited as phytoliths, amorphous silica (SiO2) bodies, which are a key component of anti-herbivore defense in grasses. Silicon transporters have been identified in many plant species, but the mechanisms underpinning Si transport remain poorly understood. Specifically, the extent to which Si uptake is a passive process, driven primarily by transpiration, or has both passive and active components remains disputed. Increases in foliar Si concentration following herbivory suggest plants may exercise some control over Si uptake and distribution. In order to investigate passive and active controls on Si accumulation, we examined both genetic and environmental influences on Si accumulation in the forage grass Festuca arundinacea. We studied three F. arundinacea varieties that differ in the levels of Si they accumulate. Varieties not only differed in Si concentration, but also in increases in Si accumulation in response to leaf damage. The varietal differences in Si concentration generally reflected differences in stomatal density and stomatal conductance, suggesting passive, transpiration-mediated mechanisms underpin these differences. Bagging plants after damage was employed to minimize differences in stomatal conductance between varieties and in response to damage. This treatment eliminated constitutive differences in leaf Si levels, but did not impair the damage-induced increases in Si uptake: damaged, bagged plants still had more leaf Si than undamaged, bagged plants in all three varieties. Preliminary differential gene expression analysis revealed that the active Si transporter Lsi2 was highly expressed in damaged unbagged plants compared with undamaged unbagged plants, suggesting damage-induced Si defenses are regulated at gene level. Our findings suggest that although differences in transpiration may be partially responsible for varietal differences in Si uptake, they cannot explain damage-induced increases in Si uptake and deposition, suggesting that wounding causes changes in Si uptake, distribution and deposition that likely involve active processes and changes in gene expression.

show abstract

Section: Discussionsupporting

confidence: 92%

Evidence for Active Uptake and Deposition of Si-based Defenses in Tall Fescue

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Translocation of Si in plants is driven mostly by transpiration (Sangster and Parry, 1971), and coordinated by specific distribution of Si transporters. Silicic acid is selectively transported to the panicle of rice during its maturation (Yamaji et al, 2015), possibly due to its increasing sink strength (Detmann et al, 2013).…”

Section: Sites Of Silicification In Grassesmentioning

confidence: 99%

“…The shrunk cytoplasm maintains its viability and the deposited silica does not interfere with cell-to-cell diffusion (Kumar et al, 2017). Silica deposition occurs also in leaf segments with very limited transpiration flow (Sangster and Parry, 1971; Kumar et al, 2017). The deposition is reduced in leaves treated with a metabolic inhibitor 2,4-dinitrophenol (Sangster and Parry, 1971) and does not occur in dead silica cells present in live leaves (Markovich et al, 2015; Kumar et al, 2017).…”

Section: Sites Of Silicification In Grassesmentioning

confidence: 99%

“…The first is based on a passive mode of silicification, relying on the spatial correlation between silica deposition and organ transpiration (Yoshida et al, 1962; Sangster and Parry, 1971; Rosen and Weiner, 1994; Euliss et al, 2005). In this case, specific cell wall components and cuticular structures may additionally affect the location of bio-silicification (reviewed by Exley, 2015; Guerriero et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Silicification in Grasses: Variation between Different Cell Types

2017

View full text Add to dashboard Cite

Plants take up silicon as mono-silicic acid, which is released to soil by the weathering of silicate minerals. Silicic acid can be taken up by plant roots passively or actively, and later it is deposited in its polymerized form as amorphous hydrated silica. Major silica depositions in grasses occur in root endodermis, leaf epidermal cells, and outer epidermal cells of inflorescence bracts. Debates are rife about the mechanism of silica deposition, and two contrasting scenarios are often proposed to explain it. According to the passive mode of silicification, silica deposition is a result of silicic acid condensation due to dehydration, such as during transpirational loss of water from the aboveground organs. In general, silicification and transpiration are positively correlated, and continued silicification is sometimes observed after cell and tissue maturity. The other mode of silicification proposes the involvement of some biological factors, and is based on observations that silicification is not necessarily coupled with transpiration. Here, we review evidence for both mechanisms of silicification, and propose that the deposition mechanism is specific to the cell type. Considering all the cell types together, our conclusion is that grass silica deposition can be divided into three modes: spontaneous cell wall silicification, directed cell wall silicification, and directed paramural silicification in silica cells.

show abstract

“…H 4 SiO 4 is transported via the xylem to the different organs and tissues, where, in general, as water is lost by evaporation, this molecule is precipitated, thus forming the amorphous silica biomineralizations (Sangster & Parry, 1971;Ma & Takahashi, 2002). Although diverse factors, such as genetics and age of the organ, affect the silica content in plants, the silica content of soils is important in the silicification process.…”

Section: Implications Of the Silicification Process In Polytrichum Stmentioning

confidence: 99%

Amorphous silica biomineralizations inPolytrichum strictumMenzies ex Brid. (Bryophyta)

Benvenuto

Honaine

Osterrieth

2013

Journal of Bryology

View full text Add to dashboard Cite

In this study, the presence of amorphous silica biomineralizations (silicophytoliths) in individuals of Polytrichum strictum collected from Tierra del Fuego, Argentina was analysed. Gametophyte and sporophyte samples were subjected to calcination and staining techniques, through which the biomineralizations obtained were observed and described by optical and scanning electron microscopes. Lastly, their composition was analysed by energy dispersive spectroscopy. In both gametophyte and sporophyte silica skeletons comprising thin elongated silicophytoliths with blunt, round or acute ends were observed. These morphologies may correspond to the silicification of the costa or midrib region of the leaves (in the gametophyte) and the seta (in the sporophyte) and to the silicification of the awns of the leaves. The other morphologies found were silica skeletons comprising silicified walls of tabular polygonal cells, probably derived from the silicification of the cells of the unistratose lamina of leaves. Energy dispersive spectroscopy analyses and the use of a phenol-staining technique confirmed the silicon composition of these biomineralizations. The results obtained comprise the first description of amorphous silica biomineralization in mosses and the implications of the silicification process in this taxon are discussed. The data obtained will be relevant not only for anatomical, but also for palaeobotanical studies, since the preservation of these structures in the soil after the decomposition of organic matter, might allow the identification of mosses in the fossil record. Figure 4 Silicified areas from gametophyte, detected by the staining technique. (A) Transverse view of the leaf; (B) silica deposits observed in the central strand; (C) silica deposits observed in awn region (aw). l5lamina of the leaf, cs5central strand. The arrows indicate the areas of silica deposits (stained rose colour). Scale bar525 mm. Benvenuto et al. Amorphous silica biomineralizations in Polytrichum strictum Menzies ex Brid. (Bryophyta) Journal of Bryology

show abstract

Silica Deposition in the Grass Leaf in Relation to Transpiration and the Effect of Dinitrophenol

Cited by 33 publications

References 13 publications

Evidence for Active Uptake and Deposition of Si-based Defenses in Tall Fescue

Evidence for Active Uptake and Deposition of Si-based Defenses in Tall Fescue

Silicification in Grasses: Variation between Different Cell Types

Amorphous silica biomineralizations inPolytrichum strictumMenzies ex Brid. (Bryophyta)

Contact Info

Product

Resources

About