Effect of ultraviolet radiation on cell division and microtubule organization inPetunia hybrida protoplasts

Staxén, Irina; Bergounioux, Catherine; Bornman, Janet F.

doi:10.1007/bf01378863

Cited by 41 publications

(20 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such rapid signalling through Trp conduction pathways may coordinate the complex organization of the microtubule cytoskeleton required for the tasks of cell division, motor protein trafficking and motility. Microtubules have been shown to reorganize in a dose-dependent manner after exposure to UV light [39][40][41][42], with the greatest effect being observed around 280 nm [42]. Feasible mechanisms for these changes include the reduction of disulfide or peptide bonds induced by photoexcitation of Trp groups [43][44][45][46], or subtle protein structural changes owing to photo-induced alterations in Trp flexibility [46].…”

Section: Resultsmentioning

confidence: 99%

The feasibility of coherent energy transfer in microtubules

Craddock

Friesen

Mane

et al. 2014

J. R. Soc. Interface.

View full text Add to dashboard Cite

It was once purported that biological systems were far too 'warm and wet' to support quantum phenomena mainly owing to thermal effects disrupting quantum coherence. However, recent experimental results and theoretical analyses have shown that thermal energy may assist, rather than disrupt, quantum coherent transport, especially in the 'dry' hydrophobic interiors of biomolecules. Specifically, evidence has been accumulating for the necessary involvement of quantum coherent energy transfer between uniquely arranged chromophores in light harvesting photosynthetic complexes. The 'tubulin' subunit proteins, which comprise microtubules, also possess a distinct architecture of chromophores, namely aromatic amino acids, including tryptophan. The geometry and dipolar properties of these aromatics are similar to those found in photosynthetic units indicating that tubulin may support coherent energy transfer. Tubulin aggregated into microtubule geometric lattices may support such energy transfer, which could be important for biological signalling and communication essential to living processes. Here, we perform a computational investigation of energy transfer between chromophoric amino acids in tubulin via dipole excitations coupled to the surrounding thermal environment. We present the spatial structure and energetic properties of the tryptophan residues in the microtubule constituent protein tubulin. Plausibility arguments for the conditions favouring a quantum mechanism of signal propagation along a microtubule are provided. Overall, we find that coherent energy transfer in tubulin and microtubules is biologically feasible.

show abstract

Section: Resultsmentioning

confidence: 99%

The feasibility of coherent energy transfer in microtubules

Craddock

Friesen

Mane

et al. 2014

J. R. Soc. Interface.

View full text Add to dashboard Cite

show abstract

“…68 Suchar & Robberecht 69 found out that repair mechanisms could not solely prevent the UV-B radiation interference with the cell division; resulting in significant reductions in leaf growth and development. Staxén et al 70 found that the exposure of cells to UV radiation has been shown to lead to a delay in the onset of mitosis using Petunia hybrida protoplasts. The divisions that occur through leaf expansion were more vulnerable to inhibition by UV-B.…”

Section: -63mentioning

confidence: 99%

Interaction of cytokinins with UV-B (280 -315nm) on the expansion growth of cucumber cotyledons

Kataria¹,

Kn²

2018

HIJ

View full text Add to dashboard Cite

The negative effect on plant responses are expected due to increased amounts of ultraviolet-B (UV-B) radiation reaching on the Earth's surface by stratospheric ozone depletion. Cytokinins (CKs) are essential phytohormones in plant growth and development. Perusal of relevant literature reveals that CKs mitigate the oxidative damage caused by abiotic stresses like salt, drought, high temperature and heavy metal due to their antioxidant effects. However, very few reports are available on the interaction of CKs with UV-B stress on the expansion growth of the cucumber cotyledons. CKs induced the expansion growth of the excised cucumber cotyledons in the darkness. CKs induced expansion growth of cucumber cotyledons in darkness was inhibited by supplemental UV-B. UV-B radiation enhanced the level of oxyradicals like superoxide and hydroxide radicals in the excised cucumber cotyledons, which was evident by EPR spectroscopy. CKs like Zeatin, TDZ, BAP and FAP reduced the level of oxyradicals produced in the dark grown cucumber cotyledons, while promoting the expansion growth of the cotyledons. Production of oxyradical in UV-B exposed cotyledons showed that these oxyradicals might partially account for inhibition of expansion growth. Since considerable amount of oxyradicals were quenched by CKs at higher concentrations (10 and 20 µg/ml) it partially restores the inhibition of expansion growth caused by UV-B stress. It indicates that overproduction of oxyradicals by UV-B could not be entirely responsible for the inhibition of CKs induced expansion growth of cotyledons; which might be caused by some other physiological changes caused by UV-B irradiation in addition to the production of oxyradicals. UV-B is also known to inactivate protein inhibitor of peroxidase in cucumber cotyledons. This may reduce the antioxidants defence and enhance the damaging effects of oxyradicals for the growth of cotyledons.

show abstract

“…Proteins may be particularly sensitive targets, since aromatic amino acids absorb UV-B radiation up to 305 nm. Moreover, proteins can undergo a variety of modifications when exposed to UV-B, including photodegradation of Trp, modification of sulfhydryl residues, increased aqueous solubility of membrane proteins, and fragmentation of peptide chains (Fujimori, 1981;Grossweiner, 1984;Caldwell, 1993;Staxén et al, 1993). These modifications can lead to inactivation of enzymes and disruption of structural proteins.…”

mentioning

confidence: 99%

In Vivo Photomodification of Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase Holoenzyme by Ultraviolet-B Radiation (Formation of a 66-Kilodalton Variant of the Large Subunit)

et al. 1995

View full text Add to dashboard Cite

lncreased levels of solar ultraviolet (290-320 nm) (UV-B) radiation could have profound effects on plant proteins because the aromatic amino acids in proteins absorb strongly i n this spectral region. We have investigated the effects of UV-B radiation on plant proteins and have observed a nove1 66-kD protein. This product was formed i n vivo when Brassica napus 1. plants grown for 21 d in 65 pmol m-* s-' photosynthetically active radiation were subsequently exposed to 65 pmol m-' s-' photosynthetically active radiation plus UV-B radiation (1.5 pmol m-' s-'). l h e protein appeared after 4 h of UV-B irradiation and accumulated during the next 16 h in UV-B. The 66-kD protein cross-reacted with an antiserum against the ribulose-1,s-bisphosphate carboxylase/oxygenase (Rubisco) holoenzyme. Analysis of soluble leaf proteins revealed that the 66-kD product had a number of isoforms corresponding closely to those of the large subunit of Rubisco (LSU). Partia1 proteolytic digests of the LSU and the 66-kD protein resulted in an equivalent pattern of protein fragments, leading to the conclusion that the 66-kD protein was a photomodified form of the LSU. A similar high molecular m a s variant of Rubisco was observed in soluble protein extracts from leaves of tomato (Lycopersicon esculentum), tobacco (Nicotiana tabacum), and pea (Pisum sativum L.) plants treated in vivo with UV-B, suggesting that it might be a common product, at least among C, plants. It is interesting that the 66-kD product appears to be generated after incorporation of the LSU into holoenzyme complexes. This conclusion was drawn from two lines of evidence. First, the LSU variant co-purified with holoenzyme complexes isolated by nondenaturing polyacrylamide gel electrophoresis. Second, a UV-B-specific 66-kD protein did not accumulate in a tobacco mutant that synthesizes the Rubisco subunits but does not assemble them into normal holoenzyme complexes.

show abstract

Effect of ultraviolet radiation on cell division and microtubule organization inPetunia hybrida protoplasts

Cited by 41 publications

References 17 publications

The feasibility of coherent energy transfer in microtubules

The feasibility of coherent energy transfer in microtubules

Interaction of cytokinins with UV-B (280 -315nm) on the expansion growth of cucumber cotyledons

In Vivo Photomodification of Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase Holoenzyme by Ultraviolet-B Radiation (Formation of a 66-Kilodalton Variant of the Large Subunit)

Contact Info

Product

Resources

About